|
On Tue, 13 Apr 2004 09:18:00 +0300, Paul Keinanen
wrote: The solar cell operates as a (badly) regulated power supply with current limiting. At low load currents, the cell operates nearly as a constant voltage source, but after a specific current (for a given illumination) it operates nearly as a constant current source and deliver approximately that current even into a short circuit. The largest power from the cell (for a specific illumination) is obtained at the point it switches from constant voltage to constant current mode, in which both the voltage is quite close (within 30 %) of both the maximum voltage (as measured at open circuit) and maximum current (as measured at short circuit). This maximum power point varies with illumination, but if the switcher always loads the cell at this maximum power point, the largest available energy at a specific time is extracted from the cell independent of illumination. Even if the losses in the maximum power point tracker is 10-20 %, usually more energy can be obtained than running the module in some non-optimal constant voltage or constant current mode. Paul I have seen elegant ckts where a simple switcher was used, regulating the *input* voltage coming from the solar cell, keeping it in max efficiency mode at all loads. This obviously only works with flexible loads such as slow chargers or such. -- - René |
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
My attitude is that rather than try to do this (and in the process lose reliability), it's better to go supersize on the cells, add more area and overall capacity to get you thru the cloudy days, and have a higher capacity overall. The argument usually goes that getting, say, 10-20% more power from a better charge controller (one of these so-called 'maximum power point controllers') can be cheaper (in additional expenditures) than getting 10-20% larger panels. It's sometimes difficult to show, though, particularly on small systems -- but MPPT controllers have been getting cheaper for awhile, now, and I expect that eventually all but the cheapest/smallest will have this functionality. ---Joel Kolstad |
Watson A.Name - "Watt Sun, the Dark Remover" wrote:
My attitude is that rather than try to do this (and in the process lose reliability), it's better to go supersize on the cells, add more area and overall capacity to get you thru the cloudy days, and have a higher capacity overall. The argument usually goes that getting, say, 10-20% more power from a better charge controller (one of these so-called 'maximum power point controllers') can be cheaper (in additional expenditures) than getting 10-20% larger panels. It's sometimes difficult to show, though, particularly on small systems -- but MPPT controllers have been getting cheaper for awhile, now, and I expect that eventually all but the cheapest/smallest will have this functionality. ---Joel Kolstad |
In my limited experience, you have to be a little careful using a
switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Roy Lewallen, W7EL René wrote: I have seen elegant ckts where a simple switcher was used, regulating the *input* voltage coming from the solar cell, keeping it in max efficiency mode at all loads. This obviously only works with flexible loads such as slow chargers or such. |
In my limited experience, you have to be a little careful using a
switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Roy Lewallen, W7EL René wrote: I have seen elegant ckts where a simple switcher was used, regulating the *input* voltage coming from the solar cell, keeping it in max efficiency mode at all loads. This obviously only works with flexible loads such as slow chargers or such. |
That is exactly the point, Joel. Upsizing 20% is several times more expensive
compared to providing an intelligent switcher to match to the illumination or to adapt a panel voltage that isn't matching the storage devices. That situation won't change unless there is a tremendous breakthrough in technology or serious new government subsidies. As to reliability, a switcher that is designed correctly and conservatively should easily outlasts the cells. Even for small installations it is easy, especially in view of the large variety of micro controllers that retail for a few Dollars. One of these plus a few discretes and an inductor can do the trick. Regards, Joerg. |
That is exactly the point, Joel. Upsizing 20% is several times more expensive
compared to providing an intelligent switcher to match to the illumination or to adapt a panel voltage that isn't matching the storage devices. That situation won't change unless there is a tremendous breakthrough in technology or serious new government subsidies. As to reliability, a switcher that is designed correctly and conservatively should easily outlasts the cells. Even for small installations it is easy, especially in view of the large variety of micro controllers that retail for a few Dollars. One of these plus a few discretes and an inductor can do the trick. Regards, Joerg. |
Roy Lewallen wrote:
In my limited experience, you have to be a little careful using a switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. -- John Popelish |
Roy Lewallen wrote:
In my limited experience, you have to be a little careful using a switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. -- John Popelish |
John Popelish wrote:
Roy Lewallen wrote: In my limited experience, you have to be a little careful using a switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. Presumably what you need is a controller that detects when the supply voltage gets down to some threshold, then regulates the supply-side current rather than the load-side voltage. Come to think of it that'd be a fun thing to design... -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
John Popelish wrote:
Roy Lewallen wrote: In my limited experience, you have to be a little careful using a switching, or even a series pass, regulator with a solar panel. Most are designed to regulate voltage coming from a relatively stiff source, and some become unstable when hooked to a high impedance source like a solar panel. This can often be overcome by putting a big capacitor across the panel, and it can of course be overcome by designing the regulator to function properly with the high impedance source in the first place. And quite a few regulators work just fine without modification. But it's something to keep in mind when using a regulator designed for more conventional applications. Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. Presumably what you need is a controller that detects when the supply voltage gets down to some threshold, then regulates the supply-side current rather than the load-side voltage. Come to think of it that'd be a fun thing to design... -- Tim Wescott Wescott Design Services http://www.wescottdesign.com |
Tim Wescott wrote:
John Popelish wrote: Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. Presumably what you need is a controller that detects when the supply voltage gets down to some threshold, then regulates the supply-side current rather than the load-side voltage. Come to think of it that'd be a fun thing to design... Very few switchers draw an instantaneously constant power from the unregulated source. Almost all can draw an average constant power (over the switching period). The difference means a lot when you consider what the variations do to the total losses in the solar cells. You missed my point, completely. -- John Popelish |
Tim Wescott wrote:
John Popelish wrote: Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. Presumably what you need is a controller that detects when the supply voltage gets down to some threshold, then regulates the supply-side current rather than the load-side voltage. Come to think of it that'd be a fun thing to design... Very few switchers draw an instantaneously constant power from the unregulated source. Almost all can draw an average constant power (over the switching period). The difference means a lot when you consider what the variations do to the total losses in the solar cells. You missed my point, completely. -- John Popelish |
On Tue, 13 Apr 2004 16:27:29 -0700, Tim Wescott
wrote: John Popelish wrote: Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. While there certainly are going to be stability issues, using a switcher with say 50 % duty cycle will draw 0 A half of the time (i.e. the PV cell is operating in the constant voltage mode) and 2 Iave the other half of the time (i.e. the cell would operate in the constant current mode) and never operate at the maximum power point (here assumed to be at Iave). Sufficient parallel capacitances and/or series inductances or some push-pull arrangement will keep the current constantly at Iave and thus at the maximum power point. Paul |
On Tue, 13 Apr 2004 16:27:29 -0700, Tim Wescott
wrote: John Popelish wrote: Just for efficiency reasons, I think you would want ot have enough capacitance across the regulator input that the cell resistance drops voltage only with respect ot the average output current, not the switcher peak value. This can be a pretty big factor in the overall efficiency. Using a switcher that has little ripple current on its input (two phase boost, for instance) makes this much easier. That's not the point. Because a switcher tends to draw a constant power from a load it's input impedance has a negative resistive component. If you match this with a source that has a too-high impedance it'll be _unstable_; a big capacitor would just slow it down in this case. While there certainly are going to be stability issues, using a switcher with say 50 % duty cycle will draw 0 A half of the time (i.e. the PV cell is operating in the constant voltage mode) and 2 Iave the other half of the time (i.e. the cell would operate in the constant current mode) and never operate at the maximum power point (here assumed to be at Iave). Sufficient parallel capacitances and/or series inductances or some push-pull arrangement will keep the current constantly at Iave and thus at the maximum power point. Paul |
Paul Keinanen wrote:
On Mon, 12 Apr 2004 13:02:38 -0700, "Watson A.Name \"Watt Sun - the Dark Remover\"" wrote: Joerg wrote: Another option might be to use a different voltage panel, whatever has a good price, and then use a small switcher to run the cells at their optimum load. Regards, Joerg. Seems foolhardy to me, to use a boost circuit, and waste a lot of power. Just put more PV cells in series to increase the voltage. The solar cell operates as a (badly) regulated power supply with current limiting. At low load currents, the cell operates nearly as a constant voltage source, but after a specific current (for a given illumination) it operates nearly as a constant current source and deliver approximately that current even into a short circuit. The largest power from the cell (for a specific illumination) is obtained at the point it switches from constant voltage to constant current mode, in which both the voltage is quite close (within 30 %) of both the maximum voltage (as measured at open circuit) and maximum current (as measured at short circuit). This maximum power point varies with illumination, but if the switcher always loads the cell at this maximum power point, the largest available energy at a specific time is extracted from the cell independent of illumination. Even if the losses in the maximum power point tracker is 10-20 %, usually more energy can be obtained than running the module in some non-optimal constant voltage or constant current mode. Paul Anybody got any real data on this stuff. I set out to build a constant power solar battery charger. I was gonna just put a PIC to measure the voltage/current and ratchet the switcher duty cycle up and down around peak power. Went out in the yard at noon and plotted some curves. Yep, there's a pronounced power peak right around 14V. At lower intensities, the shape of the curve is the same, but it moves sideways. Ok, my pulse width strategy should track that. Cool. Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. mike -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ |
Paul Keinanen wrote:
On Mon, 12 Apr 2004 13:02:38 -0700, "Watson A.Name \"Watt Sun - the Dark Remover\"" wrote: Joerg wrote: Another option might be to use a different voltage panel, whatever has a good price, and then use a small switcher to run the cells at their optimum load. Regards, Joerg. Seems foolhardy to me, to use a boost circuit, and waste a lot of power. Just put more PV cells in series to increase the voltage. The solar cell operates as a (badly) regulated power supply with current limiting. At low load currents, the cell operates nearly as a constant voltage source, but after a specific current (for a given illumination) it operates nearly as a constant current source and deliver approximately that current even into a short circuit. The largest power from the cell (for a specific illumination) is obtained at the point it switches from constant voltage to constant current mode, in which both the voltage is quite close (within 30 %) of both the maximum voltage (as measured at open circuit) and maximum current (as measured at short circuit). This maximum power point varies with illumination, but if the switcher always loads the cell at this maximum power point, the largest available energy at a specific time is extracted from the cell independent of illumination. Even if the losses in the maximum power point tracker is 10-20 %, usually more energy can be obtained than running the module in some non-optimal constant voltage or constant current mode. Paul Anybody got any real data on this stuff. I set out to build a constant power solar battery charger. I was gonna just put a PIC to measure the voltage/current and ratchet the switcher duty cycle up and down around peak power. Went out in the yard at noon and plotted some curves. Yep, there's a pronounced power peak right around 14V. At lower intensities, the shape of the curve is the same, but it moves sideways. Ok, my pulse width strategy should track that. Cool. Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. mike -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ |
mike wrote:
Anybody got any real data on this stuff. There's no shortage of information about this. Useful keywords are "insolation" and "solar insolation" (the word "solar" is slightly redundant but it's commonly included). In summer, you can expect a maximum of 1 kWatt per square metre to reach the surface of the earth. The units most commonly used are kW-Hour per square metre per day - I'll call them Units here. Insolation tables for the USA can be seen at: http://www.suntrekenergy.com/sunhours.htm These figures are somewhat suspect - the difference between "high" and "low" seems too small (a maximum of 6 Units is rather low), especially when compared with the following, which contains some good maps: http://www.wattsun.com/resources/ins...map_index.html On this page, click on Flat Plate Collector, Single Axis Tracker and Double Axis Tracker. The latter can produce up to 14 Units in summer. The improvement when tracking the sun's angle is very large. It pays to live in California. I have seen a similar table somewhere for the UK, showing that 5 Units is the best that can be expected, and maybe less than 1 Unit in winter. Bear in mind that the efficiency of Solar Cells is less than 20% in the very latest state-of-the-art devices, typically 10%, and maybe as low as 5% in reject/hobbyist cells. Generating hot water directly from flat solar collectors is probably more efficient, and certainly cheaper, but not much use if it's electricity you want. If, on a bad day, the cell voltage is less than the battery voltage, you can still charge the battery. Look at: http://www.elecdesign.com/Articles/A...262/6262.html# This article appeared in Electronic Design, Sept 14 1998. It describes a circuit for a Maximum-power-point-tracking solar battery charger. The principle is simple: the duty-ratio of a switch-mode power supply is continuously modulated at about 50Hz. The change in output on each cycle is used to determine whether a higher or lower duty-ratio would increase the output power. A phase-sensitive detector and feedback loop determines whether to increase or decrease the average duty-ratio. It settles at the point of maximum power. As the article points out, it works for other energy sources such as water-wheels and other devices where the shape of the "energy curve" is not precisely known. When used as a battery charger the voltage of the battery is fairly constant, so "maximum power" means "maximum current". At the solar cell end, we are working at maximum power, although the voltage may vary. The "maximum power transfer" condition is when 50% of the power goes to the load, and 50% is dissipated in the cell. I don't know if this is precisely true in a solar cell, but it certainly implies considerable power dissipation in the cell, which may shorten its life. On the other hand, a cell of 1 square metre will have 1000 watts of solar power falling on it, and may generate 100 watts of electrical power, of which we may get 50 watts into our battery. The 50 watts dissipated in the cell is much less than the 1000 watts from the sun - so maybe it doesn't matter. J.S.Blackburn, London UK. |
mike wrote:
Anybody got any real data on this stuff. There's no shortage of information about this. Useful keywords are "insolation" and "solar insolation" (the word "solar" is slightly redundant but it's commonly included). In summer, you can expect a maximum of 1 kWatt per square metre to reach the surface of the earth. The units most commonly used are kW-Hour per square metre per day - I'll call them Units here. Insolation tables for the USA can be seen at: http://www.suntrekenergy.com/sunhours.htm These figures are somewhat suspect - the difference between "high" and "low" seems too small (a maximum of 6 Units is rather low), especially when compared with the following, which contains some good maps: http://www.wattsun.com/resources/ins...map_index.html On this page, click on Flat Plate Collector, Single Axis Tracker and Double Axis Tracker. The latter can produce up to 14 Units in summer. The improvement when tracking the sun's angle is very large. It pays to live in California. I have seen a similar table somewhere for the UK, showing that 5 Units is the best that can be expected, and maybe less than 1 Unit in winter. Bear in mind that the efficiency of Solar Cells is less than 20% in the very latest state-of-the-art devices, typically 10%, and maybe as low as 5% in reject/hobbyist cells. Generating hot water directly from flat solar collectors is probably more efficient, and certainly cheaper, but not much use if it's electricity you want. If, on a bad day, the cell voltage is less than the battery voltage, you can still charge the battery. Look at: http://www.elecdesign.com/Articles/A...262/6262.html# This article appeared in Electronic Design, Sept 14 1998. It describes a circuit for a Maximum-power-point-tracking solar battery charger. The principle is simple: the duty-ratio of a switch-mode power supply is continuously modulated at about 50Hz. The change in output on each cycle is used to determine whether a higher or lower duty-ratio would increase the output power. A phase-sensitive detector and feedback loop determines whether to increase or decrease the average duty-ratio. It settles at the point of maximum power. As the article points out, it works for other energy sources such as water-wheels and other devices where the shape of the "energy curve" is not precisely known. When used as a battery charger the voltage of the battery is fairly constant, so "maximum power" means "maximum current". At the solar cell end, we are working at maximum power, although the voltage may vary. The "maximum power transfer" condition is when 50% of the power goes to the load, and 50% is dissipated in the cell. I don't know if this is precisely true in a solar cell, but it certainly implies considerable power dissipation in the cell, which may shorten its life. On the other hand, a cell of 1 square metre will have 1000 watts of solar power falling on it, and may generate 100 watts of electrical power, of which we may get 50 watts into our battery. The 50 watts dissipated in the cell is much less than the 1000 watts from the sun - so maybe it doesn't matter. J.S.Blackburn, London UK. |
Hi J.S.;
"J.S.Blackburn" wrote: mike wrote: Anybody got any real data on this stuff. There's no shortage of information about this. Useful keywords are "insolation" and "solar insolation" (the word "solar" is slightly redundant but it's commonly included). In summer, you can expect a maximum of 1 kWatt per square metre to reach the surface of the earth. This is miss leading. While there are places, nearer to the equator, that can have 1KW/m^2 at noon this is not the norm. The rule of thumb is 1KW/m^2 normal to the sun not flat on the ground. Or about 100W/ft^2. This is a tilted surface directly facing the sun. The units most commonly used are kW-Hour per square metre per day - I'll call them Units here. Insolation tables for the USA can be seen at: http://www.suntrekenergy.com/sunhours.htm These figures are somewhat suspect - the difference between "high" and "low" seems too small (a maximum of 6 Units is rather low), especially when compared with the following, which contains some good maps: http://www.wattsun.com/resources/ins...map_index.html On this page, click on Flat Plate Collector, Single Axis Tracker and Double Axis Tracker. The latter can produce up to 14 Units in summer. The improvement when tracking the sun's angle is very large. It pays to live in California. I have seen a similar table somewhere for the UK, showing that 5 Units is the best that can be expected, and maybe less than 1 Unit in winter. Bear in mind that the efficiency of Solar Cells is less than 20% in the very latest state-of-the-art devices, typically 10%, and maybe as low as 5% in reject/hobbyist cells. Generating hot water directly from flat solar collectors is probably more efficient, and certainly cheaper, but not much use if it's electricity you want. If, on a bad day, the cell voltage is less than the battery voltage, you can still charge the battery. Look at: http://www.elecdesign.com/Articles/A...262/6262.html# This article appeared in Electronic Design, Sept 14 1998. It describes a circuit for a Maximum-power-point-tracking solar battery charger. The principle is simple: the duty-ratio of a switch-mode power supply is continuously modulated at about 50Hz. The change in output on each cycle is used to determine whether a higher or lower duty-ratio would increase the output power. A phase-sensitive detector and feedback loop determines whether to increase or decrease the average duty-ratio. It settles at the point of maximum power. As the article points out, it works for other energy sources such as water-wheels and other devices where the shape of the "energy curve" is not precisely known. When used as a battery charger the voltage of the battery is fairly constant, so "maximum power" means "maximum current". At the solar cell end, we are working at maximum power, although the voltage may vary. The "maximum power transfer" condition is when 50% of the power goes to the load, and 50% is dissipated in the cell. I don't know if this is precisely true in a solar cell, but it certainly implies considerable power dissipation in the cell, which may shorten its life. On the other hand, a cell of 1 square metre will have 1000 watts of solar power falling on it, and may generate 100 watts of electrical power, of which we may get 50 watts into our battery. The 50 watts dissipated in the cell is much less than the 1000 watts from the sun - so maybe it doesn't matter. J.S.Blackburn, London UK. Duane -- Home of the $35 Solar Tracker Receiver http://www.redrok.com/electron.htm#led3X[*] Powered by \ \ \ //| Thermonuclear Solar Energy from the Sun / | Energy (the SUN) \ \ \ / / | Red Rock Energy \ \ / / | Duane C. Johnson Designer \ \ / \ / | 1825 Florence St Heliostat,Control,& Mounts | White Bear Lake, Minnesota === \ / \ | USA 55110-3364 === \ | (651)426-4766 use Courier New Font \ | (my email: address) \ | http://www.redrok.com (Web site) === |
Hi J.S.;
"J.S.Blackburn" wrote: mike wrote: Anybody got any real data on this stuff. There's no shortage of information about this. Useful keywords are "insolation" and "solar insolation" (the word "solar" is slightly redundant but it's commonly included). In summer, you can expect a maximum of 1 kWatt per square metre to reach the surface of the earth. This is miss leading. While there are places, nearer to the equator, that can have 1KW/m^2 at noon this is not the norm. The rule of thumb is 1KW/m^2 normal to the sun not flat on the ground. Or about 100W/ft^2. This is a tilted surface directly facing the sun. The units most commonly used are kW-Hour per square metre per day - I'll call them Units here. Insolation tables for the USA can be seen at: http://www.suntrekenergy.com/sunhours.htm These figures are somewhat suspect - the difference between "high" and "low" seems too small (a maximum of 6 Units is rather low), especially when compared with the following, which contains some good maps: http://www.wattsun.com/resources/ins...map_index.html On this page, click on Flat Plate Collector, Single Axis Tracker and Double Axis Tracker. The latter can produce up to 14 Units in summer. The improvement when tracking the sun's angle is very large. It pays to live in California. I have seen a similar table somewhere for the UK, showing that 5 Units is the best that can be expected, and maybe less than 1 Unit in winter. Bear in mind that the efficiency of Solar Cells is less than 20% in the very latest state-of-the-art devices, typically 10%, and maybe as low as 5% in reject/hobbyist cells. Generating hot water directly from flat solar collectors is probably more efficient, and certainly cheaper, but not much use if it's electricity you want. If, on a bad day, the cell voltage is less than the battery voltage, you can still charge the battery. Look at: http://www.elecdesign.com/Articles/A...262/6262.html# This article appeared in Electronic Design, Sept 14 1998. It describes a circuit for a Maximum-power-point-tracking solar battery charger. The principle is simple: the duty-ratio of a switch-mode power supply is continuously modulated at about 50Hz. The change in output on each cycle is used to determine whether a higher or lower duty-ratio would increase the output power. A phase-sensitive detector and feedback loop determines whether to increase or decrease the average duty-ratio. It settles at the point of maximum power. As the article points out, it works for other energy sources such as water-wheels and other devices where the shape of the "energy curve" is not precisely known. When used as a battery charger the voltage of the battery is fairly constant, so "maximum power" means "maximum current". At the solar cell end, we are working at maximum power, although the voltage may vary. The "maximum power transfer" condition is when 50% of the power goes to the load, and 50% is dissipated in the cell. I don't know if this is precisely true in a solar cell, but it certainly implies considerable power dissipation in the cell, which may shorten its life. On the other hand, a cell of 1 square metre will have 1000 watts of solar power falling on it, and may generate 100 watts of electrical power, of which we may get 50 watts into our battery. The 50 watts dissipated in the cell is much less than the 1000 watts from the sun - so maybe it doesn't matter. J.S.Blackburn, London UK. Duane -- Home of the $35 Solar Tracker Receiver http://www.redrok.com/electron.htm#led3X[*] Powered by \ \ \ //| Thermonuclear Solar Energy from the Sun / | Energy (the SUN) \ \ \ / / | Red Rock Energy \ \ / / | Duane C. Johnson Designer \ \ / \ / | 1825 Florence St Heliostat,Control,& Mounts | White Bear Lake, Minnesota === \ / \ | USA 55110-3364 === \ | (651)426-4766 use Courier New Font \ | (my email: address) \ | http://www.redrok.com (Web site) === |
mike wrote:
Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. Yep. It doesn't take much of an angle from perpendicular for a silicon cell to act as a pretty fair mirror. -- John Popelish |
mike wrote:
Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. Yep. It doesn't take much of an angle from perpendicular for a silicon cell to act as a pretty fair mirror. -- John Popelish |
Joel Kolstad wrote:
Watson A.Name - "Watt Sun, the Dark Remover" wrote: My attitude is that rather than try to do this (and in the process lose reliability), it's better to go supersize on the cells, add more area and overall capacity to get you thru the cloudy days, and have a higher capacity overall. The argument usually goes that getting, say, 10-20% more power from a better charge controller (one of these so-called 'maximum power point controllers') can be cheaper (in additional expenditures) than getting 10-20% larger panels. It's sometimes difficult to show, though, particularly on small systems -- but MPPT controllers have been getting cheaper for awhile, now, and I expect that eventually all but the cheapest/smallest will have this functionality. Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. ---Joel Kolstad |
Joel Kolstad wrote:
Watson A.Name - "Watt Sun, the Dark Remover" wrote: My attitude is that rather than try to do this (and in the process lose reliability), it's better to go supersize on the cells, add more area and overall capacity to get you thru the cloudy days, and have a higher capacity overall. The argument usually goes that getting, say, 10-20% more power from a better charge controller (one of these so-called 'maximum power point controllers') can be cheaper (in additional expenditures) than getting 10-20% larger panels. It's sometimes difficult to show, though, particularly on small systems -- but MPPT controllers have been getting cheaper for awhile, now, and I expect that eventually all but the cheapest/smallest will have this functionality. Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. ---Joel Kolstad |
Watson A.Name \"Watt Sun - the Dark Remover\" wrote:
Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. That said, there are many things you can do that are quite affordable. First, you could conserve energy. Replace old appliances with more efficient ones, insulate your home better, weather-strip, storm windows, compact fluorescent lights, activate the power saving on your computer, use xeriscaping and all that lot. If you are a typical homeowners then conservation alone could be as effective as putting up a $30,000 solar panel setup. Then you could buy more affordable renewable energy equipment such as solar water heaters, air heaters, ovens, stoves and the like. You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Currently the only ones available are "city cars" which turn out to be glorified golf carts but they are suitable for very local driving and can sometimes work as a second car. Some folks have even had great success with bicycles of various flavors. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. Anthony |
Watson A.Name \"Watt Sun - the Dark Remover\" wrote:
Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. That said, there are many things you can do that are quite affordable. First, you could conserve energy. Replace old appliances with more efficient ones, insulate your home better, weather-strip, storm windows, compact fluorescent lights, activate the power saving on your computer, use xeriscaping and all that lot. If you are a typical homeowners then conservation alone could be as effective as putting up a $30,000 solar panel setup. Then you could buy more affordable renewable energy equipment such as solar water heaters, air heaters, ovens, stoves and the like. You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Currently the only ones available are "city cars" which turn out to be glorified golf carts but they are suitable for very local driving and can sometimes work as a second car. Some folks have even had great success with bicycles of various flavors. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. Anthony |
Hi John;
John Popelish wrote: mike wrote: Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. Bingo, that is my opinion also. Yep. It doesn't take much of an angle from perpendicular for a silicon cell to act as a pretty fair mirror. Basically the power output will be: COS(angle) * Watts Watts is the output of the panel when aimed normal to the sun. Angle is how far off of normal the panel is oriented. 0deg = 100% 8deg = 99% 11deg = 98% 18deg = 95% 30deg = 87% 45deg = 70% However somewhere around 45deg or a bit more the cover glass begins to act more like a mirror and the panel outputs much less than allowed by the COS rule. Some panels can improve on this with anti reflective coatings. These coatings may not have a long lifetime though. Now if you use a solar tracker the panel can be oriented close to the ideal angle throughout the day. This significantly improves the energy captured per day. As an example: At summer solstice where I live, 45deg latitude, the sun subtends an angle of 270deg. That's an 18 hour day. 6 hours of the day the sun is actually behind a fixed panel. Another 6 hours or so the sun is at an angle where the output is low or negligible. Only during 6 hours or so will the panel output significant power. And the average power output is less than optimal. A solar tracker in my location can theoretically harvest 3 times as much energy as a fixed panel. OK, practically, due to weather and thick atmosphere the output is 2.4 times according to the NREL data. Other times of the year the improvement is not as much. But even at winter solstice the improvement in output is 1.4 times the fixed panel. Solar trackers, at least the electronic bits, are really low in cost, $35 for mine. The total cost including the tracking mount is much cheaper than the cost of adding more PV panels for the same outputs. There are places where the tracking costs aren't cost effective. The california sea coast and in maybe 50 miles or so is an example. The local weather has lots of fogs which lower the solar insolation except when the sun is high in the sky. One must study the NREL data to see how cost effective your location may be. -- John Popelish Duane -- Home of the $35 Solar Tracker Receiver http://www.redrok.com/electron.htm#led3X[*] Powered by \ \ \ //| Thermonuclear Solar Energy from the Sun / | Energy (the SUN) \ \ \ / / | Red Rock Energy \ \ / / | Duane C. Johnson Designer \ \ / \ / | 1825 Florence St Heliostat,Control,& Mounts | White Bear Lake, Minnesota === \ / \ | USA 55110-3364 === \ | (651)426-4766 use Courier New Font \ | (my email: address) \ | http://www.redrok.com (Web site) === |
Hi John;
John Popelish wrote: mike wrote: Then I turned the panel ever so slightly away from the sun. I was amazed at how dramatically things changed with just a small angle. Looks like I'd gain WAY more watt-hours/day by tracking the sun than by anything else I could think of. Bingo, that is my opinion also. Yep. It doesn't take much of an angle from perpendicular for a silicon cell to act as a pretty fair mirror. Basically the power output will be: COS(angle) * Watts Watts is the output of the panel when aimed normal to the sun. Angle is how far off of normal the panel is oriented. 0deg = 100% 8deg = 99% 11deg = 98% 18deg = 95% 30deg = 87% 45deg = 70% However somewhere around 45deg or a bit more the cover glass begins to act more like a mirror and the panel outputs much less than allowed by the COS rule. Some panels can improve on this with anti reflective coatings. These coatings may not have a long lifetime though. Now if you use a solar tracker the panel can be oriented close to the ideal angle throughout the day. This significantly improves the energy captured per day. As an example: At summer solstice where I live, 45deg latitude, the sun subtends an angle of 270deg. That's an 18 hour day. 6 hours of the day the sun is actually behind a fixed panel. Another 6 hours or so the sun is at an angle where the output is low or negligible. Only during 6 hours or so will the panel output significant power. And the average power output is less than optimal. A solar tracker in my location can theoretically harvest 3 times as much energy as a fixed panel. OK, practically, due to weather and thick atmosphere the output is 2.4 times according to the NREL data. Other times of the year the improvement is not as much. But even at winter solstice the improvement in output is 1.4 times the fixed panel. Solar trackers, at least the electronic bits, are really low in cost, $35 for mine. The total cost including the tracking mount is much cheaper than the cost of adding more PV panels for the same outputs. There are places where the tracking costs aren't cost effective. The california sea coast and in maybe 50 miles or so is an example. The local weather has lots of fogs which lower the solar insolation except when the sun is high in the sky. One must study the NREL data to see how cost effective your location may be. -- John Popelish Duane -- Home of the $35 Solar Tracker Receiver http://www.redrok.com/electron.htm#led3X[*] Powered by \ \ \ //| Thermonuclear Solar Energy from the Sun / | Energy (the SUN) \ \ \ / / | Red Rock Energy \ \ / / | Duane C. Johnson Designer \ \ / \ / | 1825 Florence St Heliostat,Control,& Mounts | White Bear Lake, Minnesota === \ / \ | USA 55110-3364 === \ | (651)426-4766 use Courier New Font \ | (my email: address) \ | http://www.redrok.com (Web site) === |
Watson A.Name "Watt Sun - the Dark Remover" wrote:
Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. Nice idea, although in her particular case I'd be willing to bet that she could be driving a Hummer and it'd be a small drop in the amount of energy she uses for transportation! (Due to all those jet rides...) They talked about getting every home to have a solar panel, and selling power back to the utility co. I'm all for net metering (power company has to pay you the same for a kilowatt-hour as what you would have had to pay to buy it from them), and happily it is becoming more common in the U.S. Panels and controllers are continuing to get cheaper as well. Additional government support could really help improve how many people would seriously consider sticking photovolataic panels on their roofs -- I imagine right now it's well under 1% of the population. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. We could do that as-is... there's plenty of oil in Alaska, after all, we've just made the choice that protecting the environment up there is more important right now than not importing oil from the middle east. (This is a very involved topic -- if anything, the choice of where we get our oil from is far more political than technical in nature anyway.) ---Joel Kolstad |
Watson A.Name "Watt Sun - the Dark Remover" wrote:
Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. Nice idea, although in her particular case I'd be willing to bet that she could be driving a Hummer and it'd be a small drop in the amount of energy she uses for transportation! (Due to all those jet rides...) They talked about getting every home to have a solar panel, and selling power back to the utility co. I'm all for net metering (power company has to pay you the same for a kilowatt-hour as what you would have had to pay to buy it from them), and happily it is becoming more common in the U.S. Panels and controllers are continuing to get cheaper as well. Additional government support could really help improve how many people would seriously consider sticking photovolataic panels on their roofs -- I imagine right now it's well under 1% of the population. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. We could do that as-is... there's plenty of oil in Alaska, after all, we've just made the choice that protecting the environment up there is more important right now than not importing oil from the middle east. (This is a very involved topic -- if anything, the choice of where we get our oil from is far more political than technical in nature anyway.) ---Joel Kolstad |
Anthony Matonak wrote:
That said, there are many things you can do that are quite affordable. Yes, such as building better-insulated dwellings. I find it appaling that here in Oregon where I live, the building codes don't require some apartment complexes to have any insulation whatsoever in their attics. These places additionally inevitably end up with electric heat, so the end result is that a small savings to the guy who builds the apartment complex ends up being a huge cost in additional energy to the renter as well as the corresponding impact on the environment. There are also many alternatives to a Prius. Although I understand the reasoning behind it, it's quite ironic how many people out there who live within an arguably quite reasonable bikable distance to their place of employment instead drive to work and then drive to a fitness club afterwards to work out. :-) Although I am all for people using their cars as much as they want so long as fuel taxes or whatever more or less make up for the impact to the environment, but unfortunately it's hard to translate that impact into monetary terms. ---Joel |
Anthony Matonak wrote:
That said, there are many things you can do that are quite affordable. Yes, such as building better-insulated dwellings. I find it appaling that here in Oregon where I live, the building codes don't require some apartment complexes to have any insulation whatsoever in their attics. These places additionally inevitably end up with electric heat, so the end result is that a small savings to the guy who builds the apartment complex ends up being a huge cost in additional energy to the renter as well as the corresponding impact on the environment. There are also many alternatives to a Prius. Although I understand the reasoning behind it, it's quite ironic how many people out there who live within an arguably quite reasonable bikable distance to their place of employment instead drive to work and then drive to a fitness club afterwards to work out. :-) Although I am all for people using their cars as much as they want so long as fuel taxes or whatever more or less make up for the impact to the environment, but unfortunately it's hard to translate that impact into monetary terms. ---Joel |
Anthony Matonak wrote:
Watson A.Name \"Watt Sun - the Dark Remover\" wrote: Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! [snip] You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! Anthony |
Anthony Matonak wrote:
Watson A.Name \"Watt Sun - the Dark Remover\" wrote: Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! [snip] You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! Anthony |
"Watson A.Name "Watt Sun - the Dark Remover"" wrote in message ... Anthony Matonak wrote: Watson A.Name \"Watt Sun - the Dark Remover\" wrote: Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! [snip] You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! Anthony Surprisingly enough some SUV owners actually need the SUV at the time of purchase, I personally drove through snow 70cm deep on a regular basis prior to my recent job change. Just because the people in southern California don't need it doesn't mean no one does. Charles |
"Watson A.Name "Watt Sun - the Dark Remover"" wrote in message ... Anthony Matonak wrote: Watson A.Name \"Watt Sun - the Dark Remover\" wrote: Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! [snip] You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! Anthony Surprisingly enough some SUV owners actually need the SUV at the time of purchase, I personally drove through snow 70cm deep on a regular basis prior to my recent job change. Just because the people in southern California don't need it doesn't mean no one does. Charles |
Watson A.Name \"Watt Sun - the Dark Remover\" wrote:
Anthony Matonak wrote: While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! The definition of "little" can vary. :) Would you consider 5 MPG a "little" ? http://www.fueleconomy.gov/feg/bestworst.shtml Shows the Prius at 60/51 mpg with a couple of VW's in the 38/46 range. This is only 1.6/1.1 times and not double, especially when considering highway driving instead of city driving. This means you can purchase a vehicle with good fuel efficiency without buying a Prius or even a hybrid. You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. You could chose to eliminate chicken as well as beef, eggs and dairy. I'm no expert in either nutrition or food prices but I think you could quite affordably manage a diet that does not include meat of any kind. Perhaps you should look at a group such as misc.consumers.frugal-living and ask for recipes. You could also look up many of the resources on the web for vegetarians and vegans. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. I agree, a RAV4 EV might not make sense on a financial basis. The last I heard they don't make them anymore. Any you do find are collectors items and will be priced accordingly. In fact, it might actually be rather difficult to find a brand new EV, even the golf cart style like the Chrysler GEM, as they keep getting discontinued. That said, a small neighborhood electric vehicle only costs in the neighborhood of $5,000 to $6,000 when they can be found. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! There are many worries in the world and it's always too late for some things. Time will certainly tell but there ARE some things that folks can do now if they like and without putting themselves in debt for the rest of their lives. Anthony |
Watson A.Name \"Watt Sun - the Dark Remover\" wrote:
Anthony Matonak wrote: While I'm all for using more renewable resources, and especially ones that are environmentally friendly, it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. It's not a "little" better, it more than double - 50+ MPG compared to 25! The definition of "little" can vary. :) Would you consider 5 MPG a "little" ? http://www.fueleconomy.gov/feg/bestworst.shtml Shows the Prius at 60/51 mpg with a couple of VW's in the 38/46 range. This is only 1.6/1.1 times and not double, especially when considering highway driving instead of city driving. This means you can purchase a vehicle with good fuel efficiency without buying a Prius or even a hybrid. You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. Right, but it's **you** (see above) that said to not cause yourself financial pain. Well, I _try_ to do my part to eat little or no beef, instead eat chicken. But I _have_ to pay a premium to do so, even tho it's cheaper to bring chicken to the table, just because of supply and demand issue. People consume less beef so the price drops below chicken, not because it's cheaper. So I and everyone else hasto pay extra for, helping save resources. Just what you said _didn't_make_ sense_. You could chose to eliminate chicken as well as beef, eggs and dairy. I'm no expert in either nutrition or food prices but I think you could quite affordably manage a diet that does not include meat of any kind. Perhaps you should look at a group such as misc.consumers.frugal-living and ask for recipes. You could also look up many of the resources on the web for vegetarians and vegans. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Again, you're asking for people to make a financial sacrifice when buying an electric vehicle. The last I checked, it cost $46,000 to purchase a RAV4 EV, with a good chunk of that going to the installation of an electric charger in the owner's garage. According to you, that financial pain 'doesn't make sense'. I agree, a RAV4 EV might not make sense on a financial basis. The last I heard they don't make them anymore. Any you do find are collectors items and will be priced accordingly. In fact, it might actually be rather difficult to find a brand new EV, even the golf cart style like the Chrysler GEM, as they keep getting discontinued. That said, a small neighborhood electric vehicle only costs in the neighborhood of $5,000 to $6,000 when they can be found. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. In the next 10 to 15 years, the situation may be much, much worse. The big worry in the near term seems to be China, with 1/5th of the world's population, which may have a growing economy that will gobble up an ever growing part of the world's non-renewable energy resources. In 10-15 years, it may be too late! The price of fuel in europe is already over $5 a gallon, and we Americans are currently bitching about having to pay over $2! Well, wait until it goes up to $3, or more! All those SUV owners in the U.S. will be taking tbe bus to work. Time will tell! There are many worries in the world and it's always too late for some things. Time will certainly tell but there ARE some things that folks can do now if they like and without putting themselves in debt for the rest of their lives. Anthony |
Anthony Matonak wrote:
Watson A.Name \"Watt Sun - the Dark Remover\" wrote: Last nite (Tue, 9pm) I watched a prog on PBS that was about getting people to use more renewable resources, hosted by Cameron Diaz (hot blonde movie star), who drives a Prius. They talked about getting every home to have a solar panel, and selling power back to the utility co. She also said that if everyone in the U.S. drove a hybrid vehicle, we could completely eliminate oil shipments from the middle east. Well, I'd go out and buy a Prius, but one of the guys at work has had his new Prius since xmas and it took him 4 months or so to get it after submitting a $500 earnest check to several dealerships to get on their waiting list. They say they're trying to make more of them, but I think they really don't want the prices to fall, since they're expensive to make. In any case I'd like more solar power, but the initial outlay is _not_ cheap. While I'm all for using more renewable resources, and especially ones that are environmentally friendly, I once read that it takes more energy to make, deliver, install a solar panel than the total energy you get out of it over it's 20 year lifetime. If that's true, (small scale PV) solar makes little sense from an environmental standpoint. mike it doesn't make sense to cause yourself financial pain doing so. It makes sense to buy the must fuel efficient vehicle that fits your needs but not to overspend simply because it's a little better on the gas mileage. That said, there are many things you can do that are quite affordable. First, you could conserve energy. Replace old appliances with more efficient ones, insulate your home better, weather-strip, storm windows, compact fluorescent lights, activate the power saving on your computer, use xeriscaping and all that lot. If you are a typical homeowners then conservation alone could be as effective as putting up a $30,000 solar panel setup. Then you could buy more affordable renewable energy equipment such as solar water heaters, air heaters, ovens, stoves and the like. You could also change your diet to include less animal products. Raising animals to produce food takes many times more resources (which often means energy) as plants alone require. There are also many alternatives to a Prius. One option would be to get a diesel powered car and use biodiesel or get it converted to run on straight vegetable oil. Another option is to buy an electric car. Currently the only ones available are "city cars" which turn out to be glorified golf carts but they are suitable for very local driving and can sometimes work as a second car. Some folks have even had great success with bicycles of various flavors. If you simply must have a hybrid vehicle then a much wider selection of them should be available within the next 10 to 15 years. Anthony -- Return address is VALID. Bunch of stuff For Sale and Wanted at the link below. Toshiba & Compaq LiIon Batteries, Test Equipment Honda CB-125S $800 in PDX Yaesu FTV901R Transverter, 30pS pulser Tektronix Concept Books, spot welding head... http://www.geocities.com/SiliconValley/Monitor/4710/ |
| All times are GMT +1. The time now is 04:05 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
RadioBanter.com