Question:
Newbie here – I’m looking at an article in a current magazine where the homeowners have a 12,000 watt PV system on their roof as well as being tied to the grid. At $5 a watt for an installed system, looks like they shelled out about $60,000 (and with California’s rebate system they may have recovered almost half of that). In contrast I’ve spent about $8,000 dollars over the last 5 years for both my gas and electric needs combined via SDG&E. So it would take me over 37 years to spend the $60,000 at the rate I’ve bought electricity from the grid (that I averaged over the last 5 years). And with a 50% rebate, that number would drop to over 18 years. But back to what I wanted to ask (sorry, I digress easily)… I don’t understand the wattage reference. Does that mean their system can produce 12,000 watts at once, or 12,000 watts over say a one month period of time? I’m using about 1000 kilowatt hours per month as reported on my bill. Am I comparing apples to oranges here? Any help or comments are greatly appreciated.
Response:
Let’s examine a 100 watt panel. In full sun, for 6 hours, you could produce 600 wh. times 30 days, that’s 18kwh’s. Theoretically. So If they have a 12kw system, they could possibly produce 72 kWh daily, or 2160 kWh monthly. even at only 15 days of sun, that’s over 1000 kWh, enough to completely power the most wasteful of homes. More than likely they did not get it installed for $5/watt, unless they went batteryless. Still, $8/watt sounds more norm, considering the inverter, wiring, fuses etc. — Steve Spence Subscribe to the Renewable Energy Newsletter: http://www.webconx.com/subscribe.htm Renewable Energy Pages – http://www.webconx.com Palm Pilot Pages – http://www.webconx.com/palm X10 Home Automation – http://www.webconx.com/x10 (212) 894-3704 x3154 – voicemail/fax We do not inherit the earth from our ancestors, we borrow it from our children. —
– Hide quoted text — Show quoted text -> Newbie here – I’m looking at an article in a current magazine where the > homeowners have a 12,000 watt PV system on their roof as well as being tied > to the grid. At $5 a watt for an installed system, looks like they shelled > out about $60,000 (and with California’s rebate system they may have > recovered almost half of that). > In contrast I’ve spent about $8,000 dollars over the last 5 years for both > my gas and electric needs combined via SDG&E. So it would take me over 37 > years to spend the $60,000 at the rate I’ve bought electricity from the grid > (that I averaged over the last 5 years). And with a 50% rebate, that number > would drop to over 18 years. > But back to what I wanted to ask (sorry, I digress easily)… > I don’t understand the wattage reference. > Does that mean their system can produce 12,000 watts at once, or 12,000 > watts over say a one month period of time? > I’m using about 1000 kilowatt hours per month as reported on my bill. Am I > comparing apples to oranges here? > Any help or comments are greatly appreciated.
Response:
You are using 1.38 kw per hour average. ( 1,388 watts ) or 33.3kwh per day based on 30 days a month.
– Hide quoted text — Show quoted text -> Newbie here – I’m looking at an article in a current magazine where the > homeowners have a 12,000 watt PV system on their roof as well as being tied > to the grid. At $5 a watt for an installed system, looks like they shelled > out about $60,000 (and with California’s rebate system they may have > recovered almost half of that). > In contrast I’ve spent about $8,000 dollars over the last 5 years for both > my gas and electric needs combined via SDG&E. So it would take me over 37 > years to spend the $60,000 at the rate I’ve bought electricity from the grid > (that I averaged over the last 5 years). And with a 50% rebate, that number > would drop to over 18 years. > But back to what I wanted to ask (sorry, I digress easily)… > I don’t understand the wattage reference. > Does that mean their system can produce 12,000 watts at once, or 12,000 > watts over say a one month period of time? > I’m using about 1000 kilowatt hours per month as reported on my bill. Am I > comparing apples to oranges here? > Any help or comments are greatly appreciated.
Response:
Wow, that explanation is just at my speed – thank you very much. So at $8/watt, their system comes in around $96,000 before rebates. The grid is still cheaper, although I love the idea of pulling power from the sun. Hmmm… A friend at work said he though PV’s and batts would go away when fuel cell technology gets better. He said battery recycling was/is a nightmare. I guess for now I’m going to continue looking for ways to reduce my consumption. Thanks again.
– Hide quoted text — Show quoted text -> Let’s examine a 100 watt panel. > In full sun, for 6 hours, you could produce 600 wh. > times 30 days, that’s 18kwh’s. Theoretically. > So If they have a 12kw system, they could possibly produce 72 kWh daily, or > 2160 kWh monthly. even at only 15 days of sun, that’s over 1000 kWh, enough > to completely power the most wasteful of homes. > More than likely they did not get it installed for $5/watt, unless they went > batteryless. Still, $8/watt sounds more norm, considering the inverter, > wiring, fuses etc. > — > Steve Spence > Subscribe to the Renewable Energy Newsletter: > http://www.webconx.com/subscribe.htm > Renewable Energy Pages – http://www.webconx.com > Palm Pilot Pages – http://www.webconx.com/palm > X10 Home Automation – http://www.webconx.com/x10 > (212) 894-3704 x3154 – voicemail/fax > We do not inherit the earth from our ancestors, > we borrow it from our children. > — > Newbie here – I’m looking at an article in a current magazine where the > homeowners have a 12,000 watt PV system on their roof as well as being > tied > to the grid. At $5 a watt for an installed system, looks like they > shelled > out about $60,000 (and with California’s rebate system they may have > recovered almost half of that). > In contrast I’ve spent about $8,000 dollars over the last 5 years for both > my gas and electric needs combined via SDG&E. So it would take me over 37 > years to spend the $60,000 at the rate I’ve bought electricity from the > grid > (that I averaged over the last 5 years). And with a 50% rebate, that > number > would drop to over 18 years. > But back to what I wanted to ask (sorry, I digress easily)… > I don’t understand the wattage reference. > Does that mean their system can produce 12,000 watts at once, or 12,000 > watts over say a one month period of time? > I’m using about 1000 kilowatt hours per month as reported on my bill. Am > I > comparing apples to oranges here? > Any help or comments are greatly appreciated.
Response:
1,000 KWH / month is like having one 1388 watt heater running continuously. That’s like about 116 amps from a 12 volt battery, 24 hours per day 30 days per month. – Hide quoted text — Show quoted text – >Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid. At $5 a watt for an installed system, looks like they shelled >out about $60,000 (and with California’s rebate system they may have >recovered almost half of that). >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E. So it would take me over 37 >years to spend the $60,000 at the rate I’ve bought electricity from the grid >(that I averaged over the last 5 years). And with a 50% rebate, that number >would drop to over 18 years. >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time? >I’m using about 1000 kilowatt hours per month as reported on my bill. Am I >comparing apples to oranges here? >Any help or comments are greatly appreciated.
Response:
Thanks – yikes!
– Hide quoted text — Show quoted text -> You are using 1.38 kw per hour average. ( 1,388 watts ) or 33.3kwh per day > based on 30 days a month. > Newbie here – I’m looking at an article in a current magazine where the > homeowners have a 12,000 watt PV system on their roof as well as being > tied > to the grid. At $5 a watt for an installed system, looks like they > shelled > out about $60,000 (and with California’s rebate system they may have > recovered almost half of that). > In contrast I’ve spent about $8,000 dollars over the last 5 years for both > my gas and electric needs combined via SDG&E. So it would take me over 37 > years to spend the $60,000 at the rate I’ve bought electricity from the > grid > (that I averaged over the last 5 years). And with a 50% rebate, that > number > would drop to over 18 years. > But back to what I wanted to ask (sorry, I digress easily)… > I don’t understand the wattage reference. > Does that mean their system can produce 12,000 watts at once, or 12,000 > watts over say a one month period of time? > I’m using about 1000 kilowatt hours per month as reported on my bill. Am > I > comparing apples to oranges here? > Any help or comments are greatly appreciated.
Response:
Thanks. I actually got it down into the low 900’s last month – I’m going to switch from electric water heating to a gas demand (soon as I figure out all the details and the least expensive way to do it)… …in the mean time I’m turning stuff off all the time – no more TV’s, computers and lights running in multiple rooms (that don’t contain people). Of course the systems for the stupid pool need to run daily – however those times have been reduced too. Are you the same Ben as in the Saturn NG? – Hide quoted text — Show quoted text -> 1,000 KWH / month is like having one 1388 watt heater running continuously. > That’s like about 116 amps from a 12 volt battery, 24 hours per day 30 days per > month. >Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid. At $5 a watt for an installed system, looks like they shelled >out about $60,000 (and with California’s rebate system they may have >recovered almost half of that). >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E. So it would take me over 37 >years to spend the $60,000 at the rate I’ve bought electricity from the grid >(that I averaged over the last 5 years). And with a 50% rebate, that number >would drop to over 18 years. >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time? >I’m using about 1000 kilowatt hours per month as reported on my bill. Am I >comparing apples to oranges here? >Any help or comments are greatly appreciated.
Response:
>Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid.
That seems … excessive. 
(Such a system should generate nearly, or perhaps even more than, 2000 kWh/mo in SDG&E territory. Most people already get by with about 1000 kWh/mo, even with no real attempt at conservation.) >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E.
But your electric rate per kWh went way up last summer, right? What would you have paid if every year were like that? Over the warranted 25 year lifetime of a typical solar panel, as connected into a grid-tied system, you will probably pay about $.18/kWh after the CEC buydown. Whenever your retail rate is above that, a solar PV system will win; otherwise it will cost more in dollars (although you may have your own reasons to use it anyway). >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time?
A "watt" is an instantaneous measure, sort of like gallons-per-minute on a showerhead. 12000 watts would be 12000 "watt-seconds per second". (You could say "watt-hours per hour" or "watt-days per day" or whatever, the point is that the watts need a time multiplier to become useful, just like the GPM on the showerhead does not mean anything until you take a ten-minute shower.) The "watt-second" is a real, actual unit of Electric Stuff, like a "gallon" is a real, actual unit of water. (A "watt-second" is also called a "joule", i.e., 1 joule = 1 watt-second. People really ought to go around saying "I use X joules every month" instead of talking about kWh. ) Anyway, what all this means is that their system can produce 12000 watts at once, as you said, whenever it is getting full sunlight — 1 "sol"[ar] worth of "in-sol-ation". When it gets less than full insolation, the output goes down. Take the full-sun time, add some part of part-sun time, etc., and figure out how many "peak sun hour equivalents" it gets. Since you are in SDG&E territory you get pretty good numbers here — at least 5.5 Peak Sun Hours, and perhaps as many as 6.5 Peak Sun Hours, per day. (See, e.g., http://www.oasismontana.com/systems.html and click on the map.) (This is an average over all 12 months, so you will get more sun in summer and less in winter.) >I’m using about 1000 kilowatt hours per month as reported on my >bill. Am I comparing apples to oranges here?
If you stick with kWh (or joules), you will get apples-to-apples comparisons. If you want to size a system, you can apply your "peak sun hours" number to figure out how many watts you need. For instance, if you wanted to generate that same 1000 kWh/mo, and you actually get 6 Peak Sun Hours per day, you would need 1000/30/6 kW = 5.555555555… kW of PV panels. This is: 1000 (kWh/mo) / 30 (days/mo) / 6 (PSH/day) which leaves you with units of "kWh/PSH" (kilowatt-hours per Peak Sun Hour). A solar panel delivers its rated output only when it gets that "peak sun", so the hours drop out and you have "kW/PeakSun", which is what each panel’s rating really is anyway. Thus, if you installed 5500 watts of panels, you would just not-quite-meet current daily usage. Round up to 6000W to account for system losses, and you should "over-meet" your usage, and wind up feeding power back to SDG&E over the course of a year. (For which you will get paid … nothing. ) — In-Real-Life: Chris Torek, Berkeley Software Design Inc
Response:
> A "watt" is an instantaneous measure, sort of like gallons-per-minute > on a showerhead. 12000 watts would be 12000 "watt-seconds per > second". (You could say "watt-hours per hour" or "watt-days per > day" or whatever, the point is that the watts need a time multiplier > to become useful, just like the GPM on the showerhead does not mean > anything until you take a ten-minute shower.) The "watt-second" > is a real, actual unit of Electric Stuff, like a "gallon" is a > real, actual unit of water. (A "watt-second" is also called a > "joule", i.e., 1 joule = 1 watt-second. People really ought to go > around saying "I use X joules every month" instead of talking about > kWh. )
People avoid words that they’re not certain how to pronounce. It comes from an English name (James Prescott Joule) which might be jow-el or jew-el or jow-le. My OED keys "dgaul", i.e. rhyming with newl or kewl. Most physicists say "jool". Unfortunately basic concepts of energy are not taught in elementary school, at least in the USA. Pre-metric (and pre-space-travel) the unit of energy was the easily understandable foot-pound = the amount of energy needed to lift a pound one foot. The meter kilogram is however *not* a unit of energy since the force required to lift a kilogram depends on the local gravitational attraction (being 1/6th as much on the Moon as it is on the Earth). On Earth this force is 9.8 newtons per kilogram, hence to lift a kilogram one meter requires an energy of 9.8 newton-meters = 9.8 joules = about 10 watt-seconds. While at this point most adult’s eyes began to glaze over, I do think that properly taught children would think it all perfectly natural
Response:
Thanks – great, detailed post. Yes, my rates went up, but we are being subsidized. The subsidy is going into a pot collecting interest and becomes payable in just over 2 years. Here’s some billing history for the month of March: 1996 $135 1997 $139 1998 $161 1999 $129 2000 $132 2001 $251 I’m going to work the conservation aspect first (least costly), and then go from there. Thanks again for your time and all this info.
– Hide quoted text — Show quoted text ->Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid. > That seems … excessive. > (Such a system should generate nearly, or perhaps even more than, > 2000 kWh/mo in SDG&E territory. Most people already get by with > about 1000 kWh/mo, even with no real attempt at conservation.) >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E. > But your electric rate per kWh went way up last summer, right? > What would you have paid if every year were like that? > Over the warranted 25 year lifetime of a typical solar panel, as > connected into a grid-tied system, you will probably pay about > $.18/kWh after the CEC buydown. Whenever your retail rate is above > that, a solar PV system will win; otherwise it will cost more in > dollars (although you may have your own reasons to use it anyway). >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time? > A "watt" is an instantaneous measure, sort of like gallons-per-minute > on a showerhead. 12000 watts would be 12000 "watt-seconds per > second". (You could say "watt-hours per hour" or "watt-days per > day" or whatever, the point is that the watts need a time multiplier > to become useful, just like the GPM on the showerhead does not mean > anything until you take a ten-minute shower.) The "watt-second" > is a real, actual unit of Electric Stuff, like a "gallon" is a > real, actual unit of water. (A "watt-second" is also called a > "joule", i.e., 1 joule = 1 watt-second. People really ought to go > around saying "I use X joules every month" instead of talking about > kWh. ) > Anyway, what all this means is that their system can produce 12000 > watts at once, as you said, whenever it is getting full sunlight > — 1 "sol"[ar] worth of "in-sol-ation". When it gets less than full > insolation, the output goes down. Take the full-sun time, add some > part of part-sun time, etc., and figure out how many "peak sun hour > equivalents" it gets. Since you are in SDG&E territory you get > pretty good numbers here — at least 5.5 Peak Sun Hours, and perhaps > as many as 6.5 Peak Sun Hours, per day. (See, e.g., > http://www.oasismontana.com/systems.html and click on the map.) > (This is an average over all 12 months, so you will get more sun > in summer and less in winter.) >I’m using about 1000 kilowatt hours per month as reported on my >bill. Am I comparing apples to oranges here? > If you stick with kWh (or joules), you will get apples-to-apples > comparisons. If you want to size a system, you can apply your > "peak sun hours" number to figure out how many watts you need. > For instance, if you wanted to generate that same 1000 kWh/mo, and > you actually get 6 Peak Sun Hours per day, you would need 1000/30/6 > kW = 5.555555555… kW of PV panels. This is: > 1000 (kWh/mo) / 30 (days/mo) / 6 (PSH/day) > which leaves you with units of "kWh/PSH" (kilowatt-hours per Peak > Sun Hour). A solar panel delivers its rated output only when it > gets that "peak sun", so the hours drop out and you have "kW/PeakSun", > which is what each panel’s rating really is anyway. > Thus, if you installed 5500 watts of panels, you would just > not-quite-meet current daily usage. Round up to 6000W to account > for system losses, and you should "over-meet" your usage, and > wind up feeding power back to SDG&E over the course of a year. > (For which you will get paid … nothing. ) > — > In-Real-Life: Chris Torek, Berkeley Software Design Inc
Response:
>I actually got it down into the low 900’s last month – I’m going to switch >from electric water heating to a gas demand (soon as I figure out all the >details and the least expensive way to do it)… >…in the mean time I’m turning stuff off all the time – no more TV’s, >computers and lights running in multiple rooms (that don’t contain people). >Of course the systems for the stupid pool need to run daily – however those >times have been reduced too.
I can identify with you. I went thru very similar stages. Found out as well that for already grid conected folks Solar panels aren’t going to be an obvious economic benefit to my wallet. Besides having solar means that you’re committed to using less energy anyway and starting by reducing consumption is the best thing to do. I’ve hardly modified my life at all and brought my electric down from over 1,000 kwh to somewhere in the 600’s. I put compact flourescents in everywhere but the kitchen. Pending a remodel I’ll have them there too. I switched from an old decrepit air source heat pump to propane heat. I’ve converted nearly everything now over to propane: dryer, stove (we had our first night cooking with gas tonight!), and an on-demand gas water heater. I haven’t gotten an electric bill since I put in the water heater though. I’m hoping for a big savings. However there are places that solar makes sense. I have a pool that I have to rewire the electric to the pump. They idiot contractor (before I lived here) put the line right over my septic manholes. Plus the line is right where I need to put drainage. So I figured the cost of a solar pump is actually comparable to the cost of running 60′ of wiring underground. And then of course the electric is free! And I can run my pump all day long! Also to help cool down my attic… When you figure in the cost of wiring and the time involved… a solar powered exhaust fan becomes economical. With a payback of 3-4 years I figured. So even for us folks who are tied and need more of an economic reason for going solar there are reasons for us to consider it. Of course much of my savings on electric is put into propane, but that should still be cheaper overall. Good luck, Bill
Response:
No, he’s using 1.39 kW average. Or 1.39 kWh/h average. Or 33.33 kWh/day average. You can’t use a kW per hour, since a kW is POWER, not ENERGY. You got the relationship right on a daily basis, but missed the boat on the hourly. Steven – Hide quoted text — Show quoted text – > You are using 1.38 kw per hour average. ( 1,388 watts ) or 33.3kwh per day > based on 30 days a month. > Newbie here – I’m looking at an article in a current magazine where the > homeowners have a 12,000 watt PV system on their roof as well as being > tied > to the grid. At $5 a watt for an installed system, looks like they > shelled > out about $60,000 (and with California’s rebate system they may have > recovered almost half of that). > In contrast I’ve spent about $8,000 dollars over the last 5 years for both > my gas and electric needs combined via SDG&E. So it would take me over 37 > years to spend the $60,000 at the rate I’ve bought electricity from the > grid > (that I averaged over the last 5 years). And with a 50% rebate, that > number > would drop to over 18 years. > But back to what I wanted to ask (sorry, I digress easily)… > I don’t understand the wattage reference. > Does that mean their system can produce 12,000 watts at once, or 12,000 > watts over say a one month period of time? > I’m using about 1000 kilowatt hours per month as reported on my bill. Am > I > comparing apples to oranges here? > Any help or comments are greatly appreciated.
Response:
Sleep easy….I’ll try to say 2 simple principles here. 1) The use of a system defines the system size. And the answer to your first question is "installed Capacity" meaning ability to generate at any one given time during peak conditions. the batteries will supply the home of nessasary electrical demands. Forget the $ here right now. 2) Use dollars now ! First cost / first savings will give you payback in years…..You want somewhere between 3-5 years. You must do a site demand evaluation of currently used of wanted or needed electrical stuff, then esitimate how long you use them. Account for inflation at 6% and payback on investment. – Hide quoted text — Show quoted text – >Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid. At $5 a watt for an installed system, looks like they shelled >out about $60,000 (and with California’s rebate system they may have >recovered almost half of that). >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E. So it would take me over 37 >years to spend the $60,000 at the rate I’ve bought electricity from the grid >(that I averaged over the last 5 years). And with a 50% rebate, that number >would drop to over 18 years. >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time? >I’m using about 1000 kilowatt hours per month as reported on my bill. Am I >comparing apples to oranges here? >Any help or comments are greatly appreciated.
Response:
Thanks – I’m saving these replies to digest as I go…
– Hide quoted text — Show quoted text -> Sleep easy….I’ll try to say 2 simple principles here. > 1) The use of a system defines the system size. And the answer to > your first question is "installed Capacity" meaning ability to > generate at any one given time during peak conditions. the batteries > will supply the home of nessasary electrical demands. Forget the $ > here right now. > 2) Use dollars now ! First cost / first savings will give you > payback in years…..You want somewhere between 3-5 years. > You must do a site demand evaluation of currently used of wanted or > needed electrical stuff, then esitimate how long you use them. > Account for inflation at 6% and payback on investment. >Newbie here – I’m looking at an article in a current magazine where the >homeowners have a 12,000 watt PV system on their roof as well as being tied >to the grid. At $5 a watt for an installed system, looks like they shelled >out about $60,000 (and with California’s rebate system they may have >recovered almost half of that). >In contrast I’ve spent about $8,000 dollars over the last 5 years for both >my gas and electric needs combined via SDG&E. So it would take me over 37 >years to spend the $60,000 at the rate I’ve bought electricity from the grid >(that I averaged over the last 5 years). And with a 50% rebate, that number >would drop to over 18 years. >But back to what I wanted to ask (sorry, I digress easily)… >I don’t understand the wattage reference. >Does that mean their system can produce 12,000 watts at once, or 12,000 >watts over say a one month period of time? >I’m using about 1000 kilowatt hours per month as reported on my bill. Am I >comparing apples to oranges here? >Any help or comments are greatly appreciated.
Response:
> Wow, that explanation is just at my speed – thank you very much. > So at $8/watt, their system comes in around $96,000 before rebates. The > grid is still cheaper, although I love the idea of pulling power from the > sun. Hmmm… > A friend at work said he though PV’s and batts would go away when fuel cell > technology gets better. He said battery recycling was/is a nightmare.
Thats why many who have solar still remain connected to the grid, they use the grid as their battery.
Response:
Makes sense – solar power by day, grid by night. I think the rebate program here in California requires staying connected to the grid, yet I don’t believe they’ll actual pay you for energy put back into it. (…or maybe the amount of time the meter runs backward during the day, it runs forward at night and the energy consumption is a wash…)
– Hide quoted text — Show quoted text -> Wow, that explanation is just at my speed – thank you very much. > So at $8/watt, their system comes in around $96,000 before rebates. The > grid is still cheaper, although I love the idea of pulling power from the > sun. Hmmm… > A friend at work said he though PV’s and batts would go away when fuel > cell > technology gets better. He said battery recycling was/is a nightmare. > Thats why many who have solar still remain connected to the grid, they use > the grid as their battery.
Response:
>Makes sense – solar power by day, grid by night. I think the rebate program >here in California requires staying connected to the grid, yet I don’t >believe they’ll actual pay you for energy put back into it. (…or maybe >the amount of time the meter runs backward during the day, it runs forward >at night and the energy consumption is a wash…)
This is called "net metering", and net metering is definitely available. Basically you run the meter forward at night and backward during the day, and in the end the meter turns somewhat forward, so that you pay a bit. If you have an enormous home-generation system, in the end, the meter turns somewhat backwards. Because there is a minimum charge, you still pay a bit. In other words, if you supply more power into the grid than you draw from it, you *will not* get paid for it. Clint Eastwood (yes, really) went to Sacramento to lobby for some changes to this rule. His golf country-club over near Monterey has a 32 (I think) kW photovoltaic system that runs everything and charges up the golf carts. It turns out it was oversized, so he gives PG&E free power every day. Seems he figured out that if businesses like (say) grocery stores could buy natgas-powered refrigeration systems that generate electricity, and then discovered that they would not get paid for it, they would decide not to put them in. If they could have gas-fired chillers, generate electricity, and get paid for it, they might become net electric producers. — In-Real-Life: Chris Torek, Berkeley Software Design Inc / Wind River Systems
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