Solar - after 1 year the results are in.

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willthrill81
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Re: Solar - after 1 year the results are in.

Post by willthrill81 »

harikaried wrote: Tue Sep 22, 2020 10:00 am
willthrill81 wrote: Mon Sep 21, 2020 8:23 pmHowever, the payback period in our area is 20+ years since we have some of the cheapest grid power in the nation at about 8 cents / kWh
That's what I thought too with our 8¢/kWh standard rate, but then I noticed the time-of-use rates. Only summer on-peak rates were higher than the standard rate, and solar would be producing from 1pm to 6pm even with A/C usage, so the biggest "downside" of switching to time-of-use becomes a money maker with solar. The other time-of-use rate periods are all cheaper than standard, and we're able to shift most of our electricity usage to the lowest 4¢/kWh rate.

So even with a low standard rate before solar, time-of-use rates allows us to use electricity when sending only 8% back at peak hours resulting in a 7 year payback period.
We don't have time-of-use rates. It's just cheap all the time. :D
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings
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tyrion
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Re: Solar - after 1 year the results are in.

Post by tyrion »

willthrill81 wrote: Tue Sep 22, 2020 11:58 am
harikaried wrote: Tue Sep 22, 2020 10:00 am
willthrill81 wrote: Mon Sep 21, 2020 8:23 pmHowever, the payback period in our area is 20+ years since we have some of the cheapest grid power in the nation at about 8 cents / kWh
That's what I thought too with our 8¢/kWh standard rate, but then I noticed the time-of-use rates. Only summer on-peak rates were higher than the standard rate, and solar would be producing from 1pm to 6pm even with A/C usage, so the biggest "downside" of switching to time-of-use becomes a money maker with solar. The other time-of-use rate periods are all cheaper than standard, and we're able to shift most of our electricity usage to the lowest 4¢/kWh rate.

So even with a low standard rate before solar, time-of-use rates allows us to use electricity when sending only 8% back at peak hours resulting in a 7 year payback period.
We don't have time-of-use rates. It's just cheap all the time. :D
It's wild to me to see these rates. Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
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willthrill81
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Re: Solar - after 1 year the results are in.

Post by willthrill81 »

tyrion wrote: Tue Sep 22, 2020 12:18 pm
willthrill81 wrote: Tue Sep 22, 2020 11:58 am
harikaried wrote: Tue Sep 22, 2020 10:00 am
willthrill81 wrote: Mon Sep 21, 2020 8:23 pmHowever, the payback period in our area is 20+ years since we have some of the cheapest grid power in the nation at about 8 cents / kWh
That's what I thought too with our 8¢/kWh standard rate, but then I noticed the time-of-use rates. Only summer on-peak rates were higher than the standard rate, and solar would be producing from 1pm to 6pm even with A/C usage, so the biggest "downside" of switching to time-of-use becomes a money maker with solar. The other time-of-use rate periods are all cheaper than standard, and we're able to shift most of our electricity usage to the lowest 4¢/kWh rate.

So even with a low standard rate before solar, time-of-use rates allows us to use electricity when sending only 8% back at peak hours resulting in a 7 year payback period.
We don't have time-of-use rates. It's just cheap all the time. :D
It's wild to me to see these rates. Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
You mean it's "wild" to see that some of us are paying so little for electricity?

I agree that solar is very compelling when you're paying 20 cents / kWh or more. Under that point, it depends on various factors. For those of us paying 10 cents / kWh or less, it's not financially worthwhile for most.
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings
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TomatoTomahto
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Re: Solar - after 1 year the results are in.

Post by TomatoTomahto »

tyrion wrote: Tue Sep 22, 2020 12:18 pm Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Wow. So, if I lived where you live, I could sell my battery power (32 kw) to the utility at 43 (or 50) cents. Uh, that’s $13.76 per day. A lot of the year I generate well in excess of that, but let’s assume I might have to buy some back, so average $11/day. Assuming I wouldn’t do so if bad weather was forecast, let’s say I could do so for 320 days per year. That’s $3,520 per year.
I get the FI part but not the RE part of FIRE.
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willthrill81
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Re: Solar - after 1 year the results are in.

Post by willthrill81 »

TomatoTomahto wrote: Tue Sep 22, 2020 12:57 pm
tyrion wrote: Tue Sep 22, 2020 12:18 pm Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Wow. So, if I lived where you live, I could sell my battery power (32 kw) to the utility at 43 (or 50) cents. Uh, that’s $13.76 per day. A lot of the year I generate well in excess of that, but let’s assume I might have to buy some back, so average $11/day. Assuming I wouldn’t do so if bad weather was forecast, let’s say I could do so for 320 days per year. That’s $3,520 per year.
It's almost enough to make you want to build your own solar farm. 8-)
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings
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TomatoTomahto
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Re: Solar - after 1 year the results are in.

Post by TomatoTomahto »

willthrill81 wrote: Tue Sep 22, 2020 12:59 pm
TomatoTomahto wrote: Tue Sep 22, 2020 12:57 pm
tyrion wrote: Tue Sep 22, 2020 12:18 pm Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Wow. So, if I lived where you live, I could sell my battery power (32 kw) to the utility at 43 (or 50) cents. Uh, that’s $13.76 per day. A lot of the year I generate well in excess of that, but let’s assume I might have to buy some back, so average $11/day. Assuming I wouldn’t do so if bad weather was forecast, let’s say I could do so for 320 days per year. That’s $3,520 per year.
It's almost enough to make you want to build your own solar farm. 8-)
I do have a small ground based solar farm, but Eversource rates are lower and there really isn’t residential TOU. It might not be allowed under SMART and SREC anyway, and I’d have to hire a lawyer to figure it out (my eyes glaze over when reading MA incentive program rules). But man, at $0.43 or $0.50 per kWh, I’d figure out a way. :beer
I get the FI part but not the RE part of FIRE.
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willthrill81
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Re: Solar - after 1 year the results are in.

Post by willthrill81 »

TomatoTomahto wrote: Tue Sep 22, 2020 1:10 pm
willthrill81 wrote: Tue Sep 22, 2020 12:59 pm
TomatoTomahto wrote: Tue Sep 22, 2020 12:57 pm
tyrion wrote: Tue Sep 22, 2020 12:18 pm Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Wow. So, if I lived where you live, I could sell my battery power (32 kw) to the utility at 43 (or 50) cents. Uh, that’s $13.76 per day. A lot of the year I generate well in excess of that, but let’s assume I might have to buy some back, so average $11/day. Assuming I wouldn’t do so if bad weather was forecast, let’s say I could do so for 320 days per year. That’s $3,520 per year.
It's almost enough to make you want to build your own solar farm. 8-)
I do have a small ground based solar farm, but Eversource rates are lower and there really isn’t residential TOU. It might not be allowed under SMART and SREC anyway, and I’d have to hire a lawyer to figure it out (my eyes glaze over when reading MA incentive program rules). But man, at $0.43 or $0.50 per kWh, I’d figure out a way. :beer
It's really crazy to me that Hawaii, where electricity can be 50 cents / kWh, isn't 100% solar right now. Burning diesel to make electricity there seems insane.
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings
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czeckers
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Re: Solar - after 1 year the results are in.

Post by czeckers »

We installed solar on our previous house. I was pleasantly surprised at how accurate the estimates of the annual solar production were. That was my big concern -- how do you know it's going to produce X kwh? What if it's cloudy? The annual production varied very little year to year.

We sold the house in the spring. My experience was that most potential buyers have no idea of the financial impact of having solar and they are nervous about having something they don't understand and thus don't account for it in their offer.

With respect to maintenance, we literally did nothing with the solar. It just sits there spinning our electric meter backwards on sunny days. No maintenance required.
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tyrion
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Re: Solar - after 1 year the results are in.

Post by tyrion »

TomatoTomahto wrote: Tue Sep 22, 2020 12:57 pm
tyrion wrote: Tue Sep 22, 2020 12:18 pm Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Wow. So, if I lived where you live, I could sell my battery power (32 kw) to the utility at 43 (or 50) cents. Uh, that’s $13.76 per day. A lot of the year I generate well in excess of that, but let’s assume I might have to buy some back, so average $11/day. Assuming I wouldn’t do so if bad weather was forecast, let’s say I could do so for 320 days per year. That’s $3,520 per year.
Yes, that's my understanding. Except the devil is always in the details:

There are 5 months of summer pricing. The delta on the 7 months of winter pricing (peak/offpeak) is 1 or 2 cents per KWh.

At the annual true-up they will only credit you at wholesale rates if you had a surplus (sent more to the grid than you consumed).


We will have 20 KWh of storage, planning to keep a healthy 20-30% reserve in case of outages and to not cycle the batteries too deeply, and hope to sell enough to the grid during peak summer times (west facing solar array) to allow us to increase electricity use 10-20% over current and still not have an electrical bill. Fingers crossed. Install is next week.
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Re: Solar - after 1 year the results are in.

Post by curmudgeon »

willthrill81 wrote: Tue Sep 22, 2020 1:12 pm ....

It's really crazy to me that Hawaii, where electricity can be 50 cents / kWh, isn't 100% solar right now. Burning diesel to make electricity there seems insane.
People have this crazy habit of wanting to turn their lights on at night. And run their fans and tvs and even A/C (at least in large buildings). They also like their power to keep working if heavy cloud cover from a storm system covers the islands and cuts solar production by 80%. My understanding is that the problems with too much solar dependence in Hawaii are like California's, only an order of magnitude worse because there is no large power grid for interconnection.

Battery might seem like an option, but aside from massive cost (and environmental impact) at that scale, it's not just the overnight problem - you might need several days worth to deal with storm systems.
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Re: Solar - after 1 year the results are in.

Post by willthrill81 »

curmudgeon wrote: Tue Sep 22, 2020 1:39 pm
willthrill81 wrote: Tue Sep 22, 2020 1:12 pm ....

It's really crazy to me that Hawaii, where electricity can be 50 cents / kWh, isn't 100% solar right now. Burning diesel to make electricity there seems insane.
People have this crazy habit of wanting to turn their lights on at night. And run their fans and tvs and even A/C (at least in large buildings). They also like their power to keep working if heavy cloud cover from a storm system covers the islands and cuts solar production by 80%. My understanding is that the problems with too much solar dependence in Hawaii are like California's, only an order of magnitude worse because there is no large power grid for interconnection.

Battery might seem like an option, but aside from massive cost (and environmental impact) at that scale, it's not just the overnight problem - you might need several days worth to deal with storm systems.
That's a good point.
“It's a dangerous business, Frodo, going out your door. You step onto the road, and if you don't keep your feet, there's no knowing where you might be swept off to.” J.R.R. Tolkien,The Lord of the Rings
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tyrion
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Re: Solar - after 1 year the results are in.

Post by tyrion »

curmudgeon wrote: Tue Sep 22, 2020 1:39 pm
willthrill81 wrote: Tue Sep 22, 2020 1:12 pm ....

It's really crazy to me that Hawaii, where electricity can be 50 cents / kWh, isn't 100% solar right now. Burning diesel to make electricity there seems insane.
People have this crazy habit of wanting to turn their lights on at night. And run their fans and tvs and even A/C (at least in large buildings). They also like their power to keep working if heavy cloud cover from a storm system covers the islands and cuts solar production by 80%. My understanding is that the problems with too much solar dependence in Hawaii are like California's, only an order of magnitude worse because there is no large power grid for interconnection.

Battery might seem like an option, but aside from massive cost (and environmental impact) at that scale, it's not just the overnight problem - you might need several days worth to deal with storm systems.
Kauai has a huge Powerwall plant to store solar for overnight use. Obviously that doesn't solve the problem of a storm reducing solar for several days.

https://www.cnbc.com/2017/03/08/tesla-b ... -dark.html

Ideally you would have several layers. Solar for the day, with surplus stored in batteries. Batteries for nighttime load. Bring on supplemental power plants as needed for inclement weather or unexpected need. The batteries buy you time to figure out how much supplemental power you will need. I believe it can take hours/days to bring a power plant online depending on the fuel source, with natural gas being one of the quickest but probably not available in Hawaii.
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Re: Solar - after 1 year the results are in.

Post by pondering »

I assume a large challenge in Hawaii of solar is the densely populated area of Honolulu.
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Re: Solar - after 1 year the results are in.

Post by BrandonBogle »

tyrion wrote: Tue Sep 22, 2020 12:18 pm
willthrill81 wrote: Tue Sep 22, 2020 11:58 am
harikaried wrote: Tue Sep 22, 2020 10:00 am
willthrill81 wrote: Mon Sep 21, 2020 8:23 pmHowever, the payback period in our area is 20+ years since we have some of the cheapest grid power in the nation at about 8 cents / kWh
That's what I thought too with our 8¢/kWh standard rate, but then I noticed the time-of-use rates. Only summer on-peak rates were higher than the standard rate, and solar would be producing from 1pm to 6pm even with A/C usage, so the biggest "downside" of switching to time-of-use becomes a money maker with solar. The other time-of-use rate periods are all cheaper than standard, and we're able to shift most of our electricity usage to the lowest 4¢/kWh rate.

So even with a low standard rate before solar, time-of-use rates allows us to use electricity when sending only 8% back at peak hours resulting in a 7 year payback period.
We don't have time-of-use rates. It's just cheap all the time. :D
It's wild to me to see these rates. Our cheapest super-off-peak during summer is 19 cents/KWh. 23 off peak. 43 peak (4-9pm). And that's for baseline usage, add about 7 cents/KWh if you use more than 130% of the 'baseline' which basically covers lights and a fridge.

If you want to lower your peak rate there's a special plan where you only pay 31 cents peak. But when they call for a 'reduce your use' day (up to 18 times per year) then there is a $1.16 surcharge per KWH. Surcharge.

As you can imagine solar is pretty compelling. And with mandatory TOU rates for solar users a battery system to load-shift and sell during peak and buy during off-peak is compelling as well. Not as cheap as buying additional panels to offset the difference in time of use rates, but it comes with other benefits.
Where I live I pay a flat 7.6¢/kWh most of the year, 8.3¢/kWh for part of it. However, if I switch to the time-of-use plan, I can get as low as 3.5¢/kWh. I just had solar installed (waiting the inspection to turn it on). I plan to evaluate late next year whether to switch to time-of-use.
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Re: Solar - after 1 year the results are in.

Post by Valuethinker »

willthrill81 wrote: Tue Sep 22, 2020 1:46 pm
curmudgeon wrote: Tue Sep 22, 2020 1:39 pm
willthrill81 wrote: Tue Sep 22, 2020 1:12 pm ....

It's really crazy to me that Hawaii, where electricity can be 50 cents / kWh, isn't 100% solar right now. Burning diesel to make electricity there seems insane.
People have this crazy habit of wanting to turn their lights on at night. And run their fans and tvs and even A/C (at least in large buildings). They also like their power to keep working if heavy cloud cover from a storm system covers the islands and cuts solar production by 80%. My understanding is that the problems with too much solar dependence in Hawaii are like California's, only an order of magnitude worse because there is no large power grid for interconnection.

Battery might seem like an option, but aside from massive cost (and environmental impact) at that scale, it's not just the overnight problem - you might need several days worth to deal with storm systems.
That's a good point.
And yet these things can be managed.

Batteries are currently good enough for intra-day load shifting but not inter day. To do that you need technologies like hydrogen or ammonia manufacture or heat storage.

But you have other complementary technologies as well

Wind for example blows at night or when it is raining. The periods when you have no solar insolation and no wind are small in many climates.

Its not actually impossibly expensive to have a Capacity Market where lots of reciprocating engines that are bid in to provide power at times of low renewables. 98% of the time they do nothing 2% they run.

And demand flexibility programmes such as shutting water heaters off at peak times.

Hawaii of course had reserves of Hydro electric power and biomass (and geothermal). There is a plan to link the islands by electricity cable.

Hawaii like Australia is a place of very high retail electricity prices. Solar installations pay for themselves without subsidy. The sticking point is the low voltage local distribution grid which was not designed to take large amounts of electricity coming back out of the consumption nodes.

And a problem of how to pay for the grid if local distributed generation means there's less volume demand. That upends utility economics.
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