8 ms·

We went solar and here are the real numbers (2021)

48 points by amenghra 2y ago

ggm 2y ago
The contribution of SREC to the income ROI calculation is high. That aside, with load shifting into peak production time and some judicious non battery time shifting (hot water) it's possible to reduce billable kW consumption. In oz what's happened is the SREC equivalent is now much lower and the unavoidable network and systems costs to the energy supply company went up. It's still worth having, and if you can afford the capex then arbitrage of battery can earn higher marginal return quite aside from extending your non consumption window significantly. V2G will be huge.
- szvsw 2y ago
  I agree V2G will be huge, but rolling it out will be hard, especially somewhere like the US without major financial incentives (for both the infrastructure and getting people to accept the idea that they might not fully control their rolling castle’s battery). Conceptually though, I think it’s one of the coolest ideas in sustainable tech - distributed prosumer/battery networks. There’s also some cool P2P topologies.
  - ggm 2y ago
    If all it did was be used for e.g. 10% of total car battery capacity for demand management, it would be huge. The sheer volume of batteries.
- safety1st 2y ago
  If you spend $25K on a solar installation, does the value of your home increase by $25K? This angle isn't mentioned in the article. Overall the profitability of the installation seems shaky and depends on various government interventions that probably won't be around forever. If we model the solar installation as a conversion of cash into home equity however, the calculus changes. You are buying home equity and getting reduced energy bills in the process. You almost certainly come out ahead, the panels are in a sense free, other than costing you some liquidity. Googling around a Zillow study says solar installations increase the value of a home by 4% on average. The article also didn't touch on maintenance costs.
  - wyum 2y ago
    > If you spend $25K on a solar installation, does the value of your home increase by $25K? I spent $25k to install solar in 2020 (also in DC like OP). The solar company estimated that my home value increased by $14K. As part of the install, I bundled a "heavy-up" for $5K, which is an upgrade my house needed, but not strictly part of the renewable energy system. So total cash outlay was $30K. I immediately got back 26% in a federal tax credit: $7.8K So on balance, my system cost $8K cash, which was paid down by energy savings and SRECs within three years. The SRECs made the biggest impact.
jolux 2y ago
(2021), not (2011)
adrianN 2y ago
I’m always astounded by other people’s electricity consumption. How does this person use over 50kWh per day? That’s almost as much as I use per month! Do aircons use that much power?
- wordofx 2y ago
  Per month? Do you live by yourself and not have a computer or cook at home? With 3 kids and winter time for heaters I’m using ~44/day average. ~26/day during summer.
  - punnerud 2y ago
    Around 2300kWh/months during winter in Norway and 1000 in the summer here.
    - wordofx 2y ago
      That’s about 76/day so that makes sense for heating. Must be super cold :D
  - Yoric 2y ago
    For what it's worth, my peak month this year was March at 169 kWh / month. I cook (electric) almost every day, I have a kid and I work mostly from home. Half of that energy is the (oversized) water heater. My winter months were actually a bit lower, but there's collective heating in my building, so that biases my consumption. That's in Paris, France.
    - wordofx 2y ago
      When I lived in an apartment in Australia, during winter we didn’t use the heater because it wasn’t so cold, when we moved to a landed house we couldn’t live without the heater! I don’t have any power bills from 20 years ago to know how much we used. But you’ve made me curious.
      - 2y ago
Mmskynettio 2y ago
I have a balcony PV thing. It was easy to install and saves money. Will recupe it in a few years.
deleted 2y ago
[deleted]
rini17 2y ago
I'd like to see some consideration of inflation. Maybe energy prices are expected to rise faster than inflation, that shortens the ROI time. Or maybe there's going to be so much renewables that electricity price regularly goes to zero and it will be carried over to consumers(like, no net metering around noon).
- silvestrov 2y ago
  I think dropping price of solar panels will be more important for future installs. Drop price by 50% from todays price and ROI will look very nice, especially for houses that use air condition to cool down (or heat up) the house.
throwoilterror 2y ago
Renewable energy also helps combating terrorism since oil revenues are financing terrorism in the middle East and Africa
- Simon_ORourke 2y ago
  I'm not sure there's too much oil revenue flowing into the coffers of the dudes in Peshawar and Kandahar, but it doesn't stop them knocking the s*t out of each other and anybody else there.
- audunw 2y ago
  I think energy independence is more important than not potentially financing terrorists. I don’t understand how not everyone can be on board with renewable energy and EVs. Even if your country exports more oil than it produces, like USA, it can still be dependent on oil production from the Middle East due to the logistics and differences in the type of oil produced. Even if you live ICE you should support EVs with all your heart. The less people are using oil for fuel the more gasoline the less likely it is that fuel will get more and more expensive, and the more likely it is that your country won’t be completely incapacitated when the next oil crisis hits. Do people love so much being slaves to Middle Eastern autocracies?
pyrale 2y ago
The combination of SREC and net-metering feels insane. I would like to see the evolution of electricity bills for people who can't afford to have solar panels since these laws were enacted.
- wyum 2y ago
  When we went solar in DC (like the OP), the solar company offered a zero-cost option. The way this works is that the solar company owns the panels, while the customer enjoys the energy savings and IIRC a small slice of the SRECs.
wyum 2y ago
I live in DC like the author and went solar in 2020. I want to emphasize that DC's energy credit (SREC) prices are the only reason that solar makes financial sense here - perhaps anywhere. Without SRECs, we would be losing money. Our SREC payouts have averaged $380/MWh over the past four years. When last I checked, this was by far the best price on offer in the US. I've seen "solar is a scam" posts across the Internet. Given the numbers, I'm inclined to believe that's true wherever SREC prices are below, say, $250/MWh. I keep a detailed spreadsheet and have been meaning to write a similar blog post. The short story is that we have made more money overall from SRECs than from savings on our monthly bill.
- dmurray 2y ago
  Rooftop solar can't be economically efficient without subsidies of some sort. How could it outcompete the economies of scale of putting an extra 10 panels in a utility-scale installation 50 miles away? SREC is one such subsidy - which looks enormous, twice as big as the actual retail cost of the electricity! - and the author also mentions a federal tax credit for 26% of the cost. Note that net metering is yet another subsidy. Try to sell electricity on commercial terms at "we will provide you with energy when it's sunny and withdraw when we want, at the same price" and see how quickly you get laughed out of the room. Granted, in a climate like DC peak usage (AC) is pretty close to peak solar production so it's not quite as bad as that, but batteries cost order-of-magnitude the same as solar panels, and this is asking the grid to serve as a giant battery. All these subsidies have clearly had a positive effect - rooftop solar is better than none at all, and perhaps there are some secondary benefits in job creation, environmental awareness, etc. But this is one area where the tax breaks would have been more efficiently spent enriching big businesses rather than sent directly to middle-class home owners.
  - yjftsjthsd-h 2y ago
    > Rooftop solar can't be economically efficient without subsidies of some sort. How could it outcompete the economies of scale of putting an extra 10 panels in a utility-scale installation 50 miles away? By not using expensive land (since it's on top of a building that existed anyways).
tibbydudeza 2y ago
We had to go solar last year due to our two hour per day power outages - 3,1 Kw array with 10Kw battery storage. I use about 800Kwh per month before solar was installed and now it is down to 400 Kwh - our biggest power usage is our water heater (geyser) but that is solar powered. Coolant is heated in vacuum tubes on the roof and then the heat exchanged with the water in the cylinder.
nevi-me 2y ago
Looking at the chart before reading the article, I thought that their peak hourly output is just above 1.5kWh (sort of like you'd read a speed chart in {m|km}ph). Then the author says they have an 8.28kW system. It'd have been useful to also share a normalised graph, sort of like "in the last 15 minutes we produced an equivalent of 6kWh". I had to infer it by counting the number of bars in a 3 hour interval. Then ~6kWh during peak time in their peak month, seems more informative.
- szvsw 2y ago
  It’s in the 4th par. > Our 23 solar panels are rated to produce a total of 8.28 kilowatts (kW), but in reality energy production doesn’t get that high and maximum production is for a short part of the day. We peak at about 6.6 kW kWh is energy, kW is power (which you probably know). The graph is in energy and you clearly computed it correctly. Just to clarify.
derriz 2y ago
I don't think the expectation that you can save money with rooftop solar will be economically sustainable in medium or long term. Energy (and nearly everything) produced at scale is simply cheaper whether thermal, solar PV, wind, etc. Having rooftop solar should be viewed as analogous to having a home diesel generator (without being filthy for the environment). The goal isn't to save money by "doing it yourself at home" but there are other benefits like energy independence, redundancy, backup, etc. The gridscale/utility market in PV is absolutely booming - "Solar and battery storage to make up 81% of new U.S. electric-generating capacity in 2024"[1] and is constrained by supply of batteries and PV panels. As someone deeply concerned about global warming, I'd rather any available PV panels be used in the most effective way to reduce CO2 emissions and that is in a grid-scale installation. There might have been a case for direct and indirect incentives for homeowners to install PV 10 years ago to help boost overall demand for PV panels but there is no such need these days - the industry is booming and supply is a bigger issue than demand. [1] https://www.eia.gov/todayinenergy/detail.php?id=61424 https://www.eia.gov/todayinenergy/detail.php?id=61424
- adrianN 2y ago
  You save on transmission costs, so it’s not completely implausible that rooftop solar stays cheaper.
  - kkfx 2y ago
    We save in stability: p.v. and co vary it's output far quicker than classic big power plant, this means that on grid we have more and more frequency stability issues. To compensate we need a smart grid witch is an IT nightmare and in any case it's not there. At home, in self consumption, we are in a small smart-grid. So we can do our best to shift loads on p.v. using the grid let's say "for the base load", as a result individually we spend less and have (in case of batteries) backups, at grid scale peak demand is less intense and happen less. That's the "issue" with p.v.: utilities do not want semi-autonomous homes, they do want to own, leaving others with nothing but subscriptions, paid services, this is incompatible with current state of tech while the current state of tech is perfectly compatible with small scale self-consumption. Now try to imaging a hypothetical society where people living in reasonably sunny part of earth have p.v. and batteries. On scale it's probably not doable today, but we can definitively start. We still need a grid or some other backup, but we do not need an UPGRADED grid in capacity terms because most of the loads, the biggest one at least, happen locally. Surely without seasonal storage being autonomous it's a myth, but technically we can pass most day-to-day needs in largest slice of the Earth who happen to be the most inhabited as well. This means we can converge to electricity as main energy without consuming much more than today from the grid.
woodpanel 2y ago
> we recoup the investment in about 9 years This is good, PV panels can ammortize themselves even quicker when electricity costs are higher. > Topping out at 56 kWh in a day is pretty good... The best summer days generate almost twice as much energy as the best winter day It was really worthwhile seeing the stats put in order like this, thank you. Really puts the spotlight on the technology to store the energy over longer periods (ie into the Winter). What is available on the market? AFAIK standard home batteries empty out pretty quickly even without getting used. What about Vanadium-Redox? Hydrogen-Storage is too expensive and storying it via crypto-mining feels a bit like betting.
mpweiher 2y ago
Love the candor of the writeup, for example admitting that they are effectively double-dipping. Though I think they are actually triple-dipping or even quadruple-dipping. 1-2. Net-metering and credits 3. Reduced contribution to infrastructure There are times when their PV setup produces very little or no electricity at all. At those times, they are 100% reliant on the grid to supply them with all their electricity needs. A large part of the cost of electricity supply is the fixed cost of infrastructure, whether used or not, which is paid off by the variable supply of electricity. Since they are 100% reliant on the grid at least some time, they haven't reduced the need for the fixed-cost infrastructure, but have reduced their contribution to that infrastructure. I guess this could be alleviated by capping the amount of electricity you are allowed to take from the grid? 4. Increased variability The addition of variable suppliers like PV reduces grid stability and increases the requirements for and cost of measures to stabilize the grid. Battery backup could obviously alleviate this, but if not done carefully it could just stretch out the destabilizing events and then make those fewer events worse. While I really, really like the idea of rooftop solar, (partial) energy independence, and a more distributed grid, I think we do have to figure these things out. I don't see how it makes sense at the moment.
- kkfx 2y ago
  > The addition of variable suppliers like PV reduces grid stability True, that's why large p.v. farm should be BANNED not incentivized. But it's the opposite for self-consumption. I self consume (in France, I do not know how that's regulated in USA) meaning I have the interest to do my best shifting loads on p.v. as much as I can, as a result I reduce my total energy consumption from the grid (about 50% per year, being all electric) and much reduce my consumption during peak period when the grid is stressed. I do not reduce my demand only in the coldest part of the winter where the grid is strained due the growing amount of electrical heating but I do reduce to zero in summer where air conditioning demand strain the grid (here nights are fresh so no need to cool artificially at night) witch is a much welcomed thing for the grid. In the future IF battery prices fell here like in China I might also absorb much less for heating, so far batteries are just expensive personal backups. In the future we might add a grid scale data channel to the inverters, like the one we already have (mandatory by law) to allow the grid cutting/regulating EV recharging during peak demand) allowing to inject to the grid only when the grid like it. At the moment p.v. self consumption IMO and IME makes sense both for individuals and for the grid. In the future we can be more integrated, but still the base is the same.
outcoldman 2y ago
This is also my story of purchasing the house with solar panels already installed and not working https://x.com/outcoldman/status/1791494866041545139?s=46 https://x.com/outcoldman/status/1791494866041545139?s=46 TLDR. Takes years to fix it, and only if you push pretty hard.
simonebrunozzi 2y ago
The title says 2011 but it should be 2021
ZeroGravitas 2y ago
While the micro economic stats are interesting, the macro ones are mind blowing. A powerful deflationary force that eliminates fuel price volatility and achieves efficiency gains of 75%, with paybacks in the Trillions is available to many nations right now and the main response is conspiracy theories. It's both amazing and tragic. https://www.rewiringaustralia.org/ https://www.rewiringaustralia.org/

48 points by amenghra 2y ago

ggm 2y ago

The contribution of SREC to the income ROI calculation is high. That aside, with load shifting into peak production time and some judicious non battery time shifting (hot water) it's possible to reduce billable kW consumption. In oz what's happened is the SREC equivalent is now much lower and the unavoidable network and systems costs to the energy supply company went up. It's still worth having, and if you can afford the capex then arbitrage of battery can earn higher marginal return quite aside from extending your non consumption window significantly. V2G will be huge.

szvsw 2y ago
I agree V2G will be huge, but rolling it out will be hard, especially somewhere like the US without major financial incentives (for both the infrastructure and getting people to accept the idea that they might not fully control their rolling castle’s battery). Conceptually though, I think it’s one of the coolest ideas in sustainable tech - distributed prosumer/battery networks. There’s also some cool P2P topologies.
- ggm 2y ago
  If all it did was be used for e.g. 10% of total car battery capacity for demand management, it would be huge. The sheer volume of batteries.
safety1st 2y ago
If you spend $25K on a solar installation, does the value of your home increase by $25K? This angle isn't mentioned in the article. Overall the profitability of the installation seems shaky and depends on various government interventions that probably won't be around forever. If we model the solar installation as a conversion of cash into home equity however, the calculus changes. You are buying home equity and getting reduced energy bills in the process. You almost certainly come out ahead, the panels are in a sense free, other than costing you some liquidity. Googling around a Zillow study says solar installations increase the value of a home by 4% on average. The article also didn't touch on maintenance costs.
- wyum 2y ago
  > If you spend $25K on a solar installation, does the value of your home increase by $25K? I spent $25k to install solar in 2020 (also in DC like OP). The solar company estimated that my home value increased by $14K. As part of the install, I bundled a "heavy-up" for $5K, which is an upgrade my house needed, but not strictly part of the renewable energy system. So total cash outlay was $30K. I immediately got back 26% in a federal tax credit: $7.8K So on balance, my system cost $8K cash, which was paid down by energy savings and SRECs within three years. The SRECs made the biggest impact.

jolux 2y ago

(2021), not (2011)

adrianN 2y ago

I’m always astounded by other people’s electricity consumption. How does this person use over 50kWh per day? That’s almost as much as I use per month! Do aircons use that much power?

wordofx 2y ago
Per month? Do you live by yourself and not have a computer or cook at home? With 3 kids and winter time for heaters I’m using ~44/day average. ~26/day during summer.
- punnerud 2y ago
  Around 2300kWh/months during winter in Norway and 1000 in the summer here.
  - wordofx 2y ago
    That’s about 76/day so that makes sense for heating. Must be super cold :D
- Yoric 2y ago
  For what it's worth, my peak month this year was March at 169 kWh / month. I cook (electric) almost every day, I have a kid and I work mostly from home. Half of that energy is the (oversized) water heater. My winter months were actually a bit lower, but there's collective heating in my building, so that biases my consumption. That's in Paris, France.
  - wordofx 2y ago
    When I lived in an apartment in Australia, during winter we didn’t use the heater because it wasn’t so cold, when we moved to a landed house we couldn’t live without the heater! I don’t have any power bills from 20 years ago to know how much we used. But you’ve made me curious.
    - 2y ago

Mmskynettio 2y ago

I have a balcony PV thing. It was easy to install and saves money. Will recupe it in a few years.

deleted 2y ago

[deleted]

rini17 2y ago

I'd like to see some consideration of inflation. Maybe energy prices are expected to rise faster than inflation, that shortens the ROI time. Or maybe there's going to be so much renewables that electricity price regularly goes to zero and it will be carried over to consumers(like, no net metering around noon).

silvestrov 2y ago
I think dropping price of solar panels will be more important for future installs. Drop price by 50% from todays price and ROI will look very nice, especially for houses that use air condition to cool down (or heat up) the house.

throwoilterror 2y ago

Renewable energy also helps combating terrorism since oil revenues are financing terrorism in the middle East and Africa

Simon_ORourke 2y ago
I'm not sure there's too much oil revenue flowing into the coffers of the dudes in Peshawar and Kandahar, but it doesn't stop them knocking the s*t out of each other and anybody else there.
audunw 2y ago
I think energy independence is more important than not potentially financing terrorists. I don’t understand how not everyone can be on board with renewable energy and EVs. Even if your country exports more oil than it produces, like USA, it can still be dependent on oil production from the Middle East due to the logistics and differences in the type of oil produced. Even if you live ICE you should support EVs with all your heart. The less people are using oil for fuel the more gasoline the less likely it is that fuel will get more and more expensive, and the more likely it is that your country won’t be completely incapacitated when the next oil crisis hits. Do people love so much being slaves to Middle Eastern autocracies?

pyrale 2y ago

The combination of SREC and net-metering feels insane. I would like to see the evolution of electricity bills for people who can't afford to have solar panels since these laws were enacted.

wyum 2y ago
When we went solar in DC (like the OP), the solar company offered a zero-cost option. The way this works is that the solar company owns the panels, while the customer enjoys the energy savings and IIRC a small slice of the SRECs.

wyum 2y ago

I live in DC like the author and went solar in 2020. I want to emphasize that DC's energy credit (SREC) prices are the only reason that solar makes financial sense here - perhaps anywhere. Without SRECs, we would be losing money. Our SREC payouts have averaged $380/MWh over the past four years. When last I checked, this was by far the best price on offer in the US. I've seen "solar is a scam" posts across the Internet. Given the numbers, I'm inclined to believe that's true wherever SREC prices are below, say, $250/MWh. I keep a detailed spreadsheet and have been meaning to write a similar blog post. The short story is that we have made more money overall from SRECs than from savings on our monthly bill.

dmurray 2y ago
Rooftop solar can't be economically efficient without subsidies of some sort. How could it outcompete the economies of scale of putting an extra 10 panels in a utility-scale installation 50 miles away? SREC is one such subsidy - which looks enormous, twice as big as the actual retail cost of the electricity! - and the author also mentions a federal tax credit for 26% of the cost. Note that net metering is yet another subsidy. Try to sell electricity on commercial terms at "we will provide you with energy when it's sunny and withdraw when we want, at the same price" and see how quickly you get laughed out of the room. Granted, in a climate like DC peak usage (AC) is pretty close to peak solar production so it's not quite as bad as that, but batteries cost order-of-magnitude the same as solar panels, and this is asking the grid to serve as a giant battery. All these subsidies have clearly had a positive effect - rooftop solar is better than none at all, and perhaps there are some secondary benefits in job creation, environmental awareness, etc. But this is one area where the tax breaks would have been more efficiently spent enriching big businesses rather than sent directly to middle-class home owners.
- yjftsjthsd-h 2y ago
  > Rooftop solar can't be economically efficient without subsidies of some sort. How could it outcompete the economies of scale of putting an extra 10 panels in a utility-scale installation 50 miles away? By not using expensive land (since it's on top of a building that existed anyways).

tibbydudeza 2y ago

We had to go solar last year due to our two hour per day power outages - 3,1 Kw array with 10Kw battery storage. I use about 800Kwh per month before solar was installed and now it is down to 400 Kwh - our biggest power usage is our water heater (geyser) but that is solar powered. Coolant is heated in vacuum tubes on the roof and then the heat exchanged with the water in the cylinder.

nevi-me 2y ago

Looking at the chart before reading the article, I thought that their peak hourly output is just above 1.5kWh (sort of like you'd read a speed chart in {m|km}ph). Then the author says they have an 8.28kW system. It'd have been useful to also share a normalised graph, sort of like "in the last 15 minutes we produced an equivalent of 6kWh". I had to infer it by counting the number of bars in a 3 hour interval. Then ~6kWh during peak time in their peak month, seems more informative.

szvsw 2y ago
It’s in the 4th par. > Our 23 solar panels are rated to produce a total of 8.28 kilowatts (kW), but in reality energy production doesn’t get that high and maximum production is for a short part of the day. We peak at about 6.6 kW kWh is energy, kW is power (which you probably know). The graph is in energy and you clearly computed it correctly. Just to clarify.

derriz 2y ago

I don't think the expectation that you can save money with rooftop solar will be economically sustainable in medium or long term. Energy (and nearly everything) produced at scale is simply cheaper whether thermal, solar PV, wind, etc. Having rooftop solar should be viewed as analogous to having a home diesel generator (without being filthy for the environment). The goal isn't to save money by "doing it yourself at home" but there are other benefits like energy independence, redundancy, backup, etc. The gridscale/utility market in PV is absolutely booming - "Solar and battery storage to make up 81% of new U.S. electric-generating capacity in 2024"[1] and is constrained by supply of batteries and PV panels. As someone deeply concerned about global warming, I'd rather any available PV panels be used in the most effective way to reduce CO2 emissions and that is in a grid-scale installation. There might have been a case for direct and indirect incentives for homeowners to install PV 10 years ago to help boost overall demand for PV panels but there is no such need these days - the industry is booming and supply is a bigger issue than demand. [1] https://www.eia.gov/todayinenergy/detail.php?id=61424 https://www.eia.gov/todayinenergy/detail.php?id=61424

adrianN 2y ago
You save on transmission costs, so it’s not completely implausible that rooftop solar stays cheaper.
- kkfx 2y ago
  We save in stability: p.v. and co vary it's output far quicker than classic big power plant, this means that on grid we have more and more frequency stability issues. To compensate we need a smart grid witch is an IT nightmare and in any case it's not there. At home, in self consumption, we are in a small smart-grid. So we can do our best to shift loads on p.v. using the grid let's say "for the base load", as a result individually we spend less and have (in case of batteries) backups, at grid scale peak demand is less intense and happen less. That's the "issue" with p.v.: utilities do not want semi-autonomous homes, they do want to own, leaving others with nothing but subscriptions, paid services, this is incompatible with current state of tech while the current state of tech is perfectly compatible with small scale self-consumption. Now try to imaging a hypothetical society where people living in reasonably sunny part of earth have p.v. and batteries. On scale it's probably not doable today, but we can definitively start. We still need a grid or some other backup, but we do not need an UPGRADED grid in capacity terms because most of the loads, the biggest one at least, happen locally. Surely without seasonal storage being autonomous it's a myth, but technically we can pass most day-to-day needs in largest slice of the Earth who happen to be the most inhabited as well. This means we can converge to electricity as main energy without consuming much more than today from the grid.

woodpanel 2y ago

> we recoup the investment in about 9 years This is good, PV panels can ammortize themselves even quicker when electricity costs are higher. > Topping out at 56 kWh in a day is pretty good... The best summer days generate almost twice as much energy as the best winter day It was really worthwhile seeing the stats put in order like this, thank you. Really puts the spotlight on the technology to store the energy over longer periods (ie into the Winter). What is available on the market? AFAIK standard home batteries empty out pretty quickly even without getting used. What about Vanadium-Redox? Hydrogen-Storage is too expensive and storying it via crypto-mining feels a bit like betting.

mpweiher 2y ago

Love the candor of the writeup, for example admitting that they are effectively double-dipping. Though I think they are actually triple-dipping or even quadruple-dipping. 1-2. Net-metering and credits 3. Reduced contribution to infrastructure There are times when their PV setup produces very little or no electricity at all. At those times, they are 100% reliant on the grid to supply them with all their electricity needs. A large part of the cost of electricity supply is the fixed cost of infrastructure, whether used or not, which is paid off by the variable supply of electricity. Since they are 100% reliant on the grid at least some time, they haven't reduced the need for the fixed-cost infrastructure, but have reduced their contribution to that infrastructure. I guess this could be alleviated by capping the amount of electricity you are allowed to take from the grid? 4. Increased variability The addition of variable suppliers like PV reduces grid stability and increases the requirements for and cost of measures to stabilize the grid. Battery backup could obviously alleviate this, but if not done carefully it could just stretch out the destabilizing events and then make those fewer events worse. While I really, really like the idea of rooftop solar, (partial) energy independence, and a more distributed grid, I think we do have to figure these things out. I don't see how it makes sense at the moment.

kkfx 2y ago
> The addition of variable suppliers like PV reduces grid stability True, that's why large p.v. farm should be BANNED not incentivized. But it's the opposite for self-consumption. I self consume (in France, I do not know how that's regulated in USA) meaning I have the interest to do my best shifting loads on p.v. as much as I can, as a result I reduce my total energy consumption from the grid (about 50% per year, being all electric) and much reduce my consumption during peak period when the grid is stressed. I do not reduce my demand only in the coldest part of the winter where the grid is strained due the growing amount of electrical heating but I do reduce to zero in summer where air conditioning demand strain the grid (here nights are fresh so no need to cool artificially at night) witch is a much welcomed thing for the grid. In the future IF battery prices fell here like in China I might also absorb much less for heating, so far batteries are just expensive personal backups. In the future we might add a grid scale data channel to the inverters, like the one we already have (mandatory by law) to allow the grid cutting/regulating EV recharging during peak demand) allowing to inject to the grid only when the grid like it. At the moment p.v. self consumption IMO and IME makes sense both for individuals and for the grid. In the future we can be more integrated, but still the base is the same.

outcoldman 2y ago

This is also my story of purchasing the house with solar panels already installed and not working https://x.com/outcoldman/status/1791494866041545139?s=46 https://x.com/outcoldman/status/1791494866041545139?s=46 TLDR. Takes years to fix it, and only if you push pretty hard.

simonebrunozzi 2y ago

The title says 2011 but it should be 2021

ZeroGravitas 2y ago

While the micro economic stats are interesting, the macro ones are mind blowing. A powerful deflationary force that eliminates fuel price volatility and achieves efficiency gains of 75%, with paybacks in the Trillions is available to many nations right now and the main response is conspiracy theories. It's both amazing and tragic. https://www.rewiringaustralia.org/ https://www.rewiringaustralia.org/