I have a modest set of solar panels on an entirely ordinary house in suburban London. On average they generate about 3,800kWh per year. We also use about 3,800kWh of electricity each year. Obviously, we can't use all the power produced over summer and we need to buy power in winter. So here's my question: How big a battery would we need in order to be completely self-sufficient? Background …
Basically why the grid exists to begin with. You’re not supposed to be solving these engineering problems on a household budget inside a single home.
You’d be better off simply reducing your consumption or finding alternative methods of power (nat gas or maybe wind or geothermal) during the longer winter nights.
If you really want to go crazy, you should consider investing in a bigger home with better insulation and roommates. An apartment/condo block can at least leverage economies of scale, if you’re dead set on DIY. More people benefiting from the setup dilutes the cost per person.
I recently got a solar system and came to the conclusion that if you can sell power back to the grid (not everyone can) for some reasonable percentage of what it costs to buy it, then it will always be worth it to be connected (assuming you already are).
Quite simply, if you have enough solar capacity to get you through the winter (no house is going to have months of battery storage), then you will always be creating far more than you need in the summer. Selling this excess will easily cover any costs associated to being on the grid.
Also at current prices batteries are good for backup power only, it’s always cheaper to sell excess power to the grid in the day and buy it back at night than it is to have battery capacity to get through the night. I worked out it would take 40 years for our battery to pay for itself (assuming the battery kept a constant battery capacity for 40 years…) but less than 10 years for the rest of the system to pay for itself.
We can’t, but we can do net metering, meaning we can offset costs but not get paid. So the best investment is to pay nothing through Dec. 31 and keep costs manageable at the start of the year (net metering ends with the calendar year).
Net metering is potentially better, as you are effectively getting free night usage based ob day generation. My setup pays me, but I get paid 20c per Kw (NZ dollar) and pay about 30c to buy, so there’s a 10c difference. Just as long as whatever you lose on 31st Dec is not too high, you’d be better off than me.
Agreed this is the best option. Economy of scales and our consumers wishes should dictate the Grids plan to incorporate cheap energy ( and emergency) storages.
And, also like you said, change your energy life style and insulate your house wherever you can.
I’m very ignorant on this subject, but couldn’t you just sell excess to grid and get it back for a minimal markup? Seems like a good governmemt incentive to even supplement an even exchange program. Scaling things to everyone having their own giant batteries seems like a waste of the existing infrastructure.
I’m very ignorant on this subject, but couldn’t you just sell excess to grid and get it back for a minimal markup?
Sure, but it depends on the incentives in your country. Afaik, excess energy could be sold, but you’ll have to checkout your local incentives and energy suppliers for specifics. In most parts of Europe, the are scaling down the prices for excess energy. Therefore, battery systems are being forwarded in some cases as sort of solution for solar panels maintaining like ca. 80% +? integrity efficiency over 20 to 30 years.
For example, I read that in The Netherlands the solar panel market has crashed completely or is crashing. Note here that saturation of the market ( many existing solar panels) can also cause that.
You need to find out;
energy usage
insulation options and materials
costs /benefits
energy contracts and energy incentives.
check out current physical electricity wiring and fuses in the house
DIY or professional?
budget
etc
TLDR: dont buy solarpanels if you want to be rich. And buy them according and after you’ve done everything possible to insulate your house, whether in the colder or warmer climates. The efficiency, added value, and comfort reached by insulation outweighs everything else. Then , after doing that, check your kwh usage, and buy solars according to that.
Hope this is helpful, but seems you need to go outthere and do some exploration on the topic.
Basically why the grid exists to begin with. You’re not supposed to be solving these engineering problems on a household budget inside a single home.
You’d be better off simply reducing your consumption or finding alternative methods of power (nat gas or maybe wind or geothermal) during the longer winter nights.
If you really want to go crazy, you should consider investing in a bigger home with better insulation and roommates. An apartment/condo block can at least leverage economies of scale, if you’re dead set on DIY. More people benefiting from the setup dilutes the cost per person.
I recently got a solar system and came to the conclusion that if you can sell power back to the grid (not everyone can) for some reasonable percentage of what it costs to buy it, then it will always be worth it to be connected (assuming you already are).
Quite simply, if you have enough solar capacity to get you through the winter (no house is going to have months of battery storage), then you will always be creating far more than you need in the summer. Selling this excess will easily cover any costs associated to being on the grid.
Also at current prices batteries are good for backup power only, it’s always cheaper to sell excess power to the grid in the day and buy it back at night than it is to have battery capacity to get through the night. I worked out it would take 40 years for our battery to pay for itself (assuming the battery kept a constant battery capacity for 40 years…) but less than 10 years for the rest of the system to pay for itself.
We can’t, but we can do net metering, meaning we can offset costs but not get paid. So the best investment is to pay nothing through Dec. 31 and keep costs manageable at the start of the year (net metering ends with the calendar year).
Net metering is potentially better, as you are effectively getting free night usage based ob day generation. My setup pays me, but I get paid 20c per Kw (NZ dollar) and pay about 30c to buy, so there’s a 10c difference. Just as long as whatever you lose on 31st Dec is not too high, you’d be better off than me.
Agreed this is the best option. Economy of scales and our consumers wishes should dictate the Grids plan to incorporate cheap energy ( and emergency) storages.
And, also like you said, change your energy life style and insulate your house wherever you can.
I’m very ignorant on this subject, but couldn’t you just sell excess to grid and get it back for a minimal markup? Seems like a good governmemt incentive to even supplement an even exchange program. Scaling things to everyone having their own giant batteries seems like a waste of the existing infrastructure.
Sure, but it depends on the incentives in your country. Afaik, excess energy could be sold, but you’ll have to checkout your local incentives and energy suppliers for specifics. In most parts of Europe, the are scaling down the prices for excess energy. Therefore, battery systems are being forwarded in some cases as sort of solution for solar panels maintaining like ca. 80% +? integrity efficiency over 20 to 30 years.
For example, I read that in The Netherlands the solar panel market has crashed completely or is crashing. Note here that saturation of the market ( many existing solar panels) can also cause that.
You need to find out;
TLDR: dont buy solarpanels if you want to be rich. And buy them according and after you’ve done everything possible to insulate your house, whether in the colder or warmer climates. The efficiency, added value, and comfort reached by insulation outweighs everything else. Then , after doing that, check your kwh usage, and buy solars according to that.
Hope this is helpful, but seems you need to go outthere and do some exploration on the topic.
(Ed: layout)