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 …
could be because I told them I’ll buy once I can get net zero.
I’m not following your logic. You aren’t willing to accept any savings unless you can completely zero out your power bill? Judging from your consumption I’m assuming a good chunk of that is for cooling your home? If so that means you’re likely in a pretty great place to harvest solar power. You’d reach payback of your investment on your array much faster than most, and be saving money for probably 35 years or more with little to no additional investment.
Making some guesses for how much your electricity rates are, and how much you’re consuming (assuming much from cooling), you might be a full payback in less than 7 years if you took advantage of the tax credit. Then, every month after that you’d be gaining money back.
my house is over 120 years old. it still has knob and tube in half the house. I have even found gas lines for the old sconces, that were “conveniently” used as grounds for said knob and tube in some places. the house is a nightmare, electrically speaking. the only new-ish electrical are the HVAC systems, the 200amp panel, and the basement (where the rack lives).
for me to get proper solar installed, it would cost more than the house cost to buy. For me to find it in any way cost effective, I would need my $900 a month power bill to pay for the $200k loan on top of my mortgage.
As someone who electrically renovated houses without beeing an electrician. If you find an electrician who is willing to work with you: do a full planning of the house. (What lines go where etc) ask them to go over this, and pay them for their time. If all goes well this will cost them an evening or three (depending how many flaws they find in your design). Do the wiring and drilling raw sockets yourself. Buy the top sockets wholesale, then have the electrician make a fixed price for installing sockets and wiring your fuse box , it will be much cheaper.
appreciate the sound advice. I’ve rewired plenty of houses that I’m comfortable with DIMS and know most of the NEC.
the problem is time and effort. I’m getting older and just don’t have the drive I used to have 20 years ago. the biggest problem is the house is still mostly original plaster lathe which is a huge pita for running new electrical across four floors. add to that the other litany of projects I have to do plus daily life/work. it’s a lot.
if I was 10 years younger I’d probably start one room at a time, but I’m old enough now that I look forward to taking my daily naps before bedtime.
I reserved myself to a modest retirement when I bought this house because I knew the risks going in.
I’m not following your logic. You aren’t willing to accept any savings unless you can completely zero out your power bill? Judging from your consumption I’m assuming a good chunk of that is for cooling your home? If so that means you’re likely in a pretty great place to harvest solar power. You’d reach payback of your investment on your array much faster than most, and be saving money for probably 35 years or more with little to no additional investment.
Making some guesses for how much your electricity rates are, and how much you’re consuming (assuming much from cooling), you might be a full payback in less than 7 years if you took advantage of the tax credit. Then, every month after that you’d be gaining money back.
my house is over 120 years old. it still has knob and tube in half the house. I have even found gas lines for the old sconces, that were “conveniently” used as grounds for said knob and tube in some places. the house is a nightmare, electrically speaking. the only new-ish electrical are the HVAC systems, the 200amp panel, and the basement (where the rack lives).
for me to get proper solar installed, it would cost more than the house cost to buy. For me to find it in any way cost effective, I would need my $900 a month power bill to pay for the $200k loan on top of my mortgage.
As someone who electrically renovated houses without beeing an electrician. If you find an electrician who is willing to work with you: do a full planning of the house. (What lines go where etc) ask them to go over this, and pay them for their time. If all goes well this will cost them an evening or three (depending how many flaws they find in your design). Do the wiring and drilling raw sockets yourself. Buy the top sockets wholesale, then have the electrician make a fixed price for installing sockets and wiring your fuse box , it will be much cheaper.
appreciate the sound advice. I’ve rewired plenty of houses that I’m comfortable with DIMS and know most of the NEC.
the problem is time and effort. I’m getting older and just don’t have the drive I used to have 20 years ago. the biggest problem is the house is still mostly original plaster lathe which is a huge pita for running new electrical across four floors. add to that the other litany of projects I have to do plus daily life/work. it’s a lot.
if I was 10 years younger I’d probably start one room at a time, but I’m old enough now that I look forward to taking my daily naps before bedtime.
I reserved myself to a modest retirement when I bought this house because I knew the risks going in.
Plaster Lathe. My old nemesis. Probably with reed or peat for stabilization, so it explodes everywhere once you touch it… Wish you the best of Luck.
Also: napping is important at our age.
That house sounds like a terrible investment.
lol. all houses are terrible investments, too volatile.