Seems to me his panel capacity is to small anyway.
We have 11 kWh panels, and yes in the summer we routinely produce 4 times more than we use, and we have a 7.5 kWh battery
But November December and January it’s not even close.
In the Winter you can easily have a week with near zero production:
Our Import / export from grid last year:
November 215 / 59 kWh
December 300 15 kWh
January 268 / 34 kWh
Despite we have almost 3 times the capacity, and produce more than twice what we use per year, and we have a decent battery and believe it or not, even the shortest day we can produce enough power for a whole 24 hour day if it’s a clear day! But we can also have clouds for 14 days!
But for those months we imported 783 kWh and exported 108 that could have been used with bigger battery.
But the net import was still 675 kWh!! For those 3 months, and that’s the minimum size battery we could have managed with, and then we even need 10% extra to compensate for charge/discharge losses.
Minimum 740 kWh battery in our case, despite 3 times as powerful panels.
That means it would require at least the equivalent of 10 high end fully electric car batteries. But also a very hefty inverter, which AFAIK ads about 50% the price of the battery.
PS: Already in February we exported more than we imported.
BombOmOm@lemmy.world 7 hours ago
Damn, those winter numbers would mean a full off-grid really is going to be hard with pure solar. A propane or diesel generator to top off the batteries would probably be required for winter.
Buffalox@lemmy.world 6 hours ago
It is not remotely close to economically viable to go off grid, and the exports of solar power to the grid pay for the connection anyway.
The reason to have a battery is that it lasts through the night, or even with a smaller system, it can handle dinner time, which is the most expensive time of day to buy electricity.
Now if you live in some remote area without a grid, a generator is a way better option than a huge battery.
Maybe if you live somewhere very sunny, like Spain and especially southern parts of USA you can probably do it with a modest battery that can handle a couple of days.
In the summer we can make enough electricity on by far the most cloudy days, but in the winter, the sun can’t penetrate the clouds nearly as well.
Admittedly London is south of where I live, which is close to the most southern part of Denmark, but on the other hand London is infamous for grey weather with heavy clouds.
sugar_in_your_tea@sh.itjust.works 5 hours ago
You could probably get by with a gas generator and only run it 2-3 times/year in many areas. It’s not 100% green, but it could get you off grid for a fraction of the price.
Mpatch@lemmy.world 3 hours ago
Diesel generatorsare significantly better on fuel consumption than a gas one and diesel takes alot longer to go bad than gasoline.
OhVenus_Baby@lemmy.ml 2 hours ago
Stabil 360 additive to fuel.