Comment by jacquesm
1 year ago
> That is, let's hypothesize a house uses 24 kWh per day
We're at approximately half that and it still isn't a tractable problem just for a single day, for the 1st week of January we used 88 Kwh and made 18.7 Kwh in solar, about 7.5 of which went to the grid (so would have been available to charge a battery). We'd need 4 times as much solar to get through the days and even then there would be days when there wouldn't be enough to go around. Making that work for a week would require 70 KWh of storage and a nameplate installed solar capacity of about 60 Kw, well into fantasy territory, it would never make sense from an economics perspective to set that up. You're looking at 150 to 200 panels depending on type, massive power infrastructure (your normal hookup will not even be close to enough for this) and a formidable array of batteries for storage.
It won't happen locally for that reason, much as I would like to. The only thing we can do is to try to conserve even further but we're already close to what you can do with four people in one house, approximately 3 KWh / person / day, especially in the winter. Transporting that power from the excess in the summer would be an even more impressive feat. We still have 11 months of netmetering and then that's over.
I don’t think any meaningful storage makes sense for a home, but for a grid-attached solar plant. The surface area is large but I think the cap ex (and naturally the op ex) are naturally much lower.
Even if the solar plant doesn’t generate enough in the middle of summer when demand is high, its grid connection means the batteries could be charging from surplus wind at night.
Not that this addresses my time-volume issue, just saying it’s not worth considering from the single home perspective except in unusual cases.
I'm hoping for HVDC both across both large spans of longitude and lattitude, that would be a game changer. There is plentiful solar, all we need to do is to be able to transport it across the planet to wherever the sun currently isn't shining.
'A mere matter of engineering'. But we do have that capability.