Ken Mac
Platinum Member
My point was is that my Nephew was trying to explain to me how we could be 100% solar. that's the basis of this conversation.My nephew in California who is 34 YO told me that they can get power from the grid when the sun isn't shinning or the wind isn't blowing.
YCMTSU. He thinks the grid is a giant battery.
This is the problem. Ignorance.
Though not technically correct, this is how we're taught in the solar industry to think of the relationship between a grid-tie solar power system, and the utility grid itself.
A true off-grid system, of course, has to have batteries. You need enough panels to produce plenty of surplus when they are producing, with the extra being stored in the batteries, for use during nonproductive times.
In a grid-tie system, when you're producing a surplus, you “sell” that surplus to the utility, against what you use later, when you're not producing enough. The grid provides the same function, therefore, that the batteries provide in a standalone system. The big difference is that with a grid-tie system, you don't need enough surplus when you're producing to cover what you'll use when you're not, and in fact, very few grid-tie systems achieve a net surplus. Whatever you use, in total, beyond what you produce yourself, you buy from the utility. With an off-grid system, if you use more power, in total, than you produce, then you'll run out and be without power for a while, until you can produce more.
And, of course, a grid-tie system is vulnerable to blackouts from the utility. Most grid-tie systems do not produce enough power, by themselves, to meet the needs of the building that they power, so if there's a blackout you experience it too.