RegGuheert said:
tbleakne said:
My understanding is that the fee of a "few cents"/kWh will be deducted from the retail credit price of the relevant TOU period for any net export to the grid over the time resolution of the TOU metering, which is 15 min. For example, if your system exported 1 kWh while your A/C cycled off for .5 hour, and then imported 1 kWh when the A/C cycled back on, that exchange would cost you "several cents."
Let's assume that the grid "storage" fee is 2c / kWh, we're looking at 1 hour of time, your A/C cycles on 4 times drawing 0.5 kWh from the grid every 15 minutes and your solar exports the same for a net zero consumption.
So your gross export is 2 kWh and your gross import is 2 kWh. Your grid storage fee would be 2 kWh * 2, or $0.04. I don't see how they could bill you at any rate different than that if they are billing by the kWh, no matter what the billing granularity is as the meter has the ability to measure energy in/out at a much higher frequency than 15 minutes.
If you're suggesting that the actual grid storage fee would be 0.5 kWh * 4 15 minute intervals * $0.02 / kWh, well, you still get the same answer.
RegGuheert said:
O.K., if I read that correctly, that would cost a FORTUNE. I suspect it would be cheaper to disconnect the PV and therefore ensure that the power only flowed into the house.
tbleakne said:
Other interpretations are definitely possible.
Let's hope so, but I wouldn't put it past the utilities.
If any of that were true, solar proponents would NOT have been happy about the terms and SolarCity would not have had it's stock price jump so much.
Valdemar said:
I also think they will bill for the physical energy used from the grid, not "net" (import - export) energy. Battery energy storage for solar in CA will probably start making more sense now. Good timing for Tesla PowerWall and the like.
That's exactly what's going to happen. Though at a "few cents" per kWh it doesn't shift the economics for storage all that much. Certainly not as much as the mandatory TOU time period change which puts peak hours well into the evening and past sun-down. Now THAT will certainly encourage grid storage.
Of course, all the
grid-aggregation pilots which merge the wholesale/retail markets also show some promise of giving end-users power to pull back some of these rate increases. I've made $73 the past year participating with Ohmconnect with very little effort on my part. With grid-storage and the right connectivity, it would take no effort and the rewards would be much greater. It wouldn't even take much storage - 2 kWh and a 2 kW inverter would be more than enough looking at my performance.