“”He is selling current back to the grid, so he is on the grid, unlikely to have a battery bank. The $70K investment sounds high - my ex has 48 panels on her roof, claims to have spent only $20k or so - and sells $100 of power back to the grid each month. No batteries. Not a bad ROI. I’m tempted, particularly knowing that electric is only likely to go higher in future. But I’d have to verify her figures.””
For those that do not have batteries, the problem is compounded. Residences use more electricity when its dark out (most folks work in the day and come home at night to their household activities). If this person doesn’t have batteries then he is selling electricity to the grid during the day and buying it back at night. This presents a problem for the utilities...and will lead to electricity being more expensive at night and cheaper during the day. Another problem is that utilities can’t turn electricity on or off quickly. They must maintain “spinning reserve” during times when the demand is low (daytime) and be ready to generate at full capacity less than 12 hours later (nightime). How is this an improvement over the current situation.
I didn’t say it was better for overall energy policy - I’m just reporting an incident where it seems to be a good investment for an individual. I would think that utilities are advantaged by needing less peak capacity during the day (when consumption peaks in the summer). Don’t know the energy use profile during the winter - but it is likely that during the day, more energy is used even then (industrial wheels grinding, stores open, etc.) vs. the night.
Residential use in the evening. Business use during the day. I’d like to see which uses more at any given time. I personally suspect that the power companies are happy to have that power coming in during the day.
The biggest load peak is summer daytime air conditioning. As it happens, that's the very time when solar collectors feeding back into the grid produce the most power. If anything, this is helpful to the utilities.
Solar isn't going to replace main-load energy sources, but it does provide a useful supplement.