Comment Re:Charging Batteries (Score 1) 38
I came here thinking the same thing. I see others say it's to offset peak usage hours. But still, the energy conversion needed to charge these batteries would negate the benefit, right?
Absolutely not. The charge/discharge round trip losses will be a few percent, maybe 10% if the batteries are in bad shape. The price difference between peak and off-peak is often 5-10X. Commercial users also get hit with demand surcharges based on the peak draw during the month and those can really make a huge difference. Using batteries to smooth out those peaks can be a bigger savings even than avoiding draw during peak times.
Even for residential use, the savings can be significant. I have batteries and I'm on a time-of-use plan that charges me 5X as much during peak hours (6-10PM) as the rest of the day. I make sure the system is set up so that I never draw any power during peak.