Client installed Tesla Powerwall with existing 10kW solar array here in Austin. Austin Energy is completely confused about how to bill this configuration. They're charging import fees when the battery discharges to the house, treating it like grid consumption. Meanwhile they're not properly crediting the solar generation that charges the battery during the day. The bills make no sense and customer is paying $200+ more per month than before the battery. Anyone dealt with battery + solar billing issues?
Battery storage + solar billing nightmare with Austin Energy
Vanessa, that's insane but not surprising. Most utilities haven't figured out behind-the-meter storage yet. The key issue is whether they have separate metering for solar production vs. battery discharge. If it's all behind one meter, they shouldn't be able to distinguish battery discharge from solar generation. Sounds like Austin Energy is making stuff up.
Up here in Montana we're just starting to see battery installations. NorthWestern Energy wants to install separate meters for every component - solar production, battery charging, battery discharging, house consumption. It's ridiculous and expensive. The whole point of behind-the-meter storage is it should be invisible to the utility. Vanessa, what metering configuration does your client have?
Roy, they have the standard net meter at the service entrance measuring net flow to/from grid. But Austin Energy is claiming they can "detect" battery discharge patterns in the load profile data and are billing accordingly. This seems like total BS to me. The customer should only be billed for actual net consumption from the grid, period. Everything behind the meter is their business.
Vanessa, that's absolutely wrong. Pacific Power tried similar nonsense here in Oregon with battery systems. The PUC shut it down fast - ruled that utilities can only bill based on actual meter readings at the point of service, not on speculative load profile analysis. File a complaint with the Texas PUC immediately. Austin Energy is making up rules that don't exist in their tariffs.
This is exactly why I tell my solar clients to wait on batteries until the regulatory framework catches up. Utilities are using battery installations as an excuse to experiment with punitive billing practices. Vanessa, demand Austin Energy provide written justification for these charges citing specific tariff language. Bet they can't do it because they're just winging it.