Mesa warehouse client installed 1.5MW solar + 2MWh battery storage system in March. APS billing has been a nightmare ever since. They're charging demand charges when the battery discharges to the grid, plus time-of-use charges on battery charging even when it's from their own solar. Getting different answers from every APS rep I talk to. Anyone navigate battery + solar billing successfully?
Arizona battery storage + solar billing complications
Christie - battery storage billing is still evolving. APS should have a specific rider for battery systems. Check if your client is on the right rate schedule. E-65 Customer Generation might not be appropriate for storage systems.
Glenda's right about rate schedules. California has similar issues. Battery charging from your own solar shouldn't incur time-of-use charges since it never hits the grid. That sounds like a billing system error.
Had almost identical situation with Alabama Power. Battery discharge to grid was being treated as "generation" and charged interconnection fees. Took escalating to VP level to get it fixed. APS might have similar billing system confusion.
Kevin - how did you get Alabama Power to fix it? APS customer service keeps transferring me between departments. No one seems to understand how battery storage should be billed.
Finally got through to an APS engineer who knows battery billing. They're creating a special billing adjustment to fix the charges retroactive to March. Apparently their billing system treats battery discharge as "import" rather than "export" which triggers demand charges incorrectly.