The Sacramento Municipal Utility District (SMUD), a Sacramento, Calif.-based publicly owned utility, no longer requires an AC disconnect switch on inverter-based solar systems when a home or business has a self-contained electric meter.
According to SMUD, this action will help reduce the costs of solar systems and increase the number of systems installed in the utility's service area, which includes Sacramento County and Placer County. The AC disconnect switch, which can cost as much as $300, is considered a cost barrier to some customers who are considering installing solar panels.
In addition, SMUD will no longer request that a separate production meter-base be installed, because virtually all inverters listed on the California Energy Commission's list of eligible inverters include approved onboard metering, SMUD says. Despite this new policy, some installations may have configurations that require an AC disconnect to comply with the National Electric Code and/or local building code.
The utility's AC disconnect requirement for distributed generation will continue to apply to inverter-based interconnections that have a transformer-rated meter, inverter-based generators that are not listed on the California Energy Commission's list of eligible inverters, non-inverter based generators – including rotating or machine-based generators – and special situations where generators may be impacting SMUD service to its customers.