On January 20th, MECO and the other Hawaiian Electric companies filed a proposal with the Hawaii PUC that would affect how distributed generation is interconnected and valued. In theory these changes also affect small wind turbines, but on Maui distributed generation is 95% or more solar pv. This new proposal is formally called the Transitional Distributed Generation (“TDG”) program.
- The utility has asked the PUC to expedite a decision on the TDG and act by April.
- TDG will not change the credit given for electricity produced by existing NEM systems. Those systems are “grandfathered” with regard to the value of the credit.
- It is not clear whether grandfathering will be limited to applications filed prior to January 20, or those filed prior to a PUC decision.
- For new systems, TDG would reduce the amount of credit given for energy not used on site. With most residential pv this means during the Summer months the size of the credit that rolls over to the rest of the year will be lower.
- As explained in the article from the link below, Instead of being credited at the retail electricity rate of $0.295 cents per kilowatt-hour (kWh), Oahu solar owners would get a TDG-estimated tariff rate of $0.147 per kWh; Maui solar owners would go from $0.351 per kWh to $0.223 per kWh; and on Hawaii, the credit would drop from $0.359 to $0.18.6 per kWh
- Those interested in learning more about the details may find this article from Utility Dive useful: http://www.utilitydive.com/news/hawaiian-electrics-plan-to-end-solar-net-metering-explained/356432/
- TDG would have the effect of bringing MECO policies on solar closer to KIUC policies.
- KIUC always felt that Hawaiian Electric was too generous in the amount of the credit, which causes a subsidy from those customers without pv to those with pv.
- TDG also proposes a change in one of the major interconnection standards. One of things that MECO looks at with solar pv is the amount of solar on the circuit. MECO normally takes the maximum output of all the panels on the circuit and compares that figure to Daytime Minimum Load (DML). DML has been a flawed standard from the start. DML was a response to criticism that the prior standard of Maximum Daily Load ended up being a comparison to a night time figure (on Maui most residential circuits have peak load in the evening).
- Although the move to DML sounded like a good thing at the time, people assumed DML correlated to maximum solar production. In fact DML is often late morning but solar output peaks mid-day
- Under the new proposal MECO will allow up to 250% of DML on the circuit. That is more than double the previous figure (120% of DML)
- Hawaiian Electric says that changes agreed to by the solar industry for inverters allow it to increase the standard, and that under the new rules it expects most people to be able to get pv approved without an interconnection study.