The continued explosive growth of rooftop PV has raised the total PV on some circuits to a level where more caution is needed as more systems are added.
Too much solar power connected to a neighborhood circuit without proper protection equipment is dangerous. It can put the lives of utility workers at risk and cause poor electric service, from flickers to outages. Over-voltage from high levels of PV can damage sensitive customer electronics, including computers and televisions. Over-voltage can damage utility lines and transformers as well.
We are changing the threshold to allow more PV projects to proceed without an interconnection requirements study (IRS). These changes are described in more detail below.
As we transition to these new policies and try to apply them in a way that results in the least cost to the customer who wants to install PV, there have been delays in responding to specific customers as to whether there will be an interconnection study, how long a study will take if needed, whether any safety and reliability upgrades are needed, and how long upgrades will take. These vary on a case-by-case basis.
As soon as we can tell customers like Ms. Chong what will be needed for her to connect a solar system to the grid, we will do so. To respect our customers' privacy, we do not comment on their individual dealings with us.
All this is explained on the Maui Electric Company website by going to www.mauielectric.com and clicking on "Going Solar."
Changes in Solar Policies
Going forward, single-phase projects 10 kW or smaller on circuits with up to 100 percent (increased from 75 percent) of daytime minimum load will NOT require an interconnection study. (Daytime minimum load refers to electricity demand from 9 a.m. to 5 p.m.)
In some cases, protective equipment upgrades may still be needed to interconnect safely on circuits with PV between 75 percent and 100 percent of daytime minimum load. We will determine if any circuit or project upgrades are needed through a quick supplemental review, at no cost to you. If the utility installs the circuit upgrades, most customers will pay only a prorated share of the cost, based on your proposed PV system size. We will let you know the projected cost of the upgrades. You will not be charged if you decide not to go forward.
When customers wish to add PV systems larger than 10 kW up to 100 kW on circuits still under 100 percent of daytime minimum load, no IRS will be needed. Again, if circuit upgrades are needed, we will install them whenever possible; most customers will pay only a prorated share of the cost.
For circuits already equal to or greater than 100 percent of daytime minimum load, where an interconnection study might still be needed, our engineers will proactively use experience with the supplemental reviews (at our expense) and past interconnection studies to determine if upgrades are needed, avoiding additional interconnection studies, if at all possible. If upgrades are deemed necessary, customers will only pay a prorated share.