HECO Eases Costs and Restrictions For Solar Customers


An increasing number of Hawaii residents wanting to switch to solar electricity are coming up against added costs leveled by the electric utilities on Oahu, Maui and the Big Island. 

If there is too much solar on a single circuit, the utility may require customers to shell out potentially thousands of dollars to study the system. Customers may also have to pay for grid upgrades to ensure circuits are reliable. (The cost of studies and grid upgrades vary per customer.)

The problem: too much solar on a circuit could harm the utility’s grids, cause power outages and endanger utility workers. 

Hawaiian Electric Co. has changed the rules, however, to make it easier, faster and cheaper for customers to install solar, according to a press release issued Friday by the utility. 

The utility has increased the threshold on its circuits for small solar systems (10 kw and under) that triggers the costly and time-consuming interconnection studies. The threshold for a potential study is now 100 percent of the daytime minimum circuit load — previously it was 75 percent. 

HECO will also conduct studies on several “representative circuits” and apply the results to as many solar projects as possible that are proposed for similar circuits. The goal is to lessen the number of customers that have to pay for these studies themselves. 

HECO is also asking all Oahu residential and commercial customers to contact the utility first — before signing a solar contract or beginning installation. This way, the utility can review the project and let customers know if they may have to pay for interconnection studies or grid upgrades. 

The utilities on Maui (MECO) and the BIg Island (HELCO), where penetration levels are higher, already request this, as does the Kauai utility (KIUC).

This latest move by HECO was cheered by the Interstate Renewable Energy Council. In a press release, IREC said: “HECO’s announcement shows the utility has gained sufficient experience with rooftop solar to revise when and how its engineering reviews are conducted.  The changes will allow more systems to connect to the grid more quickly without sacrificing safety, reliability or power quality. “

The solar industry has experienced remarkable growth in Hawaii, with installations doubling nearly every year since 2008. 

The State of the Grid

So far, no Oahu residents have had to pay for interconnection studies for small systems, under 10 kw. (The average size residential solar system is about 4 kw.) 

However, an increasing number of residents on Maui and the Big Island have been charged for these studies, according to data from HECO.

On Maui, there are 83 studies underway for 129 customers. An additional 57 studies have been  completed. 

On the Big Island, five studies have been initiated for a large number of customers. Two studies have been completed. 

Meanwhile, an increasing number of circuits throughout the grids are approaching or surpassing threshold levels that peak the utility’s concern. 

From HECO:

Number of circuits with DG at or above 15% of peak load, at or above 75% of daytime minimum load, at or above 100% of DML for all islands.

·         Oahu: about 200 circuits above 15% of peak load, about 100 circuits above 75% MDL, 54 at or above 100% MDL out of 416 circuits

·         Maui:  57 circuits above 15% of peak load, 42 circuits above 75% MDL, 26 circuits at or above 100% MDL out of 132 circuits 

·         Molokai: four circuits above 15% peak load, two circuits above 75% MDL, two at or above 100% MDL out of 8 circuits

·         Lanai: One circuit above 15% peak load, one above 75% MDL, one above 100% MDL out of three circuits

·         Hawaii Island: 78 circuits over 15% peak load, 33 over 75% MDL, 17 at or over 100% MDL out of 143 circuits



Photo: Photovoltaic system on Molokai (Courtesy, ProVision Solar)

Sophie Cocke 

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