Solar users’ extra power gave HECO $1.7 million during 2013

Hawaiian Electric Co. received $1.7 million worth of "free" power from rooftop solar customers in 2013.

The previously unpublished number represents the solar power that customers sent into the grid in excess of what they used in a 12-month period. If rooftop solar customers get to the end of 12 months having produced more solar power than they used, HECO gets to keep that excess power.

Solar proponents have argued the excess power given to HECO is not recognized by the company when it says rooftop solar customers are increasing costs for nonsolar customers.

HECO has said home-based photovoltaic systems placed an additional $53 million burden on the shoulders of nonsolar customers in 2014. That number does not include the excess power HECO gets from solar customers, the utility said. HECO has not provided the excess power number for 2014.

"It’s hard to swallow the $53 million number as anything more than a rhetorical throwback to yesterday’s utility business model," said Richard Wallsgrove, program director at the Blue Planet Foundation, which advocates for clean energy. "It would be much more efficient just to throw the $53 million figure out the window and do a true cost-benefit analysis."

In addition to the $1.7 million of free solar power, Wallsgrove said to accurately calculate how much solar contributes to lowering HECO’s cost, the utility should consider:

» The lower costs associated with lower daytime peak energy needs, as rooftop solar reduces demand during the day.

» The higher capital costs that HECO would have had to pay for new energy projects to meet its renewable standards if customer solar was not already installed and paid for by customers on the grid.

» The lowering of line losses, or the loss of power as it is sent long distance down a line, because solar power can be shared among nearby homes instead of moved across power lines.

HECO said those factors are not used when calculating the $53 million number.

"The calculation includes fixed costs for energy, along with some of the line item components on our bills," said Darren Pai, HECO spokes­man.

Chuck Prentiss, a Kai­lua resident with a 26-panel rooftop solar system, said he lost out on $700 worth of credits from the excess energy his system produced in 2014.

"They never add up the extra they get from 51,000 (solar customers)," Prentiss said. "From me they get just enough from one person to support more than three homes for a month."

Prentiss and other HECO solar customers sign an agreement with the utility known as net energy metering, in which HECO agrees to give solar customers credit for power they send into the grid.

Pai said the excess credit forfeited by net energy metering customers after 12 months is shared by all HECO customers.

"We do not receive any benefit from unused NEM credits," Pai said. "Those unused credits benefit all customers by reducing their bills."

Pauline Arellano, a Mili­lani resident with a 28-panel rooftop solar system, said her solar system produced $310 worth of power in excess of what she consumed in 2014.

"When we installed our system, it covered us very well. Since that time kids have married and moved out. We now produce more than we use," Arellano said. "We should not be penalized for this. … It’s not fair, it’s not right. I am not in the habit of giving $310.72 to any creditor."

HECO filed a plan with the state Public Utilities Commission earlier this year to lower the credit that new rooftop solar customers receive for the energy their systems send to the grid.

If that change is approved, new solar customers would need more solar power to cover their nonsolar electric use. That means they might not end up forfeiting part of their credits at the end of each 12-month period.