Some of SEPA-Ranked Top 10 Utilities for Solar Are Those Fighting It the Hardest


The Solar Electric Power Association releases its ranking of the Top 10 U.S. utilities. The list ranks the utilities that added the most solar power or the most solar per customer in 2013.

Today, the Solar Electric Power Association (SEPA), a Washington nonprofit dedicated to helping utilities integrate solar power into their energy portfolios, named the Top 10 American electric utilities for solar.

Before you assume this is a list of the most solar-friendly utilities, we should note what this means: these are the utilities that in 2013 added the most new solar power to their systems and the most solar on a watts-per-customer basis. That may or may not correlate with friendliness toward rooftop solar on the part of utilities.


The annual ranking is part of the seventh annual Utility Solar Rankings report. The full report, which will be released on June 5 (following an Executive Summary on May 15), identifies leading solar industry trends such as total installed capacity, market share, and industry growth rates.


What’s in the list


The rankings measured a utility’s newly installed solar power, including PV and CSP technologies that were interconnected between January 1 and December 31, 2013.


Utilities ranking in this year’s SEPA Top 10 by Solar Megawatt accounted for 82% of all capacity integrated in 2013, up from 73% in 2012. Six of the ten utilities on the list previously ranked in 2012. Newcomers include Duke Energy Progress, National Grid, and Georgia Power. This is the sixth year that Pacific Gas and Electric Company (PG&E) has topped the list.


The SEPA Top 10 Solar Watts-Per-Customer rankings take into account the number of customers each utility serves relative to its solar megawatts installed. That allows measuring small utilities on an equal footing with larger ones.


Leading the Solar Watts-Per-Customer rankings is indeed a small utility: Sterling Municipal Light Department (SMLD), a public power utility in Massachusetts that serves 3,700 customers. Another public power utility, Silicon Valley Power, made the list. Of the remaining Top 10 utilities, Hawaiian utilities and Imperial Irrigation District from California were also in the top ten in 2012.


The rankings follow; complete rankings can be found at









Annual W/Customer

Sterling Municipal Light Dept (MA)



San Diego Gas & Electric Company (CA)



Silicon Valley Power/City of Santa Clara (CA)



Arizona Public Service (AZ)



Hawaiian Electric Company (HI)



Pacific Gas & Electric Company (CA)



Hawaiian Electric Light Company (HI)



Maui Electric Company Ltd (HI)



Kaua’i Island Utility Cooperative (HI)



Imperial Irrigation District (CA)







Megawatts (MW)





Annual Capacity (MW)

Pacific Gas and Electric Company (CA)



San Diego Gas & Electric Company (CA)



Arizona Public Service (AZ)



Southern California Edison (CA)



Duke Energy Progress (NC, SC)



National Grid (MA, RI)



Public Service Electric & Gas Company (NJ)



Hawaiian Electric Company (HI)



Georgia Power Company (GA)



Duke Carolinas (NC, SC)






What it all means


Most of us would agree with Julia Hamm, president and CEO of SEPA, that more solar is a good thing. “We are thrilled to see milestones surpassed and barriers broken from coast to coast,” said Hamm in a press release today. “It’s truly inspiring to see utility partners and their consumer communities rally around implementing solar programs that are changing the nature of our national energy portfolio.”


Still, it’s a bit rattling to see big utilities like Duke Energy bragging about how much they love solar.


It’s true that two Duke businesses appeared on the list. Together, those utilities serve about 4 million customers in North Carolina and South Carolina.


But in their own press release today, Rob Caldwell, vice president of Renewable Energy Development at Duke Energy, emphasized more than once that the utility’s brand of large-scale solar is the most cost-effective: “These rankings reflect how Duke Energy is bringing cost-effective solar to our customers,” said Caldwell. He continued, “Our focus is cost-effective utility-scale solar that will have the greatest impact on our generation portfolio.”


In other words, Duke prefers large-scale solar to residential solar. Like some other large utilities, Duke has been aggressively pursuing this strategy, with just those two of its businesses on the list adding about 200 MW of new solar capacity in 2012, and looking to add another 300 MW by the end of 2015. Duke owns and operates another 145 MW of solar in eight states around the country.


The amounts of solar that Duke has brought onto the grid are still dwarfed by those of PG&E, and behind those of APS. But they represent a trend among the large utilities to add large solar that’s under their control, while in many cases fighting rooftop solar.


We’re glad to see a lot more solar coming online. The more clean energy we generate in the U.S., the better off we’ll all be. We just hope a significant portion of that can be on people’s roofs, too.