Association Highlights Most Solar-integrated Utilities

The Solar Electric Power Association (SEPA) recently announced its Top Ten rankings that reveal which utilities in the United States had the most solar electricity integrated into their energy mix as of the end of 2007.

The rankings are based on information provided through a survey of utilities and independent research.

"SEPA anticipates that utilities will quickly become the largest and one of the most important customers for the solar industry," said Julia Hamm, SEPA executive director. "Whether solar electric systems are developed by utilities, their customers, or solar companies, the utilities' proactive engagement with emerging solar technologies is important to the solar industry as a whole. This market survey and resulting rankings provide a baseline against which increased utility activity can be measured in the future."

For total solar electric capacity by megawatt (MW), Southern California Edison takes top honors as the most solar integrated utility with the most overall solar capacity and solar capacity per customer. Southern California Edison's long-standing contracts with the SEGS concentrating solar thermal plants drive its large number of solar megawatts.

In addition to overall rankings, additional Top Ten lists were released based on the amount of solar electricity interconnected to the utility in two different configurations: customer side of the meter and utility side of the meter.

On the customer side of the meter, Pacific Gas & Electric (Calif.) took the honors for both the largest amount of overall solar capacity and the highest MW per customer, but the latter category is in striking distance for several public power utilities. On the utility side of the meter, Southern California Edison is the highest ranked utility both for overall MW as well as MW per customer, which drove its No.1 total ranking.

The list diversifies when you dive down further into the data and differentiate utility types. On the customer side of the meter for public power utilities, Los Angeles Department of Water & Power is the most solar integrated in overall capacity, while Kauai Island Utility Cooperative (Hawaii) has the highest capacity per customer.

California—with its long-standing policies for solar market development—represents the majority of the highest rankings, but utilities in Arizona, Colorado, Hawaii, Illinois, Nevada, New Jersey, New York, Texas, Washington, and Wisconsin also make the top 10 in many categories.

"These top 10 rankings highlight solar-leading utilities that have put significant efforts into facilitating what have traditionally been customer-based solar solutions," says Mike Taylor, SEPA director of research. "What has become apparent however is that over the next few years, there will be an unprecedented level of new utility engagement in the solar industry that develops both centralized and distributed systems in new and unique ways. Several U.S. utilities, some of whom aren't in these rankings yet, are positioning themselves to be the solar industries largest and most innovative customers."

The full report, which includes all the rankings, is available for download at

Top Ten Utilities Ranked by Total Solar Electric Capacity (MW) – By Utility Type
Investor-owned and Public Categories

1. Southern California Edison, Los Angeles Dept of Water & Power

2. Pacific Gas & Electric Co. (Calif.), Sacramento Municipal Utility District (Calif.)

3. Nevada Power/Sierra Pacific Power (Nev.), Long Island Power Authority (N.Y.)

4. San Diego Gas & Electric Co. (Calif.), Salt River Project (Ariz.)

5. Xcel Energy (Colo.), Austin Energy (Texas)

6. Arizona Public Service Co., Kauai Island Utility Coop. (Hawaii)

7. Public Service Electric & Gas Co. (N.J.), City of Palo Alto Utilities (Calif.)

8. Tucson Electric Power Co. (Ariz.), Riverside Public Utilities (Calif.)

9. Commonwealth Edison (Ill.), Imperial Irrigation District (Calif.)

10. Central Hudson Gas & Electric (N.Y.), City of Roseville Electric (Calif.)

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