Higher cap by utility panel could help Rifle increase solar energy

Higher cap by utility panel could help Rifle increase solar energy

By DENNIS WEBB/The Grand Junction Daily Sentinel

Saturday, July 04, 2009

The city of Rifle’s hopes of fully powering a new waste- water treatment plant with renewable energy are in the hands of a state regulatory commission.

The city is waiting for the Public Utilities Commission to decide whether to lift a 2-megawatt-per-customer cap on net metering of renewable energy. An administrative law judge has made a recommendation in the city’s favor.

Net metering allows customers with their own renewable energy installations to be credited for energy they produce that exceeds their consumption of a utility’s power.

Although the cap doesn’t affect most consumers, Rifle has the largest municipal solar installation in the state. It includes a 1.7-megawatt array for the treatment plant and a 0.6-megawatt system for a raw water intake plant.

It would take a 4-megawatt system to fully power the city’s wastewater treatment plant.

Mike Braaten, the city’s government affairs director, raised the issue with the state as the PUC began considering a much broader rewrite of rules pertaining to renewable energy standards approved by state voters in 2004.

Denver and Boulder also have joined in voicing concern about the cap, in Denver’s case because it has a large solar array at Denver International Airport.

Some cities recommended an exemption for municipal customers.

Xcel Energy supported a cap consisting of the lesser of 2 megawatts or 120 percent of a customer’s average annual electricity consumption.

In April, as part of a larger package of renewable energy rule recommendations, Administrative Law Judge Ken Kirkpatrick wrote that the 2-megawatt cap is “somewhat arbitrary” and that a larger limit is warranted.

He recommends imposing only the cap of 120 percent of average annual use, no matter how large a system that allows. Braaten said that standard would meet Rifle’s needs.

The PUC is scheduled to act on the renewable energy rule revisions later this year.

Xcel spokesman Mark Stutz said the utility is not opposing the judge’s recommendation on the cap.

However, he said the concerns that Xcel raised about a larger cap continue to be relevant. Increased renewable energy capacity adds to Xcel’s challenge of providing backup electricity when the sun isn’t shining or the wind isn’t blowing.

In his recommendation, Kirkpatrick called that concern valid, but said it involves engineering and operational issues, and the cap is primarily an economic one.

Stutz said Xcel is testing batteries and molten salt as means of storing renewable energy, along with a system to use wind to produce hydrogen, which could then serve as a fuel source.