Changes in the Northwest's Power System

The load, generating resources balance, and the impact of energy efficiency

Earlier in the year, the Council looked at how loads and generating resources had changed in the Northwest over the years. At its March meeting, staff put it all together and reported on the net changes in loads and resources from 1995 through 2012.

Average load growth, after adjusting for weather, was a modest 0.46 percent per year, an increase of about 1,300 average megawatts. Improved energy efficiency is a big reason for the low load growth. On the other end, over 16,000 megawatts of new generation was added to the system. About half of this increase is from wind development to meet renewable portfolio standards, and the other half is mostly natural gas-fired plants.

At the same time, generating capacity at the federal dams has declined by more than 5,000 megawatts from operational changes to protect salmon and steelhead, 

Fortunately, the region's new resources, along with energy efficiency, have more than compensated for this loss, while increasing our generating capacity by about 2,000 megawatts.

In a related presentation, energy efficiency, in addition to meeting load growth, also appears to help reduce peak-hour loads. Although the region's end-use data is 25 years old, the Council estimates that the region's energy savings from 2010 through 2012 were about 780 average megawatts, which reduced winter peak-hour loads by 950 megawatts.

Tom Eckman, conservation resources manager for the Council, notes, "We know energy efficiency has an effect on peaks, but in order to really measure its impact on hourly demand, we need to update the end-use load profiles for appliances and equipment."

Using a limited set of load profile data recently updated through a Bonneville Power Administration project, the Council found that energy efficiency reduced peak loads even more--from 950 megawatts to 1,070 megawatts. Having updated information would provide a more accurate picture of the impact of energy efficiency, and the Council expects to work with the region to address the need.