Western U.S. power grid can accommodate large increase in wind and solar generation


Debra Lew,
Project Manager,
Golden, CO, U.S.A. — (METERING.COM) — May 21, 2010 – Wind and solar capacity sufficient to produce 35 percent of power requirements by 2017 can feasibly integrated into the grid without extensive additional infrastructure, although key changes to current utility operational practice would be required.

These are among the conclusions of a new study from the National Renewable Energy Laboratory (NREL) assessing the operational impacts and economics of increased contributions from wind, photovoltaics and concentrating solar power on the power system operated by the WestConnect group of utilities in the mountain and southwest states of Arizona, Colorado, Nevada, New Mexico, and Wyoming.

The Western Wind and Solar Integration Study found that while wind and solar output vary over time, it is operationally possible to accommodate 30 percent wind and 5 percent solar energy penetration. To accomplish such an increase, utilities would have to substantially increase their coordination of operations over wider geographic areas and to schedule their generation deliveries, or sales, on a more frequent than next hour basis to allow adjustment for wind and solar generation variabilities.

The study also found that existing transmission capacity can be more fully utilized to reduce the amount of new transmission that needs to be built, and that the use of wind and solar forecasts in utility operations would be essential.

According to the study if utilities generate 27 percent of their electricity from wind and solar energy across the Western Interconnection grid, it would lower carbon emissions by 25 to 45 percent. It would also decrease fuel and emissions costs by 40 percent, depending on the future price of natural gas, and substantial savings could be made by reducing the need for additional back-up generation, such as natural gas-burning plants.

“If key changes can be made to standard operating procedures, our research shows that large amounts of wind and solar can be incorporated onto the grid without a lot of backup generation,” said Dr Debra Lew, NREL project manager for the study. “When you coordinate the operations between utilities across a large geographic area, you decrease the effect of the variability of wind and solar energy sources, mitigating the unpredictability of Mother Nature.”

The study complements the recently completed Eastern Wind Integration and Transmission Study, which found that the integration of 20 percent wind energy in the Eastern Interconnection (central and northeastern U.S.) by 2024 is technically feasible, but would require significant expansion of the transmission infrastructure and system operational changes for it to be realized.

The studies were aimed at evaluating wind energy penetrations up to 30 percent of annual electric energy demand across the nation. The solar component was added to the Western study as solar is rapidly growing in the west and given the region’s solar potential.