Findings from GE studies of three areas of the North American electrical grid suggest that with prudent investment—including transmission upgrades and regulating reserves—operators can boost renewables' share of the fuel mix while maintaining grid reliability and achieving fuel cost savings.

GE's Hawaii Wind & Solar studies utilized modeling tools to evaluate cost-effective ways to support the growth of renewables on the islands of Oahu and Maui. The study identified several operational changes that would be required to successfully integrate more renewables, including:

· Grid operators should carry “regulating reserves” to offset potential short-term variability in renewable power, which could come from thermal plants, demand response, storage and even wind and solar. Allowing renewables to provide reserves, the grid could save up to $50 million per year and integrate an additional 200 GWh of wind and solar.

· Modifications that allow thermal units to operate at lower levels could save up to $80 million/year and accommodate up to an additional 110 MW per hour of renewables.

· As wind and solar penetration increase, in some scenarios it could be more economical to turn thermal generation off, which could reduce curtailment by up to 40% and save approximately $19 million per year in a high-renewable scenario.

Renewable integration potential based on GE studies. Image credit: GERenewable integration potential based on GE studies. Image credit: GE GE's study of the Western Interconnection determined that it could reliably meet more than 30% of the region’s electrical power needs by integrating renewables. Wind and solar could provide a 40% fuel savings compared to traditional generation, while reducing coal plant dispatch by 80%, the study concluded.

GE's renewable integration study of PJM—which includes service territories in parts of 14 states and territories in the mid-Atlantic and Midwest—found that to achieve the 14% (40 gigawatts) renewable portfolio standard PJM wants to reach would require an annual transmission investment of approximately $4 per megawatt-hour of renewable energy. Further, the study found that the fuel cost savings from renewable generation (~$70 per MWh) could offset the costs of the necessary transmission investments over time.

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