A utility executive previewed a new study for the Federal Energy Regulatory Commission, saying pumped-storage hydroelectric plants are needed to support expanded renewables portfolio standards.
Executive Vice President Pedro Pizarro of Southern California Edison Co. detailed key findings of the soon-to-be-released independent analysis during a March 2 technical conference convened by FERC to examine integration of renewable energy generation into the wholesale electricity grid.
Pizarro and dozens of other participants presented information on challenges posed by integrating large amounts of variable renewable generation into wholesale markets and grids.
With funding from SCE, Pacific Gas &Electric Co., and San Diego Gas &Electric Co., the study evaluated integration and operational issues associated with relying on high levels of intermittent, renewable resources such as wind and solar power.
Pizarro said the study found higher percentages of renewables in utilities’ generating portfolios would require higher planning reserve margins to back up the system when intermittent resources are incapable of producing sufficient energy. Higher ancillary service levels also would be required to maintain proper voltage and frequency levels. Pizarro said that requires proper generation and storage technologies to meet system regulation, load following, and ramping requirements.
The study found that higher renewables portfolio standards could result in significant amounts of surplus energy that cannot be used on the grid or sold to others. Additionally, the study found, the typical six- to 11-year lead time for transmission construction is a barrier to integrating renewables.
In the week before the conference, Energy Secretary Steven Chu called for increased investment in pumped-storage hydropower to support an expanded electricity transmission grid that would carry a greater share of intermittent generation from wind and solar sources. (HNN 2/25/09)
FERC chairman: New grid infrastructure is essential
FERC Acting Chairman Jon Wellinghoff opened the conference, speaking about the need to support development of transmission infrastructure to deliver electricity from renewables.
ï¿½I believe that developing the transmission infrastructure needed to deliver electricity from renewable energy resources is essential to meeting our national energy goals, such as reducing greenhouse gas emissions, strengthening our national security, and revitalizing our economy,ï¿½ Wellinghoff said.
Wellinghoff noted FERC has created procedures to provide incentives for investment in electric transmission, including advanced transmission technologies, as defined by the Energy Policy Act of 2005. Both Congress and FERC have recognized pumped storage as advanced transmission technology. (HNN 4/16/08)
Hydropower’s role discussed
Brian Parsons of the National Renewable Energy Laboratory said wind energy could be increased by utilizing existing grid flexibility, including hydro, through expanded transmission, expanded smart grid applications, scheduling, and updating dispatch schedules.
Parsons said simulations from another study showed increased use of existing pumped storage to accommodate renewable energy’s grid integration. However, he added, those same simulations indicate existing pumped-storage facilities might be adequate for the task.
Technology Vice President Clark Gellings of the Electric Power Research Institute discussed a plan to support wind generation by using PG&E’s 1,050-MW Helms Pumped-Storage project (No. 2735). Gellings said the California Independent System Operator is considering a plan to connect wind generators in the Tehachapi area to the Helms facility.
Helms, the largest energy storage facility on the California grid system, could provide regulation services when it is in the generating mode. Helms could be used in combination with Tehachapi wind generation, but would require an upgrade to transmission facilities in the region to deliver Tehachapi energy to the Helms plant. Such a project also would enable the use of a third pump to store more energy from renewable resources for more hours annually.
Brian Silverstein of Bonneville Power Administration said the federal Columbia River hydropower system currently provides wind integration services for the bulk of the Pacific Northwest’s wind fleet. He said the cost of integrating wind with hydropower is increasing. He added the federal hydropower system is reaching the limits of the wind integration services it can supply.
FERC solicits industry comments
FERC said it would accept industry comments until April 30 on subjects addressed at the conference.
Conference transcripts are to be available under Docket AD09-4 on the eLibrary system of FERC’s Internet site, www.ferc.gov. Nearly three dozen presentations prepared for the conference already are on the site.
The National Hydropower Association board of directors has developed a position statement that recognizes growing importance of transmission policy to achieve renewable energy goals in the United States. NHA said improving electric transmission infrastructure is critical to develop renewable energy resources fully. It supports development of policies for a balanced, nationwide approach to transmission issues that will bring renewable electric energy from production centers to load demand centers.
NHA said reliability and integration issues are of particular interest to the hydropower industry as operators are beginning to observe effects of large-scale wind generation on the operations of hydropower facilities. Additionally, it said, pumped storage can shift off-peak energy to times of peak energy demand and can relieve transmission congestion by providing critical load balancing services.