BONNEVILLE POWER ADMINISTRATION
Grid Mod: Dialing in hydroelectric generators' responses to market signals

How do you reduce error between scheduled hydro-generation and the actual power produced? BPA's answer: Form a tight partnership with the U.S. Army Corps of Engineers and evaluate existing systems and processes for areas of improvement.

For years BPA, USACE and the Bureau of Reclamation have dealt with varying levels of Station Control Error (SCE) on the non-big 10 federal projects. The non-big 10 are those hydroelectric facilities that are part of the Federal Columbia River Power System that BPA markets power from but are not located on the mainstem Columbia or Snake rivers.

SCE is the difference between scheduled or requested generation and actual generation.

"We try to adjust for the imbalance elsewhere in the hydro system," explained Elsa Chang, "but SCE can have drastic impacts on grid stability and reliability if frequencies suddenly deviate on our transmission system."

BPA operates the FCRPS more conservatively to accommodate for operational uncertainties by retaining an energy "safety buffer." If we reduce the volatility associated with SCE, then BPA would be able to operate the system more optimally and reliably, which may allow us to increase revenue. Looking forward, as BPA positions itself to potentially participate in new markets such as the Western Energy Imbalance Market operated by the California Independent System Operator, SCE could result in an unpredictable financial consequence. Minimizing SCE will become even more important for our financial health if BPA does decide to join the EIM.