US Grid Ready for Large-Scale Offshore Wind Power Boost
US electrical grid has the potential to handle scores of gigawatts (GW) of installed offshore wind capacity which would also lead to less pollution and reduced electricity costs, according to a study carried out by researchers from the University of Delaware and Princeton University.
The researchers, who have completed a first-of-its-kind simulation with the electric power industry, consulted with PJM Interconnection — a grid operator supplying electricity to more than 60 million people in 14 states — to develop a computer model that simulates how the electric grid would respond to injections of wind power from offshore wind farms along the East Coast at five build-out levels, between 7 and 70GW of installed capacity.
One hurdle grid operators face is how to integrate increasing amounts of naturally fluctuating offshore wind into a network that has to deliver reliable power to customers, 24-7.
The UD and Princeton team showed conservatively that, with some upgrades to transmission lines but without any need for added storage, the PJM grid can handle over 35GW of offshore wind. They also found that the PJM grid could in the future handle twice that amount, up to 70GW, as wind forecasting improves, allowing the power operator to better predict and harness more wind.
“Our goal was to replicate this very human-made energy system under all kinds of scenarios,” said Cristina Archer, associate professor of physical ocean science and engineering at the University of Delaware.
“What would you do as a grid operator if you thought it was going to be windy today and it isn’t, or if the wind storm arrives earlier than expected? We simulated the entire PJM grid, with each power plant and each wind farm in it, old and new, every five minutes. As far as we know, this is the first model that does this.”
The model of PJM, called Smart-ISO, created at Princeton, is designed to handle both the variability and uncertainty of growing inputs of offshore wind energy, simulating what happens over an extensive power grid with more than 60,000 miles of transmission lines.
“The uncertainty of wind will require that we develop strategies to minimize the need for spinning reserve,” said Warren Powell, professor and lead researcher at Princeton in charge of the SMART-ISO model, referring to electric generators that need to keep “spinning” and be ready for any electricity shortage.
“Although we found that reserves were needed — 21 percent of the 70 gigawatt wind capacity — there are a number of strategies that could be investigated to better handle the variability as wind grows in the future.”
The first US offshore wind farm, consisting of five wind turbines at Block Island, Rhode Island, with a generating capacity of 30MW, had not been built yet when the researchers began their study five years ago. The 70GW offshore modeled in this study would be almost equal to the total US wind power capacity installed on land through the end of 2016.
Archer says that adding more offshore wind farms would lower consumers’ electricity costs and reduce pollution by replacing coal and natural gas power plants.
“We saw up to a 50 percent reduction in carbon and sulfur dioxide and up to a 40 percent reduction in nitrogen oxides emissions at the highest build-out level, a 70-gigawatt set of wind farms. Plus, the costs of electricity would go down every month except in July when air conditioning is at a peak,” Archer said.
“Wind power is a very good idea—for people’s health and their wallets.”
The research was supported by the US Department of Energy.