PUBLISHED: JUly 18, 2017
By Jonathan Thompson
High Country News
On a few sunny days this spring, California’s solar and wind power plants generated so much juice that grid operators had to throw it away, or curtail generation. The sun was shining, the wind was blowing, but the generators were shut down. The state lost enough electricity from January through June to power 50,000 homes for six months.
The problem is not that there’s too much renewable power; the problem is that the electrical grid is divided up in a way that makes it hard for different utilities to share power. Now, a growing cadre of renewable energy advocates, engineers and utility officials are working to fix that.
We often describe the Western electrical grid as if it’s a single, unified, vast machine comprising 1,000 power plants and high-voltage wires that reach across nearly 2 million square miles. We imagine electrons from wind plants in Wyoming zipping at the speed of light to laptops in California. Not quite.
The grid is physically interconnected but operationally balkanized, broken up into 38 distinct islands, or balancing authorities. Critics compare it to a train with a separate driver for each car, or a creature whose every organ is controlled by a separate nervous system. It’s clunky and slow, suited to outdated power sources and antiquated modes of power consumption.
“The current system is too balkanized in its operations, too costly to consumers and too inefficient in its use of power and transmission infrastructure to be successful,” says Carl Zichella of the Natural Resources Defense Council. The only way to take advantage of the increasing amount of renewable energy sources, and to abandon fossil fuels, he says, is for all the separate balancing authorities to come together as one.”
An integrated grid, as its proponents envision it, would allow multiple utilities to share that generating capacity. It would tear down the borders between balancing areas, bridge the rifts between the now-distinct grids with new infrastructure if necessary, create a centralized power market and put a single team of pinheads — also called an independent system operator — in charge of following the load of the entire West, with a huge fleet of generators at their disposal. Operators could then send excess California-generated solar power to New Mexico to meet that state’s demand peak, and pump Wyoming wind power California-way to keep up with the late-afternoon air-conditioner rush.
A sort of integrated Western grid “lite” is already in operation, giving a sense of how the big grid would work. In 2014, the California Independent System Operator, or CAISO, which runs most of the state’s grid, joined up with utility giant PacifiCorp to form a centralized market where they could buy or sell power in real time to make up for unforeseen supply-and-demand imbalances.
Several other utilities have joined, including Arizona Public Service and the Los Angeles Department of Water and Power. Salt River Project, the Arizona operator of the coal-fired Navajo Generating Station, signaled its intent to join the market shortly after the plant shuts down in 2019. Public Service Company of New Mexico, which is looking to ditch coal altogether by 2035, is also interested in participating, and NV Energy, which shut down Reid Gardner coal plant this spring, has long been a member.
When California has extra solar, the market allows other participants to buy it far more cheaply than coal or natural gas, allowing neighboring utilities to displace some fossil fuel generation. The Energy Imbalance Market, as it’s called, or EIM, has so far saved participants $173 million, according to CAISO, and helped California avoid major solar curtailments.
Yet the real-time EIM is a mere shadow of a truly integrated grid, because it applies only to imbalances, which make up just about 5 percent of the wholesale electricity market. The bulk of the market is made up of day-ahead trades, where pinheads use sophisticated models to forecast the following day’s net power demand on an hour-by-hour basis, then commit generators to ramp up accordingly. An integrated grid would take the EIM model and apply it to all power purchases. It would radically transform the way the Western grid works, and CAISO estimates that it would save participants more than $1 billion per year. “It’s cleaner, cheaper and more reliable,” says Zichella.
The integration effort is moving ahead, albeit slowly. Most of the utilities that are involved in the EIM are eager to take the next step toward full integration. California lawmakers are hoping to ease neighboring states’ concerns about loss of control by restructuring CAISO’s board to include members from other states.
“The trend away from high carbon fuels is clear, and we believe irreversible,” Zichella says. “Regional integration accelerates this trend. … In a climate in which new national policy initiatives for climate mitigation are highly unlikely, regional integration provides an elegant and non-coercive mechanism for the clean energy transition across the West.”