by James A. Bacon
California is getting a vivid lesson on the trade-offs between sustainability and reliability of the electric grid. Pacific Gas & Electric has taken the extraordinary action of cutting off electric power to 700,000 customers in California to reduce the risk of sparking forest fires. Many customers could go without power for as long as a week; the prolonged outages could cost customers billions of dollars in lost economic activity. Silicon Valley may have the most advanced technology in the world, but the Golden State increasingly resembles a Third World country. (Don’t get me started on the armies of homeless people.)
Virginians need to take notice. Virginia is not California, and Dominion and Appalachian Power Co. are not PG&E. … not now. What is happening in California will not be replicated here. But in our determination to build a “sustainable” zero-carbon grid, other equally horrendous scenarios are possible if we fail to pay sufficient attention to electric reliability.
PG&E filed for bankruptcy this year after being held liable for billions in damages and the loss of lives caused by wildfires ignited by poorly maintained electric lines. As a Wall Street Journal editorial summarizes the train of events:
For years the utility skimped on safety upgrades and repairs while pumping billions into green energy and electric-car subsidies to please its overlords in Sacramento. Credit Suisse has estimated that long-term contracts with renewable developers cost the utility $2.2 billion annually more than current market power rates.
PG&E customers pay among the highest rates in America. But the utility says inspecting all of its 100,000 or so miles of power lines and clearing dangerous trees would require rates to increase by more than 400%. California’s litigation-friendly environment has also increased insurance rates for tree trimmers and made it hard to find workers.
Meantime, opposition to logging and prescribed burns in California’s forests compounded by a seven-year drought has yielded 147 million dead trees that make for combustible fuel. Rural communities are at especially high fire risk when winds kick up as they have this week.
Wild fires aren’t a big problem in Virginia (although they aren’t unknown either). But we have our own challenges such as hurricanes, solar vortexes, and ice storms. Unfortunately, I don’t hear anybody discussing how a zero-carbon grid, which Governor Ralph Northam has identified as a goal by 2050, would hold up under extreme conditions, much less how a zero-carbon, zero-nuclear grid advocated by some environmental groups would fare.
Let us envision what a zero-carbon grid would look like. All coal-fired and gas-fired power plants would be retired. Virginia would rely primarily upon solar power across most of the state, supplemented by what could be the nation’s largest offshore wind farm off the coast of Virginia Beach. As we have noted ad nauseum on this blog, solar and wind are intermittent power sources that rely upon favorable weather conditions to generate power. Even under ideal conditions, it would be impossible for a solar-dominated electric grid, in which power generation peaks around noon, to meet the electric load that peaks in the late afternoon without extensive energy storage capacity.
Broadly speaking, there are three ways to square the supply of renewable power with the demand for electricity. One is pumped storage, in which excess electricity is used to pump water into a reservoir, which then releases water to generate hydroelectric power when needed. The other is battery storage. There is no technological risk associated with pumped storage, but it is very expensive. Battery storage is far more flexible and responsive, but it is too expensive to shift power supply on a large scale. That may change, but the progress of battery storage technology is uncertain. A third alternative would be to import power from outside Virginia when needed. But that would require a massive expansion of electric transmission capacity — and electric transmission lines, as we all know, are highly unpopular and construction is subject to lengthy regulatory delays.
But let’s assume for purposes of argument that we get all those problems ironed out. The year is 2050. In very rough numbers, 80% of our electricity statewide comes from geographically distributed solar power and 20% from wind power, most of which is highly concentrated off the Virginia coast. Let’s say we have huge banks of electric batteries capable of storing enough electricity to address the daily imbalances in supply and demand and offset intermittent power generation. And let’s say Virginia has upgraded its transmission grid to allow the import of more out-of-state power as back-up. (You can see that there would an extraordinary amount of redundancy built into this system, which would be very expensive, but let’s set aside that issue.)
Now, pick your disaster scenario.
Polar vortex. Every two or three years, a massive blob of Arctic air barrels through Virginia, subjecting the state to four, five, or six days of extreme sub-zero temperatures. Electricity consumption for heating shoots through the roof. But in our zero-carbon/zero-nuclear scenario, there is no nuclear power base-load, and there is no fossil-fuel surge capacity. Polar vortexes often are accompanied by cloudy weather conditions (see photo above) and light winds, and electric generation falls. Electric batteries, configured to meet daily needs under normal conditions, are sucked dry within a few hours. While solar power may be sufficient during a deep-freeze to meet the state’s needs for a couple of hours during the day, there is not enough power to meet peoples’ needs for 24 hours a day — and don’t forget, the days are shorter during the winter — much less replenish the electric batteries. The wind power generated off the Virginia coast is not nearly sufficient (even assuming the wind is blowing like normal) to make up the deficit. Meanwhile, other states in the PJM regional transmission grid are suffering the same challenges and don’t have power to spare, even if Virginia has upgraded its transmission lines. Within a day or two, PJM (which gives orders to Dominion and Apco) has no choice but to order industrial and commercial customers to shed load, preserving electricity for hospitals, water treatment facilities, and other critical infrastructure as well as homes. Even then, there’s no guarantee of sufficient electric power to heat homes 24 hours a day. How many days of this before thousands of people freeze to death?
Category 3 hurricane. Virginia is vulnerable to hurricanes. We’re not as exposed as some other Atlantic Coast states, such as Florida or North Carolina, but major cyclones does plow through the state every few years. Let’s envision a hurricane like Isabel (seen at right) blasting through the state. First thing that happens: All offshore wind turbines go off-line to protect the blades against high winds. Boom, Virginia loses a big chunk of its electric generating capacity for the duration of the high winds. Meanwhile, extremely heavy cloud cover and heavy rains reduce solar production to a tiny fraction of normal. Electric batteries are quickly drained. Importing electric power from out of state is problematic, especially if high winds knock down transmission lines. The duration of a hurricane is likely to be shorter than a polar vortex, but the disruption to electric power production will be more pronounced. What would the economic impact be if, in addition to the typical hurricane damage of downed power lines, electric generation fell to 10% or so of normal for two days? Then there is the aftermath. Maybe the turbines withstand the pounding of the waves, maybe not. We simply don’t know because the turbines have not been tested for conditions they would experience off the Virginia coast. Maybe solar panels in the thousands of acres of solar farms stand up to hurricane-strength winds, depending upon rigor of the building codes, maybe they don’t. We won’t know until it happens.
Virginia can’t afford to design an electric grid to work 364 days a year. It has to hold up under rare but foreseeable conditions that occur once or twice a decade or we invite catastrophe. Maybe there are work-arounds to these scenarios. Maybe we can build in enough redundancy in a solar/wind/battery grid that we can survive worst-case events. But at what cost, and at what risk? The fact that Virginians can contemplate a 100% renewable grid within 30 years without even asking these questions tells us how we have succumbed to a massive failure of imagination.
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