The recent incident of rolling blackouts that occurred in the Texas ERCOT power grid raises some interesting issues for home owners, residential energy professionals and others concerned about energy policy. A recent article by Michael Giberson posted on The Energy Collective is a good early analysis.
All power grids have their vulnerabilities; it’s too costly to build in 100% reliability. In this ERCOT event, a number of factors came together in a so-called perfect storm to result in peak demand for electricity exceeding available capacity. The peak demand at one point was 53,000 MW (million watts). To prevent a cascading collapse of the entire Texas grid, rolling blackouts amounting to about 3,000 MW were implemented.
Energy efficiency and conservation can make an important contribution to power grid stability. When the grid gets stretched to its limit, it’s a fine line between blackout and normal operation. It’s a balancing act for grid operators to have enough capacity to serve the peak demand, but not too much excess capacity, which would be costly and inefficient. It is generally recognized that building in efficiency and conservation is less expensive per MW than building new power plants. Also, when we have weather excursions into extremely low temperatures, improved building envelopes with less air infiltration and more insulation value will require less energy, regardless of the efficiency of the heating and air conditioning systems.
A number of gas-fired power plants were temporarily shut down, as high gas usage during the cold snap led to low gas line pressures in some areas, and regulatory requirements for preferred customers in others. This brings into question the current policy of increasing reliance on methane (natural gas) for both peak and baseload power generation. To the degree that there is variable and intermittent power on the grid, such as wind and solar, there must be methane peak power available to immediately replace their output as it fluctuates. Giberson tells us that Texas’ significant wind turbine fleet on the ERCOT grid was producing normally for this time of year, about 3-4,000 MW. He concludes that it did not cause the blackouts, but that wind power did not present any solution either. My concern is that as the percentage of renewable power sources increases on a power grid, vulnerability may increase because of more reliance on methane supplies and pricing, and on unusual long periods of no wind or sun during times of peak demand.
Using methane to replace coal for baseload capacity places a further demand on methane supplies. While it is generally agreed that buring methane has lower greenhouse gas emissions than coal, some ongoing life cycle analysis studies are indicating that methane may not be as “clean” as believed previously. In addition, more and more of the new supplies of methane in this country are produced by the process of fracking, or hydraulic fracturing, which is causing great concern about the possible contamination of groundwater.
Answers? Conservation and energy efficiency continue to be a slam-dunk. Put your dollars there first, whether you’re a home owner or a power utility. Proceed with caution on renewable power, which may cause problems for the grid as deployment increases, and its high cost per unit of power produced may take limited resources away from other needed areas. In my opinion, we need to take a good hard look at using nuclear power to provide the majority of our baseload electrical generating capacity. Nuclear power is the only way to reach our carbon emission targets by 2050, and the only way to systematically take fossil fuel baseload power plants out of service relatively quickly.
This post originally appeared on Home Energy Consultants' House Whisperer Blog.