Is a Renewable Electric Grid a Mirage?
September 1, 2019 | View PDF
Reducing greenhouse gas emissions to curb climate change will require enormous sacrifice. The enormity of the required sacrifice suggests that we should have consensus on the goal before acting.
Recent discussions of the Green New Deal have highlighted some of the required sacrifices, but I suspect that the full implications of an all renewable power electric grid remain obscure.
The Green New Deal was sponsored by New York Congresswoman Alexandria Ocasio-Cortez and Massachusetts Senator Edward Markey. The proposal highlighted measures like a renewable energy electric grid, eliminating greenhouse gas emissions in transportation (including phasing out air travel), and creating a smart electric grid. Limiting atmospheric carbon dioxide to 440 ppm, the European Union’s goal, will require these changes and then some. Assessing whether aggressive mitigation of climate change is worthwhile requires recognizing the full cost.
An all-renewable energy electric grid appears feasible. Over 30 states already require a minimum portion of electricity generation from renewable sources; Hawaii will require 100 percent renewables by 2040. Renewable fuels are certainly costly, but the consequences go way beyond cost.
Wind and solar power and batteries are the components of a zero emissions grid. Yet wind and solar generate power only about 30 percent of the time.
Currently utilities rely on fossil-fuel-powered plants to provide backup; a zero emissions grid will require batteries. The Manhattan Institute report, “The ‘New Energy Economy’: An Exercise in Magical Thinking,” demonstrates the flaws of such an approach.
One concern involves simply building enough wind farms and solar panels to meet electricity demand. In 2018, the U.S. had 1.1 million megawatts of electricity generation capacity, 62 percent from natural gas and coal. Due to intermittent production, we would need perhaps 3 million megawatts of wind or solar capacity for the grid. If we used only wind turbines, we would need a wind farm larger than Texas. We would need perhaps 1.5 million turbines, each requiring 150 acres for an undisturbed flow of air, or 350,000 square miles.
Even this is almost surely an underestimate. Wind energy potential maps have already allowed use of the best wind farm sites. Electricity demand has been steadily rising and would jump further to charge the electric cars, trucks, and trains and eliminate gas and diesel-powered vehicles.
The battery numbers are also troubling. One year’s production of batteries from Tesla’s “Gigafactory” can store enough power for the U.S. grid for three minutes. The “New Energy Economy” report contends that 1,000 years of “Gigafactory” production would be needed to store just two days of power.
Producing such quantities of turbines, solar panels, and batteries will use enormous quantities of fossil fuels. A standard wind turbine requires an estimated 900 tons of materials, including concrete and metal. The lithium, cobalt, nickel, and other needed chemicals for solar panels and batteries must be mined and transported. In addition, turbines, panels and batteries will need replacing periodically. The power grid has long operated on adding capacity to meet demand.
Millions of decisions have been made based on this principle. We assume we can power our air conditioners, refrigerators, and computers, and soon charge electric cars in a timely fashion. Gas-powered generators provide backup as needed.
A zero emissions grid will not just involve much more expensive electricity. The supply of electricity will be insufficient to meet the demand. “Smart” appliances will ration electricity by running only when electricity is available. After ensuring hospitals and fire stations have power, we may be unable to charge our cell phones and electric cars.
The ripple effects will be enormous. How do we get to work if our electric car didn’t charge overnight? How will we heat and cool our homes? Could global supply chains still operate? The Green New Deal has highlighted some of the dramatic changes required to aggressively combat climate change. But I doubt that Americans understand the consequences of ending on-demand