Demand for electricity was at an all-time high because of the heat, and the water needed to cool the state’s coal, nuclear and gas power plants was in short supply. In some places, water levels had dropped below intake pipes; in others, the available water was too hot to provide effective cooling. Texans were warned that rolling blackouts were possible.
In the end, ERCOT met demand without blackouts, though it came close. To keep its power plants operating, the state was even forced to take water away from farmers and ranchers who held senior water rights — something that is never supposed to happen.
A key factor in keeping the power flowing during the drought was that Texas had been aggressively developing wind power. Texas generates more power from the wind than any other state. During the summer of 2011, about 10 percent of the electricity Texans needed came from wind, as much as 18 percent on some days. Wind power is a resource that requires no water, unlike a thirsty source like coal. If the contribution from wind had come from Texas coal plants instead, blackouts probably could not have been avoided.
Another factor was that state and federal energy-efficiency regulation had slowed the growth in demand. A variety of rules for lighting, air conditioners, refrigerators and the like helped dampen demand even as the state’s population grew. Lower demand means lower risk of problems when droughts occur.
Texas is periodically subject to dry cycles, which can last a decade or more. The last time Texas was as dry was during the 1950s, and that drought lasted seven years. Before that, there was the Dust Bowl. The state climatologist at Texas A&M has said the state is probably midway through one of these dry cycles.
There are two main differences, though, between the current cycle and prior ones. Many more people reside in the state, living very different lifestyles that demand much more water. Second, according to recent research, the sort of drought that occurred in 2011 is 20 times more likely now than it was 50 years ago.
Given the facts concerning the water situation in Texas, one could be forgiven for holding a fairly pessimistic view of the state’s energy-water future. That’s certainly how I felt before CNA, the research center I work for, undertook a study to look at water issues in the power sector supported by the Regulatory Assistance Project. RAP is a global nonprofit group that supports power sector regulators all over the world, including Texas.
During the course of the work, however, I came to believe that while there are still significant near-term challenges, there is cause for some optimism about the power sector’s ability to dramatically cut its water use and so its vulnerability to future droughts. First, some background.
Across the United States, the electric power sector is responsible for half of all water use. But how power plants use water varies greatly. The amounts used depend on whether the power is produced thermally (by generating steam to run turbines) or by the wind or the sun. Nuclear and coal- and natural gas-fired plants are all thermal and require cooling. Water is run through the power plants to cool them and is returned to the river or lake it came from. As in 2011, if too little water is available or the available water is too warm, the plants can’t be cooled and so can’t run. There are numerous examples every year of shutdowns from water problems where there are droughts in the U.S.
Power plant efficiency is also key. Plants fired by natural gas turn about two-thirds of the energy into electricity, so they have less waste heat to get rid of and a smaller water requirement for cooling. Coal-fired power plants are much less efficient and need about twice as much water as gas plants. Nuclear plants use the most water. Wind and solar photovoltaic power use almost no water, except that required for occasional cleaning.
For the study we did for RAP, which also included studies of China, India and France, we were interested in understanding what approaches might reduce the vulnerability of the power sector to water problems. To help us understand the situation, we developed a model of the power sector that could account for water use and water constraints. Though water availability is clearly such a critical issue for the power sector, we found that neither the U.S. Department of Energy nor the U.S. Environmental Protection Agency has a policy models that includes water.
So, for example, even though the EPA regulates the power sector, which uses more water than any other, the agency is unable to consider the effect of its regulations on water use. For the Department of Energy’s Energy Information Administration, which produces the government’s official long-term energy forecasts, water is simply not considered. What our modeling showed was that considering water availability, or lack thereof, can dramatically alter how the power sector would develop. For Texas, this means that current trends in the state could result in major cuts in its water use over the long run.
The best choices to cut water use in the power sector are through energy efficiency, renewables (especially wind and photovoltaic), and substituting gas for coal. Fortunately, Texas has significant cost-effective opportunities for all these.
A 2007 study by the American Council for an Energy-Efficient Economy, or ACEEE, reported that if Texas moved aggressively to implement efficiency standards and demand-side management, by 2023 it could almost completely avoid the need for new electricity-generating capacity. This would provide an obvious advantage in that no new power plants means no water needed to cool them. But there is another advantage in that efficiency is also the cheapest choice.
We modeled an energy-efficiency program somewhat less aggressive than that proposed by ACEEE, cutting future demand by 30 percent by 2040. We found that a program of this sort could cut water withdrawals and consumption by 40 percent, whereas continuing with current trends would cut it by 27 percent.
Texas is blessed with an abundance of renewable energy potential in the form of wind and sunlight, as every Texan knows. Starting with Gov. George W. Bush in 1999, the state adopted policies to encourage renewable energy sources, particularly wind. The main impetus of the program was economic development for West Texas, but the result has undoubtedly saved water and cut air pollution as well. ERCOT has seen the percentage of wind-generated energy on the grid grow steadily, made possible by improvements in management and weather forecasting. The most recent figures, from October, show that wind was regularly generating 25 percent of Texans’ daily electricity demand.
In addition, a large new transmission line nearing completion will enable ERCOT to expand the wind power on the grid by an additional 50 percent. Every megawatt of wind-generated electricity eliminates the need for water for power plant cooling.
Natural gas is also an important component of Texas’ water-saving future. The boom in shale gas fracking, which started in Texas and spread to Pennsylvania and other states, has cut the price of natural gas about 75 percent in the last five years. At current prices, electricity generation from natural gas is much cheaper than coal. Construction of coal-fired power plants has stopped in favor of gas plants, and old coal plants are being converted to gas or shut down across the country.
Although it is controversial, the EPA’s proposed rule to prohibit the construction of new coal-fired power plants unless they capture and sequester the carbon dioxide emitted will simply lock in market dynamics that are already happening. Fracking is playing a much bigger role in pushing out coal than new regulations.
There is a great water advantage in moving from coal to gas, too, as natural gas is typically about twice as efficient and so needs just half the water for cooling. When gas replaces coal in power generation, it not only cuts water use but also eliminates coal’s emission of mercury, sulfur dioxide and particulates, and it reduces nitrogen oxide emissions by 90 percent. Carbon dioxide emissions are also cut by 50 percent.
The fracking process has its own environmental issues, which makes the overall coal-gas comparison somewhat problematic. Natural gas (methane) has 21 times more global warming potential than carbon dioxide, so methane leaks could nullify any climate benefits. Leaks of methane and other gases, as well as the emissions from the engines and trucks needed for fracking, can cause substantial local and regional air pollution. However, finding and fixing leaks, using best practices and switching engines and trucks to run on natural gas could mitigate these problems. Moreover, the water needed for fracking is small compared with the cooling water savings from switching from coal to gas.
Perhaps our most surprising research finding was that the power sector’s moves to increase efficiency, increase the use of wind power and switch from coal to gas are all going to substantially cut carbon dioxide emissions, the chief component of the greenhouse gases that cause climate change.
It’s hardly a secret that Texas is not on board with federal proposals to limit greenhouse gas emissions. Yet, because of the synergies between options that conserve water and also cut carbon dioxide emissions, Texas could very well be in the forefront of states’ efforts to control climate change. This may also apply to other Western states that follow Texas’ lead and adopt efficiency, develop renewables and substitute gas for coal.
The fact that there exists a potential synergy between conserving water and cutting greenhouse gas emissions in the power sector suggests that there is a productive conversation to be had between those concerned with energy and water use, and those worried about energy and climate change.
For the power sector, which has the largest carbon dioxide footprint, the approaches that will reduce water use and improve system reliability are the same ones that will reduce greenhouse gas emissions. They are also the same ones that will support adaptation to climate change, especially in drought-prone areas such as Texas. Recognition of these facts by both sides could be a way to end an unproductive stalemate and create benefits for everyone.
Paul Faeth is the director of energy, water and climate at the Institute for Public Research at CNA, a national not-for-profit research and analysis organization.
Reprint from Dallasnews.com