Water and energy – we’re using a lot of the former in order to harness the latter, which poses an increasingly urgent dilemma for stakeholders across society. The energy we rely on to maintain our living standards typically comes from burning fossil fuels, which, in turn, not only draws down and degrades our water resources, land and air quality, but intensifies the negative effects of climate change.
Having reached a critical juncture at the nexus where energy and water meet, U.S. society is now faced with a stark choice. Continue to rely on fossil fuels to supply the energy we require or aggressively shift to a more diversified and distributed mix of cleaner, less resource-intensive and less destructive renewable energy resources, while at the same time pursuing across-the-board gains in energy efficiency, according to the Energy and Water in a Warming World Initiative (EW3) organized by the Union of Concerned Scientists (UCS).
Generating electricity in a warmer, water-constrained world
Pursuing a business-as-usual path will lead to increasing demand for water by the energy sector, shortages, rationing and the potential for conflicts while intensifying degradation of water and other natural resources and exacerbating climate change, according to EW3′s, “Water Smart Power: Strengthening the U.S. Electricity System in a Warming World,” the second in a series of studies examining the ramifications in coming decades of the energy choices we make today.
Pursuing “a low-carbon ‘water-smart’ electricity future” based on renewable energy and energy efficiency gains, in contrast, would drastically reduce both energy sector water usage and natural resource degradation, as well as realize drastic reductions in carbon and greenhouse gas emissions, thereby mitigating climate change.
The power sector places great demands on both our water resources and the air we breathe, the result of choices made regarding how best to produce electricity. Electricity generation accounted for one-third of U.S. carbon and greenhouse gas (GHG) emissions in 2011 and more than 40 percent of water withdrawals in 2005. Requiring vast amounts of water for cooling purposes, some of which is lost to evaporation, the power sector is one of the largest consumers of fresh water outside the agricultural sector, the EW3 report authors note.
The extreme weather events and anomalous weather patterns experienced in recent years, such as the record-setting heatwaves and droughts of 2011 and 2012, have been heightening the strains on power plants, shining “a harsh light on the vulnerability of the U.S. electricity sector to extreme weather,” they write.
U.S. power plant operators across the country have been increasingly running into three big problems in recent years: incoming cooling water too warm for efficient and safe operation; cooling water that is too hot to be released safely into rivers or lakes; and inadequate water supplies. As the EW3 report authors recount,
During the historic 2011 drought in Texas, power plant operators trucked in water from miles away to keep the plants running, and disputes deepened between cities and utilities seeking to construct new water-intensive coal plants.
In 2012, heat and drought forced power plants, from the Gallatin coal plant in Tennessee to the Vermont Yankee nuclear plant on the Connecticut River, to reduce their output or shut down altogether.
That summer, amid low water levels and soaring water temperatures, operators of other plants—at least seven coal and nuclear plants in the Midwest alone—received permission to discharge even hotter cooling water, to enable the plants to keep generating. These consecutive summers alone revealed water-related electricity risks across the country.
The pressing need for a more sustainable, climate change-resilient energy infrastructure
The current system of power generation in the U.S., according to EW3, “clearly cannot meet our needs in a future of growing demand for electricity, worsening strains on water resources, and an urgent need to mitigate climate change.”
What’s urgently needed, they assert, is a system of power generation that is much more resilient – one that is not only much less dependent on water, but one that can operate sustainably in a warming climate and, at the same time, help mitigate climate change. With the release of its second report, EW3 advocates making decisions today that puts U.S. society firmly on such a path.
Based on new research examining the implications for water resources in light of electricity choices across a range of alternative paths at the national, regional, and local levels, EW3′s second report,
…aims to provide critical information to inform decisions on U.S. power plants and the electricity supply, and motivate choices that safeguard water resources, reduce carbon emissions, and provide reliable power at a reasonable price—even in the context of a changing climate and pressure on water resources.”
U.S. energy in transition: Choosing the right path
The U.S. power infrastructure is already in the midst of a major transition, the report authors note. Operators of coal-fired power plants are taking advantage of cheap, and now plentiful, natural gas supplies and switching to natural gas to an unprecedented degree. Adding to this, renewable energy capacity continues to come online at record rates, while energy efficiency gains are being realized across all spheres of society.
EW3′s research team constructed two long-term scenarios in order to better understand and analyze the implications of decisions made today regarding electricity production in the U.S. in terms of water usage and greenhouse gas emissions.
Pursuing a business-as-usual path that would see natural gas combustion growing to account for 60 percent of U.S. power generation in coming decades “would fail to reduce carbon emissions, and would not tap opportunities to safeguard water,” EW3′s research team found. In sharp contrast, both water usage and carbon emissions in the power sector would drop much further, and faster, under a “renewables-and-efficiency” scenario.
Under the renewables-and-efficiency scenario, both water withdrawals and consumption by the power sector would be less than half of today’s levels by 2030. By 2050, water withdrawals would be 97 percent below today’s levels while water consumption would drop 85 percent – nearly 80 percent below the business-as-usual scenario.
The differences between the two scenarios are also striking in terms of realizing carbon emissions reductions. As the report authors state,
Under our renewables-and-efficiency scenario, the use of more efficient heating, cooling, lighting, and other technologies would more than offset projected growth in electricity demand by 2050, while deeply reducing carbon emissions. Renewable sources such as wind, solar, and geothermal could supply 80 percent of the remaining electricity demand.
Moreover, EW3′s research team found that pursuing the renewables-and-efficiency path “could also provide the lowest cost to consumers, with consumer electricity bills almost one-third lower” than those under the business-as-usual scenario.
Putting the U.S. on a low-carbon, water-smart energy path
Setting U.S. society firmly on a low-carbon, water-smart energy pathway is going to take concerted action by stakeholders across society, EW3 points out.
No single platform exists for sound, long-term decisions at the nexus of electricity and water, but those made in isolation will serve neither sector. Instead actors across sectors and scales need to engage.
For example: plant owners can prioritize low-carbon options that are water-appropriate for the local environment. Legislators can empower energy regulators to take carbon and water into account. Consumer groups can ensure that utilities do not simply pass on to ratepayers the costs of risky, water-intensive plants. Investors in utilities can demand information on water-related risks and seek low-carbon water smart options.
Researchers, meanwhile, can analyze climate and water conditions and extremes in an effort to better inform planners, policy makers and the public. Scientists and engineers, for their parts, will need to continue to focus on advancing renewable energy technologies and realizing energy efficiency gains with a principal aim being to realize reductions in the cost of low-water energy options.
“Understanding and addressing the water impact of our electricity choices is urgent business,” the report authors conclude. “Because most power sector decisions are long-lived, what we do in the near term commits us to risks or resiliencies for decades.”
“We can untangle the production of electricity from the water supply, and we can build an electricity system that produces no carbon emissions. But we cannot wait, nor do either in isolation, without compromising both.”