Industry critics of solar and wind power are quick to assert that there will be problems for renewable energy when the sun doesn’t shine and the wind doesn’t blow. But a new Civil Society Institute (CSI) report prepared by Synapse Energy Economics suggests that dirty energy sources – including coal-fired electric power, nuclear power, and natural gas from fracking – face an even bigger challenge: What are you going to do if the water doesn’t flow?
The CSI report notes: “Currently, 97% of the nation’s electricity comes from thermoelectric or hydroelectric generators, which rely on vast quantities of water to produce electricity … Water is increasingly becoming a limiting factor on U.S. energy production and a key obstacle to maintaining both electricity output and public health and safety. The constraints range from insufficient water supplies to meet power plants’ cooling and pollution control needs—a challenge likely to be exacerbated by climate change, population growth, and competition from other sectors—to the high costs of energy-related water contamination and thermal pollution.”
Key report conclusions include the following:
Thermoelectric plants withdraw 41% of the nation’s fresh water—more than any other sector.
- The amount of water available to serve diverse needs is a growing concern across the country, from the arid western states to the seemingly water-rich Southeast. Thermoelectric generation compounds the stress already faced by numerous watersheds and adds additional risk for the future. If current trends continue, water supplies will simply be unable to keep up with our growing demands. Factors that are likely to exacerbate the problem include climate change, water shortages, and carbon capture and sequestration (CCS). For example, CCS is projected to increase water consumption rates for existing coal plants by 83% and natural gas plants by 91%. Failure to address these constraints now is bound to lead to further intersectoral conflicts and forced plant shutdowns that will jeopardize electricity production and constrain economic growth in the future.
- On an average day, water withdrawals across the nation amount to an estimated 85 billion gallons for coal plants, 45 billion gallons for nuclear plants, and 7 billion gallons for natural gas plants. Additional water is required to extract, process, transport, and store fuel, and this water is often degraded in the process.
- Coal mining consumes between 70 million and 260 million gallons of water per day.
- Natural gas fracking requires between two and six million gallons of water per well for injection purposes.
Synapse Associate Melissa Whited said: “Our electric system was built on traditional, water-intensive thermoelectric and hydroelectric generators. The water requirements of this energy system are enormous and leave it vulnerable to droughts and heat waves. Going forward, our water resources will be further squeezed by population growth coupled with the impacts of climate change. The massive water use of coal, nuclear, and natural gas generators will be increasingly challenged, particularly when alternatives that require little water, such as wind and solar, are readily available.”
CSI Senior Energy Analyst Grant Smith said: “Continued reliance on water-intensive electric generation technologies puts consumers and regional economies at risk of interruptions in electricity supply or on the hook for costly infrastructure investments. To ensure a reliable, cost-effective supply of energy, these water-related risks must be fully accounted for in energy planning and regulation. Once the environmental costs of conventional fuels are recognized, it becomes clear that energy efficiency and renewable energy are bargains by comparison. These clean alternatives cause little if any harmful environmental impacts. On a full-cost accounting basis, clean energy would win out as the least-cost solution and solution that harbors the least risk, as our energy system would no longer threaten (or be vulnerable to) the quantity and quality of our water.”
Fuel production and use impacts
According to the report, energy-sector impacts on water quality are significant, and are likely to increase if the United States continues to rely heavily on thermoelectric power plants. The following are just a sample of the impacts associated with fuel production and use:
- Coal mining: Elevated and unsafe levels of arsenic and other heavy metals have repeatedly been found in drinking water in coal mining areas.
- Uranium mining and milling: Runoff from uranium mine tailings is contaminated with uranium and other radioactive materials and with toxic heavy metals.
- Natural gas production: Seepage of fracking fluids into groundwater has contaminated drinking water with toxic chemicals such as benzene.
- Thermal pollution: Once-through cooling systems withdraw water from rivers, lakes, and estuaries, use it for cooling, then discharge it at a much higher temperature. These thermal discharges can harm phytoplankton, accelerate the growth of bacteria, increase algal blooms, and otherwise disrupt fish habitats.
On April 17, 2013, a CSI study conducted by Synapse found that, in an envisioned 2050 scenario with a heavy reliance on renewables, regional electricity generation supply could meet or exceed demand in 99.4% of hours, with load being met without imports from other regions and without turning to reserve storage. In addition, surplus power would be available to export in 8.6% of all hours, providing an ample safety net where needed from one region of the U.S. to the next.
In 2011, Synapse prepared a study for the Civil Society Institute that introduced a “Transition Scenario” in which the United States retires all of its coal plants and a quarter of its nuclear plants by 2050, moving instead toward a power system based on energy efficiency and renewable energy. The Synapse study for CSI showed that this Transition Scenario, in addition to achieving significant reductions in emissions of carbon dioxide (CO2) and other pollutants, ultimately costs society less than a “business as usual” status quo strategy — even without considering the cost of carbon. The 2011 study also projected that, over 40 years, the Transition Scenario would result in savings of $83 billion (present value) compared to the status quo strategy.
To achieve these lower-cost and low-emissions results, the Transition Scenario included large amounts of renewable energy resources with “variable output,” such as wind and solar. While the need for variable-output resources is well defined, questions have been raised about the impact of large-scale wind and solar integration on electric system reliability. To address this, Synapse paid careful attention to the amount of wind and solar in each region when designing the Transition Scenario for the 2011 report, taking steps to ensure that the projected regional resource mixes could respond to all load conditions.
The April 2013 study took the 2011 analysis one big step farther, in order to explore the extent to which the Transition Scenario’s resource mixes for 2030 and 2050 are capable of meeting projected load for each of the 10 studied regions — not just during peak demand conditions, but in every hour of every season of the year as consumers require.
Civil Society Institute
American Clean Energy Agenda
Synapse Energy Economics, Inc.
Filed Under: News, Policy