There has been growing interest in expanding hydroelectric power generation. An article written earlier this month by Linda Church Ciocci, the executive director of the National Hydropower Association, spells out the case for the increased use of hydroelectric generation. The article notes support for this position from the Union of Concerned Scientists and the Nature Conservancy. In April, the Oak Ridge National Laboratories and the Department of Energy released a report indicating roughly 65 GW of untapped hydroelectric power capacity in American rivers and streams. But while these articles outline the potential and reasons to consider expanded hydropower production, three key issues need to be addressed.
First, Section 316 (b) of the EPA’s Clean Water Act. This rule specifically targets cooling water intakes for power plants and factories, but it’s not a stretch to imagine its implications for hydroelectric plants, since the end goal is protection of aquatic life forms. Even the Union of Concerned Scientists recognizes both large hydroelectric dams and smaller run-of-the-river plants have at least some general environmental impact as well as a specific impact on aquatic life.
Second, and of more immediate concern, are drought conditions. This year’s drought in California created concerns about electricity production, since hydroelectric power is a major generation source in the state. With over 400 hydroelectric plants capable of 14,000 MW of generation capacity, hydro usually supplies about 14% of California’s electricity needs. But in 2013, because of the drought, it only accounted for 9%. Some of the lost capacity was filled by newer forms of renewable generation, such as wind and solar. But more of the gap was filled with natural gas generation, which now accounts for nearly half of the electricity generated in the Golden State. The drought’s impact on utilities caused Fitch, a global investment rating agency, to consider downgrading the operational and financial performance of utilities in the state. In essence, hydro is less reliable in areas routinely hit by drought.
The third (and biggest) issue is the growing demand for water. According to the U.S. Geological Service (USGS), irrigation is accountable for nearly 60% of the world’s fresh water withdrawals – and growing populations mean even more crops. Manufacturing’s demand for water can also be huge – for example, it takes over 700 gallons of water to make a single cotton t-shirt. Finally, the USGS estimates each person in the U.S. uses somewhere between 80 and 100 gallons of water daily.
In the western U.S., there are few fresh water sources, with the primary one being the Colorado River. As more and more communities spring up in western states, limited water resources are becoming even more strained. While (theoretically) hydroelectric generation simply maximizes/utilizes the flow of water, the Save the Colorado group lists dams and diversions among the more serious threats to the river, claiming that over 10% of the river’s water evaporates every year in hydroelectric dam reservoirs along its path.
In the South, increasing demand for water in the growing Atlanta metropolitan area has sparked a fight over Tennessee River water rights between Georgia and Tennessee. A 200-year-old surveying mistake has led to a heated battle between state legislatures which could potentially end up in the Supreme Court.
While expanding hydroelectric generation should certainly be considered, public perception should be a part of the analysis. Americans are starting to recognize that water is in very limited supply (many are realizing this through direct and recurring experiences with outside watering bans). Utilities should be very careful about messaging around expanding hydro, since the image of a dam could be just as easily associated with blocking access to (or wasting) a precious limited resource as it could be with clean, low-cost energy generation.