Current research suggests that hydropower plants emit tons of methane into our atmosphere every year. However, some start-ups have a solution to the problem.
As part of the energy transition, the use of hydroelectric power plants has become established alongside solar and wind power. However, hydroelectric dams, which we need for hydropower generation, have also proven to be a source of methane emissions.
Methane is a greenhouse gas that is more than 80 times more potent than carbon dioxide over a 20-year period. Dams release the gas when water flows through the turbines. The methane escapes from dissolved organic material that decomposes at the bottom of reservoirs.
Some start-ups such as Bluemethane are currently developing technologies to capture this methane and use it as an energy source. This could reduce methane emissions and at the same time provide a new source of energy. This is because methane from water reservoirs can be used as biogas to generate electricity or converted into “green” natural gas.
Hydropower plants release methane
The process of methane release begins as soon as microbes decompose the organic material on the ground in the absence of oxygen. This produces methane, which dissolves in the water. When the water flows through the turbines of the dams, it is heavily mixed.
The gas then escapes into the atmosphere due to the forces at work. These methane emissions contribute to climate change, as methane is responsible for around 30 percent of global warming since the industrial revolution.
Bluemethane is therefore currently working on a technology that captures methane bubbles before they reach the surface of the water. According to the company, the system can be integrated into existing infrastructures such as sewage treatment plants and dams.
The technology uses gravity to keep energy consumption to a minimum. One example is the KivuWatt project on Lake Kivu. This is a deep lake on the border between Rwanda and the Democratic Republic of Congo.
Methane from reservoirs could become a valuable source of energy
The lake contains large quantities of methane, which is released by geological activity below the surface. The region is now using this methane to generate energy and, consequently, electricity. The commercialization of the technologies could be particularly beneficial in countries with high hydropower use.
At the same time, Bluemethane is working on measuring methane in 20 hydropower reservoirs worldwide to identify the best locations for using the system.
The capture and use of methane from hydropower plants thus offers a double opportunity. On the one hand, the reduction of greenhouse gas emissions and the creation of a new, renewable energy source. The technologies could thus make an important contribution to combating climate change and at the same time bring economic benefits.
