Are Damless Hydro Power Plants the Future of Electricity?

Interview conducted by Isabelle Robinson, M.Sc.Feb 8 2018

Currently, the world relies on the use of finite energy sources such as coal, gas and oil. These fossil fuels are not only being consumed at an alarming rate, they are also notoriously bad for the environment. An assessment report released by the Intergovernmental Panel on Climate Change (IPCC) in 2007 revealed that the Earth is close to the point that when carbon dioxide rises, released by burning fossil fuels, it will bring irreversible changes to the Earth.

Globally, 64.2% of electricity is generated by fossil fuels, followed by hydroelectric plants which stand at 18.4%¹. However, with crude oil deposits set to be exhausted by 2052 based on current consumption and expected population growth³, the energy industry and global governments are investing in reliable renewable energy sources.

Image credit: InnaVar/shutterstock

Renewable energy resources are mainly natural processes that can be continuously replenished. Examples of this include solar, wind and geothermal energy all of which have their own advantages and disadvantages. As mentioned previously, the most common type of renewable energy used around the globe for electricity generation is hydroelectric power. Simply put, hydroelectric power plants use dams to store river water into a reservoir. Water is released systematically through an opening in the dam. As the water flows through it turns the turbine which, in turn, activates the generator⁴.

Unlike traditional hydropower plants, damless hydropower plants are, like the name suggests, damless. Also known as run-of-the-river plants, they are thought to be ideal for energy generation for settlements near a river or stream. In these cases, the course of the river is not altered due to the fact that a dam is not built. This alleviates the need to flood large areas of land which is the largest disadvantage associated with conventional hydropower plants.

Damless hydropower plants divert a section of the running body of water into a pipe that runs downwards through a turbine. The power plant uses the force of the water flowing downwards via gravity to turn the turbine and generate electricity. The water is then returned to the flowing river without depleting the rivers natural resources.

One company that specializes in damless hydropower plants is the Belgian company Turbulent. Relatively new to the industry, only being founded in 2015, they believe that the future of electricity generation lies in decentralized and connected devices. In other words, micro hydropower plants. Last year (2017) the team created its first 15kW low head hydropower turbine that could be installed into any flowing body of water with a small height difference (i.e. a waterfall or a downhill running river).
Though still in test phase, the whirlpool inspired technology has been positively received by the public. Their test video uploaded to YouTube on October 10th 2017 has received over 1.3 million views⁵ further showing the widespread support of innovative green technology.

The turbine has a full flow of 1.8m3/s with a given height difference of 1.7m. During the test phase, this gave a useful electricity output of 15kW at an efficiency of 50%. This is enough to power up to 60 houses in Chile given an average household power demand of 0.25kW.  

The team boasts being inspired by nature and aims to be able to deliver clean energy to everyone at a low cost without harming the local environment. The energy produced by their technology can be directly connected to appliances or inject the unused power to the national distribution grid, in order to maximize revenue through a net billing connection; an alternate approach to net metering². In addition to this, the new turbine lets fish and debris pass through safely.

As stated earlier, one of the largest benefits of run-of-the-river hydropower plants in comparison to traditional hydropower plants is the elimination of the need for dams and reservoirs. Flooding of land has always been a cause of opposition to hydropower projects due to the destruction of natural habitats the need to relocate those who have homes or land along the river bank. There is also the additional benefit of eradicating the risk of carbon monoxide or methane emissions that occur due to decomposition of organic matter in still bodies of water.

Conversely, micro damless hydropower plants have their own disadvantages. While being able to install these plants with some ease due to the size of the technology, it is vital that the site location has a steep height difference and a relatively straight part of the river. This means that the micro plant may be more suitable to some regions more than others. Currently, the technology has had great success in regions such as Chile, Brazil and Canada.

The largest problem with this type of electricity generation is the lack of capacity to store the energy generated. Unlike other types of energy generation, damless hydropower plants can’t adapt to electricity demand. By using the natural flow of the river to generate power it is obvious that the turbines will generate more power as the river is higher during wet periods. On the other hand, the turbines could produce less energy during hot months when the river is too low or during cold months when the rivers freeze over and now water can flow through the turbine. This unpredictability does not make it a reliable source of energy and therefore should be used in conjunction with other renewable energy sources (Slachmuylder, 2017).

The field of renewable energy research is one that is brimming with innovation. Emerging research into damless hydropower plants is both popular and promising. More communities are investing in this type of renewable energy scheme, especially developing and mountainous regions. Companies like Turbulent Hydro are dedicated to developing new technology can operate in lower water drops.
Tests on the low head turbine will be complete in July 2018.

References

1. Central Intelligence Agency. (2018). The World Factbook. Retrieved from CIA Library: https://www.cia.gov/the-world-factbook/about/
2. Clean Energy Solutions Center. (2015). Net Metering and Net Billing. Retrieved from cleanenergysolutions.org: https://cleanenergysolutions.org/instruments/net-metering-net-billing
3. Ecotricity. (2018). The End of Fossil Fuels. Retrieved from Ecotricity.co.uk: https://www.ecotricity.co.uk/our-green-energy/green-electricity
4. National Renewable Energy Laboratory. (2017). Renewable Electricity Futures Study. Retrieved from NREL.gov: https://www.nrel.gov/analysis/re-futures.html
5. Turbulent Hydro. (2017, October 10). Turbulent Is Ready to Change the World! Retrieved from Youtube.com: https://www.youtube.com/watch?v=XiefORPamLU&feature=youtu.be