Hydro: why its important
To understand why hydropower is important, first, think scale. The five largest power stations in the world are hydro and the top fifteen largest are either hydro or nuclear. The largest hydropower project in the world in about 30 times the size of a typical coal-fired power station. In total, 16% of worldwide electricity generation comes from hydro power. Then, think about the impact in terms of decarbonization. Today if a country has very low emissions per capita but still has reliable energy it almost always means it gets the majority of its power from hydro. As shown in this report from IRENA, Norway's generation system is almost 100% hydro. In 2010, hydro accounted for 84% of total generation in Brazil and 74% in Venezuela. Central and South America generate nearly 64% of all their electricity from hydropower and there are a number of countries in Africa that produce close to 100% of their grid-based electricity from hydro. Combine this current scale and impact on emissions with potential growth in the future. While hydro is the most mature of our energy technologies and it won’t grow much in “mature markets” like the US and Canada, emerging economies are significantly increasing their share of hydro and this will only continue to grow. Currently 32% of Africa’s electricity comes from hydro but the continent is only using 3% to 7% of its potential.
Hydropower can provide very low-emission, reliable energy. But as I’ve written about before on China and Ethiopia, hydropower has its issues. A poorly implemented project can be disastrous for the local environment and can even lead to war. The world’s largest project - the Three Gorges Dam in China - has had a number of issues raised about it - from people being displaced to being blamed for major earthquakes. Local environmental damage is a common problem for hydropower projects. Finally, although a number of hydro projects are pretty much emission-free, emissions from hydroelectric plants built in tropical areas or temperate peatlands can be quite high due to the vegetation and soil in these areas decomposing and releasing both carbon dioxide and methane. More research needs to be done around the release of methane from reservoirs which could have a significant impact on how “clean” hydro really - especially as high methane release in tropical areas could apply in particular to a number of our Cleanleap countries in Asia and Africa.
Currently 32% of Africa’s electricity comes from hydro but the continent is only using 3% to 7% of its potential.
For all these reasons we think its important to focus on hydro and if we’re going to do that then it's really about what China is doing in this space.