Hydropower reservoirs are actually planetary killers. Don’t believe that? Any lake with water supply collects a lot of biodegradable material. Plants, trees, dead animals floating in it. The reservoirs catch them and this sinks to the ground mixing with silt. It’s a giant fermenter. In a normal lake, much of the methane and the CO2 produced would remain in the floor of the lake. But always changing water levels in power plant reservoirs change pressure levels constantly making sure that the gases in the ground can evacuate to the atmosphere. And you thought your car’s exhaust is the big baddie when it comes to planetary warming.
The number of hydropower projects has risen substantially in the last few years, though critics warn it can prove a dangerous energy source. Just what are the benefits of hydropower, and should we use it?