Is Hydropower Really Clean Energy?
Hydropower has been around for a very long time and is recognized as the most reliable renewable energy source. However, in recent years, many are beginning to question if it is really a clean or emission-free source.
The actual process of generating electricity does not produce any emissions. The water at a higher elevation passes through turbines to a lower elevation, which spins a turbine. This generates electricity.
However, the water within the reservoir is producing emissions. At least, sometimes it is.
How Do Reservoirs Produce Emissions?
So the big question is how does a body of freshwater actually produce emissions?
This is actually not a problem just reservoirs face. By design, a reservoir is actually an artificial lake that is placed on top of the land. And lakes actually produce 10% of the natural methane emissions each year.
Thus, a reservoir is just adding to this. but how does it work?
Well, the vegetation that is located at the bottom of the reservoir does not survive the process. This results in all of the plants decomposing and releasing their carbon back into the atmosphere. But this is only an initial burst of emissions.
Over time, the real issue is methane. This comes when lakes experience hot weather conditions and underwater oxygen levels decrease. As a result, bacteria that do not require oxygen often grow during this time.
These bacteria actually produce methane discharges, which means that lakes and reservoirs both continuously produce emissions.
How Much Of An Impact Does This Have?
First, it’s important to note that not all reservoirs are equal.
There has been a lot of research into this specific area, but all of the information is on a site-by-site basis. Some of these artificial lakes may actually do the opposite and become carbon sinks.
For one kilowatt-hour, on average, hydropower facilities generate 18.5 gCO²-eq/kWh (grams of carbon dioxide per kilowatt-hour). To put this into perspective, coal generates 820 gCO²-eq/kWh.
As you can see while there are some emissions, it’s nothing compared to fossil fuels. Even coal’s replacement, natural gas, emits 490 gCO²-eq/kWh. Fossil fuels simply produce more emissions many times over.
And another fun fact, nuclear generates 12 gCO²-eq/kWh, which is less than hydropower.
Should We Still Expand Hydroelectric Facilities?
As the most reliable form of renewable energy, there is no denying the usefulness of hydropower. And I strongly believe it is still worth pursuing and growing.
On top of generating electricity, these structures also help in water management, irrigation, flood protection, and many other benefits. The very small amount of carbon and methane they may produce is something worth accepting.
After all, it can easily be offset by planting trees nearby.
In the future, it may also be possible for these structures to use carbon capture technology. This technology will be an essential part of becoming a net-zero world and is still in the development phase. However, there’s no denying the potential is there.
Regardless, it’s clear that hydropower is cleaner than any fossil fuel by a mile and offers numerous advantages.
Robert has been following and writing about environmental stories for years at GreenGeeks. He believes that highlighting environmentally friendly practices can help promote change in every household.
