#16 Hydropower
The most used source of renewable energy
Read time: 4 minutes
In this week’s issue you will learn about using the flow of rivers to produce electricity reliably: Hydropower
“Hydro remains the largest renewable source of electricity, generating more than all other renewable technologies combined“ - International Energy Agency
Top Hydropower News 🗞️
Decrease in hydropower production: Droughts in several parts of the world led to a 0.4% decrease in 2021 despite the increase in capacity.
World’s 2nd largest hydropower plant: It just opened in China, where the largest is also located.
Let’s dive in 🧠
Hydropower is our main source of renewable energy, both in terms of installed capacity and electricity production.
It’s about using flowing water. We started with mills used to grind cereals. Today we use turbines and generators to turn that flow into electricity.
We have been building hydropower plants for over 140 years so there must be some reasons why we love this renewable energy source so much.
Why is it so nice?
Reliability: Compared to other renewables like wind and solar, hydropower is quite reliable as long as there is enough water in the rivers used.
Price: Despite the high initial building costs, it provides one of the cheapest forms of renewable energy.
Source: International Renewable Energy Agency Compatibility: Works well with other renewables since it can be used as base-load power, which means it provides the minimum amount of power needed and other renewables help to meet the spikes in demand.
They way it works is quite simple, you get the flow of the river to move a turbine and with that you produce electricity.
There are 2 main types of hydropower:
Run of the river: Just a portion of the river is diverted so the flow of water can go through a turbine. It is more intermittent than dam hydro since it relies on natural water variability but it’s also better for the ecosystem since it barely affects the river and its wildlife.
Source: Student Energy Dam: A lot of water is stored in a reservoir so when it goes through the dam it can move the turbines really fast.
In some cases there is also a reservoir in the lower part, after the dam. Here, the water is stored to be pumped back up into the higher reservoir when it’s cheaper to do so. This is called pumped storage hydro.
Source: Student Energy
Most hydropower today comes from massive dam projects. These are great for regions with big rivers with enough gradient since they help produce a lot of energy but in many parts of the world that’s not the case.
In such places micro-hydropower run of the river projects are the best since they require lower investment, they are better for the environment and they work on way smaller rivers.
Cons
Price: Building these projects is extremely expensive and many are on hold as costs of construction have gone up and it can take up to 10 years to build them!
Environment: Changing wildlife habitats, blocking fish passage, forcing people in nearby communities to move somewhere else. Dam failures can be catastrophic claiming the lives of those living downstream.
Water amounts: If there are severe droughts, there might not be enough water in the river to produce electricity. Also, those downstream from the dam can suffer from extreme water scarcity, since the little water available would be stored in the reservoir. It can also cause upstream flooding.
All of these issues barely apply in the case of micro-hydropower run of the river projects.
Top Hydropower Companies 💰
The massive projects are developed by huge electric companies together with governments.
But here are two startups building much cheaper and smaller solutions for regions with not so ideal hydropower conditions.
Turbulent: They make “vortex turbines” that work on very small rivers and do not disturb fish life. Great for small communities in remote areas.
BladeRunner Energy: Their micro-hydro solution consists of a rotor attached to a platform. Both are placed on almost any type of river and produce electricity without damaging the ecosystem.
❗Extreme knowledge area❗
Three Gorges Dam: This dam located in China is the biggest power plant in the world. Check out this video about its controversy and outsized proportions.
World’s smallest hydropower plant: A cool portable solution for isolated populations.
Pumped hydropower: A great video explanation of how the most popular form of hydropower works.
That’s it for today, 1 climate tech topic in under 5 minutes.
Next week… Sustainable Aviation Fuel! 🤯
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