• Question: how does hydropower work and what does it doto aid the environment?

    Asked by rest485naw on 21 Jun 2023.
    • Photo: John Grasmeder

      John Grasmeder answered on 21 Jun 2023:

      Hydropower usually starts by building a large dam across a river in the hills or mountains to turn that river into a huge lake or reservoir full of water. That of course affects the environment becuase lots of land becomes flooded. The water is then made to flow through pipes down the hill and it spins large turbines which generate electricity. At quiet times when there is low demand for electricity, pumps can be used to pump the water back up the hill into the reservoir so that the process can start again the next day. So the electricity is generated without burning coal, oil or gas, so it is called low-carbon electricity.

    • Photo: Alexander De Bruin

      Alexander De Bruin answered on 21 Jun 2023:

      as John has said, hydropower generates energy my a flow of water past a turbine of some sort. Because there is no burning of anything, there is no carbon emitted, but, as John says, there are some potential ecological downsides if you’re building a dam and flooding an ecosystem. Another option is using tidal flows, but that’s still experimental

    • Photo: Luke Humphrey

      Luke Humphrey answered on 21 Jun 2023:

      John & Alexander have already answered well. I just want to add that when energy is stored as gravitational potential energy (i.e. water stored high up) this is essentially a lossless way to store energy (no energy leaks out over time, as with most chemical or electrical storage methods.

      This is another environmental impact since effective energy storage is crucial to effective renewable energy sources (solar, wind etc.) which rely on the weather to generate electricity. The electric grid must match energy usage and generation **exactly** from moment to moment. If too much electricity is generated it can damage the grid. If too little is generated, it can cause blackouts. Energy storage gives us the “wiggle room” to store excess energy when we generate too much, and draw on that store when we generate too little.

      In short, hydroelectric dams also help wind/solar to be more effective by storing the electricity we generate when it’s windy and sunny to be used any time we need it, regardless of the weather. This reduces our reliance on fossil fuels to generate electricity, which reduces carbon emissions, which reduces the progression of climate change.

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