Non-fossil Renewable Energy (Overview)

Water-Based Renewable Energy

Climate change is upon us, and is causing devastating effects already, with more to come.  One area it is affecting is our water resources (see  But water can be enlisted as an ally in the fight against global warming.  Several different forms of renewable energy are water-based.


The most widely used form of water-based renewable energy is hydropower.  Turbines are placed in streams, rivers, and other small bodies of water with a current.  The current of water turns the turbine, and this motion is converted to usable electricity.  Hydropower currently supplies about 2% of the electricity used in the United States and 20% worldwide.

Pros: Hydroelectric power is relatively cheap and produces low carbon emissions.

Cons: In many cases dams are used to facilitate the current; these dams can have a negative ecological impact on the surrounding area.  Suitable locations for hydropower turbines are nearly exhausted in the United States, though there is more potential in other countries. 


Geothermal energy is another promising renewable energy.  Naturally occurring hot springs provide an influx of hot water or steam, which can be converted to electricity.  Geothermal currently supplies 0.3% of the electricity used in the United States.

Pros: Geothermal energy comes from a constant source and produces low carbon emissions.

Cons: There are limited extractable sources and high capital costs associated with geothermal energy.


Tidal power harnesses the motion from tidal flows in coastal areas using turbines or dams.  Tidal power technology is in its infancy, and as such its current deployment is very limited.

Pros: Tidal power is a predictable and consistent source, and produces low carbon emissions.

Cons: Tidal power relies on primitive technology and limited locations, can result in negative ecological consequences if dams are used, and is not yet economically competitive.


Wave power captures the power inherent in ocean waves.  Like tidal power, wave power technology is largely undeveloped.

Pros: Wave power has massive potential for electricity generation, and produces low carbon emissions.

Cons: Wave power technology is primitive, can potentially result in negative ecological consequences, and is not yet economically competitive.

Though all of these forms of renewable energy come with a cost, all are superior to dirty fossil fuels and all have a place in the future of meeting the world’s electricity needs.

Stay tuned for a discussion of the other sources of renewable energy we have at our disposal.





Dash, R. (2011). Water-Based Renewable Energy. Retrieved from


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