Environmental impacts of electricity generation

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(Image: Flickr user ssedov)

Electricity. How do we make it? How does it affect our environment? There are several forms of energy that can be converted to electrical energy. And there are environmental issues related to each of these power sources. Here’s a list of power sources:

  • Nuclear
  • Water (hydroelectric power and tidal power)
  • Geothermal
  • Biomass
  • Solar
  • Wind
  • Fossil fuels

Lightning (scientists have tried harvesting lightning energy) and static electricity (triboelectric effect) are two rather unconventional ways that people have tried to obtain electricity from. Scientists have also tried to obtain energy by splitting water (fuel cells). Each of the above power sources has their environmental limitations/issues. Let’s try to understand these one by one.

Fossil fuels:

Fossil fuels such as coal and natural gas are burnt and there is a release of energy that needs to be stored and transported. In case of coal, the energy obtained from burning it drives a steam turbine generator. While, the energy obtained from burning natural gas drives a combustion turbine. These power stations are called as coal fired power stations and natural gas fired stations respectively.

Each of these stations spews tons and tons of greenhouse gases that lead to proliferation of atmospheric temperature. Just like volcanoes, but at a relatively higher scale. Studies report that projected anthropogenic CO2 emissions amounted for 35 billion metric tons (gigatons) in 2010. This amount of CO2 overshadows the annual CO2 emissions of all the world’s degassing subaerial and submarine volcanoes.

Then there is soot or black carbon. Soot is carbon particles produced from incomplete combustion of hydrocarbons. The black smoke that comes out of a car contains this soot. It causes global warming. Unlike other aerosols/particulate matter, black carbon absorbs sunlight instead of reflecting it back. Hence, the atmospheric temperature increases with increase in black carbon.

But what about natural gas? Isn’t it the cleanest fossil fuel? It is clean when compared to coal. ‘Clean’ or ‘green’ are nothing but relative terms. One technology is ‘better cleaner and greener’ than the other. Let’s not forget that natural gas is mainly methane and methane is a far more potent greenhouse gas than carbon dioxide.

Nuclear power:

Nuclear power is what keeps us on our toes more than any other power source out there. It has the potential to solve all our energy woes and at the same time is also capable of huge destruction. The recent Fukushima Daiichi nuclear disaster means we are yet to perfect this technology.

Water (hydroelectric power and tidal power):

Hydroelectricity can only comes from dams. Dams mean an interruption to the natural flow of water and disturbance to the aquatic system. Dams have also triggered earthquakes. Tidal power on the other hand has the same disturbing effect on the aquatic system.

Geothermal:

While extracting heat from underneath Earth’s surface, we also unleash various greenhouse gases but are relatively far less in quantity than that emitted by fossil fuels. Hydraulic fracturing is used to extract geothermal energy, hence it can trigger earthquakes.

Biomass:

Leftover biomass is a good candidate for power generation. ‘Leftover’ is better than crops that are specifically produced for power generation. Because if they are new crops, we’d be needing pesticides etc. to produce these crops and this would consume energy, land and time.

Solar and wind power:

We can see that not all are perfect energy sources. Now, compare all of them to solar and wind. Problem is with the creation of panels and wind mills. If these production processes become less and less polluting and provide us with good return on investment in terms of energy and materials, we may see solar and wind power eventually become the best of the best.

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