The environmental impacts of renewable energy

Zero–impact does not exist

Every type of energy utilisation for electricity generation has environmental consequences. The main consequences of burning fossil fuels and of nuclear power are well-known. Renewable energy sources (wind, solar, biomass, hydroelectric, geothermal, etc.) are generally thought of as harmless, but this doesn’t mean they have no environmental consequences at all. Most of them have a significant aesthetic impact and require large areas of land. Some also have a significant impact on the eco-system (birds, fishes, etc.).

No decision tool available

Not all of the environmental impact is included in the price of electricity. Part of it, the so-called externalities, is paid indirectly by society. Moreover, some environmental impacts are local, others regional, and others even global. That makes it very complex to compare the environmental impact of various energy sources and to take a well-founded decision on which energy source to use.

In their paper Environmental Effects of Electricity Generation, The Institution of Engineering and Technology (IET) published a table that compares the environmental impact of all major renewable energy sources for generating electricity (see paper page 53 table 13). It is an interesting overview, but should be used only for illustrative purposes. For decision-makers having to determine the future energy supply, a generally accepted quantification technique of the environmental impact is still lacking.

Avoiding greenhouse gases

The CO₂ emissions of fossil fuels are currently the most worrying energy-related environmental problem. Up to now, nuclear power is still the only solution applicable everywhere on a large scale that has no CO₂ emissions. How to process nuclear waste however is still a problem that largely remains to be solved. And despite maximum efforts, safety will always remain an issue for nuclear power due to its potential for large scale contamination.

Renewable energy is still used on too small of a scale to replace all fossil fuels. If one day current renewable energy systems are applied to replace present fossil fuel output, the resulting aesthetic impact and land use will be large.

Since every type of energy utilization has some degree of environmental impact, energy conservation should get top priority in every instance, no matter which mix of primary energy sources is used.