Renewable energy sources are less harmful to the environment than conventional sources considering the emissions of:
- greenhouse gases
- particulate matter
- heavy metals
- gases causing acid rain
- gases causing ground-level ozone.
Electricity production from a renewable energy source saves fuel which would otherwise be used by a conventional power plant for the production of the same amount of electricity.
For example, a few MW of electricity produced by a wind power plant saves a few tons of coal that a coal-fired power plant would use to produce the same amount of MW.
In addition, renewable energy sources cannot be used up. For example, wind can be used as long as it blows. The lifetime of a wind power plant is limited only by the lifetime of the structure of the wind turbine and its equipment.
CO2 emission over the lifetime of the power plant
(SOURCE: Dones, R. et al.: Greenhouse gas emissions from energy systems – comparison and overview, PSI Annual Report 2003 Annex IV, Paul Schere Institut, Viiligen, Switzerland)