Clean, efficient energy sources are critical to a sustainable future. Renewable energy is heat and electricity generated by fuel sources that renovate themselves over a short period of time and do not decrease.
Although some renewable energy systems have an impact on the environment, renewables are considered environmentally preferable to conventional sources, since they have significant potential to reduce greenhouse gas emissions. However, not only does renewable energy have little or no greenhouse gas emissions, but also other air multipollutant emissions which cause smog, acid rain or air toxics pollution are zero for most forms of renewable energies.
When low emitting technologies of renewable energy are used to replace fossil fuel-based energy systems, reductions in air emissions occur and better air quality is the result. Nevertheless, those renewable energy technologies based on biomass combustion, such as residential wood combustion, do cause some toxic multi-pollutant air pollution that contributes strongly to mortality and morbidity due to fine particulate matter and polycyclic aromatic hydrocarbons, and do affect climate change due to the black carbon deposition over glaciers. On the other hand, geothermal energy from geological sources can release sulfur dioxide which will contribute to acid rain and air pollution.
For the transportation sector, the bioethanol combinations have ranked lowest overall and with respect to climate, air pollution, land use, wildlife damage, and chemical waste. Cellulosic ethanol has ranked lower than corn ethanol overall, primarily due to its potentially larger land footprint based on new data and its higher upstream air multi-pollutant emissions than corn ethanol. However, more studies have to be done to analyze the real health impact of producing cellulosic ethanol, as well as, of using more biodiesel fuel on urban transportation and its increased NOx releases. Finally, and as for fossil fuels, pollution control technologies can be used to reduce these multi-pollutant emissions.
Several studies suggest that some renewable energy technologies may be responsible for increased health effects due to air pollution, mainly for fine particulate matter, volatile organic compounds, nitrogen oxides, sulfur dioxide, and air toxics. This has an important implication in relation with the size and chemical composition of the particles and hazardous air pollutants, but also for monitoring and control strategies of those air multi-pollutants. Policy- makers should take into account these aspects along with economic considerations if protection of the public health is one of their major concerns for using renewable energies.
