Renewable energy is likely the most intuitive response to the climate challenge due to the technologies’ zero-emission qualities. It is a very diverse group of technologies including biomass, solar energy, wind, hydro, geothermal and tidal energy.
Biomass is a hugely diverse group of projects. It encompasses biofuels, energy production from biomass waste, gasification and utilisation of liquid wastes such as manure. It accounts for approximately 15% of global primary energy use and 38% of the primary energy use in developing countries.
Harnessing the sun’s energy is less diverse and succeeds in two distinct ways. Solar thermal energy exploits solar energy for heat production, either at low temperatures commonly used in households, or high temperatures for steam and power production. Photovoltaic (PVs) is generating electric power by using solar cells to directly convert energy from the sun into electricity.
The installation of wind turbines continues to accelerate, while turbines are growing in size and increasingly moving to sea in off-shore installations. Currently, 80 countries use wind for power production reaching close to 2% of the world’s electricity.
Geothermal energy is increasing rapidly, though still at a significantly lower level than wind energy, while hydro projects – beyond doubt the oldest form of renewable energy – supply 20% of world electricity through dams or run-of-the-river projects.
Lastly, and much less mature, is the technology for utilisation of tidal forces. In places with shallow waters, narrow fiords or inlets, the difference between high and low tide can be as much as 20 metres. Such places have tremendous forces that can be exploited for energy production.
CDM projects are found in all of the following categories: