Renewable energy sources

Renewable technologies - The natural alternatives

Renewable energy is energy derived from sources that are being replaced by nature, such as water, wind, solar, biomass or geothermal. Renewable sources will always be available (within the limits set by nature’s capacity to replenish them) and are essentially non-polluting if applied correctly.

Key renewable energy sources

• Hydro Power ranges from hydro-electric power stations, to tidal power and wave power.
  
  
• Wind power is becoming increasingly popular and production costs are dropping rapidly, making it increasingly competitive to fossil power production.
  
  
• Solar power is now 90% cheaper than it was in the 1970s. Houses with solar roofs can generate more electricity than is needed at certain times in the day, and sell this back to local electricity companies.
  
  
• Biomass energy is the term used to describe the generation of energy from organic sources. The energy stored in plants can be captured for energy generation by several different methods such as decomposition, combustion or gasification.
  
  
• Geothermal energy involves using the earth's heat to supply power. Geothermal heat pumps can be used nearly anywhere.
  

WWF does not include nuclear power on its list of viable energy alternatives. Although it is sometimes promoted as a way to fight global warming WWF is strongly convinced that nuclear power is not a sustainable source of energy.

Global energy consumption

Global energy consumption in 2000 amounted to approximately 410,000 PJ (1 petajoule = 278 million kWh). Among the renewable energies, currently hydro power and biomass make a significant contribution to meeting global energy demand (biomass 10%, hydro 6%) and global electricity demand (19%). Roughly 80% of global energy demand is met through the use of fossil fuels (oil: 35%, coal: 23%, gas: 21% - IEA 2004).

The potential of renewable energy

The technical potential of renewable energy sources (i.e. the amount of energy that can be derived from the natural supply of renewables using current technologies) is far higher than global energy consumption.



Solar radiation on Earth is roughly 7,000 times greater than current global energy consumption. Theoretically, current global energy consumption could be met through the installation of photovoltaic cells across an area of 700 km by 700 km. However, technical potential does not correlate to the real available potential once economic (let's talk about money) and environmental factors are taken into account. It also takes time to develop the infrastructure and know-how.

Rising energy demand?

A lot of energy (and climate change) projections are based on a continuing rise in energy demand. It is important to bear in mind that not all our focus should be directed on improving the energy supply by moving to renewable energies. WWF is also a major advocate of creating savings on the demand side. Energy demand doesn't necessarily have to continue to rise. There is huge scope to achieve major efficiency improvements.

Easing tensions

While most developing countries currently depend on imported fossil fuels (think about the impact of rising oil prices, especially in developing countries); renewable energies open up the opportunity for a more decentralised energy supply.

Such decentralised production of renewable energies produces locally added value, creates more employment, and is far less prone to corruption, catastrophes and crises than the fossil energy system. Renewable energies not only offer prospects for the environmentally compatible restructuring of our energy supply., they also help to ease tensions in the world energy market, thus contributing to political and economical security.

Nature conservation

The pro-active expansion of renewables will make a substantial contribution to reducing the environmental burdens associated with conventional energy supply. In particular, it will conserve fossil fuels and reduce greenhouse gas emissions.

Climate change poses a major threat to the natural environment. Besides leading to rising sea levels, greater extremes of temperature, droughts, and stronger and more frequent storms, it could also result in up to one million terrestrial species committed to extinction by 2050. Climate change is therefore likely to be the single most significant cause of biodiversity loss.