This page will serve as an entry point to more PURE documents and information resources.
PURE Co-operative - Documents
What is Renewable Energy?
- Let's compare renewables vs. conventional sources -
Energy comes from many sources. Renewable energy comes from sources which are essentially unlimited (unlike, for example, fossil fuels, of which there is a finite supply). Renewable sources of energy include hydroelectric power (falling and moving water), wood, waste, geothermal, waves and tides, wind, solar photovoltaic, and solar thermal energy. Passive solar orientation and design, energy-saving design, landscaping etc. are also part of the renewable energy equation. Conservation of energy is the key to balancing renewable supplies with demand.
"Alternative Energy" is another term often used for renewables because they are alternatives to conventional sources such as coal, gas and nuclear power. Hydroelectric power is a conventional source with some renewable aspects to it.
|Conventional Energy||Renewable Energy|
|fuel source is limited; extracted from underground resources||fuel source is virtually unlimited or "free"* (wind, sun), or from agricultural sources|
|fuel extraction has a huge environmental footprint (eg. mining, forest and marine habitat destruction)||fuel is free, or fuel extraction (if any) can be done sustainably (eg. wood harvesting)|
|fuel extraction causes many "downstream" effects (eg. oil spills, air pollution, CO2, radioactive waste and leaks)||fuel extraction (if any) does not cause massive downstream side-effects|
|energy and materials are not cycled; fuel makes a one-way trip from source to sink||energy and materials are used in cycles (eg. CO2 -> trees -> energy -> CO2)|
|vast energy is spent to extract the fuel; and fuel must continue to be extracted||fuel costs are minimal or zero (wind, sun); system cost is mostly "up-front", ie. at project installation time|
|vast amounts of waste (CO2, NOx, mercury, highly-radioactive materials, etc.) are created and dumped into air, water and land||little or no waste is created; CO2 (if any) is re-absorbed by next fuel cycle|
|huge government subsidies are needed to prop up uneconomic industries (fossil fuel and nuclear industries receive billions in direct subsidies or tax breaks)||little or no government subsidies are needed or available; systems are typically smaller, more decentralized, and donít require huge infrastructure costs|
|typically delivered by vast, subsidized centralized agencies with little local accountability; links between producers and consumers are vague||projects can be scaled from one household to whole communities; decentralized structures are a key feature; much more direct linkage between producers and consumers; enhanced accountability|
|few choices exist for power production methods (eg. burn coal or gas; nuclear reactor); few options for location and distribution; suitable only for high-demand applications||a vast diversity of options is available to produce power so renewables are suitable for any situation, location, demand, etc.|
|full life-cycle costs are typically ignored (eg. fuel extraction, waste disposal, environmental damage, etc.)||full life-cycle costs are typically well understood and accounted for; environmental impact is minimized|
|seems "cheap" compared to renewables, but only because the prices are heavily subsidized, and full life-cycle costs are typically not accounted for (ie. add ALL costs over a 30-year period for installation, fuel, waste, etc.)||seems relatively expensive compared to conventional, but not so if subsidies and full life-cycle costs are properly accounted for; without a level-playing field - renewables cannot compete against subsidized megaprojects|
|conservation of energy is often minimized or overlooked due to the above distortions||conservation is very important, because initial costs seem high - but are in fact, reflecting true, life-cycle costs|
* Note: "free" is deceptive - there are still large installation costs for both renewables and conventional energy projects, and only so much real estate is available and appropriate for some projects - therefore energy conservation and efficiency is still a high priority for any solution.