ENCYCLOPEDIA OF ALTERNATIVE ENERGY AND SUSTAINABLE LIVING. Renewable energy. Renewable energy is generally defined as energy that comes from resources which are naturally replenished on a human timescale such as sunlight, wind, rain, tides, waves and geothermal heat. Renewable energy replaces conventional fuels in four distinct areas: electricity generation, hot water/space heating, motor fuels, and rural (off-grid) energy services. About 16% of global final energy consumption presently comes from renewable resources, with 10%  of all energy from traditional biomass, mainly used for heating, and 3.4% from hydroelectricity.
New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) account for another 3% and are growing rapidly. At the national level, at least 30 nations around the world already have renewable energy contributing more than 20% of energy supply. Renewable energy resources exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries. Overview. Intermittent energy source. An intermittent energy source is any source of energy that is not continuously available due to some factor outside direct control.
The intermittent source may be quite predictable, for example, tidal power, but cannot be dispatched to meet the demand of a power system. Effective use of intermittent sources in an electric power grid usually relies on using the intermittent sources to displace fuel that would otherwise be consumed by non-renewable power stations, or by storing energy in the form of renewable pumped storage, compressed air or ice, for use when needed, or as electrode heating for district heating schemes. The use of small amounts of intermittent power has little effect on grid operations. Using larger amounts of intermittent power may require upgrades or even a redesign of the grid infrastructure. Terminology Several key terms are useful for understanding the issue of intermittent power sources.
Intermittency of various power sources Solar energy Main Page - PESWiki. Wind & Solar.
The environmental impact of electricity generation is significant because modern society uses large amounts of electrical power.
This power is normally generated at power plants that convert some other kind of energy into electrical power. Each system has advantages and disadvantages, but many of them pose environmental concerns. Water usage The amount of water usage is often of great concern for electricity generating systems as populations increase and droughts become a concern. Still, according to the U.S. Steam-cycle plants (nuclear, coal, NG, solar thermal) require a great deal of water for cooling, to remove the heat at the steam condensors.
Thermal cycle plants near the ocean have the option of using seawater. Hydroelectricity's main cause of water usage is both evaporation and seepage into the water table. Reference: Nuclear Energy Institute factsheet using EPRI data and other sources.hOE Source(s): Adapted from US Department Of Energy, Energy Demand on Water Resources. Cost of electricity by source. Cost factors While calculating costs, several internal cost factors have to be considered. (Note the use of "costs," which is not the actual selling price, since this can be affected by a variety of factors such as subsidies and taxes): Capital costs (including waste disposal and decommissioning costs for nuclear energy) - tend to be low for fossil fuel power stations; high for wind turbines, solar PV; very high for waste to energy, wave and tidal, solar thermal, and nuclear.Fuel costs - high for fossil fuel and biomass sources, low for nuclear, and zero for many renewables.Factors such as the costs of waste (and associated issues) and different insurance costs are not included in the following: Works power, own use or parasitic load - that is, the portion of generated power actually used to run the stations pumps and fans has to be allowed for.
Calculations It can be defined in a single formula as: where System boundaries Discount rate . Avoided cost Blog » Clarity on the true cost of electricity. The question of electricity cost is tricky. Most of us know oil prices go up and down – and are currently at record highs – which in turn affects the power price. And we know that not only to the costs of importing such fuels change constantly, they also – unlike renewables – produce carbon, which has to be paid for. But while more and more people are saying onshore wind energy is at “competitive” price levels, others still insist that renewables are expensive and impractical.
In order to clear up the issue , EWEA has developed an online tool that instantly calculates electricity costs, including any fuel and carbon risks, for five different technologies – gas, coal, nuclear, onshore and offshore wind. The users are free to type in their own assumptions on, for example, coal and gas prices, future carbon costs, capital cost and availability.
Try the tool for yourself: Carbon cycle. This diagram of the fast carbon cycle shows the movement of carbon between land, atmosphere, and oceans in billions of tons of carbon per year.
Yellow numbers are natural fluxes, red are human contributions in billions of tons of carbon per year. White numbers indicate stored carbon. The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Along with the nitrogen cycle and the water cycle, the carbon cycle comprises a sequence of events that are key to making the Earth capable of sustaining life; it describes the movement of carbon as it is recycled and reused throughout the biosphere. The global carbon budget is the balance of the exchanges (incomes and losses) of carbon between the carbon reservoirs or between one specific loop (e.g., atmosphere ↔ biosphere) of the carbon cycle.
Relevance for the global climate Main components Atmosphere Terrestrial biosphere 5 Myths About Renewable Energy" Solar electricity isn't the only renewable energy whipping boy out there.
Wind power has also taken more than its share of lumps, frequently saddled with a reputation for excessive noise and energy inefficiency. Plus, if some of the rumors are true, wind harvesters of the world have steadily been turning the planet's bird population into an airborne puree of blood and feathers. To be fair, wind turbines do kill birds -- but so do vehicles, skyscrapers, pollution and the introduction of invasive species into their habitats. Humans have had bird blood on their hands for ages, and as daunting as a field of wind turbines may look, they're responsible for statistically few bird deaths -- less than 1 in every 30,000 [source: U.S. Department of Energy]. But even without the death cries of a thousand birds, aren't wind turbines a noise nuisance?
Finally, there's the issue of cost. A winning solution for renewable energy and CO2 reduction? Two scientists are proposing the use of high-pressure carbon dioxide, instead of water, for extracting geothermal heat from the Earth Image Gallery (2 images) A promising new innovation in geothermal technology, that offers a novel solution to climate change, has been created by two researchers from the University of Minnesota's Department of Earth Sciences.
The technology focuses on tapping heat from beneath the Earth's surface. By using high-pressure carbon dioxide (CO2) instead of water to extract the heat, the system has the potential to produce significantly more efficient renewable energy. At the same time, by sequestering CO2 deep underground, it actively reduces atmospheric CO2. The approach, coined the CO2-plume geothermal system (or CPG) was discovered by Earth sciences faculty member Martin Saar and graduate student Jimmy Randolph, in the University of Minnesota's College of Science and Engineering. Saar and Randolph are now planning to move the CPG into the pilot phase. “Green Nukes” An Important Climate Change Mitigation Tool.
Adam Curry interviewed Curt Stager, the author of Deep Future: The Next 100 Years of Life on Earth for his Big Book Show.
During the interview, Curry and Stager spent several minutes discussing the potential for “green nukes” to be an important climate change mitigation tool. Aside: Adam Curry interviewed me four years ago about Adams Engines; he has been interested in new nuclear power plants for a long time. End Aside. There are many terrific reasons to favor the rapid development of nuclear fission technology. For some odd reason, possibly having to do with certain brands of political ideology, many nuclear professionals are reluctant to emphasize that last feature.
There are also many people employed in nuclear-related activities who are energy agnostics. I have a different point of view. As Curt Stager and other researchers like him have determined, the material will be suspended in our atmosphere and affecting our climate for at least 100,000 years. My plan is to visit Dr. Connect: Renewable Energy Used to Make Drinking Water From Air Humidity – Blue Living Ideas. Availability Published on June 18th, 2009 | by Jennifer Lance Scientists have discovered a way to make drinking water from the air’s humidity, even in arid regions.Â The system completely uses renewable energy and could provide water for many applications.
Models have been built and tested in laboratories at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB in Stuttgart. Image by hamed saber Scientists can make drinking water from desert air. Even in areas where there is no surface water or plant life, there is still moisture in the air. The process uses thermal solar collectors and photovoltaic cells, so it can function where thereâ€™s no electricity, such as in deserts. Removing the humidity from the air to make drinking water is a unique solution, but I wonder what the meteorological consequences would be to the environment.Â Would it affect precipitation in non-arid regions?
About the Author.
Blue Energy. Smart grid. Vehicle. Energy Trees & Teams. How Information Can Save Energy. In 2007, an astounding 2.2 million residents of Sydney, Australia turned off their lights in the first ever Earth Hour organized by the World Wildlife Fund (WWF).
Over time, more cities and homes have come to participate in this annual event, conceived by the WWF to increase awareness about climate change and encourage energy efficiency. The Earth Hour is a laudable event to educate ordinary people on energy use. There is still, however, a need to increase information dissemination efforts from merely annual events to a regular part of daily life. In fact, experts say that making energy information as available and accessible as possible will help consumers make informed decisions and thus minimize the risk of irresponsible energy use. This was evidenced by an experimental study on residential electricity consumers conducted by the US National Bureau of Economic Research.
Humphrey Kariuki Ndegwa is a recognized leader in the energy and oil sector. Tagged as: Energy, Green Environment.