Group items matching

in title, tags, annotations or url

Geothermal power plants, which use heat from deep inside the Earth to generate steam to make electricity. Geothermal heat pumps, which tap into heat close to the Earth's surface to heat water or provide heat for buildings.

At a geothermal power plant, wells are drilled 1 or 2 miles deep into the Earth to pump steam or hot water to the surface.

hot springs, geysers, or volcanic activity, because these are places where the Earth is particularly hot just below the surface.

The growth of the waves depends on the strength of the wind, its duration, and the open ocean distance (fetch) over which it blows

Ocean waves are created by surface winds.

Europe has a long history of employing tidal forces to generate power, and tide mills dating back to the Middle Ages can be found across the continent. A dam with a sluice was constructed spanning a tidal inlet, or a section of a tidal estuary was turned into a reservoir.

Light striking a silicon semiconductor causes electrons to flow, creating electricity. Solar power generating systems take advantage of this property to convert sunlight directly into electrical energy.

If hydrogen extraction is performed using electricity from a coal-driven power plant, it doesn't matter that the fuel cell doesn't pollute because the pollution occurred when the hydrogen was extracted. If hydrogen is to be a true nonpolluting power source, the electricity used to extract the hydrogen will need to be produced by a nonpolluting method such as solar power.

There’s a much cheaper way to produce hydrogen: spray steam on white-hot coals and out comes mostly hydrogen gas (40 percent) and carbon monoxide (50 percent), a mixture known appropriately as “water gas.” It’s the least expensive way to make hydrogen. Unfortunately, the carbon monoxide produced along with it is highly poisonous. To extract the last bit of energy, the carbon monoxide can be burned, and that turns it into the greenhouse gas carbon dioxide.

Electric cars powered by hydrogen fuel cells don’t produce greenhouse-enhancing carbon dioxide. But producing hydrogen does-and if we want to reduce our petroleum dependence, we’re going to have to reconcile ourselves to that fact.

Although solar panels provide clean energy while in use, a variety of factors during the manufacturing and disposal of these panels have the potential to greatly damage the environment.

The most commonly used solar panels are silicon-based panels that share many of the same materials and manufacturing processes as semiconductors. Solar panels have the potential to create an e-waste burden if the proper infrastructure is not developed before the first wave of panels begins to come down.

Because they don’t go through the combustion process, there’s none of the pollution that’s associated with pollution, there’s no nox, there’s no particulate formation.

The Pelamis is an offshore wave energy converter that uses the motion of waves to generate electricity.

The machine operates in water depths greater than 50m and is typically installed 2-10km from the coast. The machine is rated at 750kW with a target capacity factor of 25-40 per cent, depending on the conditions at the chosen project site. On average one machine will provide sufficient power to meet the annual electricity demand of approximately 500 homes.

The Pelamis machine is made up of five tube sections linked by universal joints which allow flexing in two directions. The machine floats semi-submerged on the surface of the water and inherently faces into the direction of the waves. As waves pass down the length of the machine and the sections bend in the water, the movement is converted into electricity via hydraulic power take-off systems housed inside each joint of the machine tubes, and power is transmitted to shore using standard subsea cables and equipment.

Let’s not hide the fact that manufacturing solar panels requires resources, fossil fuels that release CO2 emissions and add to our carbon footprint. However, it’s been shown in numerous studies that solar panel production releases nowhere near as much CO2 and other greenhouse gases as electric generated from coal, oil, natural gas, etc. (And you still need to produce the equipment to generate electricity from those sources as well.)

y growing plants can be achieved by producing biofuels from

Balance between the carbon released by biofuels and carbon uptake by growing plants can be achieved by producing biofuels from feedstocks (raw materials) that come from managed forests or sustainably cultivated crops.

Solar technologies produce few negative environmental impacts during collector operation.

Somewhat surprisingly, the hot air that carries the heat from the earth at geothermal sites also contains carbon dioxide, CO2, the Greenhouse Gas that sends anti-technologists into a frenzy.  The suite of 20 geothermal sites from which Southern California Electric is obligated to buy electricity produces 730 tonnes of CO2 for every gigawatt-hour (GWh) of electricity produced.  Across the spectrum of all natural-gas power plants in the US, the average CO2 production is 519 tonnes per GWh.  That is, the geothermal power plants, which burn no fossil fuels whatsoever, produce 41% more CO2 than the run-of-the-mill natural gas power plant for the same amount of electrical energy produced.

Ethanol, for instance, is an alcoholic biofuel easily distilled from sugary or starchy plants. It has been used to power cars since Ford’s Model T and, blended into conventional petrol, constitutes about 10% of the fuel burned by America’s vehicles today.

If solar panels are manufactured using electricity from coal-burning plants, they indirectly emit greenhouse gas emissions. That makes them less clean than a panel that’s manufactured using renewable energy.

hexafluoride