Renewable Energy Sources
Renewable energy is energy generated from natural resources-such as sunlight, wind, rain, tides and geothermal heat-which are renewable (naturally replenished). In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning. Hydroelectricity was the next largest renewable source, providing 3% (15% of global electricity generation), followed by solar hot water/heating, which contributed 1.3%. Modern technologies, such as geothermal energy, wind power, solar power, and ocean energy together provided some 0.8% of final energy consumption.
Video: The ailing World Using Fossil Fuel: With Renewable Energy It Doesn’t Have to be This Way
Climate Change and Oil Prices Lead to Increased Global Investments
Climate change concerns coupled with high oil prices, peak oil and increasing government support are driving increasing renewable energy legislation (see article/analysis on the 2010 proposed American Power Act), incentives and commercialization. Investment in sustainable energy worldwide has more than doubled in the last two years, from $27.5 billion in 2004 to $49.6 billion in 2005 and $70.9 billion in 2006.
In 2007, the upward trend continues, with capital investments occurring in sectors and regions previously considered too risky and too illiquid to merit the attention of the institutional investment community, according to the UNEP’s Report: Global Trends in Sustainable Energy Investment 2007, (p. 4).
In the U.S., 2008 seen an all-time high in venture capital flow into renewable projects, with almost $8 billion invested. Already in the first quater of 2009 VC investment in green technologies totaled more than $836.1 million in 59 deals, according to Greentech Media.
Both Grid and Off-Grid Projects See Growth
Wind Power Receiving Greatest Share of Funds in Mega Projects
Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of over 100 GW, and is widely used in several European countries and the United States.
The manufacturing output of the photovoltaics industry reached more than 2,000 MW in 2006, and photovoltaic (PV) power stations are particularly popular in Germany and Spain.
Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert.
The world’s largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country’s automotive fuel. Ethanol fuel is also widely available in the USA.
Solar Power Favored by Smaller Off-Grid Applications
While there are many large-scale renewable energy projects and production, renewable technologies are also suited to small off-grid applications, sometimes in rural and remote areas, where energy is often crucial in human development. Kenya has the world’s highest household solar ownership rate with roughly 30,000 small (20-100 watt) solar power systems sold per year.
Video: off grid Wind and Solar use
Some renewable energy technologies, like wind, are criticised for being intermittent or unsightly, yet the market is growing for many forms of renewable energy. In response to the G8’s call on the IEA for “guidance on how to achieve a clean, clever and competitive energy future”, the IEA reported that the replacement of current technology with renewable energy could help reduce CO2 emissions by 50% by 2050.
Renewable Technologies Overview
Video:10 types of Renewable energy: Consider for a class project
Hydropower
Hydropower is created by running water from a reservoir through a hydraulic turbine that spins and drives a generator shaft to create electricity. The distance between the water’s sources to its outflow (called the “head”) is a major factor when determining a site’s potential for hydroelectric generation. The greater the elevation change, the greater the potential for power generation. Hydropower facilities are very useful for managing peak load and for power regulation purposes (keeping supply and demand in balance), as well as restoring the grid after a blackout.
Wind Power
Wind power is harnessed through wind turbines which are large windmills that are designed to capture air and convert it to electricity. The wind turbines are connected to generators that then produce electricity. This electricity then goes into power lines that bring it right into people’s homes.
However, in order to gather the most electricity, the wind has to be constantly blowing. This doesn’t happen very often, so wind power does not always generate enough electricity. Currently, there are technologies being explored to convert wind energy to hydrogen. This is a promising technology, as hydrogen is the simplest and most abundant element in the universe, which is an energy carrier that can be stored. Through an electrolysis process, the hydrogen compound is broken down and, when energy demand is high, the stored hydrogen can then be used for electricity (see the video at right titled Wind to Hydrogen).
Biomass or Biofuel Energy
Biomass can be algea, trees, plants, corn, sugar cane, plant waste-basically any plant matter that can be burned for heat/electricity or turned into fuel, which can be liquid (ethanol/methanol) or gaseous. Fuel made from biomass has great potential for being the next big source of energy for transportation. See recent article on LS9 ’s new technology to convert e-coli bacteria to biodiesel,( July 29, 2010).
Biofuels life cycle:
Type of biofuels and applications:
Information on ethanol and ethanol vehicle conversion, station locator, and other FAQ.
Information on Biodiesel, how it’s made, commercial applications, and FAQ’s.
Informartion on Cellulostic Ethanol and how it’s made.
Solar Power
The sunshine that warms us contains energy that can be collected as electricity toheat our water and keep our lights and appliances running. Many homes are now being designed to better harness the energy from the sun. The sun’s energy is converted in two main ways: the photovoltaic process and solar thermal electric process.
The word photovoltaic (PV) means “converting light to electricity.” PV panels, seen more and more often on roof tops, are composed of cells that contain a semi-conducting material, usually silicon. The semi-conducting material absorbs light energy from the sun and converts it into electricity.
Solar thermal systems function relatively simply; heat from the sun is collected in sealed tubes that contain a liquid. The liquid acts as a heat transfer. The heat from the sun warms up the liquid and the liquid is carried from the collector through a heat exchanger into a storage tank. The storage tank holds the water until it is needed for domestic use (showers, laundry, etc.) or for space heating.
Follow this link for more infomration on solar energy.
Geothermal Energy
Many technologies have been developed to take advantage of geothermal energy-the heat from the earth. This heat can be drawn from several sources: hot water or steam reservoirs deep in the earth that are accessed by drilling; geothermal reservoirs located near the earth’s surface, mostly located in western states, Alaska, and Hawaii; and the shallow ground near the Earth’s surface that maintains a relatively constant temperature of 50°-60° F.
This variety of geothermal resources allows them to be used on both large and small scales. A utility can use the hot water and steam from reservoirs to drive generators and produce electricity for its customers. Other applications apply the heat produced from geothermal directly to various uses in buildings, roads, agriculture, and industrial plants. Still others use the heat directly from the ground to provide heating and cooling in homes and other buildings.
Other geothermal resources exist miles beneath the earth’s surface in the hot rock and magma there. In the future, these resources may also be useful as sources of heat and energy.
The three types of Geothermal Power Systems.
Trash
Even trash can be used for power! Solid waste can be burned in plants to produce electricity and a gas called methane can be harvested from landfills as solid waste decays.
A Renewable Future
The United States and other countries around the world are investing in research around renewable energy. How can these sources be used more effectively? What technology needs to be implemented to get the most energy out of things like the wind? Scientists and researchers are working towards answers to these questions. Maybe one day the world will run on renewable sources!