Renewable energy is energy generated from natural resources such as sunlight, wind, rain, tides, geothermal heat and wood – which are all renewable (naturally replenished). Renewable energy technologies include solar power, wind power, hydroelectricity, micro hydro, biomass and biofuels.
In 2006, about 18% of global final energy consumption came from renewables, 13% from traditional biomass,
such as wood-burning. Hydropower was the next largest renewable source, providing 3%, followed by hot water/heating, which contributed 1.3%. Modern technologies, such as geothermal, wind, solar, and ocean energy together provided some 0.8% of final energy consumption. The technical potential for their use is very large, exceeding all other readily available sources.
Renewable energy technologies are sometimes criticised for being intermittent or unsightly, yet the market is growing for many forms of renewable energy. Wind power is growing at the rate of 30 percent annually, with a world-wide 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. 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.
Critics suggest that some renewable energy applications may create pollution, be dangerous, take up large amounts of land, or be incapable of generating a large net amount of energy. Proponents advocate the use of “appropriate renewables”, also known as soft energy technologies, as these have many advantages.
Market overview of Wind Energy: Globally, sustainable energy is being led by wind power. In fact, wind is rapidly developing into a mainstream power source in several countries, and is playing a key role in meeting the energy challenges that the world is facing today. Wind power is a renewable, economic, non-polluting and environment friendly source of energy. With an average annual growth rate of more than 26% since 1990, wind is the fastest growing energy source in the world.
Global wind energy generating capacity at the end of 2006 was over 74 GW, a 25.4% increase over 2005. The Global Wind Energy Council (GWEC) in its ‘Wind Force 12’ forecast estimates that by 2020, wind would become a US $67 billion business in annual terms. Thus, global installed capacity could increase to 135,000 MW by 2010, meeting 12% of the world’s electricity requirements.
Market overview of Bio Energy: Biomass is an important energy source contributing to more than 14% of the global energy supply. About 38% of such energy is consumed in developing countries, primarily in the rural and traditional sectors of the economy.
Further, the vast agricultural produce in India also makes available large quantities of agro-residues, which can be used to generate power. The strong demand for bio-fuel is in response not only to high crude petroleum prices, but also the growing concerns about global climate change. Two major bio-fuels for the transportation sector, bio-ethanol and bio-diesel have gained world-wide acceptance.
Market overview of Solar Energy: The availability of abundant solar energy enables organisations to meet the energy challenge and provides an opportunity to offer new and cost effective solutions. In the solar photovoltaic sector, the photon chasing has moved from expensive silicon wafers (owing to paucity of polysilicon world-wide), to the growth of technologies such as thin film-based high concentration photovoltaics, concentrating solar power (C S P ) and nanosolar.
The race is on to significantly cutback on material use, find alternative materials, reduce cost and increase conversion efficiency. This is possible with the emergence of new generation technologies, innovative manufacturing techniques and increasing volumes. The cost of electricity generation from CSP is expected to drop to US $0.050-0.07 per kWh by 2020. For solar thermal, the global installed collector capacity was a robust 111 GW at the end of 2005. Almost half of this capacity is installed in China, followed by Germany, Japan, Turkey and USA.
Market Overview of Hydro Energy: Hydro-power is considered to be the oldest renewable energy technique know to mankind for electricity generation. It is a non-polluting and environmentally benign source of energy. Hydroelectricity currently supplies about 715,000 MW or 19% of the world’s electricity, accounting for 63% of the total electricity from the renewable energy sector.
Hydro Power has a prominent role to play in responding to the energy challenges. The electricity generated from Small Hydro Power (SHP) projects is cost-effective. Such projects are simple to operate, have a relatively short gestation period, and are environment friendly. In addition, SHP projects can be located in remote areas for generating power. The global estimated potential of SHP is about 180,000 MW.
DEVELOPING COUNTRY MARKETS: Renewable energy can be particularly suitable for developing countries. In rural and remote areas, transmission and distribution of energy generated from fossil fuels can be difficult and expensive. Producing renewable energy locally can offer a viable alternative.
Renewable energy projects in many developing countries have demonstrated that renewable energy can directly contribute to poverty alleviation by providing the energy needed for creating businesses and employment. Renewable energy technologies can also make indirect contributions to alleviating poverty by providing energy for cooking, space heating, and lighting. Renewable energy can also contribute to education, by providing electricity to schools.
Kenya is the world leader in the number of solar power systems installed per capita (but not the number of watts added). More than 30,000 very small solar panels, each producing 12 to 30 watts, are sold in Kenya annually. For an investment of as little as $100 for the panel and wiring, the PV system can be used to charge a car battery, which can then provide power to run a fluorescent lamp or a small television for a few hours a day.
More Kenyans adopt solar power every year than make connections to the country’s electric grid. Potential future utilisation present renewable energy sources supply about 18% of current energy use and there is much potential that could be exploited in the future. As the table below illustrates, the technical potential of renewable energy sources is more than 18 times current global primary energy use and furthermore several times higher than projected energy use in 2100.