Renewable energy: Introduction

June 5, 2009

The energy crisis which began in 1973 caused petroleum supplies to decrease and prices to rise exorbitantly. This crisis forced developing countries to reduce or postpone important development programs, so they could purchase petroleum to keep their economies operating. It created the urgent necessity to find and develop alternative energy sources, such as other fossil fuels (coal, gas), nuclear energy, and renewable energy resources.

Coal is found primarily in industrialized countries, with Latin American and African reserves making up less than 1 percent of the world total. Thus, it is unlikely that this part of the Third World will be able to use large quantities of coal. The nuclear alternative is undesirable; the associated accident risks, waste disposal difficulties, nuclear terrorism, and nuclear weapon proliferation are dangerous in themselves, and make this form of energy excessively expensive (Brown et al, no date). Acquiring nuclear energy from the industrialized world could, moreover, result in greater technological and economic dependence on developed countries. A more feasible alternative to petroleum, coal, and nuclear reactors in developing countries is the direct and indirect use of solar energy, which is renewable, abundant, decentralized and non-polluting.

Each day, the sun sends to earth many thousands of times more energy than we attain from other sources (the equivalent of 200 times the energy consumed by the United States of America in one year). This energy can be captured directly as radiation or – even more significantly – indirectly in waterfalls, wind, and green plants. Countries in the humid tropics in particular contain enormous forest biomass resources, which, properly managed, could significantly contribute to the solution of their energy problems, as well as provide wood for other uses. Countries in the humid tropics also possess abundant water resources and high levels of solar radiation, which show promise in generating electrical and thermal energy.

Taking into account that the technology needed for exploiting renewable energy resources is simple and relatively economical, it is important from a strategic point of view that energy planning in Third World countries, particularly in the humid tropics, be oriented to developing the solar alternative. It offers them one of the few opportunities to develop independently of the industrialized countries. To this end, energy planning also must encourage energy conservation and optimize the use of organic by-products and residues generated by economic and domestic activities.

Most of the Earth’s energy comes from the Sun

Solar power, that’s obvious, but the energy in coal originally came from the Sun too. Prehistoric plants stored the Sun’s energy in their leaves, and when they died and eventually formed coal seams, that energy was still there. So when we burn coal (or any fossil fuel), we’re releasing chemical energy that was stored in plants millions of years ago.

The same goes for Wind and Wave power. Waves occur because of winds, and winds blow because the Sun warms our atmosphere. Warm air tends to rise, and winds are due to other air moving in to replace it.

Most power stations burn coal, oil or natural gas to run the generators. Others use uranium, or the flow of water. Electricity is sent around the country using high-voltage power lines. Nearly all of the power we use comes from large power stations, although some places such as isolated farms, or hospitals, have their own diesel generators.

What is Renewable Energy?

Renewable energy is any sustainable energy source that comes from the natural environment. The most common forms of renewable energy are solar, wind, water or hydro, biomass and geothermal energy. Renewable energy sources are maintained or replaced by nature after use. Other energy resources, such as coal, oil and natural gas, cannot be replenished by nature as fast as they have been used; it took hundreds of millions of years to form fossil fuel deposits and they are in limited supply.

Sunlight, wind, water and biomass are the sources for most of  Nepal’s renewable energy. Sunlight can be converted to electricity using photovoltaic (solar electric) panels. This electricity can be used to operate a multitude of electrical appliances. The sun’s energy (light, heat, ultraviolet) can also be converted into heat using solar thermal (heating) panels. The heat can be used to heat water or air for residential, commercial and industrial use.

Wind and flowing water can be used to generate electricity.

Trees can provide wood for heating and materials for buildings, while grains, such as corn and wheat, can be fermented into ethanol and used as a fuel for automobiles.

Reasons for Renewables
Global environmental concerns, the depletion of the earth’s finite resources and economic considerations are all incentives to interest consumers in renewables. Although renewables cannot yet replace all existing energy sources, they can supplement power generated by utilities and increase the diversity of our energy supply. Global climate change due to pollution and the effects of pollution on the environment have become major environmental issues since the Rio Summit in 1992.

As well, the two oil crises in the 1970s forced the industrialized world to examine carefully its resource use and reconsider its virtual dependence on a single fuel source. Intensive research has been undertaken in the developed world to find technology-driven clean energy substitutes for traditional fossil fuels.

The rapidly increasing industrialization in developing countries puts a strain on already limited resources and adds to the continuing deterioration of the global environment. Finding alternative sources of energy is crucial.

Economically, the advances that have been made in renewable energy technologies in the last two decades, including higher efficiencies, improved quality and increased reliability, have made applications of renewable energy more attractive. On a small scale, renewable energy is not competitive when compared to bulk power generation, but it does have practical applications in innovative niche markets, such as consumer products, remote/off-grid and telecommunication applications. The cost of renewable energy technologies will drop once the benefits of renewable energy, including its sustainable nature and the minimal pollution it creates, are recognized by a larger percentage of the population.

Renewables are Not New
Renewable energy sources have been used for centuries. Until the mid-1800s, most of our energy came from two biomass sources, wood and peat. The location of many large plants and mills during the industrial era in Europe and North America was determined by the availability of fast flowing streams to generate power.

It wasn’t until the latter stages of the Industrial Revolution, the mid-1850s, and following the widespread incorporation of the steam-engine into factories, that fossil fuel use, mainly coal and oil, became commonplace. By incorporating fossil fuels into the manufacturing process instead of using water, industrialists were not limited to locations by rivers or streams. Plants could be located closer to sources of raw materials, markets or major shipping ports.

Renewable Energy in Remote Areas
One of the greatest benefits of renewable energy is its potential to provide affordable and clean sources of electricity to remote populations in Nepal and to developing countries. Although many people do not have connection to an electrical grid, renewable energy technologies can capture natural sources of (electrical and heat) energy in non-conventional locations and in non-conventional ways. It has been estimated that up to three billion people do not have electricity and renewable energy can play a key role in the economic development and modernisation of areas where many of these people live.

Renewables and Global Warming
The earth’s atmosphere acts like glass in a greenhouse: sunlight can pass through, but the resulting heat can not escape. Gases, such as carbon dioxide, are particularly effective at trapping heat. When burned, coal, oil and natural gas increase the amount of carbon dioxide in the atmosphere and the earth’s average temperature is raised. Renewable energy initiatives will result in reduced demand for fossil-fuelled electricity generation, thereby reducing greenhouse gas emissions.

Renewing Sustainable Development
In 1987, a United Nations commission chaired by Gro Harlem Brundtland, the then Norwegian Prime Minister, was formed to determine how to reconcile economic development with environmental protection. The term ‘sustainable development’ was first used in the commissions’ report, Our Common Future. The report recognized that renewable energy sources are essential for sustainable development because they provide us with constant sources of energy with fewer effect on the environment. It also identified that globally, there was the need for more efficient use of energy and that the industrialised world, especially, had to improve its conservation efforts to lessen the impact of economic development on the environment.

Renewable Energy Sources
The following terms are used to describe the various forms of renewable energy:

Active solar energy
The sun can be used directly to heat water for pools, homes and industry, to provide space heating and to generate electricity. The sun’s energy can also be used to distill water and cook food.

Biomass energy
The sun’s energy is stored in organic materials such as wood, grains and peat. Wood and peat are both burned to provide heat. Grains can be fermented into ethanol and used as a liquid fuel.

Geothermal energy
Heat from the earth’s core can be used to generate electricity. It can also be used directly (with heat pumps) to heat and cool buildings.

Passive solar energy
Passive solar energy is incorporated into energy efficient building and landscape design, e.g. window placement to heat retaining walls and floors.

Small hydro
Small hydro projects will generate power by using falling water at an average capacity of 20 megawatts or less. A ‘run-of-the-river’ project also uses falling water by directing water to the turbine using pipes, rather than dams.

Wave or tidal energy
The movement of waves and tides, particularly in shallow water, can be harnessed and converted to electricity.

Wind Energy
The energy from the wind can be harnessed by wind turbines and windmills to generate electricity and also to pump water.

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