Green energy
March 2010
By Sharukh Vazifdar
Our conventional energy reserves are running out; It’s just a matter of time. How much do we know about the other kind of energy – Green energy?
While starting this I asked myself and was asked by others, the reason for the term ‘alternative’. In what way are these sources of energy alternative to the other sources? As I began to think about it, it dawned upon me that it isn’t the source of energy or the properties of the energy that are alternative, but rather the thought behind them that is different and holistic. To be more specific, they are eco-friendly sources of energy.
Unlike coal, oil and gas, the world’s most popular power sources, eco-friendly sources are non-polluting; and unlike biomass and nuclear energy, two upcoming sources of energy, eco-friendly sources do not pollute the environment. For far too long the human race has been inconsiderate to the planet and its inhabitants with the amount of pollution it generates. The turn of the 20th century brought with it the internal combustion engine, followed by the airplane and ocean liners. Advancement of these technologies has pumped unlimited volumes of pollution into the atmosphere and oceans.
In the movie, An Inconvenient Truth, which is based on global warming, Al Gore informs us that if the earth were depicted as an apple, the atmosphere is as thick as the layer of wax on the apple skin! Staring up from the surface, we cannot gauge how far up or high the atmosphere goes, but we do know that the most harmful pollutants, the most toxic gases, stagnate between the surface and just one kilometre above it. Bharat Mansatta, an environmental activist involved with natural regeneration, says, “Fossil fuels have taken millions of years and millions of tons of dead vegetation and sunlight to form. When we use it all up in just a span of 150 years we are releasing a lot of energy, which is proving disastrous.”
Alternative sources
So which are these alternative sources of energy, lovingly called green energy? They include wind energy, solar energy, tidal energy, geothermal energy, and hydro energy. Currently, less than five per cent of our energy is derived from these alternative sources, the rest being from coal, oil, gas and nuclear material.
Amongst these, solar power is the most promising and the least tapped source. If only 0.02 per cent of the solar energy falling on the planet is tapped, it will meet all existing power demands. With the solar cell industry doubling in size every two years, and their efficiency and cost achieving an optimal balance, it isn’t long before solar power becomes the primary source of energy for the planet. Thought of only as the solar cells which generate electricity, solar energy is also used to concentrate the incidental heat and raise temperature and pressure of a fluid, mostly water, to generate power. Spain and the US are the current world leaders in solar power generation. You could also run your home entirely on solar power, although currently it is very expensive to do so. The economical solar cookers and water heaters are becoming very common in India, and more so in the smaller towns. A particular temple in Shirdi, for example, has its entire terrace filled with solar water heaters.
India holds the proud place of being the fifth largest producer of wind-powered energy in the world, producing 11,000 megawatts of electricity. Wind farms, what a group of wind turbines located together are called, may consist of a few dozen to several hundred turbines, with the land in between them used for agriculture, cattle grazing or other activities. A recent turbine set up in Antarctica, is powering part of New Zealand and US camps’ power. The only major problem with this source being its non-uniform supply since the wind can suddenly die down during a peak power demand, and hence has to be supplemented with another source of power.
Tidal power is a form of hydropower that converts the energy of the tides into electricity. Not yet widely used, tidal energy can be more accurately predicted than solar or wind energy. As the Earth’s tides are caused by the tidal forces due to gravitational interaction with the Moon and Sun, and the Earth’s rotation, tidal power is practically inexhaustible. A tidal energy generator uses this phenomenon to generate energy. The stronger the tide, either in water level height or tidal current velocities, the greater the potential for tidal energy generation. However, it is expected to severely affect marine life and silt deposition and so is not a very popular choice.
One would think that the entire volume of rain that falls in a certain place is absorbed by the ground, whereas in reality a very small percentage actually is. Most rainwater is either used up by plants, evaporates or flows along the surface and is called surface run-off. Even in an open unpaved area, the mud can only absorb a certain amount of water, the rest is run-off. Rainwater harvesting aims to collect this run-off water and use it, reducing dependency on lakes and reservoirs. This water can also be used to replenish the water table by directing it to a specially created hole in the ground.
Conserving energy
While the long-term aim is to switch to these alternative sources of energy, what we often don’t see is the energy we waste every day. Any sort of packaging material for food, furniture or other goods requires a great amount of energy to produce. Each time we discard it, we are wasting energy. Using locally grown food, and locally manufactured goods helps save the environment from the pollution that transportation would have caused. Conservation is another habit that needs to be ritually promoted. Unknowingly we waste water, fuel, food, electricity and the like. Shut off any electrical appliance from the wall socket when not in use, since it still draws power. Shutting off the water when not used or simply having a bucket bath will help save a lot of water.
Having made electricity an integral part of our daily lives, one cannot imagine living without it, even for a few hours. We shouldn’t reach a stage where we are forced to make a sudden change from eco-polluting to eco-friendly energy. We still have time to allow a gradual change and reduce any dramatic impact economically and environmentally. Although we are experimenting with solar and wind power, we may find it too costly. Maybe it’s time we stopped valuing life just on economic standards, and recognised the cost the environment, us included, has had to pay for this.