Green energy is defined as including all natural energetic processes that can be harnessed with little pollution. It must be clarified right at the outset that there can be no ‘ideal’ green energy source, as harnessing any energy source will cause some pollution or environmental harm; though this small harm is usually more than offset by the benefits of such installations.

A number of green resources are known and are either being harnessed or are in various phases of development and commercialisation. The primary driving philosophy behind the shift from traditional sources to green sources is sustainability; both in terms of the environmental sustainability and the long term availability of the fuel being consumed. There are obviously other economic advantages like the greatly reduced cost of energy and energy access to everyone.

The traditionally known and used sources of green energy are anaerobic digestion, geothermal power, wind-power, small-scale hydro power, solar energy, biomass power, tidal power, wave power, and some forms of nuclear power. There is some debate about the potential environmental threats of nuclear power, due to the resulting nuclear waste that requires much care for safe disposal. But newer forms of reactor setups can digest waste till its harmful effects are greatly reduced.

POLICY VERSUS TECHNOLOGY
It is easy to talk romantically of shifting to green sources and saving the planet. But what is commonly overlooked is the rift between policy and cost of technology.

Consider India: There is proven green energy potential to satisfy over 60% of our current energy needs; yet the associated cost is too high. The government chooses to rather spend that money on more immediate tasks and pick the alternative of comparatively harmful, but cheaper fossil fuel energy. The thrust for greening of energy production is high, especially from the developed nations, and a unique run-around the cost problem has been implemented. The richer countries have to buy ‘carbon-credits’ for energy they use that is produced by carbon based fuels. This money is then necessarily invested in green projects in developing and underdeveloped countries. The method is ideal, but requires a high degree of international collaboration and diplomacy: The farce that is the Kyoto Protocol is a telling reminder of the gap between promises and vested interests.

There are other impediments from the technology side of it as well. Green sources like wind power and wave/tidal energy are located in remote areas and carry the burden of extra costs required to transfer the generated power to areas that demand it. Not to mention that the cost of generation of green energy from all sources (apart from large-scale hydroelectric plants) is very high compared to traditional generation techniques. There is the added disadvantage of the inability of existing grids and distribution networks to incorporate green electricity at a large scale.

A number of solutions have been suggested to overcome these technological hurdles. Apart from national policy commitments towards reducing cost and investing in infrastructure, numerous self-generation projects, small scale captive plants etc. have been set up to reduce transmission losses and costs. But experts argue that a fundamental change is necessary in the way we look at and use energy today to efficiently harness green energy mere ad-hoc substitution will not work as required.

NEW TECHNOLOGIES
Numerous new technologies have emerged to cater to specific energy needs like heating requirements. Effective usage of geothermal energy, which is harnessed due to the steady temperature gradient in the earth’s surface, is one such example. This technology has been extensively used in cold countries, which have higher geothermal activity (Finland and Iceland). Apart from new energy sources, focus has also been laid on incremental efficiency of traditional sources. These are known are green processes.

One such green process that has found wide acceptance is ethanol-blended fuel. Ethanol, produced by fermentation of biomass, like sugarcane bagasse, is blended with gasoline to increase fuel efficiency. The United States and Brazil are the world’s leading consumers of ethanol-blended fuel, with almost all gasoline being sold in the United States having at least 10% blended ethanol (E10 petrol). Leading auto companies like GM and Ford are already selling flexible-fuel cars. The most popular green fuel in EU is biodiesel, which is made from vegetable oil, animal fat, and recycled grease. Governments have also promoted biofuel usage via tax breaks and subsidies. The intent is clear: A complete shift to green fuels requires a long-term road map, one that does not rule out improving usage and efficiency of traditional fuel systems.

POSITIVE GROWTH
The world has increasingly realised the importance of shifting to green fuels with the foreknowledge that if affirmative steps are not taken now, it might be too late. With this shared conviction, numerous governments, through international agreements and internal policy, have fuelled the shift towards sustainable energy production. The setting up of international energy agencies, self-imposed emission cuts and funds earmarked towards set energy goals has caused a positive shift in the direction of greening the future. The global installed capacity for renewable energy is close to 350 GW - this contributes to 19% of global energy consumption; India stands fifth in the world ranking of installed renewable energy capacity. Continued investment and stimulus holds the promise of a greener and sustainable future for the generations to come. The International Energy Agency estimates that 80% of world energy needs will be fulfilled via green energy sources by 2050.

IMPORTANCE FOR DEVELOPING NATIONS
Green energy sources also hold the solution to numerous energy problems faced by developing nations. Problems like energy accessibility, capacity shortfall, and high energy costs can be easily solved with green resources.

The Indian government, in a participative model, has run many pilot projects where population in remote areas have been able to build and sustain captive green energy plants at affordable rates. This not only adds to the environment positively, but also empowers the remotest of populations to access technology and improve the standards of living. With tremendous opportunities ranging from biogas to biofuel, these environment friendly energy sources not only create sustainable development opportunities, but are also viable business models for the rural poor.

Despite political and technological hurdles, green energy holds the key to the future, which is only possible when the environment is not compromised by growth of the human civilisation. Many positive indicators are definitely promising, but more needs to be done in terms of international co-operation - and also individual activism and responsibility - to pass on a healthy planet to the generations yet to come.