New Energy Sources

NEW ALTERNATIVE ENERGY SOURCES

INTRODUCTION

Conventional energy sources based on oil, coal, and natural gas have proven to be highly

effective drivers of economic progress, but at the same time damaging to the environment and to

human health. Furthermore, they tend to be cyclical in nature, due to the effects of oligopoly in

production and distribution. These traditional fossil fuel-based energy sources are facing

increasing pressure on a host of environmental fronts, with perhaps the most serious challenge

confronting the future use of coal being the Kyoto Protocol greenhouse gas (GHG) reduction

targets. It is now clear that any effort to maintain atmospheric levels of CO2 below even 550 ppm

cannot be based fundamentally on an oil and coal-powered global economy, barring radical

carbon sequestration efforts.

The potential of renewable energy sources is enormous as they can in principle meet many times

the world's energy demand. Renewable energy sources such as biomass, wind, solar,

hydropower, and geothermal can provide sustainable energy services, based on the use of

routinely available, indigenous resources. A transition to renewables-based energy systems is

looking increasingly likely as the costs of solar and wind power systems have dropped

substantially in the past 30 years, and continue to decline, while the price of oil and gas continue

to fluctuate. In fact, fossil fuel and renewable energy prices, social and environmental costs are

heading in opposite directions. Furthermore, the economic and policy mechanisms needed to

support the widespread dissemination and sustainable markets for renewable energy systems

have also rapidly evolved. It is becoming clear that future growth in the energy sector is

primarily in the new regime of renewable, and to some extent natural gas-based systems, and not

in conventional oil and coal sources. Financial markets are awakening to the future growth

potential of renewable and other new energy technologies, and this is a likely harbinger of the

economic reality of truly competitive renewable energy systems.

In addition, renewable energy systems are usually founded on a small-scale, decentralized

paradigm that is inherently conducive to, rather than at odds with, many electricity distribution,

cogeneration (combined heat and power), environmental, and capital cost issues. As an

alternative to custom, onsite construction of centralized power plants, renewable systems based

on PV arrays, windmills, biomass or small hydropower, can be mass-produced "energy

appliances" capable of being manufactured at low cost and tailored to meet specific energy loads

and service conditions. These systems can have dramatically reduced as well as widely dispersed

environmental impacts, rather than larger, more centralized impacts that in some cases are

serious contributors to ambient air pollution, acid rain, and global climate change.

Renewable energy sources currently supply somewhere between 15 percent and 20 percent of

world's total energy demand. The supply is dominated by traditional biomass, mostly fuel wood

used for cooking and heating, especially in developing countries in Africa, Asia and Latin

America. A major contribution is also obtained from the use of large hydropower; with nearly 20

percent of the global electricity supply being provided by this source. New renewable energy

sources (solar energy, wind energy, modern bio-energy, geothermal energy, and small

hydropower) are currently contributing about two percent. A number of scenario studies have

investigated the potential contribution of renewables to global energy supplies, indicating that in the second half of the 21st century their contribution might range from the present figure of nearly 20 percent to more than 50 percent with the right policies in place.

Renewable energy sources are abundant and well distributed around the world. Insolation, wind, biomass and hydro have proved to be the most useful renewable energy sources and these resources are being harnessed in a number of ways world-wide. Solar energy can be used to generate electricity through PV panels or for heating purposes directly or by employing solar thermal system. Along with it, solar energy can be used for cooking, pumping water, refrigeration and desalination of water. The same is true for all the renewable energy sources. They can be harnessed to produce electric energy or any other forms of energy such as low-grade thermal, medium-grade thermal etc. Currently all of the power plants, either based on fossil fuels or renewable sources, convert all the available energy forms to electricity to supply loads. The end product, electricity, can then be used to provide energy for any of the needs such as heating, cooling, pumping water etc. This is mostly suitable for urban and industrial sectors where electricity is the only form required to supply any kind of need. However, the case is quite different in rural areas, where electrical loads are few as compared to other loads. Electrification of a rural society is not the efficient and economical way to achieve a sustainable society.In remote areas electrical load is very small as compared to other energy needs such as cooking, heating etc. Hence, rural electrification is not the ideal solution in these areas. Providing energy needs in various forms to match the needs allows the end users to benefit from such system. For instance, medium grade heat required for cooking can be satisfied