Sunday, October 21, 2007

POWER FROM THE WIND IN INDIA

THE ARTICLE YOU ARE ABOUT TO READ SHOULD OPEN OUR EYES ON ELECTRICITY GENERATION IN AFRICA. INDIANS HAVE RECENTLY BEEN APPOINTED MANAGEMENT CONSULTANTS FOR NIGERIA"S TRANSMISSION COMPANY.

Wind Energy Is Growing In India

Power generation from wind has emerged as one of the most successful programmes in the renewable energy sector in India, even as this source of power is emerging as an alternative in fast-growing countries like India and China that are avidly seeking new energy sources.

With a rapidly growing economy, India’s energy needs are increasing, and are largely met by electricity from oil and coal fired power stations.

Industry analysts say that energy is a major input for overall socio-economic development and renewables are expected to play a key role in accelerating development and sustainable growth in the second half of the current century, accounting then to 50 to 60 per cent of the total global energy supply.

Reports suggest that wind generation is the fastest growing energy source in this decade and is expanding at 25 per cent per year. The industry experts recognises India as a new "Wind Superpower".

Available figures suggest that at the end of April 2007 India had 7113.6 MW of wind generating capacity and is the fourth largest market in the world. There are about a dozen wind pumps of various designs providing water for agriculture, afforestation, and domestic purposes, all scattered over the country. The states of Tamil Nadu, Karnataka, Andhra Pradesh, Gujarat, Rajasthan and Maharashtra lead in the field of wind energy

The growth of power generating capacity in India is today driven largely by increasing energy needs. The short gestation periods for installing wind turbines, and the increasing reliability and performance of wind energy machines has made the sector a favoured choice for capacity addition.

South region Tamil Nadu is the state with most wind generating capacity and western Maharashtra is second only to Tamil Nadu in terms of generating capacity. Suzlon has been heavily involved in the state.

The technical potential that is based on the availability of infrastructure, for example the availability of grid, is estimated to be around 13, 000 MW. In India, the wind resources fall in the low wind regime, the wind power density being in the range of 250 -450 W/m. It may be noted that this potential estimation is based on certain assumptions.

With ongoing resource assessment efforts, extension of grid, improvement in the wind turbine technology, and sophisticated techniques for the wind farm designing, the gross as well as the technical potential would increase in the future.

The leading countries in wind power installation are Germany, Spain, the USA, India, and Denmark. India has overtaken Denmark and is the fourth largest wind market in the world.

Wind turbines offered in India range from 250 kW to 2 MW capacities. Currently, there are 7 manufacturers of wind turbine generators in India.

According to a recent study from Emerging Energy Research (EER) entitled Asia-Pacific Wind Power Markets and Strategies 2006-2015, Asia-Pacific is emerging as the new frontier of the global wind industry, with the region expected to add over 46,000 MW of wind power in the coming decade.

In fact, the region’s market leaders - China and India - are expected to add over 41,000 MW between them by 2015. Together they will represent over 80 per cent of the Asian wind market during the period. Japan and Australia will each add between 150 MW and 450 MW per year, followed by less developed markets in South Korea, New Zealand, Taiwan, Pakistan and the Philippines.

Report further says that after a good year in 2006 in which around 1800 MW was added, India will retain its position as Asia’s leading wind power market in terms of total megawatts installed until 2015, when it will be overtaken by China.

Wind is a significant source of electricity in Denmark, Spain and Germany. Denmark generates 14% of its total electricity from wind sources, Spain 9% and Germany 5%. Among developing countries, wind was an important source of electricity in India, contributing around 1% to total electricity generation. Globally, wind generated electricity is still less than 1% of total electricity generation.

By T C Malhotra
http://www.poweralternatives.com/nc/power_stories/display_news/article/wind-energy-is-growing-in-india/492.html

Sunday, October 14, 2007

UNDERSTANDING SOLAR ELECTRICITY

HI,
I AM SORRY I HAVE BEEN OFF THIS PAGE FOR QUITE SOMETIME NOW, BUT I CAN ASSURE YOU I AM BACK TO SERVE YOU BETTER, BECAUSE I STRONGLY BELIEVE IT'S HIGH TIME AFRICANS FIND WAYS OUT OF THE POWER SUPPLY DEBACLE THAT HAS TRULY KEPT THE CONTINENT DARK. SO I AM CONTINUING WITH ELECTRICITY FROM THE SUN. ENJOY READING AND PLEASE BE FREE TO POST YOUR COMMENTS


Energy from the sun for thousands of years
has been harnessed for several purposes. However it is vital that we see this energy in three forms and properly understands the separate applications.
  • Solar energy as passive heat: This we receive from the sun naturally and is taken into account in the design of buildings so that less additional heating is required.
  • Solar thermal energy: Where the sun's heat provideshot water for homes or swimming pools.
  • Photovoltaics (PV): where energy from the sun is employed to createelectricity which runs appliances and lighting.
NOTE! PV requires only daylight - not direct sunlight - to generate electricity.

MODE OF OPERATION
Photovoltaic systems through cells convert solar radiation intoelectricity. The PV cell consists of one or two layers of a semiconductingmaterial, usually silicon. When light shines on the
cell an electric field is formed across the layers, hence electricity flows. The flow of electricity is detemined by the light intensity
There are three main types of solar cells viz
• Monocrystalline: made from thin slices cut from a single crystal of silicon. This has a typical efficiency of
15 per cent.
• Polycrystalline: made from thin slices cut from a block of silicon crystals. This has a typical efficiency of around12 per cent.
• Thin Film: made from a very thin layer of semiconductor atoms deposited on a glass or metal base. This has a typical efficiency of 7 per cent.

The PV cells are connected together to form a module. Modules are then linked and sized to meet a particular load (electrical energy demand). The result is a PV array which supplies power to the building it is fitted on. If the building has mains electricity, any excess electricity can be exported to the national grid (as is the case in the US and some parts of Europe).
Alternatively, when demand is high, extra electricity can be purchased from the national grid through the utility companies in addition to the PV electricity. In the event of a mains power failure, PV arrays can be
used to charge batteries.
PV arrays are in a variety of shapes and colours,ranging from grey 'solar tiles' that look like roof tiles, to
panels and transparent cells that you can use onconservatories and glass to provide shading as well as
generating electricity.