Technologies
solar
wasted sunshine
POTENTIAL:
India receives 5,000 trillion kilowatt hours per year of solar energy, estimated at 20 mw
per sq km.
INSTALLED: 0.385 million solar lanterns; 0.18 million home lighting
systems; 41,000 street lighting systems, 4,204 water pumping systems; about 1.2 mw
aggregate capacity of stand alone power plants, 1.8 mw of grid interactive power plans. |
Solar energy is by far the best option for remote areas where connection to the power grid is not viable. Solar photovoltaic (
spv) technology enables the direct conversion of solar energy into electricity, while solar thermal technologies tap solar energy for thermal applications like water heating, cooking and power generation. Though technological developments in
spv have been impressive, the high cost of the silicon wafers used in the solar
pv modules hinders the development of solar energy worldwide. An investment in
spv requires about Rs 30-40 crore per mw as compared to thermal power, which is about Rs 4-6 crore per mw. "Till a technological breakthrough is achieved, solar energy will remain viable only for inaccessible areas. There will be no mass production and distribution will be niche-based," says P V Ramana, assistant resident representative, United Nations Development Programme (
undp).
Prices of
spv has fallen globally - by 5 per cent each year over the last 20 years. But the problem is that the price of fossil fuel energy has also fallen over the same period.
spv remains uncompetitive without large investments in research to cut costs. Researchers in Japan, Germany and the
us are working to reduce the cost and increase efficiency of solar cells. According to an assessment done by Greenpeace and the European Photovoltaic Industry Association, the capital cost of installing a
pv system ranges from
us $5-12 per watt. As a result, the life cycle costs for
pv generated electricity ranges from
us $0.25 kilowatt hour (kwh) up to
us $1 kwh.
In India, the
pv cost has declined from Rs 225 per watt in 1992-93 to Rs 160 per watt in 2002, says B Bhargava, director, ministry of non conventional energy sources (
mnes). "However, as long as silicon is used as a raw material, the lowest limit would be Rs 120 per watt," he adds. Currently
r&d is focused on thin film alternatives, which are more suitable for making solar cells and can help to reduce the price to Rs 40-60 per watt.
India is a manufacturer of solar cells and modules - in 2000, it produced 31 mw and domestic production is expected to cross 100 mw during 2002. To protect the domestic manufacturers, government imposes an import duty for wafers (cells) and finished solar panels in the range of 15 per cent. Even while the cost of solar panels is decreasing globally, this advantage is not fully reflected in India, says Harish Hande, managing director of
selco, a Bangalore-based solar energy services company.
Over the years, thousands of solar lanterns and lights - typical lantern is 10 watt module with a battery designed to work for about 3-4 hours a day - have been installed across the country. If it runs well, solar lantern can save 100 litres of kerosene each year. Power generating systems - stand alone or interactive with the grid - hold a tremendous technological opportunity. The most remarkable are the nine power plants with combined capacity of 252 kw in Sagar island and Sunderban area of West Bengal. Here each plant provides electricity to 100-120 households.
Solar thermal heating systems are also becoming popular in industries, hotels and hospitals. For instance, the Kerala-based Casino Group of Hotels, with hotel chains dispersed in many south Indian states have installed solar thermal water heating systems with a total capacity of about 43,700 litres per day. Says Jose Dominic, its proprietor: "We use solar thermal water heaters not only because it is environment-friendly, but because it is also very economical." A study done by Solar Tech, a Cochin-based agency, shows that heaters save 717,373 kwh of electricity amounting to Rs 55 lakh per year.
On the other hand, solar cookers have not fared well, mainly due to the availability of other energy options, the need for cooking outdoors and their bulkiness. "The solar cookers failed mainly because the ministry focused on design specification, rather than performance," says Ashok Khosla of Development Alternatives, a Delhi-based non-governmental organisation (
ngo).
biogas Where's the muck?
POTENTIAL: 12 million
biogas plants
INSTALLED: 3.13 million biogas plants |
This clean, cheap and efficient energy, which contains about 55 to 70 per cent methane, is one of the most widely disseminated technologies. "This is a proven technology and is one of the most successful programmes undertaken by the
mnes," says Ramana. Under the National Project on Biogas Development (
npbd) programme,
mnes promotes family-type biogas plants and has a small component of community plants. The most popular design is the Khadi and Village Industries Commission model, with a floating metal drum. A low-cost variant, called the Deenbandhu model with a bottom made of concrete and dome of ferro-cement, is gaining ground. A standard biogas plant costs between Rs 8,000-10,000 and generates 2 cubic metres of gas per day.
Though tremendous progress has been made in this technology, the water intensive nature of biogas is a hurdle for many parts of the country. The technology requires equal amount of water and cattle dung with temperature about 30
c to generate gas. "If water is insufficient, the slurry cannot flow out and clogs the pipe, rendering the plant non-functional," says Kailash C Khandelwal, advisor and head, rural energy,
mnes. This causes operational problems in areas with water scarcity and low temperatures even if there is sufficient cattle population. "This is why in many states only half the number of districts can fully utilise this technology," adds Khandelwal.
Even availability of dung is a problem. One kg of fresh dung produces 35 litres of biogas. A 2-cubic metre size plant needs dung from 5-7 cattle. In villages dung is a precious resource -- used for manure or cooking. Research is being done to find alternative feedstock. Like the centre for Application of Science and Technology for Rural Areas (
astra) in Bangalore, which is designing a leaf biomass-based biogas system.
Though the ministry claims that 87.5 per cent of the biogas plants in the country are functional, Parliament's Standing Committee on Energy report counters by stating that a very small number of family-size plants are functional. "This is because most of the biogas plants lack proper monitoring and maintenance by the implementing agencies," says an official from Indian Rural Energy Network (
irenet), a Delhi-based non-governmental organisation.
biomass gasifiers Raw deal
POTENTIAL: 19,500 mw
(estimated at 57,000 mw
by others. With 41,000 mw from dedicated plantations and 16,000 mw from crop residues)
INSTALLED: 400 mw |
Biomass gasification is one of the most promising energy technologies for rural applications, but only 2 per cent of the potential has been tapped. N H Ravindranath from centre for Application of Science and Technology for Rural Areas (
astra), Bangalore, calculates the potential -- 57 mw of power could be generated by burning firewood, charcoal and crop residues in a gasifier which converts biomass in the first partial combustion into gas and charcoal and then to a combustible producer gas comprising mainly carbon monoxide and hydrogen. One of the oldest plants is designed and run by
astra, in which a 4-8 hectare (ha) intensive energy plantation is used to generate 20 kw power in two gasifiers in two villages of Karnataka.
mnes estimates that around 3,500 mw of power can be produced if 430 sugar mills in the country switched to co-generation technologies.
In India, gasification technology is now growing beyond the demonstration stage. Most gasifiers use gas and diesel in the ratio of 80:20. Ongoing research focuses on 100 per cent replacement of diesel. "This will be a tremendous relief for people in remote locations who need to travel great distances to obtain diesel," says Joe Madiath, executive director of Gram Vikas, an
ngo based in Orissa, who intends to start a field demonstration project with 10 biomass gasifiers in villages across Orissa. Gram Vikas is involved in energy plantation on more than 4,046 ha of revenue wasteland across 250 villages in Orissa. "When the forest department refused to grant permission to use forestlands, we approached the revenue department, which granted permission after a series of 'advocacies'," says Madiath. The forest department has enormous wasteland, but local people are not permitted to use the land, he adds.
One of the cited successes is the biomass gasification project in Orchha, Madhya Pradesh of Development Alternatives (
da). This 100-kw plant designed by the Indian Institute of Science, Bangalore, was set up with a capital investment of Rs 22 lakh and has been in operation for four years. It requires roughly one tonne of biomass per day to generate 80-100 kw supply of power to
da's campus, Taragram, which employs more than 100 workers.
Under the recently-restructured National Biomass Gasifier Programme, the government plans to focus on village electrification and industrial applications by investing in larger plants -- from 100-250 mw capacity. But the key problem with most gasifiers remains supply of raw material. Projects fail because no study is done to understand the biomass availability and possibility of growing plantations, say energy experts.
wind Blown away
POTENTIAL: 45,000 mw
INSTALLED: 1500 mw |
Wind energy has come a long way since it was first installed in the early 1980s. After a long period of stagnancy, wind energy gained momentum during 2001-02 when 250 mw was added. Says Jami Hossain, programme officer, energy and environment, Winrock International India, "The economic viability of wind energy was established in 1987 and soon many demonstration farms sprang up. We have reached the stage of big time business now." Over the years, the size of wind turbines increased from 55 kw capacity in the mid-1980s to 1,000 kw capacity in 2002. The size of wind farms also increased from 0.5 mw during 1985-87 up to 10 mw by 2002. In the mid-1990s, the cost of installation was 4.69 crore per mw. It has also been estimated that annual cost of generation from wind turbines of 225 kw rating is Rs 4.52 per kwh.
"Initially, discarded wind turbines were exported to India from developed countries, but these were not suited to the Indian wind conditions. But after 20 years of experience, the investor is no longer naive," says Rakesh Bakshi, managing director, Vestas
rrb, an Indo-Danish joint-venture company.
The location of the turbine is vital to capture the capacity of wind. Most wind turbines do not perform to their maximum capacity because their site is not exact. A common complaint is that the wind farms work at a low average capacity of around 8-20 per cent of their full potential. "Muppandal in Tamil Nadu has one of the highest capacity utilisation in India at 42 per cent due to good siting," says Bakshi.
Wind farms face problems of reactive power, or the electricity drawn by the wind energy generators from the conventional grid to start power generation. For instance, the Tamil Nadu Electricity Board does not permit reactive power of more than 30 per cent of the wind energy generated. But due to the unpredictability of wind energy, it can go up to 60 per cent at times.
"The technology still requires support. Whether the technology is proven or not will be known when the incentives are withdrawn," says Ramana. Experts suggest that companies should be made accountable by rewarding them with incentives on the basis of their performance. "Since the technology is mature in India, the urgent need is policy intervention to make the sector grow," adds Bakshi.
In Germany policy initiatives are the reason for growth of the wind energy sector. In 1991, the Electricity Feed Law was introduced, which obliges electric utilities to purchase renewable energy. Under the 250 mw programme, wind energy operators are given an incentive of
us $0.03-0.04 per kilowatt hour depending on whether the energy is fed into the grid or used by the operator.
hydro power Big hurdles
POTENTIAL: 15,000 mw
INSTALLED: 1,423 mw |
Calling 25 mw projects as
small hydropower (
shp) is not something Anil Joshi, from the Himalayan Environmental Studies and Conservation Organisation agrees. "The government only likes big projects, since they are economically viable for private companies but ignores small ones because these are for communities." According to him, technology is a constraint. He explains, "Companies come and install sophisticated technology developed at the Indian Institute of Technology (
iits) of Rourkee and Delhi and never return. When there is a technical snag, local people have problems repairing the machine."
Instead of new technology, the old technology of the water mill -- commonly found across the Himalayas -- should be upgraded to generate power. According to the National Watermillers Association, half a million watermills (
gharats ) can generate about 2,500 mw of electricity at the rate of 5 kw per mill. Taking cue, the Uttaranchal government has recently declared water mills as small-scale industries, which now allows their owners to upgrade their
gharats or water mills to produce electricity.
The Union ministry of non conventional energy sources (
mnes) has identified over 4,000 sites in different states to install small hydel projects. The policy is to encourage private sector participation. But pace of penetration has been poor. The investment costs of small hydro technology are higher because of the inaccessibility of the terrain. Energy demand is not much in remote areas. Moreover, transmission costs -- connecting to the network of distant grids -- make this energy source prohibitive. As a result, the private sector is not interested in investing in this sector.
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