As India grapples with power shortages, soaring energy prices, and looming threat of global climate change, solar energy has emerged as the most attractive sustainable energy option. Solar photovoltaics (PV) is an increasingly important energy technology as it contributes to global energy supplies with virtually no negative environmental impact, such as air pollution or hazardous wastes.
Looking at all aspects, there is no denying that this technology will help garner maximum benefits, however, current demand for solar power within the country is comparatively low. “But the future shines as bright as the sun,” says Vivek Chaturvedi, global head, sales and marketing, Moser Baer Solar Ltd. “The Indian solar PV market is expected to generate 700 MW-800 MW of power by 2011 and 4 GW-5 GW by 2014-15.” Moser Baer Solar Ltd is one of the leading manufacturers of solar cells, modules (panels) and is also an engineering procurement construction (EPC) player in India.
By Richa Chakravarty
Monday, April 11, 2011: Application of solar modules
Solar PV energy, a substitute for conventional energy, not only supplements existing power grid systems but generates electric power to remote areas that are far from conventional power lines. With stimulus from the government, grid and off-grid installations are the major application areas for solar modules. Today, solar panels are being used in homes and offices (solar panels are being installed on the rooftops of business establishments and residential buildings), lighting kits, telecom towers, solar charging stations, traffic signals, streetlights, rural households, irrigation pumps, etc. Most importantly, in rural areas, solar systems are providing villagers with access to basic electricity. “The rural populace have maximum use of solar power due to the non-availability of a regular grid supply. There are more than 69,000 villages, which are unelectrified. Uttar Pradesh, Bihar, Chattisgarh, West Bengal, Jammu and Kashmir, Maharashtra, Karnataka and Kerala utilise solar power for off grid applications,” says Raghu Nandan, vice president, engineering, Kotak Urja Pvt Ltd. The company not only manufactures crystalline PV but is also an integrated solutions provider.
The National Solar Mission is one of the major drivers that has led to the wider application of solar modules. “The focus of the solar mission in India is to build solar farms in the first phase and then move on to the rooftop category in the second phase. The third phase is about solar application,” informs Vivek Chaturvedi. The use of solar panels to generate commercial electricity is slowly gaining popularity.
Another wide use of solar panels is in charging electronic devices like cellphones. Solar power in the telecom industry has registered huge growth. The government is planning to make it mandatory for mobile phone towers to be powered by solar energy, hoping to cut pollution and cut down on a key guzzler of diesel in the country. Over 200 billion litres of diesel are used every year by up to 3,50,000 cell towers across the country. This initiative for cell towers will help cut the use of noisy, smoke spewing diesel gensets in tower operations and will prevent telecom operators from benefiting from the government’s subsidy on diesel, which is meant for the more disadvantaged sections of the population.
“Nowadays, most applications require a low voltage DC source or AC grid to supply the requisite power. Hence, battery charging, lighting, communication equipment, inverters, and onsite electricity generation, are some other primary applications of solar PV panels,” informs Sunil Goel, vice president, Maharishi Solar Technology Pvt Ltd. The company manufactures multi-crystalline silicon wafers for solar cells and modules.
The concept of passive solar architecture and building is also emerging. This architectural innovation promises to take on 40 per cent of the electrical load requirements of government and private buildings, especially in energy deficient areas.
What’s the latest in solar panels?
Wafer based silicon and thin film PV panels have been ruling the market. The high cost of crystalline silicon wafers has led the industry to look at less expensive materials to make solar cells. Thin film PV cells employ silicon and other thin films on supporting substrates such as glass, polymers, aluminium or stainless steel. The potential of thin solar panel film is excellent as manufacturing capacities are growing steadily. Recently introduced thin film materials show significant properties in terms of spectral response, temperature coefficients, flat incidence absorption and degradation effects. However, thin solar panel films are being looked at to reduce grid parity.
Estimated data shows that thin film solar modules in India are generating 5-8 per cent more energy than their installed capacity.
“In the thin film solar panel category, various other developments have taken place, such as amorphous silicon, which is the most developed of the complex thin film technologies. The industry has developed tandem and even triple layer devices that contain p-i-n cells, stacked one on top of the other. Thin film cells are being laminated to produce a weather resistant and environmentally robust module. Although they are less efficient, thin films are potentially cheaper because of their lower materials costs and larger substrate,” explains Ashok Thangavel, DGM, sales and marketing, XL Energy Ltd.
Currently, solar cell encapsulation is being used in panels. This improves performance and effectively lowers cost per kWh of solar power. Cell encapsulants rely on the UV stability of the silicon molecule to deliver improved durability and increased efficiency of crystalline molecules. This provides an ultra transparent layer of protection for the solar cell in the panel and can replace incumbent technologies.
Mitramax Energy’s latest innovations offers panel level energy optimisers. “Solar panels essentially converts every SPV module into a full fledged and independent solar power source, which in turn, enables what is called all parallel array architecture,” informs S Narayanamoorthy, director, Mitramax Energy Pvt Ltd. The company, division of Aplab Limited, provides innovative technology solutions for trendsetting solar power conversion. Their unique internationally patented super energy harvester helps harvest minimum 20 per cent extra energy over the conventional SPV system.
Developing technologies
While silicon PV dominated the market for a long time with a market share of 80-90 per cent, now companies are looking for innovative technologies. Concentrator solar power (CSP) is one of them. A concentrator is a mirror that reflects additional sun radiation to the solar panels. By this method, the solar panels get more light and produce more electricity. Although concentrators have not yet achieved widespread application in PV, solar concentration has been widely used in solar thermal electricity generation technology, such as generating power from a turbine. “The key benefit of the concentrator device is in reducing the physical size of the receiver relative to the area in which light is gathered. Concentrated PV has the highest efficiency of all the available PV technologies. However, it is more suitable for sunny locations as it will not operate under cloudy conditions,” informs Raghu Nandan.
Organic solar PV is another technology that is being developed. This latest technology can produce solar panels that are like transparent plastic sheets. The optical absorption coefficient of organic molecules is high, so a large amount of light can be absorbed using fewer materials. With this technology, not only will the new solar cells be easier to install, but they will be cheaper compared to the current PV technology. The new organic solar PV technology will dramatically increase the possible applications for solar technology. However, the disadvantages associated with organic PV cells are low efficiency, low stability and low strength compared to inorganic PV cells.
Oerlikon Solar, a Swiss company’s proprietary Micromorph module technology combines two different silicon materials—amorphous silicon and a micro-crystalline silicon in a top and bottom cell, respectively. The amorphous top cell converts the visible part of the sun’s spectrum, while the micro-crystalline bottom cell absorbs the sun’s power in the near infrared spectrum. Consequently, Micromorph module technology boosts efficiency levels up to 50 per cent higher than traditional amorphous single cells. This process not only reduces energy production costs, it also has the potential to achieve conversion efficiencies of more than 10 per cent.
“With technological upgradation, we are in a position to offer the entire spectrum of solar panels—from a small panel for solar lanterns to the world’s largest thin film panels for solar farms. We are focusing on introducing lighter products that are eco-friendly and are easy to install,” says Vivek Chaturvedi.
According to Ashok Thangavel, “The use of laser doped selective emitters (LDSE) is picking up globally. This technology uses a laser in the presence of a phosphorus doping source to melt the silicon lying beneath the overlying anti-reflection coating/phosphorus source. This improves performance compared to standard screen-printed solar cells using the same wafers and materials. It is highly suited to large scale commercial production because of its simple, low cost, high-throughput characteristics.”
Cost of installation
Though the government’s generous incentives have ignited the market’s interest, there is still significant financial pressure on solar project developers, as financial and economical viability is severely constrained by the high cost of technology. There are various factors that come into the picture while deciding the cost of panels—it depends on the type, wattage and brand of the panel. Solar panels of the same size may produce variable amounts of electricity, depending on their quality and the technology being used to produce these modules. New technology has not only opened new avenues but the prices of solar cells have also reduced. Moreover, as the government is in favour of this technology, the current budget provides exemption on excise duty for solar cells. This will have a direct impact on the cost of solar panels and related products.
Other factor impacting module cost is the watt-peak (Wp) concept. It is due to the high cost of installation that solar energy is not yet commercially viable. Today, the cost of grid installation is around Rs 130-140 billion per MWp.
Buyers face challenges
“The lowest cost of ownership and the highest yield is the prime demand of buyers,” informs Kumud Tyagi, vice president, Bergen Associates Pvt Ltd. Apart from the choice of technology and the quality of panels, cost is one of the deciding factors for buyers today. Short delivery periods, low cost and flexibility is what buyer want. She strongly feels that buyers should always check the value of their investments.
“With technological upgadation, buyers today prefer to have low weight modules along with lesser light induced degradation,” says Ashok Thangavel.
The biggest challenge faced by buyers today is lack of information and knowledge about a reliable partner on whom they can depend upon in all segments. “The absence of large reliable players has resulted in the import of substandard products, which do not last or perform well. This has resulted in erosion in the public’s belief in solar products. This is where large established brands can play a major role in rebuilding confidence in solar energy,” opines Vivek Chaturvedi.
Since this technology involves huge capital investments, the quality of panels is the most important aspect in a solar PV system, which translates into reliability for off grid applications and bankability for grid applications. Since this product needs to be warranted for 25 years, the credentials of the vendor become extremely important. “Now solar is the buzz word for many. And every one is aggressive for getting a pie. Hence, identifying the right product and right supplier and their past reputation is of paramount importance,” adds S Narayanamoorthy.
Along with quality, after sales support is another problem faced by buyers. Warranties and maintenance should be carefully studied in order to minimise failure in power generation. The important factor here is to check the credibility of guarantees and warranties provided by the supplier. The developer should have the confidence that the company giving 25 years of warranty will remain in the business to honour that guarantee.
Mostly buyers end up facing problems like low output, safety, lower capacity supply than ordered, lower efficiency of cells and obsolete technology. Buyers should always go in for standard and certified products that will help them in the long run. It is essential for a buyer to select the modules from IEC certified companies.
Leading players in the solar modules domain
- Bergen Associates Pvt Ltd
- Bharat Heavy Electricals Ltd
- Central Electronics Limited
- Indosolar Limited
- Kotak Urja Pvt Ltd
- Maharishi Solar Technology
- Moser Baer Solar Ltd
- Microsol Power (P) Ltd
- Oerlikon Solar Ltd
- PV Powertech Pvt Ltd
- Reliance Industries Ltd
- Sharp Business Systems (India) Ltd
- Tata BP Solar India Ltd
- USL Photovoltaics Pvt Ltd
- XL Energy Ltd
How to take a sound purchase decision
While making a purchase decision, buyers should make sure that they choose the best technology that suits their requirements. Power output tolerances, warranty conditions, and product reliability feedback should be taken into consideration. Kumud Tyagi strongly feels that buyers should check value for their investments. “A buyer should be careful during the installation of the panel and when designing the system’s installation, as these play extremely important roles,” she adds.
“Efficiency of modules, credentials of the supplier and a bankable brand which indeed leads to a quality product are the safest options for the buyer,” opines Ashok Thangavel.
The best way to check out efficiency while making a purchase decision is to ask for the kilowatt hours/kilowatt peak that will be delivered by the farm, in the particular geography, informs Vivek Chaturvedi.
Next to cost comes the performance of the modules. The standard test condition (STC) needs to be understood while buying modules. “The efficiency is a direct function of power output in the given area of the module. The power generated by it at STC will the STC data and field performances will vary to some extent. Customers can do a FAT (factory acceptance test) before the shipment of modules to a site,” informs Raghu Nandan.
Another element that comes into the picture is the EPC contractor. Solar power generation being a new field, it is attracting a lot of new players, some with no prior experience. So the buyers should go ahead with companies with proven track records of delivering on large scale projects. Installation of these panels and design play an important role in power generation. Thus, the systems integrator should have a thorough knowledge of the technology, which would benefit the buyer.
So, while making a purchase decision, look for the following:
• Efficiency of the modules—the higher the efficiency, the more watts of electricity the consumer will get per volume of material used in the solar panel. Generally, the higher the efficiency, the smaller the panel a buyer will need.
• Buyers should check the history of the supplier since the warranty period on the output is quite long—20-25 years—and the initial investment is high.
• A customer should check the financial stability of the supplier because of the long warranty period. This is to make sure that if something goes wrong with the modules in the future, the customer should not have to bear the loss.
• The modules should adhere to international safety standards.
• Buyers should check the supplier’s records of the output diminishing curve over the life period of the modules.
• The technology used in production matters a lot.
• Technical parameters, especially for grid-tie power generation projects, should be checked.
• The capability of the supplier to deliver on time needs to be checked.
Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine
