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SOLAR DEVELOPMENT IN INDIA

Niyant Singh, Department of Electronics and Telecommunication, Bharati Vidyapeeth College of Engineering, Navi Mumbai.

Abstract

Today, India has the largest decentralized solar energy programme, the second largest biogas and improved stove programmes, and the fifth largest wind power programme in the world. Primarily my aim is to explain people about the emerging solar field in India. The main reason for no quick development is because general public is still unaware about solar products and the benefits of renewable energy. Photovoltaic’s can provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between. Concentrating solar power technologies use reflective materials to concentrate the sun's heat energy, which ultimately drives a generator to produce electricity. Hence in this report I have covered every single aspect of solar power from basic solar cell to uses applications, products, market and future plans. This report gives an overview of the menu of technologies and the scope for solar development in India. It tells the people in brief about the current position of solar energy in India, the potential in various areas and the targets that the country has set for itself, thus preparing the ground for more comprehensive information and a ready reckoner. We realize the purchase of a photovoltaic system can be a challenging task. Here you can find information about how solar power is generated, how solar systems are constructed and function.

ALL YOU WANTED TO KNOW

ABOUT SOLAR CELLS

How is solar energy generated and how

much of it can be tapped?

Solar energy is generated by converting sunlight into electricity. The potential of solar power can be estimated from fact that, on an average, each square meter of land is exposed to enough sunlight to produce 1700 kWh (or units) of power every year. That’s enough to power two 100W bulbs for 24 hours a day, throughout the year.

What are the main technologies used to

harness solar power?

Photovoltaic (PV) systems and concentrating solar power (CSP) plants are the two most important solar technologies. In India, the technology most commonly in use domestically is the solar water heating system.

How does a PV system work?

Figure 1: Working of a PV cell

At the heart of the PV systems are PV cells that do the conversion. A number of PV cells combine together to make a PV module or the so called ‘panels’. Normally the bigger the panel, the higher it’s power generating capacity. The panels collect photons- particles of solar energy- from the sun, and convert them into electrical power. The power created then flows into an inverter to convert it into a form (AC

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current) that is acceptable to electrical applications.

Figure 2 : the basic solar Cell, a Module or Panel

and an Array of solar cells

How do CSP Plants work?

CSP or Solar thermal power plants generate power like conventional power systems. But instead of using fossil fuels, they use solar energy. Gigantic arrays of mirror reflectors concentrate the suns radiation to produce steam, which drives a turbine to generate electricity.

Figure 3: solar Power tower surrounded by a field

of heliostats( huge mirrors) which concentrate

sun’s heat at one point

What are the major applications of PV

and CSP systems?

PV systems have been used to power small and medium sized applications, from the calculator, which is powered by a single cell, to off-grid houses, which are powered by an array of cells. Multi-megawatt (MW) PV plants are also slowly gaining ground. CSP is used for large scale generations of electricity, It is ideal for Sun-drenched regions like Parts of Rajasthan and Gujarat- for utility scale generation, Abengoa’s solar 11 MW solar power tower

near Seville in Spain produces electricity with 624 large movable mirrors called heliostats(see picture)

Figure 4: A CSP plant showing mirrors

concentrating sun’s energy on thermally insulated

steel pipe carrying heated water to turbines

How energy efficient is PV technology?

Efficiency is measured by the proportion of sunlight that a PV cell can convert to electrical energy. The first Solar cell, Created in 1883, had an efficiency of 1%. Today, most commercial PV devices have efficiencies of 16-20%. Incredibly, the National Renewable Energy Laboratory (NREL) in the US recently engineered a device that converts a stunning 40.8% of sunlight that hits it into electricity.

Figure 5: A simple solar PV Panel (first of its kind)

What are the different kinds of PV cells?

There are three generations of Photovoltaic cells, based on the materials they are made of (see pictures).

The first generation, Crystalline Silicon, is made of one or more small silicon crystals. It accounts for about 90% of cell production today. To make an effective PV cell, silicon is "doped" to make it n-type

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and p-type. The challenge here is to carve the thinnest of Wafers, as this translates to smaller quantity of expensive Silicon- and therefore, lower costs. Wafer thickness has dropped from 0.32 micrometres in 2003 to 0.17 micrometres in 2008 (1 micrometre =

1/1000 millimetre).

Figure 6: A C-Si (Crystalline silicon) solar panel

Thin films are the second generation. Thin film modules are made by depositing extremely thin layers of photosensitive materials on to sheets of glass, stainless steel and even plastics.

Today, amorphous silicon is commonly used for solar-powered consumer devices that have low power requirements (e.g., wrist watches and calculators).

Amorphous silicon absorbs solar radiation 40 times more efficiently than does single-crystal silicon, so a film only about 1 micron (one one-millionth of a meter) thick can absorb 90% of the usable solar energy. This is one of the most important factors affecting its potential for low cost. These characteristics make amorphous silicon the leading thin-film PV material.

The third generation comprises nano and organic PV (OPV) cells. Nano materials possess higher strength and flexibility and have displayed the ability to trap more energy than conventional PV cells. OPV cells mostly contain organic molecules. Some scientists believe OPV cells will be a cheaper alternative to traditional inorganic cells due to the economics of scale derived from large-scale production of organic polymers.

Figure 7: A Nano solar cell

Silicon is still the most popular solar-cell material for commercial applications because it is so readily abundant (it is actually the second most abundant element in the Earth's crust-second only to oxygen!). However, to be useful in solar cells, it must be refined to 99.9999% purity.

Balance of System

We may think of a complete PV system as comprising three subsystems. On one side, we have the PV devices (cells, modules, arrays, etc.) that convert sunlight into direct-current (dc) electricity. On the other side, we have the load, or the application for which the PV electricity is intended. Between these, we need a third subsystem to enable the PV electricity to be properly applied to the load. This third subsystem is generally referred to as the "balance of system" or BOS

Figure 8: balance of system

This simple illustration shows the elements required to get the power created by the PV system to the end load (in this example a house). The stand-alone system (a) uses battery storage to provide dependable dc

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electricity day and night. Even for a home connected to the utility grid (b), PV can produce electricity during the day (converted to ac through the power conditioner). This configuration is desirable because extra electricity can be sold to the utility during the day, and the utility can in turn provide electricity at night or during poor weather.

The BOS typically consists of structures for mounting the PV arrays or modules and the power-conditioning equipment that adjusts and converts the dc electricity to the proper form and magnitude required by an alternating-current (AC) load. If required, the BOS also includes storage devices, such as batteries, for storing PV-generated electricity to be used during cloudy days or at night

Do Solar systems produce Electricity all

the time?

They can if they store the Sun’s energy either in batteries or any other medium. Otherwise they will generate electricity only when the sun is shining.

Do they work when it’s cloudy or cold?

Yes, on cloudy days their output reduces, in proportion to sunlight they receive, when it’s cold (and sunny), they work well and, in fact, generate more power at lower temperatures. This is because, as with most electronic devices, they operate more efficiently when it’s cooler.

How long do PV systems last? Are the

PV modules brittle?

A PV system that is designed, installed and maintained well should run for atleast 20 years. The basic PV module has no moving parts and can last more than 30 years, unless struck with heavy force, PV modules will not break easily. They are designed to withstand all kinds of extremes, including arctic cold, desert heat, tropical humidity, high- speed winds, even hailstones. Even if they break, unless the cells are damaged, the system will continue to work.

What is Grid parity?

It is the point at which the cost of producing solar energy is equal to or

cheaper than existing grid power. The current challenge in the race to achieve grid parity is to push down manufacturing cost of PV cells to sub-dollar levels, from $2-2.5 (for crystalline silicon) and $1.35 (for thin films) today.

APPLICATIONS OF SOLAR

ENERGY:

Today, solar-generated electricity serves people living in the most isolated spots on earth as well as in the centre of our biggest cities. First used in the space program, PV systems are now both generating electricity to pump water, light up the night, activate switches, charge batteries, supply the electric utility grid, and more. Whether you are a homeowner, farmer, planner, architect, or just someone who pays electric utility bills, PV may already touch your life in some way.

Simple PV systems

The same sunny days that dry out plants, make animals thirsty, and heat up buildings and cars are also good days for generating electricity with photovoltaics. This electricity can be used to power water pumps for irrigation and drinking wells, and ventilation fans for air cooling. For this reason, the simplest PV systems use the dc electricity as soon as it is generated to run water pumps or fans.

Figure 9: A woman drawing water from PV

powered pump

PV with battery storage

Storing electrical energy makes PV systems a reliable source of electric power day and night, rain or shine. PV systems with battery storage are being used all over the world to power lights, sensors,

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recording equipment, switches, appliances, telephones, televisions, and even power tools

Figure 10: A Solar Lantern with batteries powered

by PV system.

PV systems with batteries can be designed to power dc or ac equipment. People who want to run conventional ac equipment add a power conditioning device called an "inverter" between the batteries and the load

PV connected to utilities

Where utility power is available, a grid-connected PV system can supply some of the energy needed and use the utility in place of batteries.

Figure 11 : A PV battery charging station for

electric vehicles

The owner of a grid-connected PV system can not only buy, but can also sell, electricity each month. This is because electricity generated by the PV system can be used on site or fed through a meter into the utility grid. When a home or business requires more electricity than the PV array is generating (for example, in the evening), the need is automatically met by power from the utility grid.

Utility-scale Power

Large-scale photovoltaic power plants, consisting of many PV arrays installed together, can prove useful to utilities. Utilities can build PV plants much more quickly than they can build conventional power plants because the arrays themselves are easy to install and connect together electrically. Unlike conventional power plants, PV plants can be expanded incrementally as demand increases.

Figure 12 : A nuclear to solar converted 2 MW

power plant in California serves 660 homes.

Hybrid Power systems

Hybrid systems combine a number of electricity production and storage pieces to meet the energy demand of a given facility or community. In addition to PV, engine generators, wind generators, small hydro plants, and any other source of electrical energy can be added as needed to meet energy demands and fit the local geographical and temporal characteristics. These systems are ideal for remote applications such as communications stations, military installations, and rural villages.

Figure 13 : A hybrid (wind and Solar) power

system

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Water Heating and Cooking

Figure 14 : A typical Solar water heating system

Solar hot water systems use sunlight to heat water. Total installed capacity of solar hot water systems growth is 14% per year. China is the world leader in the deployment of solar hot water systems with 80% of the market. Solar water heating is highly efficient (up to 86%) and is particularly appropriate for low temperature (25-65 °C) applications such as domestic hot water, heating swimming pools and space heating. The basic components of a solar water heating systems are solar thermal collectors, a storage tank and a circulation loop.

Solar cookers and CSP systems use sunlight for cooking, drying and pasteurization. Solar cookers offset fuel costs and reduce demand for local firewood. Solar cookers also improve local air quality by removing a source of smoke. The most common designs are box cookers, concentrating cookers and panel cookers

Figure 15 : Women in Rajasthan Using CSP system

to cook

ADVANTAGES AND DRAW-

BACKS OF SOLAR ENERGY:

Advantages:

Solar energy is a renewable resource. Although we cannot utilize the power of the sun at night or on stormy, cloudy days, etc., we can count on the sun being there the next day, ready to give us more energy and light. As long as we have the sun, we can have solar energy.

Solar cells are totally silent. They can extract energy from the sun without making a peep. Now imagine the noise that the giant machines used to drill for and pump oil make!

Solar energy is non-polluting. Of all advantages of solar energy over that of oil, this is, perhaps, the most important. The burning of oil releases carbon dioxide and other greenhouse gases and carcinogens into the air.

Solar cells require very little maintenance (they have no moving parts that will need to be fixed), and they last a long time.

Although solar panels or solar lights, etc., may be expensive to buy at the onset, you can save money in the long run. After all, you do not have to pay for energy from the sun. On the other hand, all of us are aware of the rising cost of oil.

Solar powered lights and other solar powered products are also very easy to install. You do not even need to worry about wires.

Disadvantages:

Here are the only disadvantages of solar

energy:

Solar cells/panels, etc. can be expensive (until 2010; now things are changing).

Solar power cannot be created at nights still now methods have been researched to store solar generated electricity through various ways.

As you can see the advantages of solar energy create a much longer list that the disadvantages and the disadvantages are

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things that can be improved as technology improves.

SOLAR POWER, THE BIG

PICTURE:

The Cost Factor

One area that needs a stimulus is the manufacturing space. India cannot afford to miss the solar bus as it did the electronics one decade ago. The need to ramp up and bring in economics of scale is imperative. In solar the fundamental challenge is technology and cracking the barrier of $ per watt manufacturing cost to enable grid parity. Unlike in other sectors, it’s not merely a volume up, cost down game in solar. The key is to pursue electron-level strategies, improve efficiency and cut-off costs.

In sophistication, accuracy and efficiency we are as good s the west. The question is “can they do it cheaper than us”.

Oil’s well, but Solar is better

The shift to solar is inevitable because other energy sources have limitations. Designing and building a nuclear plant can take as long as eight years. Oil on the other hand, may seem attractive today, at $ 35 a barrel, but it is volatile. It would be foolish for India to wait until the next round of high oil prices to act. Moreover, oil is finite. OPEC countries, sitting on insufficient oil assets, nearing end-life, will have to make huge investments in production. “It won’t be profitable for OPEC to sustain low prices for long. Oil will go to $ 80 a barrel and above within the year.” predicts shubhranshu Patnaik, Executive Director, Pricewaterhouse Coopers.

Again, coal, which fires the majority of India’s power plants, is expected to suffer a global supply shortage. By 2011-12, importing costly coal will be unviable as generation cost will go up three times,” says SP Gon chaudhuri, Managing Director of WBGEDC. Even among renewable options such as wind, hydro or biomass-based generation, solar scores, and policymakers are factoring this into

stratagems. “The energy challenge is critical, it cannot wait,” says Shyam Saran, The Prime minister’s special envoy on climate change “Solar Power appears to be most promising when compared with other renewable sources.”

Nearly 76 million Rural Households in India do not have access to electricity. While efforts to take grid power to them are on, the general belief is that they are unwilling or unable to pay for modern forms of energy, such as solar power. This is a myth, and villagers from different corners of India have proved it to be so. Take the case of Gorhori Maity, a poor farmer who ekes out as living from 1.5 bighas of land; Maity pays Rs. 100 for three light points drawn from a 110 kW solar mini-grid in the sundarbans. “It’s difficult but I scrape through,” he says. Down south, in Karnataka, Narayanpatti, a silk Farmer in Devenhalli village, has been paying monthly bank instalments of Rs. 1,200 for a solar home lighting system [SHS] costing Rs. 23,000. In Bhopu Dhani village, Rajasthan, Hema Ram purchased an SHS without even seeking government subsidies. “The paperwork is cumbersome,” he says. The village is supposedly on the future grid-extension map and official’s invariable fob off villagers seeking solar subsidies. “We have waited long enough for grid power,” Says Ram.

Grid power is a carrot that successive government have held out as the solution to all power problems, urban or rural. Where it is not technically or economically feasible to link remote and inaccessible villages, the government has been pushing renewable. But the fact is, much more can be done. Large chunks of the rural hinterland can be provided power through decentralised distributed generation systems. Solar power has proved very successful wherever it has been tried. Be it through standalone SHSs or mini grids, it has delivered electricity locally, where it is needed. However, while its feasibility has been proven form some time now, it lacks scale –penetration has been appallingly low. Around 800,000lanterns have been delivered in Rural India. The west Bengal Energy Development agency solar power plants in sunderbnas have aggregate

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capacity of 707 kW. It benefits only 3450 households. Another 35000 households owns SHS. Even then 20 % of population is served. Even in Sunny Rajasthan 83 villagers have 10 kW solar power plants. 10 kW power plant serve 50 house hold on an average. The one area of worry for the penetration is the cost of the solar system offered to the villagers. Even with 50 % subsidy they are not able to go ahead with the solar power plan

JOB CREATOR

Solar energy will create a new class of jobs when they are most needed. On the one hand solar energy will make a long way in addressing India’s mammoth power requirements. On the other, it will generate employment by creating jobs. Given Unemployment is rising by the day the latter will prove to be a boon. The ILO (International Labours Organization) predicts that the number of unemployed people will rise from 190 million in 2007 to 210 million by end of 2009.due to the financial meltdown. The so called ‘Bottom of the pyramid’ is set to widen as another 40 million will join those below poverty line. India will feel the impact.

Situations Vacant:

2010 2015 2030

Installation 166,518

486,219

2,770,569 Production 47,306 128,12

1 524,729

Wholesaler 14,192 38,436 157,419

Research 6,150 16,656 68,215

Supply 17,740 48,045 196,773

Total 251,906

117,477

3,717,705 Table 1: Jobs in Solar sector in future years

(source: (EPIA) European photovoltaic industry

association)

However there is hope. Solar Power has the potential to generate jobs across hierarchies, quickly. That is why President Barack Obama wants to invest $150 million on renewable, to meet 30% of Americas energy needs by 2030 and would create over 5 million jobs. A conservative estimate by the European photovoltaic industry association predicts nearly 4 million jobs in PV-sector worldwide by 2030(See Table)

LET THERE BE MORE LIGHT

Rays of Hope

To stimulate demand for solar power, some countries have adopted renewable energy programmes employing various financial incentives. On the supply side, the ongoing credit crisis is limiting the availability of capital or simply cautioning institutions to lend less. The shadow of recession is impending new projects and the political will to fund incentive programmes. At the same time, we are seeing the emergence of more financing schemes.

California has proposed to issue bonds to finance the installations of solar power systems, with repayment over an extended period as a surcharge on property taxes. In Germany renting out the commercial roof space for solar power is providing adequate returns to investors. The rising demand for PV modules has led to shortages in raw material. This supply crunch pushed process up, which acted as n incentive for the silicon industry to bring additional production into the market. Increase in supply will bring down module prices. This will in turn bring solar generation tariffs down to the level of grid tariffs, leading to more investment flowing into solar generation projects.

Gleaming Future

In India, solar power generation, at only about 2.5 million units per years, forms a negligible part of the country’s renewable energy portfolio. Earlier this month, the ministry of New and renewable energy launched a scheme to provide financial support for the installation of grid interactive solar power in the 11th five year plan (2007- 2012); the limit is 50 MW for the country and 5 MW for individuals plants. The programme is better suited to solar PV plant due to the low generation limit on individual plants. Solar thermal plants require a larger generation capacity to be visible and would, therefore, not benefit much from such scheme.

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Commercial funding options for standalone solar generation projects, especially in developing countries like India, have not yet taken off. This is because the cost of generation hasn’t reached grid parity.

A successful solar venture should be structured with a narrow, well-defined target market so that the investment offering can be adequately addressing a relatively homogenous set of needs.

Economics of scale play a big role in making solar project sustainable. Without a sizeable service population, a private solar company cannot run into collection issues and maintaining systems.

A supportive legal environment is critical. these includes factors like incentives for solar energy or absence of competing subsidised electricity, long term government electrification plan and legal basis for enforcing loan collections.

Commercial grid tied projects are becoming increasingly important in countries where the local solar PV market is beginning to build scale or in countries like India, China and Algeria, where incentives or subsidy programs have been announced. This would help long term investors in preparing the ground for anticipated future growth.

CONCLUSION

Even though energy from renewable energy sources is growing rapidly, the overall share is only expected to increase marginally over the coming decades as the demand for energy also grows rapidly, particularly in many developing countries. In India, the scientific focus is deliberately moving towards transforming coal into clean energy as well as harnessing hydropower. The recent surge in nuclear energy is also diverting focus from the solar energy enhancement. In all probability, the Indian government will support off-grid solar energy production through a decentralized manner. In spite of this, India needs to focus research on solar

energy and cheaper photovoltaic’s to provide affordable energy to all.

Also we should learn ‘What it takes to innovate technologies is different from what it takes to industrialize them’

In conclusion, the question is not whether, but when, the goal of a self –sustaining solar market in developing country like India will be achieved.

References:

• ‘Shadows and Light’ and ‘What, Where, How…..’ by Naren Karunakaran in Business Outlook magazine -Feb 09.

• ‘Island in the sun’ and ‘Power to the people’ by Naren Karunakaran in Business Outlook magazine- Feb 09.

• ‘Let there be more light’ by Soumya Banerjee and Priyanka Sood in Business Outlook magazine-Feb 09.

• www.suryaprakash.com/tech.htm

• http://web.mit.edu/newsoffice/topic/solar.html