With clear, sunny skies for around 300 days of the year, arguably nowhere in the world is better placed to benefit from solar energy than India, where over 5,000 trillion kilowatts per year of potentially harness-able sunlight falls onto its land surface each year.

To exploit this huge natural resource, and position the country as a global leader in solar power, the government has set ambitious goals for the burgeoning domestic renewables market, launching the Jawaharlal Nehru National Solar Mission in 2010, which aims to see 20,000 MW of grid connected solar power by 2022 and drive down the cost of solar generation.

One of the key approaches set out for meeting those targets is the encouragement of large scale installations - and those do not come any larger than the plans recently announced for a new solar plant at Sambhar, in Rajasthan, which is set to be the most powerful in the world.

The world's largest solar plant

At a nominal capacity of 4 gigawatts, everything about the project comes on a grand scale. It will occupy some 77 square kilometres - 23,000 acres - of ground, be built over four phases at a total cost of around $4.4 billion USD, and could ultimately support up to an estimated 20,000 jobs. With just Phase 1 commissioned, scheduled for late 2016, at 1,000 megawatts it will be India's largest solar facility by a factor of ten; once fully completed, by around 2021, it will itself contribute three times the entire country's current grid-connected solar-power capacity.

Phase 1 is to involve a joint-venture of state-owned companies, including Bharat Heavy Electricals, the Solar Energy Corporation and the Power Grid Corporation, with the models used to implement subsequent phases being influenced by experience gained during the initial phase.

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Described as a trend-setter for large-scale solar power developments by Solar Energy Corporation director Ashvini Kumar, the generation cost projections for the plant suggest that solar energy could finally achieve grid parity in India - a big step towards the goals of the National Solar Mission.

Competitive costs

India has boosted its installed solar capacity from just under 18MW in 2010, to more than 2,000MW, and the falling prices of photovoltaic cells, coupled with their improved efficiency have played a significant part in that progress. Over the period, the cost of solar generation has been steadily dropping - from about 18 rupees per kilowatt-hour ($0.29USD /kWh) then, to around 7 rupees ($0.11USD) today, according to figures from the Ministry of New and Renewable Energy.

Economies of scale at the proposed Sambhar plant are tipped to cut that still further, to perhaps as low as 5 rupees per kilowatt-hour ($0.08USD/kWh) - and that would begin to bring it near enough to the typical prices for coal, nuclear or natural gas generation to make solar genuinely competitive.

Ultra Mega Green Solar Power Project

"Small scale local initiatives – particularly solar home lighting projects – have already met with notable success across rural India."

There are other benefits too. With an estimated life of 25 years, and expected to supply 6.4 billion kw/h of 'clean' electricity per year according to government sources, the plant could help slash India's CO2 emissions by over 4 million tonnes a year. It might also go a long way towards cutting the 100,000-plus annual death toll, and millions of cases of respiratory ailments, that a report last year from the Mumbai-based Conservation Action Trust blamed on pollution from coal-fired generation.

It has been dubbed the "Ultra Mega Green Solar Power Project" - a reference to the country's ultra mega coal-fired schemes - but not everyone is convinced that bigger is always better when it comes to renewable energy.

Chandra Bhushan of New Delhi's Centre for Science and Environment is one who has raised concerns. Calling for a decentralised approach, he argues that a larger number of much smaller solar schemes, spread throughout the country's vast rural areas, would bring considerably more social and developmental benefit and points to problems with the grid. Transmission and distribution losses account for a fifth of the power in the system and around half of the people living outside cities have no access to electricity at all.

Small scale local initiatives - particularly solar home lighting projects - have already met with notable success across rural India, and there is no escaping the fact that solar power is probably the most well-suited of all renewables for such community-based applications. Reaping the full rewards of the upcoming generation of big grid-connected plants will, clearly, require a major infrastructure upgrade, but many worry that it could come at the expense of these smaller projects.

Stumbling blocks in the quest for sustainable solar

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Long before that, however, there are other potential stumbling blocks on the road ahead. India has something of an unfortunate history of bureaucratic roadblocks when it comes to mega-projects, at times bogging them down in delays and red-tape. With both local and international private industry being lined up to finance the second, third and fourth phases of the Sambhar plant, it remains to be seen how possible investors will view things, despite the evident support of the Indian government.

If that funding were to prove slow to appear, much of what the project is hoped to achieve might be called into question, not least because it is only with the economies of scale that result on full completion, that the crucial drop in generation costs becomes achievable.

Future directions for India's solar power industry

Looking to the wider ambitions of India on the global solar stage and Prime Minister Manmohan Singh's stated aim to put the sun "centre-stage" in the national energy mix, it is clear that even with this project in the offing, there is still some way to go. With China having installed 12GW in 2013 and the goal of having 35GW by 2015, market intelligence company Bridge to India concluded:"In comparison, the National Solar Mission target of 20GW by 2022, does not look as ambitious anymore." Nevertheless, as World Bank country director Onno Ruhl said at an international energy seminar last year, India does have the potential to be a world leader.

Harish Hande, managing director of the Solar Electric Light Company India, has described India's state of "paradox between an overdeveloped and an underdeveloped world" and urged a shift in thinking, away from the old models which worked in the past, towards more localised solutions for the nation's energy needs. To date, it appears that the Indian solar market has been largely shaped by policy driven schemes to meet capacity demands; delivering Hande's vision may call for more and different options to be considered as the country moves into its solar future.

If that can be achieved, India's ambitions will be within its grasp, and the millions of Indians who perform the devotional namaskara to the Hindu sun god Surya at dawn will have reason to remember that one of his alternative names is Mitra - often taken to mean 'friend'.