Chemical Guide

The relatively small scale of India’s largest solar power plant, the 5-megawatt Sivaganga project that constructor Moser Baer brought on stream in the southern state of Tamil Nadu last month, illustrates the enormity of the renewable energy challenge ahead for the world’s third largest energy consumer behind China and the United States.

India has set a target of generating 20 gigawatts (GW) of installed solar power by 2022, up from only about 15 MW now that is grid-connected.

That sounds a substantial increase, but China — which is already the world’s largest maker of photovoltaic (PV) solar panels — aims to hit the 20-GW mark well before 2020, and the United States aims to expand its domestic capacity of PV systems to as much as 10 GW by 2015.

As well, the US is pushing ahead with utility-scale concentrating solar power plants, which use reflectors to concentrate the sun’s heat energy and ultimately drive a generator to produce electricity. In the past few months it has given loan guarantee approvals to seven plants in the desert areas of California and Arizona with total capacity of up to 3 GW, including NRG Energy’s 392-MW Ivanpah project in the Mojave Desert that aims to be operating by mid-2013.

Globally, the largest solar power plants now in use are the 80 MW photovoltaic plant at Sarnia in Canada’s Ontario province, and the 60 MW Olmedilla photovoltaic park in Spain.

There are scores of other plants around the world in the 20 MW to 50 MW range, and the US Department of Energy in recent weeks has given crucial lending commitments to two more large-scale projects in Arizona state: NRG’s 290 MW Agua Caliente photovoltaic project in Yuma county, and the 250 MW Solana project near Gila Bend. Solana is a concentrating plant which will use 900,000 mirrors in a parabolic trough to concentrate heat.

The US government says it will be the first large-scale solar plant in the United States capable of storing the energy it generates.

The global push for affordable solar power is driven by the realisation that even with intense energy conservation measures, energy demand will only grow as more of the world’s 6-billion-plus people join the consuming class.

According to the International Energy Agency’s mid-range scenario released in November last year, global energy demand will grow 36 per cent between now and 2035.

Though fossil fuels such as oil, coal and natural gas will remain the dominant sources of energy through to 2035, nuclear power and renewable energy sources such as solar power will shoulder a greater share of the burden.

The IEA says that for power generation, the role of renewables will grow from 19 per cent in 2008 to 32 per cent by 2035. It also says that decisions by China and India will shape much of the energy demand outlook.

Under its National Solar Mission plan unveiled two years ago, India aims to have 1300 MW of solar power installed by 2013, rising to 10 GW by 2017 and eventually 20 GW by 2022.

As a part of that plan, the government last month chose 37 companies to build solar power projects of up to 100 MW in size. But will it be some time before many of those plants come on stream, and most of them are in the “pilot project” 1-5 MW range.

In the meantime, Indian optical disc-maker turned solar power pioneer Moser Baer has commissioned the $20 million Sivaganga solar plant for Tami Nadu’s Energy Development Agency on December 21, and connected it to the state’s 110-kV grid. The International Finance Corporation and the IDBI bank backed the project, which has 61,000 modules of solar panels arrayed on a 26-hectare site. Moser Baer said the plant used its amorphous silicon thin film technology, which is considered among the most suitable technology for Indian climatic conditions.

Power from Sivaganga will contribute to the peaking power supplies for nearby parts of Tamil Nadu over the next 25 years.

Moser Baer has other projects in the pipeline, including in Gujarat state and another 5 MW plant on the books for a site in Osiyan, Rajasthan, in the heart of the Thar desert. This is one of the sunniest and driest places in India, making it ideal for solar power. In the next few months another Indian solar energy pioneer, Astonfield Renewable Resources, is expected to commission its own 5 MW solar PV plant at Osiyan.

While India’s solar plants look small-scale, there is another dimension to the industry – the thousands of micro projects that already use solar-powered panels and batteries. Farmers across rural India are replacing diesel power with solar to run their water pumps, there are more than 50,000 solar street lighting systems, close to a million solar lanterns and home lighting systems, plus water heaters, cookers and hundreds of small power plants atop office buildings and homes.

Wind power is also in the global energy mix. China already leads with production and use of wind turbines, while last month US Energy Secretary Steven Chu announced a partial loan guarantee for a US$1.3 billion loan to support the world’s largest wind farm. This is the Caithness Shepherds Flat project, an 845-megawatt in eastern Oregon state.

In China, as in the US, the solar power goal is utility-scale and cost-competitive plants that will join wind and nuclear power in reducing China’s dependency on fossil fuels. To that end, earlier this month China Guangdong Nuclear Solar Energy Development signed a memorandum of understanding with the leading US thin-film PV maker First Solar to start work this year on a 30-MW demonstration plant in Ordos, Inner Mongolia. This is the first phase of a three-stage project under which First Solar and its Chinese partners will build a 2-GW solar power plant at Ordos over the next 10 years.

India has no project of comparable size on its planning horizon. Its biggest is a 500-MW solar farm announced by Gujarat state last month, where construction of the first phase is expected to begin in December this year.