An experimental project in India is combining solar photovoltaic panels with an irrigation system in an attempt to save water while generating electricity. A 1 MW array has been built over nearly half a mile of the Narmada Canal in the state of Gujarat.

The combination will not only produce electricity but also conserve land and water, according to officials of the state government . The project is meant to show an efficient use of land in an agricultural region by putting solar panels over a waterway rather than over fertile ground. It also should reduce evaporation of the canal water by an estimated 237,750 gallons of water each year. The Gujarat State Electricity Corporation developed the project and hired U.S.based SunEdison to build it.

This is not the first time someone has thought of putting solar panels over water to save space and preserve scarce water supplies. It is still relatively uncommon, however. A New York Times story last year outlined several projects – including two at California vineyards – that have installed solar panels over ponds. The story also talked about the idea of covering the California Aqueduct with solar panels, but an official from the state agency overseeing the aqueduct expressed concerns over the stability of solar panels and the ability of repair workers to fix leaks and other problems at the 400-mile canal if they have to contend with massive structures of solar panels and their mounting systems.

Gujarat has seen many solar arrays installed in recent years. The state encourages solar panels by guaranteeing premium prices for the solar electricity, boasts at least 600 MW of solar and 2,580 MW of wind energy generation, which makes it one of the largest renewable energy producing states in the country.

The 1 MW project only covers a small section of the canal, the main waterway of which runs for nearly 285 miles. If all the side channels are included, then the overall length is about 11,806 miles. So there is potentially still plenty of space to put more solar panels over them.

Close on heels of commencing use of wastelands in northern districts and rooftops in towns and cities, Gujarat is set to potentially use the existing 19,000 km-long network of Narmada canals across the State for setting up solar panels to generate power.

The Chief Minister, Mr Narendra Modi, will inaugurate the first of a series of this project, known as Canal Solar Power Project, when he launches a 1 megawatt (mw) pilot project, which is already commissioned, on Narmada branch canal near Chandrasan village of Kadi taluka in Mehsana district on Tuesday.

According to Business Line, last week, he inaugurated a 600-MW solar power project spread across 11 districts. This included a 214MW Solar Power Park, the largest such generation centre at a single location in Asia. Also, Azure Power, leading independent power producer in solar sector, announced a 2.5 MW rooftops project in Gandhinagar.

Gujarat, which invests nearly Rs 2,000 crore an year on renewable energy, has attracted investments of Rs 9,000 crore so far on solar energy projects.

The pilot project has been developed on a 750-m stretch of the canal by Gujarat State Electricity Corporation (GSECL) with support from Sardar Sarovar Narmada Nigam Ltd (SSNNL), which owns and maintains the canal network.

The pilot project will generate 16 lakh units of clean energy per annum and also prevent evaporation of 90 lakh litres of water annually from the canal, an official told Business Line here on Monday. The concept will, therefore, tackle two of the challenges simultaneously by providing energy and water security.

The cost of per megawatt of solar power, in this case, is likely to be much less than the estimated Rs 10-11 crore, as the two banks of the canal will be used to cover the canal by installing solar power panel and the government will not have to spend much on creating basic infrastructure, including land acquisition .

Today, Gujarat has about 458 km of open Main Canal, while the total canal length, including sub-branches, is about 19,000 km at present. When completed, the SSNNL’s canal network will be about 85,000 km long. Assuming a utilisation of only 10 per cent of the existing canal network of 19,000 km, it is estimated that 2,200 MW of solar power generating capacity can be installed by covering the canals with solar panels. This also implies that 11,000 acres of land can be potentially conserved along with about 2,000 crore litres of water saved per annum.