1 MW of Canal-top solar power in Gujarat, the western tip of India, promises to produce power and prevent water loss.
Gujarat is the small, westernmost state in India, home to over 60 million people, many of which are without access to electricity or water.
The national electrical grid in India is unstable and inefficient. During transmission and distribution, it loses 22% of what it generates in centralized coal, hydroelectric, natural gas and nuclear power plants. India’s grid remains chronically short on generating capacity and has a history of massive power failures (July 2012 blackout in India left 10% of the world population without power). It also does not extend to the remote, western parts of India.
Water supply is also a problem in Gujarat. With relatively low rainfall and a semi-arid to arid climate, Gujarat has poor surface water resources. In an effort to bring water to rural districts, the state developed a massive web of concrete and cement-lined canals, diverting water from the Narmada River for irrigation and drinking water purposes for thirsty, growing populations. However, due to extreme heat and dry conditions, much of this water is lost through evaporation.
Not surprisingly, the state of Gujarat has immense solar power potential. It has some of the strongest solar resources in the country. By installing solar PV panels atop the Narmada canal, nearby Gujarat residents will have access to reliable off-grid power that simultaneously prevents water loss through evaporation by shielding the canal’s water from sun and wind.
This suspended system is the first of its kind since it is mounted over a water canal. It spans about a kilometer of the canal, but does not touch the water. Solar Edison was commissioned in 2010 to engineer and construct the project. Their design includes 1 MW of power over a narrow strip of one of the canal branches since the main Narmada canal is extremely wide. The site was selected because there are reliable roads and access to the electrical grid nearby. The canal also runs North-South, which maximizes the amount of sun that shines on the panels and therefore, the amount of power produced. An added benefit of installing panels over water is water will keep the panels cooler, which improves PV efficiency. Solar panels over water will end up producing more power over a longer lifespan than panels mounted on land in extreme dry conditions.
Solar Edison’s design promises to save an estimated 7,000,000 L of drinkable water per year by preventing evaporation and preventing algae growth in the canal. Algae can clog the irrigation pumps, which increases maintenance costs and lowers productivity. The state appreciates that this system both will generate clean energy and conserve water. They also appreciate that it does not require new land acquisition. The next proposed phase of this project will double the solar power capacity installed over the canal to 2 MW.
 Electric power transmission and distribution losses (% of output), World Bank, 2010 estimate <http://search.worldbank.org/data?rows=20&qterm=india+electricity&language=EN>
 NY Times: “2nd Day of Power Failures Cripples Wide Swath of India” July 31, 2012