New Delhi, Oct 8: As solar pumps are being suggested as an alternative to electricity-driven pumps, for crop irrigation experts cautioned that excessive running of the pumps will hit the ground water table.

The experts said that due to non-stop use of solar pumps, ground water table will get depleted and it will create an environmental imbalance that will ultimately hit the agriculture sector.

Speaking during a discussion on use of solar pumps being used for crop irrigation, water expert Dr Tushaar Shah said that when a farmer uses solar pumps without interruption to irrigate his crop and sell the electricity from his solar array to other farmers, it adversely impacts ground water table.

"Once solar pumps are installed, there is no way of external control of its operating hours. Since solar pump runs on a free energy, farmers try to utilise it as much as they can. But this adversely depletes groundwater. So, replacing electric and diesel pumps by solar pumps can result in accelerated depletion of groundwater," said Dr Shah, a Senior Adviser to the Director General of the Colombo-based International Water Management Institute, while speaking during a programme on using clean energy for sustainable development.

"Since buying solar pumps is one-time investment, a farmer tries to earn more and more money by running the pump. Besides irrigating his land, a farmer irrigates nearby crop of farmers by charging them. This uninterrupted running of pumps to extract ground water for irrigation depletes the table," Dr Shah said.

The session, Energising Agri-Food Value Chain through Clean Energy Investing in Entrepreneurship and Sustainable Development, was organised by The Energy and Resources Institute at Vigyan Bhavan on Oct 6 as part of its World Sustainable Development Summit.

Dr Shah suggested that the governments should set up solar cooperatives in villages where the surplus solar energy will be sold to local power grids and then sold to consumers.

"This concept will save the ground water table from exploitation and will enable a farmer to earn money for selling energy to local power grids," Shah suggested.

Citing an example of one such successful cooperative in Dhundi, a village in Gujarat's Anand district, Dr Shah said that members of this cooperative - the first of its kind in the world - are using solar power not only to run irrigation pumps, but also pool their surplus energy to sell to the Madhya Gujarat Vij Company Ltd (MGVCL)at Rs 4.63 per unit under a 25-year power purchase agreement (PPA).

"This is a 'cash crop' that can be 'grown' without any seeds, fertilisers, pesticides, irrigation or backbreaking labour. Income from it is also free of risk from drought, floods, pests and diseases. All that is required is land for erecting panels," Dr Shah said.

He said that the Dhundi farmers initially were worried about the land-footprint of the solar panels. "But they are already experimenting with a range of high-value crops like spinach, carrots, garlic, beet and a few medicinal plants that grow well under panels."

Dr Shah added that the buyback scheme could also protect farm incomes in the event of crop failure. "And, if adopted widely, this could help ease pressure on the state's overburdened electricity board. Solar crops' are a very exciting example of a 'triple' win - for farmers, the state, and the precious water reserves, all benefit from a single intervention," Shah said.

Earlier, two young entrepreneurs showcased their projects that enables farmers to produce clean energy for sustainable development in agriculture. One projects was a bio-gas plant, developed by Himanshu Mishra and another was solar pump by Kartik Wahi.