If God appeared in the dream of a paddy farmer in India’s West Bengal and said, “You have made me happy with your hard work, make any three wishes and they will be granted,” the farmer will say “I want rain, rain, rain.”
That thought kept playing over and over in my mind, after interacting with farmers in the paddy fields of the Siliguri and Jalpaiguri districts of West Bengal. Located in India’s northeast, the area is famous for its scenic beauty, tea plantations and paddy fields. While the region’s fertile soil makes it ideal for a variety of crops, it is almost entirely dependent on rainfall for irrigation, like anywhere else in the world.
To reduce their dependence on the monsoons, India’s farmers have taken 12 million electricity connections and 9 million diesel pump sets with which they pump up groundwater for irrigation.
Although agriculture’s share of India’s economy is declining—it contributes to less than 15% of India’s GDP—it still employs 50% of the country’s workforce. Not surprisingly, perhaps, up to 20% of all the electricity used in India is for agriculture, mostly for irrigation. In some states, this can account for as much as 30-50% of all the electricity used in the state.
There are many states where power for agricultural purposes is highly subsidized, and this, combined with an unreliable supply of electricity, often causes farmers to leave their pumps on all the time. This wastes both electricity and water, with too much energy being used and too much groundwater being extracted, often way more water than needed.
Since more than half of India’s cultivated land is yet to be irrigated, a business-as-usual scenario will lead to a huge rise in India’s energy needs for agriculture alone.
But there is an alternative—solar energy.
With decreasing solar modules prices (70% in the last 4 years), solar pumps are fast becoming a viable financial solution for irrigation.
However, there are several questions about the use of solar pumps that need to be answered:
Won’t solar pumps only make farmers more lax about using energy resources and wasting groundwater?
In several Indian states like Punjab and Haryana, electricity for agriculture-related tasks is provided at no cost to farmers, usually at night, to ease off-peak daytime loads. This encourages the uncontrolled use of electric pumps, with farmers often leaving pumps running through the night, resulting in over irrigated farms and low ground water levels, not to mention all the wasted electricity.
One could argue that, with solar power, the problem could get worse. Since solar power is abundant in India, farmers could feel even less obligated to monitor the use of solar pumps, leading to even lower groundwater levels.
But what if it doesn’t? Savvy farmers won’t take long to realize that they have the option of selling their surplus solar electricity to the grid at good rates. That means they’d think twice before pumping up groundwater unnecessarily.
The state of Karnataka is banking on just that with its “Surya Raitha” scheme. The state electric utility announced a tariff of almost 18 U.S. cents per unit for every unit of solar power sent to the grid. Currently, 300 farmers are piloting this approach and have turned in their traditional diesel-run pumps voluntarily. The scheme is being monitored to understand if it works or not.
Also, a World Bank irrigation project in West Bengal is exploring a service contract model for solar pumps, where payments are made to the contractor depending on the amount of water delivered from the pumps. This can be monitored through inexpensive GPRS and remote sensing technologies. This business model can help put a price on the use of water and help maintain ground water levels if the government sets and enforces proper limits. The project is also looking at using solar pumps, small agro-mills and drying crops during non-irrigation season.
Aren’t costs to install and operate solar pumps prohibitive?
Here is how the costs break down—the upfront cost of a solar pump (say 2 HP, equivalent to irrigating 5 acres of land) is about 10 times that of a conventional pump ($5,000 vs $500), despite a significant reduction in solar module prices (from $3 per watt in 2009 to less than $1 in 2015). Small and marginal farmers may not have the equity to buy solar pumps or the ability to raise debt from a commercial bank, since banks are still don’t consider solar pumps as "bankable technology."
But one must think about the long-term returns. The cost of running a solar pump is virtually zero. It can pump water for at least 25 years with little overhead and management costs. The cost of power production from a diesel pump is around $0.30 per unit (compared to $0.15 for a solar pump) and the payback period is around 6-9 years. A solar pump is clearly the more viable option in the long run and once commercial and public banks in India start lending to install them, it could have a significant impact on the lives of farmers.
Is solar energy reliable in all seasons?
In many parts of India, there are 60-70 days in a year when weather conditions (clouds) prevent solar water pumps from working. But it rains a lot of those days, so irrigation may not be necessary then. That still leaves a few days where you might not see the sun, leaving about a 90% reliability factor for solar water pumping. But adding energy or water storage could offset that issue. Also, small land holdings reduce the applicability of larger solar pumps unless water brought up by using solar pumps can be shared among a group of farmers.
Are solar pumps environment friendly?
India uses more than 4 billion liters of diesel (13% of total diesel consumption in India) and around 85 million tons of coal per annum (19% of total coal consumption in India) to support water pumping for irrigation. If 50% of these diesel pumps were replaced with solar PV pump sets, diesel consumption could be reduced by about 225 million liters/year (7.5% of total diesel consumption in India).
Farmers tend to turn to the rain god—Indra—when all else fails. Perhaps they could give the sun god—Surya—a shot as well? Once solar pumps’ impact on groundwater levels and implementation are investigated and understood, I believe it can answer prayers and ease the lives of millions of farmers.