Agriculture SunEdison solar water pumps

Published on February 25th, 2015 | by Tina Casey

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Diesel Braces For An Avalanche Of Solar Water Pumps

February 25th, 2015 by  



Leading global solar company SunEdison has been quietly introducing solar water pumps to farming communities for the past few years, and it looks like things are really going to start opening up. That will spell big trouble for diesel, which to date has held a virtual monopoly on non-electric irrigation pumps for small farms in India, Africa, and other underserved regions.

As another example of “diesel-killing” solar technology, SunEdison’s solar water pump involves more benefits than simply cutting down on greenhouse gas emissions, so let’s take a look under the hood.

SunEdison solar water pumps

The Eradication Of Darkness

SunEdison and its panelists made a good case for killing off diesel at Tuesday’s “Eradication of Darkness” summit in New York, hosted by the company and its Social Innovations platform.

The idea behind the summit was to drum up investor interest in a sustainable business model for introducing solar power to small farmers in communities that either have no grid connection, or that have unreliable connectivity.

One point that SunEdison representatives hammered home is that while charity has an important role to play in providing off-grid equipment, the key to success is providing communities with a knowledge base for maintaining and repairing the stuff.

“Diesel Generators Are Pretty Dumb”

We’re particularly interested in the solar water pump angle because, as described by the panelists, it provides such a clear contrast with diesel generators.

While solar energy is “free” once the panels go up, diesel generators continue to suck resources out of the community in the form of expensive fuel payments and repairs.

Even when diesel generators are functioning, depending on their age and quality, they can require constant monitoring, sucking labor away from more productive tasks. That can be especially true of donated generators, when the donor fails to include repair and maintenance training in the package.

We had a chance to speak with Social Innovations President Alakesh Chetia right after the summit, and he filled us in on another disadvantage of diesel generators.

“The diesel generators are pretty dumb,” he said. “You turn them on and they keep pumping until you turn them off.”

What that means is that diesel generators can easily overdo it, providing more than enough irrigation water while wasting fuel.



Solar Is Smarter

Solar energy could also run into over-pumping issues, but as Chetia explained, the SunEdison solar water pump is customizable with a “smart” control system, so that it provides water more closely tailored to the farmer’s actual needs.

That brings us to another clear advantage of solar water pumps. With diesel generators, once you’ve pumped sufficient water the equipment sits idle. In order to put it to other uses — generating electricity for lighting, for example — you have to spend more resources on fuel.

The picture is totally different with solar. Once your irrigation needs are met, your fuel continues to be free. Aside from the potential for charging up batteries for on site use, Chetia foresees a net metering solution that could provide solar water pump owners with an additional source of revenue.

As for the business side of things, SunEdison’s model is based on the relatively low yields and small number of harvests that are the norm when farmers depend on rain. With a reliable supply of power for irrigation, farmers can increase their yields and their harvests, providing additional income to pay off a low-interest loan.

Run Diesel, Run

Along with our sister site PlanetSave we’ve covered a number of SunEdison’s high-profile, large scale solar investments, and the company has recently expanded into large-scale wind, but its Social Innovation platform has also demonstrated that small-scale solar can be a profit sector that adds up to a lot of wattage.

Last month, for example, SunEdison hooked up with India’s Omnigrid Micropower Company for at total of 250 megawatts distributed among 5,000 villages in that country.

After catching part of the Eradicate the Darkness summit on livestream and chatting with Mr. Chetia, we’re convinced that’s just the tip of the iceberg.

The missing link seems to be a clearinghouse for hooking up lenders with solar experts, so that financial institutions don’t have to reinvent the wheel for small-scale solar loans, but based on what we heard at the summit it won’t be long before the chain is complete.

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Photo credit (cropped): Courtesy of SunEdison.





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About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.



  • Donald Zenga

    Yes, priority should be given to replace expensive polluting diesel with cheaper cleaner solar panels. India is planning massive investments in solar power.

  • spec9

    An elevated water tank is a natural energy storage system.

  • vensonata

    That is what I use. 300 ft well, 1000gallons of storage, 15-20 people in residence. off grid. Whenever the sun is shining I run the well pump from PV which by the way is a grundfos at 250 watts/hour. Regular brute force well pumps take 1250 watts to deliver the same amount, So grundfos are like l.e.d. lightbulbs compared to incandescent bulbs. Notice I do not use battery,if I can avoid, it for pumping water, the water storage is the battery but 100 times cheaper and basically the tanks last for 30 years or more. You also do not need an inverter for these pumps…they run on either ac or dc without any need to modify your source. Diesel gen which I have runs now only 30 hours per year. With more batteries can kill the last 3% of generator contributed electricity. But be aware the last 3% production by solar is the worst return economically. Here are the numbers: Diesel gen, 2.5 liters/hour x 30 hours = $100/year. Batteries to store equivalent winter PV production $6000. So 60 year payback! Not good, but as a science experiment I might do it anyway.

    • Kevin Fink

      Grundfos makes a lot of pumps. What model do you use and what makes it so much more efficient than “regular brute force well pumps”?

      • Ulenspiegel

        IIRC modern pumps have more efficient motors and usually pressure sensors which adjust power to actual demand.

      • vensonata

        Compare standard AC well pumps, commonly used in rural homes, ranches , farms. Their up front cost is maybe $650. Start up surge is enough to blow your breaker. Then they will bring up 2.5 gal per minute for 300 ft. at 1250 watts per hour. Grundfos SQ Flex. $1800. no start surge. 220 watts for the same gallons. If you are functioning off grid with PV it is a no brainer. As well, the best house pressure pumps can also be one fifth the power demand of off the shelf pumps. In general, all North American pumping systems were energy pigs, European makers re thought it and now the U.S. needs to replace virtually all their pumps (with some exceptions since TACO (American) and a few others have recently started using the same tech). Also radiant hydronic pumps and air blowers should all be replaced by low energy pumps. I have a shelf full of pumps that fully qualified plumbers installed based on their training from the 90’s that I have had replaced. Its the difference between the mileage on an old half ton pick up and a Prius.

        • NiCuCo

          “watts per hour” ?

    • Martams

      That’s good to store it first. But you would need batteries for precision drip watering and metering.

  • JamesWimberley

    The secret of Narendra Modi’s reform of the electricity market in Gujarat state when he led it was to split the market in two: farmers, who continued to get the subsidised electricity they have come to see as an entitlement, but with no guarantee of service; and a normal urban sector, paying market prices for a reliable supply. The farmers didn’t mind irregular supply as their main use was irrigation pumps, which need to run for only a few hours a day.

    • Martams

      With proper knowledge of your soil profile & properties along with crop grown, you may only need to water once every two weeks, that is why battery storage and smaller panels are what you would need.

  • jburt56

    The pumped water is a store of energy but much cheaper than batteries.

  • Great story. Pity you don’t show some real numbers to compare the economics.

    • Will E

      too often no numbers
      with numbers its a blowaway story.

      and more plans for solar like this

  • Joseph Dubeau

    good article. Next we need a solar powered plow.

    • JamesWimberley

      Actually, you can often do without a plough (link).

    • spec9

      Easy . . . an electric tractor and solar PV panels.

      • Joseph Dubeau

        Batteries are expensive.

  • Martams

    Goodbye diesel!
    In California, solar pumps with battery storage would be the ticket. Installing an electric pump would cost $100K just to have electric utility service to the pump sites. That is why some pumps in California are powered by diesel. Watering plants is best by trickle. And the other water demand coincide with sunshine availability.

    • Omega Centauri

      Why battery storage? Simply pump the water when the sun shines, the water can be stored in a tank and used when you want it. No expensive batteries needed.

      • Matt

        When you pump all the water you need, charge batteries for lights.

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