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Published on March 25th, 2015 | by Tina Casey

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Double-Teaming Diesel With Solar & Energy Storage (CT Exclusive Interview)

March 25th, 2015 by  


Fresh on the heels of its diesel-killing solar water pump initiative, SunEdison has teamed with the energy storage company Imergy Power Systems in a new venture that will bring solar-generated electricity to 1,000 villages in India. That’s just for starters. The end goal is 5,000 villages in India alone, and even more in Africa and other regions where gaping holes in the electrical grid exist.

The question is… who’s gonna pay for all this?

SunEdison partners Imergy energy storage

A Sustainable Business Model For Solar Energy

That’s a good question, right? When it comes to introducing solar energy into communities with few financial resources, one conventional approach is the charity model.

SunEdison has been involved in the solar donation movement, and based on those experiences the company has also begun to develop sustainable business models that could kickstart solar investment in previously untapped regions.

The trick is to create a model that can attract investors with limited resources.

That sounds pretty tricky all right, but SunEdison already has a running start. Last month we told you about the company’s “Eradicate the Darkness” initiative and its solar-powered water pump model for killing off diesel. In that model, small farmers who invest in solar can pay off their loans slowly, using the additional income they receive from planting more irrigated crops.

That’s not entirely risk-free, but it does give small farmers an affordable pathway out of the diesel trap.

Solar For The Whole Village

The hookup between SunEdison and Imergy builds on the business model concept by leveraging existing technology in and near the targeted villages.

The two companies had an embargoed press release at the ready but it was a little thin on details, so we’re happy to give you some extra information provided to us from an exclusive phone interview with Imergy CEO Bill Watkins and SunEdison’s general manager for advanced solutions, Tim Derrick.

The secret sauce is the telecom businesses scattered throughout India. The 5,000 villages were selected due to their proximity to an existing telecom, and the basic idea, as Bill explained to us, is that the telecom will serve as the anchor tenant for a combined solar and energy storage system that serves as a microgrid for the nearby community.

The system is expected to exceed the electricity needs of the telecom, and it can sell the excess to other users — so, essentially, anyone hooked up to the microgrid can get their hands on solar-generated electricity without having to make an upfront investment in infrastructure.

As for the attraction of solar energy for telecoms, it’s twofold. Telecoms in India currently juggle an unreliable grid with diesel generators and conventional lead-acid batteries. Replace all of that with SunPower’s solar technology and Imergy’s high-efficiency, low-maintenance vanadium flow batteries, and you’ve got a reliable flow of electricity 24/7.

Aside from being assured of increased reliability, telecoms could also see their income from electricity sales grow, in addition to an increase in their foundational business. Once nearby residents get accustomed to a reliable electricity supply, it’s safe to assume that demand will rise. Here’s Tim on that topic:

…the real opportunity is to build up the system over time… many of the people who will benefit from this have not had electricity in the past, so demand will rise.

In other words, households on the microgrid can shake off the often-hazardous chains of petroleum dependency — namely, kerosene lamps and diesel generators.

Solar-generated electricity could also replace kerosene and liquified petroleum gas used for cooking, and it could contribute to the clean cookstoves movement to the extent that it replaces wood and animal dung in open cooking fires.



Energy And Power

The first 1,000 villages are getting Imergy’s mid-range model, which comes in a 20-foot container. It can easily be scaled up for more energy storage within the same footprint.

That brings us to the difference between energy and power. As Bill puts it, scaling up conventional batteries is not an efficient solution for rural electrification, because they don’t separate energy from power.

Think of the difference between what comes from your car’s engine (power) and its gas tank (energy) and you can see what he’s talking about. To go farther on a tank of gas, you don’t need a more powerful engine. All things being equal, what you need is a bigger gas tank.

The gas tank thing is an apt metaphor for vanadium flow batteries. Like the name says, flow batteries work by forcing two complementary liquids to flow adjacent to each other.

If you want to store more energy, you don’t have to use more powerful pumps — you can just use bigger tanks to hold your fluids.

You can check out some more details about flow batteries at our sister site Planetsave, but for those of you on the go, here’s a quick video from Imergy that explains the whole thing:

Did I get all that straight? As always, if I screwed up that energy and power thing, please drop a note in the comment thread.

Follow me on Twitter and Google+.

Image Credit (screenshot): Outdoor Microstation 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+.



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