Sweet smell of renewable energy

Sugar cane as a source of bioenergy? An Arlington, Va.-based start-up works with sugar mills in Brazil, using a sugar waste product to create electricity.
Written by Melanie D.G. Kaplan, Inactive

With a sweet tooth like mine, there aren't a lot of sugar products I haven’t met (and loved). But Mark Smith and Pete Messman surprised me with their Arlington, Va.-based company, Claren Power, which partners with sugar mills in Brazil to build modern, cogenerational (making heat and power simultaneously) facilities. The fuel comes from sugar cane waste—called bagasse—which apparently doesn’t look or taste like the sugar in my ice cream or cupcakes, so I don’t have to worry about Claren as competition. I asked Smith to explain how this sweet model works.

For those of us who don’t understand how sugar turns into electricity, describe the process.

Sugar cane can be used for a number of different purposes—you can distill it and create ethanol or rum, you can create molasses, you can dry it for sugar. We’re using the waste product of the sugar after the stalks are crushed, ground and shredded and the juice is squeezed out. What’s left is bagasse, which looks like husky sawdust. We use this as the fuel for our boiler, which heats water at a very high temperature and pressure to generate steam. This pressurized steam drives a turbine, which is connected to a generator that converts this energy into electricity.

So where is this energy going?

Most plants consume about a third of the energy (steam and electricity) that we generate during the harvest, leaving the other two-thirds to export to the electrical grid. Our goal is to help make plants more efficient so that we have more excess energy. We’re using the same resources but providing three times more energy.

Why Brazil?

Brazil is the largest sugar producer in the world. There’s a solid regulatory structure for selling independent power; it’s a lot easier than in the United States. You have this huge stock of bagasse that’s out there, and you have mills that are capable of being upgraded and producing this power differential.

Is it catching on in other countries?

The inspiration for this project came from Guatemala. Guatemala gets 12 percent of its power from sugar mills. It’s also being done in India, which is the second largest sugar producer in the world. We see that as a great potential opportunity, as would Colombia and some of the Caribbean countries. Anywhere on the tropical belt where there is the right regulatory structure, the right price and enough sugar.

How many mills are you working with?

Our target is to develop five large-scale cogeneration projects over the next five years. The target is to bring 300 megawatts online by 2015. That’s the equivalent of 847,117 barrels of crude oil per year, or one-ninth of the generating capacity of the Hoover Dam.

This post was originally published on Smartplanet.com

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