Invention Awards: A Generator That Runs on Kitchen Grease

The Vegawatt provides restaurants' power using their leftover cooking oil

By Gregory Mone Posted 05.28.2009 at 12:03 pm 7 Comments

Oil Man James Peret wondered why restaurant owners gave away their excess grease instead of using it to power their business. Then he discovered that no one had given them the option John B. Carnett

Today's featured Invention Award winner kills two birds with one stone: providing a simple and cheap alternative energy source while widening the market for delicious fried foods. Everybody wins!

The nondescript six-foot-tall box behind Finz restaurant in Dedham, Massachusetts, looks like a tool shed, but actually it's a self-contained grease refinery and five-kilowatt generator. Engineer James Peret's Vegawatt is the first all-in-one device that processes grease to continuously provide a building with electricity and hot water, heralding a significant change in alternative-fuel applications. "It's a brilliant idea," says Josh Tickell, author of Biodiesel America. "A waste stream to an energy source, with no intermediary."

Last December, after a year of 80-hour weeks on the development, Peret, 33, installed the first Vegawatt at Finz, a joint that offers loads of fried seafood. With patents still pending, he's reluctant to give specifics on its inner workings, but it begins with staff members pouring in 10 to 12 gallons of used deep-fryer oil each day. Before going into the Vegawatt's generator, the bread-crumb-filled muck is deposited into a reservoir and undergoes a multi-stage cleaning, treatment and filtration process. At this stage, the oil is prepared for combustion with a method Peret devised that draws heat from the exhaust system. After that, the processed grease moves into a tank that feeds the modified 15-horsepower diesel generator. Heat from the Vegawatt's engine coolant is used to warm the water in the building's pipes, further reducing the restaurant's energy needs.

The Vegawatt can process about 80 gallons of grease a week (standard for large restaurants) and produces five kilowatts of energy an hour, which could translate to monthly savings of $1,000, a 10 percent reduction in power costs. Peret is now selling the machine through his start-up, Owl Power Company, pitching it as the perfect way to go green, save money, and serve delicious fish and chips at the same time.

Invention: Vegawatt
Inventor: James Peret
Cost: $300,000
Time: 4 years
Is It Ready Yet? 1 2 3 4 5

Vegawatt: How It Works: Dirty grease passes through a series of tanks and filters that scrub, heat, and refine it into fuel that burns clean in a diesel generator Bland Designs

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7 Comments

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cowboy82

05/28/09 at 12:56 pm

I say this with all respect for the author of the article, and Mr. Peret, to wit: Duuuuuuuuuuuhh.

Once again, it takes a working stiff to point out the amazingly obvious.

Good work, Jim. No, sincerely, good work.

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geebob

05/28/09 at 3:27 pm

1000 dollar savings a month? That'll only pay for itself after 25 years! Longer if we figure in maintenance.

As for greening things up, I don't know, is there less carbon emissions involved if the power is produced at a coal plant?

Seems to me that a clearer green alternative is still burning up grease in a modified diesel car (since that represents fuel that would be burned anyway) or (this is really is a guess) feeding it to livestock instead of the fish oil which contributes to depleting our taxed oceans.

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mark456

05/28/09 at 10:34 pm

This is a wonderful opinion. The things mentioned are unanimous and needs to be appreciated by everyone.

mark456

adult

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I.Q.142

from las vegas, Nevada

05/29/09 at 2:22 pm

The $300,000 price tag was to build the prototype, if and hopefully when it is massed produced you could see it sell for a tenth or less than the original cost. Also considering coal power is the MOST polluting power source we have it stands to reason that it would pollute less. Not to mention the value of not being dependent on a central power grid. We need more inventors and innovators like Mr. Peret.

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3DTOPO

05/29/09 at 11:47 pm

It took him $300k to buy a diesel generator? And he gets an award for it?

Ridiculous! Any diesel engine will run directly off of vegetable oil, provided two conditions are met: (1) filter the oil through a micron filter and (2) it is preheated to 150F first.

(1) is a real no brainier, you can set it up for about $20.
(2) is easy seeing how the generator creates waste heat as it runs - you just have to start up with regular diesel to warm things up and use a heat exchanger (read copper tube coil), or have a fish tank heater or something heat the oil.

That cost $300k to develop? What a waste!

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geebob

05/30/09 at 1:01 pm

Noting that this is the price of the prototype is a good point.

as for this though:

Also considering coal power is the MOST polluting power source we have it stands to reason that it would pollute less.

I don't know that this is clearly the case. Coal power may be the most polluting power source for mass production of power, but does that hold true when compared to small scale diesel engines? I would assume that mass production generally is more efficient (and potentially less polluting) than small scale power production.

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