High level engineering recycles French fry oil into energy
by Tony Rosenfeld
Even among smartphones and hybrid cars and all the other new tools of modern technology, the Vegawatt, from Owl Power Company of Boylston, Massachusetts, stands out. This nondescript white booth, about the size of a two-door refrigerator, is a biomass generator. That sounds impressive, but what does it mean? Quite simply, on-site energy for a restaurant from its discarded frying oil.
The Vegawatt takes the relatively recent practice of recycling restaurant cooking grease to a new level. Instead of trucking dirty fry oil to an off-site recycling plant and converting it into some form of biofuel (or just disposing of it, as do many restaurants), the Vegawatt does this conversion on the premises. It takes the grease and turns it into power. Part of this cleaned fuel gets converted into the restaurant’s electrical system, and the remainder heats cold water before it travels to the restaurant’s hot water tank. The whole thing sounds very futuristic. The Vegawatt’s name hints at the extraordinary, suggesting that you might be able to throw some carrot and potato scraps in there and turn them into electricity, too; Ben Prentice, the company’s sales guy, explains that the machine isn’t quite that advanced.
Though the development of this machine required high-level engineering by James Peret, the start-up company’s founder, it’s relatively easy to understand. Simply put, the Vegawatt cleans fry oil so it can become fuel. It does this through four stages of filtering, at the end of which the fry oil has been transformed into a clean fuel that powers the Vegawatt’s self contained diesel engine. The engine has a generator head heat pump, which connects it to the restaurant’s electrical system and hot-water tank.
This technology means that whoever is working the fryolator can take a pail of the used grease out back to the Vegawatt (it’s meant to be situated outside of a restaurant, much like a central air-conditioning system) and pour it in, knowing that within one or two hours (or instantly if there’s a reserve of cleaned oil already in the machine), the machine will be sending electricity back into the restaurant.
Peret first started toying with the idea of the Vegawatt a couple of years ago, when the price of gas skyrocketed, and waste oil (and its energy potential) became more attractive. As inventive as turning fry oil into biodiesel was, he wondered if there was a way to avoid the unwanted carbon footprint created by trucks hauling off the waste. Peret realized he could eliminate this step and also give some value back to restaurants—an industry confined by tight margins, particularly the high cost of energy.
The Owl Company estimates that the Vegawatt can save a restaurant between 10 to 25 percent on its energy expense, a figure approaching $1,000 a month. George Carey, owner of two Finz establishments in Massachusetts, verifies these savings. “I’m a big fan of the Vegawatt,” he explains of the prototype machine at his Dedham location. “We always wanted to go green, and this is something really great we can do without having to spend a ton of money.” Carey had looked into installing solar panels on top of his restaurant but instead decided on the Vegawatt, which was less than half the cost and offered the same monthly return on investment.
This all sounds great, although the Vegawatt does have a couple of drawbacks for prospective businesses. One concern is that you need to produce a relatively large amount of waste oil (at least 50 to 80 gallons per week) to maximize the machine’s capabilities. The other is that the Vegawatt comes with a substantial up-front expense ($10,000 to $30,000). However, this cost can be greatly reduced by the energy rebate programs recently enacted by the state and federal governments as part of the American Recovery Act (ARA). And after a couple of years, the Vegawatt should pay for itself. By that point, restaurateurs like Carey can sit back and enjoy the transformation of waste into renewable energy, one of technology’s cool new tricks.