Disposing of used grease can be a pain in the…kitchen. (In fact, we wrote about grease’s effect on kitchen wastewater not so long ago.)

Overflowing buckets, missed pick-ups, mess—waste cooking oil is a mucky business. And it’s not like you have a choice—you can’t simply wash fats, oil and grease down the drain, at least not if you want to avoid clogged pipes and an irate municipal bylaw officer.

Many restaurants now sell their waste vegetable oil (WVO) to companies that collect it, then convert it into biodiesel. Other restaurants pay disposal companies to cart away their used oil. Regardless, once it’s fried fish, french fries or onion rings, used cooking oil is waste. Right?

Not anymore.

Waste vegetable oil = energy

Enter the Vegawatt—an on-site cogeneration system that allows you to convert your WVO into supplementary electricity and hot water. Pour your used cooking oil directly into the Vegawatt, and—depending on what size unit you’ve got—you’ll get from four to 12 kW of electricity and from 20,000 to 47,400 BTUh of hot water.

This isn’t enough to power a restaurant solely on veggie oil, but it’s an important supplement that can help reduce your energy costs. (Plus, with additional wiring, you can use your Vegawatt as a backup generator in case of a power outage.)

How does it work?

When you pour your WVO into the Vegawatt unit (which is installed outside), it’s cleaned, then powers a compression-ignition engine. The unit is connected to your electricity panel the same way a solar generator would be, and hooks into your existing water heater.

The different sizes of Vegawatt units—4 kW up to 12 kW—are designed to consume all of a restaurant’s waste vegetable oil, from 25 to 120 gallons per week.

Energy cost savings from vegetable oil

The company estimates that Vegawatt units can provide from 10% to 25% of a restaurant’s electricity and hot water needs, and can make used fryer oil worth up to $4.00 (the average is around $3.00).

Monthly energy savings can be from $1,050 (4 kW unit) to $3,000 (12 kW unit) per month.

Environmental benefits of using waste vegetable oil

There are obvious environmental bonuses as well. By not having your oil hauled away in a truck, you’re reducing pollution. And, if you’re in an area with coal-generated electricity, reducing your electricity consumption will help reduce greenhouse gas emissions.

The fuel produced by a Vegawatt doesn’t require chemicals (as traditional biodiesel does) and doesn’t produce any liquid byproducts.

And, finally, installing a Vegawatt will garner you 11 LEED green building points—an important consideration if you’re looking at green certification.

So how much does it cost?

That’s the big question, isn’t it? Units can start around $45,000 and go up from there, to over $100,000 for a 12 kW unit. Not a small outlay, certainly, but financing/leasing is available, and there’s a seven-year maintenance program included. The simple payback period is about five years for businesses in Ontario.

Vegawatts catching on in the US

Vegawatts have been installed in several restaurants and foodservice facilities in the United States, including Billy’s Chowder House in Wells, Maine and Fogarty’s Restaurant in Berwick, Maine, as well as at American University and a Marine Corps base in California. As yet, there are no units installed in Canada, but Vegawatt’s Canadian distributor, Sunbeam Energy, is optimistic that the first units will be going in soon.

What do you think? Does the Vegawatt sound like something you’d install in your restaurant? Leave your thoughts in the comments section.