The oven in your favourite pizza joint could soon be providing the heating for the business and cutting natural gas consumption, courtesy of Hamilton-based Harvest Systems Inc.

Spun out of research from McMaster University in 2018, the company taps into the waste heat from highly inefficient restaurant gas-powered appliances to offset the use of gas-fired hot water equipment. Not only does it reduce the carbon emissions from the restaurant, it saves thousands of dollars in energy costs, co-founder and CEO Jim Cotton told Sustainable Biz Canada in an interview.

“If we could have a relatively low-cost solution that can drive savings immediately over a 20-year period, it’s very appealing.”

The company's potential earned it a spot on Foresight Canada's 2024 list of the Top-50 investible cleantech companies in Canada.

Having partnered with Pizza Pizza in Ontario for early tests, Cotton said the encouraging results have fuelled a plan for rapid expansion to manufacture and sell thousands of its units.

Harvesting heat

Cotton, a mechanical engineering professor at McMaster, founded Harvest with COO Jeff Girard and board member Gerard Campeau to change regulatory standards and pilot its projects in restaurants.

A problem the three sought to solve was the enormous amount of energy wasted by gas-powered equipment. Pizza ovens, Cotton said, are only 10 per cent efficient – around 90 per cent of an oven's heat flies up the chimney.

His former student Girard conducted research into oven exhaust flows, which led to studies into the regulatory environment. Campeau is a long-time colleague of Cotton, and the leader of a company designing and manufacturing technology that converts waste heat into electricity.

Harvest’s technology for pizza ovens, named POWER (Pizza Oven Waste Energy Recovery), attaches a heat reclaimer on the oven’s chimney, functioning as a water boiler. The heat from the oven warms up a water tank to high temperatures for dishwashing and sanitation, displacing natural gas heating.

“By using their own waste heat, they don’t need electricity or natural gas. So we’re directly offsetting carbon emissions,” Cotton explained.

Between six to 20 tonnes of carbon dioxide emissions could be eliminated per year per unit, depending on the size of the restaurant, the heating source and the amount of hot water used.

A trial with Pizza Pizza found one pizza oven can supply hundreds of litres of hot water per day for the restaurant’s needs, with a back-up electric heater rarely used. The performance of the oven is not impacted.

Energy costs can be slashed by thousands of dollars per year, and the targeted average payback period for a full-service restaurant is approximately two years.

Beside pizza ovens, Harvest is developing a system for deep fryers and is aiming to adapt its waste heat solutions for griddles and conveyor ovens.

Getting past the regulatory hurdles

A critical step Harvest must overcome before it is ready for commercialization is regulations. The market for waste heat recovery has not been serviced because of the “antiquated regulatory standards”, Cotton said.

Girard has been working to remedy this with the Canadian standards organization CSA Group and Technical Standards and Safety Authority. Progress has been steady; final approval for Harvest’s POWER is anticipated by the end of this year.

Harvest’s business plan is shaping up as equipment direct sales combined with a maintenance program. Other choices could be leasing and renting, the CEO said.

Cotton said the company’s ambition is to expand across Canada’s full-service restaurant market through brands such as Recipes Unlimited's Swiss Chalet and The Keg. Franchises WingsUp!, Cora and A&W have expressed interest in the technology, and Harvest also hopes to build a presence in the U.S.

Harvest hopes to have thousands of units installed in the next five years, and in 10,000 restaurants by 2030. Pizza Pizza is an early customer, placing an order for 340 of Harvest’s units over the next three years.

Harvest collaborated with the pizza franchise on research and development at its training centre in Toronto, and deployed POWER at three of its locations.

Restaurants are the current priority, but the food processing sector is a “huge opportunity” for Harvest, according to Cotton, along with grocery stores, hotels, cruise ships, cooling towers, data centres and sports arenas.

The waste heat recovery could also be reworked for the make-up air system of a restaurant to provide ventilation, and the energy could be exported to nearby buildings for further sustainability gains.