A previously announced program to help an estimated 37,000 Ontario homeowners receive cash rebates to retrofit and renovate their homes went into effect Monday.

Ontario Premier Kathleen Wynne said the program is an effort by the province to reduce energy bills and combat climate change.

"Families want to make sure that their kids have great, warm places to play in the basement, even if their house is 150 years old," Wynne said outside the home of a Toronto family who received rebates for energy audits and retrofits for their home this year.

"They want to make sure they are paying the lowest cost possible for those homes."

Under the home energy program, Ontario homeowners could be eligible to receive rebates ranging from $500 to $2,000 for energy audits — an assessment of a home to find ways to lower its energy bill — and for renovations such as installing energy efficient furnaces, windows and insulation.

Wynne said Union Gas and Enbridge already provide similar rebate programs and the program will benefit those not necessarily customers of those companies. That means an additional 37,000 homeowners, she said.

The Ontario government will run the program in partnership with Enbridge and Union Gas. It is offered to homeowners who use natural gas, propane, oil or wood as their primary heating source.

The government said the $100 million needed for audits and retrofits over the next three years will come from its Green Investment Fund, a $325 million fund the province set up last year as a "down payment" on future revenues from its cap-and-trade plan designed to reduce greenhouse gas emissions.

It said the audits and retrofits are expected to reduce greenhouse gas emissions by 1.6 million tonnes over the life span of the renovations.