Consumers will struggle when they see an increase in their hydro bills in Ontario, say critics, after the Liberals revealed Saturday that a new levy will help cover $53 million of the government's conservation and green energy program.

The regulation, entitled "Assessments for Ministry of Energy and Infrastructure Conservation and Renewable Energy Program Costs" has not been announced yet, but Liberals said the levy will likely appear on hydro bills in May.

It comes as consumers are hit with the 13 per cent harmonized sales tax on consumer goods and as smart meters are rolled in.

The Liberals said the cost will be minimal, adding up to a $4 annual increase to customers over the course of a year.

"You're looking at four dollars a year, which is a bargain when you compare it will the alternatives, which is investing much more than that to build nuclear or other types of infrastructure," said Energy and Infrastructure Minister Brad Duguid in an interview.

But critics lashed out Saturday, calling it a hidden tax, saying ratepayers will already be beleaguered by the merging of the provincial sales tax and federal goods and service tax July 1. The harmonization will mean customers will pay 13 per cent instead of 5 per cent on their hydro bills.

"It's not only a tax, it's a hidden tax. It's really low," said Progressive Conservative energy critic John Yakabuski. "They're just going to be dealing with the implementation of the HST, which is going to add 8 per cent onto those hydro bills."

Duguid acknowledged there will be a cost to consumers, but said the alternative is to leave the next generation with an unhealthy, jeopardized planet.

He said the increase is not a tax, but part of introducing green energy sources under the Green Energy Act, which was passed last spring.

"We're transforming the energy system from the old days when we were polluting the lungs of our kids by using dirty coal to modern times where we're producing cleaner types of energy," said Duguid.

Duguid said the money would pay for home energy audits and a program that helps industrial and commercial firms switch to solar power.

"We're focusing on conservation because it's the most economical way to save ratepayers the cost of new infrastructure," said Duguid.

But critics said the increase will mean more money out of consumers' pockets.

"All of those people who are producing this so-called green power are profiting mightily at the expense of the consumer," said Yakabuski, adding it amounts to another "piling on" of costs to consumers.

"How much green do you think we can actually create in Ontario? We can't run the province on windmills, said Yakabuski "You have to have something you can control and dispatch."

NDP Leader Andrea Horwath said consumer need an affordable option.

"We need to see some kind of action that will help people actually conserve," said Horwath.