Two years ago, it wasn't unusual for Nelson Tomalty's monthly Manitoba Hydro bill to be more than $1,000 during the winter.

"I was in business then and I had cash flow, so we just paid and paid and complained and complained,” he said.

Every time Tomalty complained, Manitoba Hydro said his bills were accurate, and he only paid for the electricity he used.

Tomalty has power running to both his home south of Gimli, Man. and his machine shop out back.

With costly bills continuing to roll in, Tomalty had his meter inspected about 10 years ago.

"They came in and said you must have a leak, so they come in to check for a leak and didn't find anything, so they just left,” Tomalty said.

In December of 2015, Tomalty's meter was replaced when it expired.

He said his very next monthly hydro bill was cut in half.

"I see this tremendous change. The first 30 days, you know?”

Tomalty went back over his previous statements. He compared bills and meter readings from a month before the meter was changed with the same period after. He based his calculations from his minimum bills.

He said prior to the meter being replaced, he was paying at minimum $15 a day for hydro, and is now paying about $5 a day with the new meter.

Based on the differences, Tomlaty estimated what Manitoba Hydro owes him.

"$612,746.46, that's up to, with interest, up to the end of February."

Meanwhile, Manitoba Hydro vehemently denied Tomalty was ever overcharged.

It said when the meter was replaced, it was tested and was found to be functioning accurately. It’s now been put back into circulation.

"The consumption that was recorded was accurate, but there are a number of factors that can go into that change in consumption, whether it be occupancy of the home, whether it be use of machinery or equipment in a shop,” said Scott Power, manager of public affairs with Manitoba Hydro.

Hydro said it measures and tests meters based on federal regulations. If meters are found to be inaccurate, hydro rebates the customer the money,

"There's no benefit to us to have inaccurate meters,” Powell said.

“That's why we have to follow the Measurement Canada standards. We want to ensure that our meters are accurate. We want to ensure that our billing is accurate,” he said.

Powell said Measurement Canada can also independently test meters if customers are concerned they aren’t functioning properly.