ARLINGTON, Texas (CBSDFW.COM) – In the middle of record low temperatures, Ty Williams of Arlington received a home electric bill so high he couldn’t believe it – $11,527.89.

“And that’s just for half of February,” said Williams. “It just blows my mind. I really did think it was a mistake. There is no way that this is happening.”

Based on Williams’ electricity usage, had he been on a fixed rate plan ($0.11 per kWh), his bill would have been $334.70.

Other customers of the electric company Griddy also reported astronomical bills.

“They (Griddy) took $300 from my account on the 13th and then took another $300 on the 15th,” said Kristin Schlinker of Arlington, who, like most Griddy customers, is on a pay as you go plan. “I just about had a heart attack. It was crazy!”

Griddy is a wholesale electric retail provider. For a monthly fee of $9.99, Griddy charges its customers real-time wholesale energy prices with no mark-up. Griddy only makes money off its monthly membership no matter the price of electricity.

However, while thousands of Texans face huge electricity bills, experts say most homeowners should not have a bill out of the ordinary.

“If you are on a fixed rate plan, you have nothing to worry about,” said Matt Oberle, owner of the electricity brokerage firm TexasElectrictyRatings.com. “If anything, there’s a good chance their bill should be lower if they had huge chunk of days without power that they were not been paying for energy at all.”

In most parts of Texas, consumers can pick an energy plan.

Most go with a fixed rate plan where you pay the same rate every month for the duration of a contract.

In Texas, you can also choose a variable plan where rates can change month to month.

An indexed rate plan is similar to a variable rate plan with the difference being an indexed plan is based on a formula.

Similar to other variable plans, Griddy’s rates also vary but the prices can change minute by minute based on the real-time wholesale price.

On Griddy, during low-peak times the price per kilowatt is often less than a penny. Customers can even be credited money when wholesale prices dip into the negatives.

However, in extreme weather events, Griddy customers are fully exposed to dramatic upswings in the price of electricity.

Last week, at times Griddy customers were paying $9 a kilowatt, compared to the $0.11 many fixed rate consumers were paying.

For an average Texas home, this month on a fixed rate plan your bill will be around $132.

On Griddy, it will be closer to $4,800.

When prices peaked last week, Griddy sent out emails and recorded voice messages encouraging its customers to leave.

However, most other providers would not take on new customers until the market stabilized.

“I started calling other providers but everyone was telling me the same thing,” Schlinker said. “No one could switch me. I said this is an emergency situation.”

On Griddy’s website, the company wrote, “Transparency has always been our goal. We know you are angry and so are we. Pissed, in fact.”

“We intend to fight this for, and alongside, our customers for equity and accountability – to reveal why such price increases were allowed to happen as millions of Texans went without power.”

Griddy did not return the CBS 11 I-Team’s request for an interview.

Governor Greg Abbott and the Public Utility Commission temporarily banned power companies from billing customers or disconnecting them for non-payment.

However for most Griddy customers, they pay as they go so their money is already gone.

Abbott said the issue of high electricity bills is now the top priority for the Texas legislature.

“We’ll never go back ever again,” said Williams who was eventually able to switch electricity companies.