Meridian, Contact, Genesis and Mercury made a collective $2.7 billion in operating profits in the just ended financial year.
Contact Energy is the only privately-owned company of the four, and made $573 million before tax - a 5 percent increase from 2022.
Contact Energy chief executive Mike Fuge told Morning Report the company recognised ordinary Kiwis were "doing it hard at the moment" but the profits were in line with the "incredible amount of investment that's going in to the industry at the moment to decarbonise".
Asked if it was making too much money, Fuge said: "No, what you've always got to look at if you invest money, then you have a reasonable expectation. Just like when you put money in the bank, the more you put in the more returns you expect, that's just ordinary economics."
It was important the industry continued to invest and decarbonise, he said.
"If you look at our investment for three years 2018 to 2020, what we've invested in the last 3 years is four to five times that amount."
Consumer NZ said it was concerned the rise in profits came when many New Zealanders could not afford to heat their homes.
A Consumer NZ survey showed 19 percent of households in Aotearoa had trouble paying their monthly power bill in the past 12 months, while 12 percent of households reported being cold because they had to cut back on heating due to its cost.
Consumer NZ chief executive Jon Duffy said it estimates 40,000 households have gone without power at some point in the past year because they could not afford to pay.
"We acknowledge that profits are a healthy and normal part of business, but there's a question around what is excessive," he said.
"While consumers have the ability to save on their power by shopping around, that only goes so far."
Duffy said fueling issues was a lack of meaningful competition among retail providers and genuine competition could lower prices for everyone.
Fuge said Zealand had one of the most competitive electricity markets in the world.
"What we've seen is that the market has actually protected consumers, so while wholesale has gone up enormously, most consumers have only seen prices increases at or below inflation.
"We welcome competition. We don't agree with the basis of the Consumer Report but the basis of let's have more competition, absolutely, that's a great idea."
The industry and Contact Energy had a range of measures for people experiencing hardship, like energy hardship grants, he said.
"We ourselves, we don't charge disconnection fees for our prepay customers, we absorb those costs and so there's a range of measures.
"I also think for ordinary New Zealanders who are stuck in the middle, we have a range of prepay plans which allow them to shift their power into periods where there is no charges whatsoever and families have been able to engage in that and save energy costs that way as well."
Consumer NZ said its latest survey showed six percent of households said they had to switch to a prepay plan because they had had trouble paying their electricity bills.