The sector has come under fire in recent weeks as a Labour Party pledge to temporarily freeze customers' bills was followed by a round of price rises.
There have also been large fines levied on companies including SSE and ScottishPower for their door-to-door sales practices.
Ms Knight was speaking ahead of a key week for the industry as it gathers in London for the annual Energy UK conference and Perth-based SSE and Scottish Gas owner Centrica publish financial figures.
Ms Knight, a former Treasury minister, said: "The industry does put its hand up to having made mistakes such as door-step selling. We were wrong, we have made mistakes and we are obviously paying for it. It has added to people saying 'I am not sure I trust them'."
She said the industry would use its conference, which is being held under the shadow of the Houses of Parliament at the headquarters of the Institution of Civil Engineers, to set out its importance to the UK economy, including the provision of 650,000 jobs, and in undertaking massive infrastructure investment.
In Scotland, ScottishPower and SSE alone employ around 27,000 people.
She said it is hard for the sector to get a fair hearing.
"I do not think people are listening at the moment," she said. "It is the nature of the time. It is also the result of the way that the (price) increases are being taken and put into the party political arena."
Ms Knight insisted that 30% of energy bills are not under the control of the sector, coming for instance, from green levies and the industry is bearing the brunt of wider concerns about the rising cost of living.
Nevertheless she accepts reform is need. "We have got a lot to do in picking up customer complaints and dealing with the quickly and in speeding up switching," Ms Knight said.
She also said the industry needs to make bills more easily understandable.
Ms Knight she said the energy industry is "looking past" the 2014 independence referendum in Scotland, confident the single energy market would remain intact.
"We see that the common market in energy will continue regardless of the outcome of the referendum vote," she said.
Rather, she said, the industry is more concerned about "stop-start" in investment due to policy changes at Westminster and Holyrood. "We need a long-term stable framework," she said.