JANINE FREEMAN, 38, is head of the National Grid’s sustainable gas group, a job that makes her responsible for ensuring that gas is a sustainable source of fuel in a low-carbon future. She also lobbies the British and US Governments as part of her role to raise awareness of renewable gas.

Freeman explains that gas can be produced from biodegradable matter such as food waste or sewage instead of fossil sources. This could help to solve the problems of limited landfill capacity for waste and the need to move to a low-carbon agenda.

One of the most exciting aspects of her job is that she and her team are doing ground-breaking work that could see the UK and America leading the way. She says she persuaded Westminster to include support for renewable gas in the Energy Act that went through last November.

“I’ve become very passionate about this. There is a real opportunity to develop new technology. I find it amazing that I can have such influence and, potentially, make such a difference to the world,” she says. Freeman took a degree in maths at Oxford before training to be an accountant at Deloitte & Touche and moving to the National Grid a decade ago.

NICHOLA GREGORY, 35, is head of green IT consulting services at Dell, which involves selling the benefits of power management within the company and to customers. Her role is to explain the benefits of green technology.

Dell’s Energy Smart initiative combines hardware and software technology, services and tools for customers to save energy. For example, when workers leave their office at the end of the day the computers can be turned off then switched on and off automatically during the night, for IT maintenance. When Dell tried the smart energy system on 50,000 of its desktops worldwide, the company saved £1.12 million in a year.

Gregory, who took up her post in Surrey 18 months ago, gets great satisfaction from making a difference to the environment.

She has worked for Dell for ten years, after beginning her IT career when she found a job on a helpline in her final year of a degree in French and Spanish. It was unusual then for a woman to work in IT but that is changing, she says.

EMMA BAKER, 36, manages about 50 people in her role as the area environment manager in north Wessex. Baker, who has been with the Environment Agency for 12 years, was appointed 18 months ago and is involved in setting the agency’s strategy.

She describes her job as “exciting and challenging”. One of her responsibilities is to advise on the environmental standards that should be met if plans for two nuclear power stations in Somerset and Gloucestershire are given the go-ahead. Baker looks on this as working alongside progress rather than trying to stop it. “It’s less about preserving and more about adapting because of climate change.”

Born and bred on a farm, she always wanted to work in the environmental field and to make a difference. Baker did her degree in biology and ecology then followed up with a masters in water resource management after a spell at the National Rivers Authority.

She acknowledges that there are huge challenges ahead, such as climate change and the energy shortage, but declares: “I am passionate about this. I love my job.”