Age seems to be no barrier for pioneering scientist and South Australia's Senior Citizen of the Year Monica Oliphant.

After more than half a century dedicating her life to the renewable energy sector, she has hardly slowed down, at a time when clean energy has become very much mainstream.

"There's no limit almost to what they can be used for," she said.

"Power generation, charging electric vehicles, charging up your mobile phone, lots of applications."

But when the passionate physicist began working in the sector, all of those applications were just a thought bubble.

So too were women in science.

In the early 60s, Ms Oliphant was the only female in her class to complete her honours in physics.

That is where she met her husband Michael, the son of Australia's pre-eminent scientist and former South Australian governor, Sir Mark Oliphant.

She said her father-in-law pushed her to continue with her work.

Mark Oliphant with Monica and her husband Michael at her graduation. ( Supplied )

"I was in awe of him but he did inspire me to always say your mind and to not be frightened of saying what you think," she said.

It was advice she held on to throughout her 18 years at South Australia's Electricity Trust, when renewables were viewed with suspicion.

"When I first wanted to get into the area, solar was for water heating, wind was for water pumping and the dunlite sort of generators in farms and solar cells were for satellites," she said.

"It was really quite depressing working for a utility that at that stage when I joined was looking for new coal fields.

"Gas was growing, and renewables were not cost effective and really I was just somebody in the corner they tucked away."

Renewable energy vision becomes mainstream

Slowly, she worked her way out of the corner, with her research helping to prove the worth of solar panels, as the sector became more financially viable.

"I would think that the big break was the German-introduced feed-in tariff," Ms Oliphant said.

"South Australia was the first to pick up in Australia and that has helped reduce costs and it has taken off since then.

"We did some houses and put them up [solar panels] and looked to see what the impact was and it was fairly clear that they were going to reduce consumption.

"We [also] did a wind survey of the state which in 2003 led to South Australia being really ready when the time was right."

Now in her late 70s, Ms Oliphant is still helping out in the field.

Last year she travelled overseas to help with a renewable energy project in China.

Monica Oliphant says South Australia does not need to embrace nuclear power. ( Supplied )

Ms Oliphant considers herself a tree-hugger and despite beginning her career in atomic energy, she said there was no need for South Australia to invest in nuclear energy.

A royal commission is currently underway into the state's nuclear fuel cycle.

"For South Australia, with 41 per cent of intermittent renewables on our energy mix, we just don't need nuclear energy," Ms Oliphant said.

She said from the beginning, she was confident renewable energy would one day move from the fringe, to the mainstream.

"I was sure that it would eventually, not sure why, but I was sure and I wanted to be with it all the way," she said.

Ms Oliphant is in the running to become the Australia's Senior Citizen of the Year.