Ex-Greenpeace activist Martin Cotterell is founder of alternative energy expert SUNDOG. CM caught up with him in between mountain rescues

After university I worked in Antarctica, measuring the Ozone hole just after it was discovered.

I then worked at Greenpeace on a variety of environmental campaigns. Towards the end of my time there, I did a lot on renewable energy. Together with my electrical background, that led me to set up Sundog.

Sundog feels like a natural progression from my campaigning days, from talking about the problems to providing the solutions. I still get a buzz every time we switch on a system.

We've never wanted to be any particular size, just to excel in what we do. By that I mean installing technically excellent and appropriate systems, in a safe, efficient and friendly manner. But we're really busy. We employ eight people now but need more.

I also work on Solar PV standards. I co-authored the DTI's guide to the installation of PV systems, the benchmark in the current grant scheme and I'm working on the next edition.

I've also worked on a wind installation guide and on various grid connection issues in the UK.

I also work on international PV standards.

I'm a deputy team leader for Patterdale Mountain Rescue Team, which covers a patch around the Ullswater valley in the Lake District, including Hellvellyn. We undertake about 60 rescues a year and also train most weeks.

If my pager goes off or the police call, while I am at home or in the office, I drop what I am doing and go.

Rescues vary from twisted ankles to fatalities. Falls from Hellvellyn are often fairly grizzly. Luckily we don't get too many of them. The most recent rescue was a climber who had a broken leg and was stuck in the snow and cloud near the summit of Raise.

I helped lead a young people's expedition to the Arctic island of Spitsbergen last summer. It was a mixture of kids from the UK and Saudi Arabia. It was aimed at giving them a chance to experience the wilderness and to learn about themselves.