The final episode looks at the solutions to our problems. Wales may be a small nation but it punches well above its weight. It was the crucible of the Industrial revolution, and could today be the driver of clean energy.

Energy and transport is the theme of this episode, and both are major key issues in Wales. Public transport is not as efficient as it would need to be to take cars off the road, and many homes are old and draughty. Lizzie, who tries to take the train everywhere, discusses the rail network and road issues with transport expert Mark Barry.

In the nineteenth century, a scientist from Swansea, William Grove, devised the fuel cell, where hydrogen and oxygen re-unite to form water, giving off energy. The arrival of the combustion engine put his device on the back burner until NASA needed a clever way to power space capsules. Back came Grove's fuel cell - a brilliant way of producing energy, with water as the waste product. Spool on to today, and this is the basis of Hydrogen Cars. Guto Owen from Ynni Glan explains to Lizzie why and how this could be the transport of the future.

As for heating our homes, Dave Worsley introduces Lizzie to futuristic ways that will transform our buildings, making them into power stations in themselves, and demonstrates some new, and life changing, materials. Lizzie talks to Llion Evans about nuclear fusion, which might be the ultimate answer.

But let's not forget the simple answers. Lizzie discovers over the series that solutions also lie with individuals and communities. Paula Roberts and Meleri Davies are both involved in separate community hydro schemes, reminding us that Wales has a wealth of natural resources, which not only produces energy, but injects that community spirit for which Wales is so famous. Show less