 For me the biggest problem facing the planet is energy. How are we going to find enough energy without warming up the planet so much that we destroy our environment? I was a research student here in the 1970s and looking around the quad as much as it was then. No big changes, the trees have grown up but there's one thing that has changed and that's the air we breathe. The air here in Newcastle has changed. It contains far more carbon dioxide now than it did then and that's down to the way people use their fossil fuels to make their energy. So the one source of energy that is abundant across the developed and the developing world is the sun's energy. We need to learn how to use more of the sun's energy to generate both our electricity and our fuels. We use the sun's energy already to generate some of our electricity but I look at plants and think that if the plants can convert the sun's energy to fuels that they store as starch, why can't we do that too? If we look back at the Royal Society journals we find Jim Barber in 2007 describing in intimate detail how plants use the sun's energy to generate oxygen from water. He also shows how we might learn from the plant's mechanisms how to do our own artificial version of photosynthesis in the lab. I take inspiration from that and from his own mentor George Porter the Nobel Prize winning photochemist who set about measuring the first steps of photosynthesis with the aid of laser flashes lasting a millionth of a millionth of a second. Back in 1978, Porter wrote in the Royal Society journals on the possibility of using the principles of natural photosynthesis to teach us how to do artificial photosynthesis. So I'm here to catch up with Libby Gibson. Libby was a research student with me but she's now moved to Newcastle and she's setting up her own lab to do work on this very subject. So we're using chemistry to convert sunlight into electricity and all of our work's based on dye-sense-tyed solar cells so these are different from the conventional crystalline silicon panels that you may be used to seeing on rooftops. So what goes on with these dye cells? Well, unlike in crystalline silicon where you have the silicon semiconductor doing the light absorption and transporting the charge doing all of the work where you need really pure material and large quantities, we separate all the processes out so a dye absorbs the light and then the semiconductor and electrolyte solution do the charge transport. So this means that we can use less amounts of materials and less pure materials to do our work. But it sounds much more complicated than the silicon with all these different components to get going. Yes, but that's what makes the field so interesting that you can have so many different components and then tune each to have different properties to hopefully improve the efficiency and also to suit to different applications. So we've opened up new opportunities for different applications of solar energy. So what can you do with the solar energy that you couldn't do with that silicon panel that I have on my roof? So the problem with silicon panels is that you need direct sunlight. So they work best on a sunny day at lunchtime but light isn't direct. You can see in the room it's diffused and scattered off objects so by using semiconductors, crystals that are nanoscale nanoparticles we can collect light in all different orientations so in all different types of light conditions even indoors if we want to. So in my lab we're working on tandem dye-sensitive solar cells and this has taken advantage of the fact that we've got dyes in our devices that absorb light so we can make different coloured dyes to absorb different parts of sunlight so we can capture the full spectrum in one device which you can't yet do with a semiconductor like silicon. The other thing that we're doing is avoiding using precious or rare metals because if we want to generate power on a global scale we don't want to be limited by the materials that we're using. How did you get interested in solar energy? Well you know I've been doing photochemistry for ages and I was always fascinated by reactions that you could start with light but you couldn't do it all without light and so as it became obvious that we really have to work at our solar energy I looked to the natural systems and there were fantastic advances in the natural systems and that's what really inspired me to get going on solar energy. It also reminds me about the greenhouse effect it was around the same time that Arrhenius, a Swedish chemist got his ideas about the greenhouse effect and carbon dioxide and the climate but the actual discovery of the greenhouse effect went back even further and that was back to a paper in Phil Trans published by John Tyndall in 1861 and then you go back further and think of the giants who first investigated light, Newton particularly Another of the pioneers of the Royal Society was John Evelyn He was worried that we were destroying all our forests and we needed alternative fuels so the worry about fuels goes back a long way too. And the chemistry community is now working really hard to try and use photochemistry to make fuel and there's an enormous effort in this area. We know that the science works and we can get there and what's really important and is really encouraging is that industry is so keen to take on this new technology and we can see that with the interest of many very large international companies in the pilot Dysense Tie Solar Cell plant that they have in Swansea. At the heart of the concept of a building as a power station is the ability to print and coat different materials The way that we're able to print and coat those materials down gives them different properties So if you print them in one way you can make a solar cell If you put things down in another way you can make a battery but the concepts of printing and coating allow you to produce very cheap, low energy materials which can be used for generating, storing and releasing energy So I'm optimistic that we can find a solution to producing power on a global scale and without being limited by the availability of the materials that we use. But what about you? Well I think it's incredibly important that we put maximum effort into this We need lots of scientific effort to do it We've got to really push hard on the solar fuels and the solar electricity if we're going to have enough renewable energy