cells on top of each other we call multi junctions, and the simplest multi junction is a tandem cell, two solar cells on top of each other. and the perovskite we tune to match perfectly silicon. it absorbs only the visible light and we let the silicon absorb all the infrared. and in doing that we actually fundamentally improve the efficiencies. if we made a perfect perovskite on silicon tandem cell, that would top out at about 45%. so we ve fundamentally lifted the ceiling. and if we went one step further to anotherjunction, triple junction, three junctions, that would top out at just above 50%. so what perovskite does is lift the ceiling for potential efficiency and gives us a new path forward to go to higher and higher efficiency. so, i mean, substantial gains in efficiency here. how close is this really to being a real technology? is this now, or this is far flung future? this is very near term.
so we are now going to go to scotland, to alastair, who has a question about nuclear energy. alastair? hello, today we ve got representatives of wind and solar, which are often portrayed as the two examples of clean energy. but there are still huge challenges with the amount of land required and energy storage required challenges which aren t faced by existing nuclear power technology, something i would argue we really need to prioritise. i wonder if you think nuclear should form a key part of the clean energy mix, and should be a large part of the discussion today, and if not, how do we ensure we invest in and choose the most effective technologies that are going to make the biggest difference to stopping climate change? i m going to give that one over to kristian here. nuclear, it s a fair point, isn t it? we ve talked about wind, we ve talked about solar, we ve talked about ways of storing, but nuclear is here and could do thejob. why aren t we talking about that? |well, the major
deployed in the world. so this is all fantastic, this is state of the art technology and engineering that is market ready or nearly market ready. so is the message that i should get that you are going to gallop to my rescue when it comes to climate change? that i can carry on with my life as i always have, and everything is going to be fine, because the engineers are going to sort it all out? henry, i want to start with you. is that what i should be taking away from this? that is not what you should be taking away, but you should feel encouraged that there can be solutions. but we all need to. it s a challenging road ahead. there s a lot of scale that needs to happen from the industry, and we all need to embrace it, and embrace this change. the technology s there, but if it doesn t get employed and deployed, then it s not going to work. thank you. kristian? yeah, i think accepting - what is happening on that side, as henry mentions, is crucial. and then an aspect that. i would emphasis
energy as unacceptable. - we can t waste energy in any form of action. i so when the energy is going to be challenging to harvest at large scale, we re solving parts of harvesting as much energy- as we can in good ways, and then we have to use that energy as efficiently as possible. and before we open it up to questions, danielle, when it comes to the threat that climate change presents to us, who is going to do the heavy lifting? is it going to be the engineering or is it going to be the individuals? i think the biggest changes will happen at the country level. there s going to be a need for us, in terms of our public policy, to support these kind of technologies at scale. it will certainly develop and deliver lower cost solutions that are good for the individual, but the biggest challenge ahead of us isn t technology, it s public acceptance. it s support for improved permitting and collaboration on changes to ensure that migration patterns
and we let the silicon absorb all the infrared. and in doing that we actually fundamentally improve the efficiencies. if we made a perfect perovskite on silicon tandem cell, that would top out at about 45%. so we ve fundamentally lifted the ceiling. and if we went one step further to anotherjunction, triple junction, three junctions, that would top out at just above 50%. so what perovskite does is lift the ceiling for potential efficiency and gives us a new path forward to go to higher and higher efficiency. so, i mean, substantial gains in efficiency here. how close is this really to being a real technology? is this now, or this is far flung future? this is very near term. you can t go out today and buy perovskite solar cells, but we re building a production line at the moment. we re talking about next year, the first cells and modules will be in production and start to be