in different regions and stack these materials on top of each other. now, this stacking of solar 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
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 for birds are known, and we don t site wind turbines in those areas or wind farms in that space. but there can tjust be a wholesale rejection of this technology because of the threat of something that would be negative. that collaboration is the real opportunity for us to work together. so it s a partnership, really, it s you delivering the technologies that make the future possible, and us adopting them and making the right choices to protect us from this growing threat. thank you so much. we re going to move to questions now. this is the engineers: clean energy. we ve been discussing
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 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? i think accepting what is happening on that side, | as henry mentions, is crucial. and then an aspect that.
permitting and collaboration on changes to ensure that migration patterns for birds are known, and we don t site wind turbines in those areas or wind farms in that space. but there can tjust be a wholesale rejection of this technology because of the threat of something that would be negative. that collaboration is the real opportunity for us to work together. so it s a partnership, really, it s you delivering the technologies that make the future possible, and us adopting them and making the right choices to protect us from this growing threat. thank you so much. we re going to move to questions now. this is the engineers: clean energy. we ve been discussing the future of solar energy, wind power and electrical storage, and i m going to ask who would like to ask a question of any of our clean energy initiatives. hi, i m ajay gambier, - iworkjust around the corner at the grantham institute
so it s traditional power stations but using green hydrogen as the power source. thank you. i m going to look for another question in the room here at the v&a. hi, my name is shivika from imperial college. i just want to know about the future regarding the airborne wind turbines. what do you think that in the near term there is a future for airborne because google investing in airborne wind turbine system, we ve seen one first wind turbine system in germany. so what is the future of that technology? so, we ve had land, we ve had sea and now we re asking about air turbines. i m fascinated to hear the answer to this. for those who haven t heard about this concept the airborne based wind farms, are essentially like kites or tethered aeroplanes that are released up into the very high atmospheres, essentially at a very high altitude. they circulate and move around in the sky and generate electricity through their motion. generally they re much more costly than traditional wind