WEBVTT 00:00:01.938 --> 00:00:04.705 You may have noticed that I'm wearing two different shoes. 00:00:06.720 --> 00:00:08.390 It probably looks funny -- 00:00:08.414 --> 00:00:10.136 it definitely feels funny -- 00:00:10.160 --> 00:00:11.840 but I wanted to make a point. 00:00:12.571 --> 00:00:16.884 Let's say my left shoe corresponds to a sustainable footprint, 00:00:16.908 --> 00:00:20.106 meaning we humans consume less natural resources 00:00:20.130 --> 00:00:22.354 than our planet can regenerate, 00:00:22.378 --> 00:00:26.890 and emit less carbon dioxide than our forests and oceans can reabsorb. 00:00:27.532 --> 00:00:29.568 That's a stable and healthy condition. 00:00:30.374 --> 00:00:33.642 Today's situation is more [like] my other shoe. 00:00:33.666 --> 00:00:35.213 It's way oversized. 00:00:35.982 --> 00:00:39.161 At the second of August in 2017, 00:00:39.185 --> 00:00:43.510 we had already consumed all resources our planet can regenerate this year. 00:00:44.764 --> 00:00:48.275 This is like spending all your money until the 18th of a month 00:00:48.299 --> 00:00:51.577 and then needing a credit from the bank for the rest of the time. 00:00:51.601 --> 00:00:53.982 For sure, you can do this for some months in a row, 00:00:54.006 --> 00:00:55.902 but if you don't change your behavior, 00:00:55.926 --> 00:00:58.423 sooner or later, you will run into big problems. NOTE Paragraph 00:00:59.219 --> 00:01:03.912 We all know the devastating effects of this excessive exploitation: 00:01:03.936 --> 00:01:05.323 global warming, 00:01:05.347 --> 00:01:07.085 rising of the sea levels, 00:01:07.109 --> 00:01:09.416 melting of the glaciers and polar ice, 00:01:09.440 --> 00:01:12.865 increasingly extreme climate patterns and more. 00:01:14.417 --> 00:01:17.079 The enormity of this problem really frustrates me. 00:01:18.306 --> 00:01:21.649 What frustrates me even more is that there are solutions to this, 00:01:21.673 --> 00:01:24.026 but we keep doing things like we always did. 00:01:24.599 --> 00:01:26.363 Today I want to share with you 00:01:26.387 --> 00:01:31.311 how a new solar technology can contribute to a sustainable future of buildings. NOTE Paragraph 00:01:32.504 --> 00:01:36.761 Buildings consume about 40 percent of our total energy demand, 00:01:36.785 --> 00:01:38.139 so tackling this consumption 00:01:38.163 --> 00:01:40.753 would significantly reduce our climate emissions. 00:01:41.436 --> 00:01:43.755 A building designed along sustainable principles 00:01:43.779 --> 00:01:46.163 can produce all the power it needs by itself. 00:01:46.814 --> 00:01:47.964 To achieve this, 00:01:47.988 --> 00:01:51.346 you first have to reduce the consumption as much as possible, 00:01:51.370 --> 00:01:54.263 by using well-insulated walls or windows, for instance. 00:01:54.621 --> 00:01:56.819 These technologies are commercially available. 00:01:57.828 --> 00:02:00.466 Then you need energy for warm water and heating. 00:02:01.130 --> 00:02:03.810 You can get this in a renewable way from the sun 00:02:03.834 --> 00:02:05.648 through solar-thermal installations 00:02:05.672 --> 00:02:07.999 or from the ground and air, with heat pumps. 00:02:08.023 --> 00:02:09.983 All of these technologies are available. NOTE Paragraph 00:02:10.972 --> 00:02:13.323 Then you are left with the need for electricity. 00:02:13.964 --> 00:02:17.860 In principle, there are several ways to get renewable electricity, 00:02:17.884 --> 00:02:21.154 but how many buildings do you know which have a windmill on the roof, 00:02:21.178 --> 00:02:23.141 or a water power plant in the garden? 00:02:23.490 --> 00:02:26.509 Probably not so many, because usually, it doesn't make sense. 00:02:26.533 --> 00:02:30.042 But the sun provides abundant energy to our roofs and facades. 00:02:31.390 --> 00:02:35.840 The potential to harvest this energy at our buildings' surfaces is enormous. 00:02:36.699 --> 00:02:38.502 Let's take Europe as an example. 00:02:39.166 --> 00:02:43.460 If you would utilize all areas which have a nice orientation to the sun 00:02:43.484 --> 00:02:45.167 and they're not overly shaded, 00:02:45.191 --> 00:02:48.226 the power generated by photovoltaics 00:02:48.250 --> 00:02:51.715 would correspond to about 30 percent of our total energy demand. NOTE Paragraph 00:02:52.303 --> 00:02:54.871 But today's photovoltaics have some issues. 00:02:55.610 --> 00:02:58.180 They do offer a good cost-performance ratio, 00:02:58.204 --> 00:03:00.872 but they aren't really flexible in terms of their design, 00:03:00.896 --> 00:03:02.719 and this makes aesthetics a challenge. 00:03:03.123 --> 00:03:05.575 People often imagine pictures like this 00:03:05.599 --> 00:03:08.032 when thinking about solar cells on buildings. 00:03:08.056 --> 00:03:09.962 This may work for solar farms, 00:03:09.986 --> 00:03:13.390 but when you think of buildings, of streets, of architecture, 00:03:13.414 --> 00:03:14.836 aesthetics does matter. 00:03:15.520 --> 00:03:19.543 This is the reason why we don't see many solar cells on buildings today. 00:03:19.567 --> 00:03:20.892 They just don't match. NOTE Paragraph 00:03:21.765 --> 00:03:26.073 Our team is working on a totally different solar-cell technology, 00:03:26.097 --> 00:03:29.571 which is called organic photovoltaics or OPV. 00:03:29.595 --> 00:03:31.432 The term organic describes 00:03:31.456 --> 00:03:35.306 that the material used for light absorption and charge transport 00:03:35.330 --> 00:03:37.424 are mainly based on the element carbon, 00:03:37.448 --> 00:03:38.643 and not on metals. 00:03:39.339 --> 00:03:42.053 We utilize the mixture of a polymer 00:03:42.077 --> 00:03:44.636 which is set up by different repeating units, 00:03:44.660 --> 00:03:46.690 like the pearls in a pearl chain, 00:03:46.714 --> 00:03:49.690 and a small molecule which has the shape of a football 00:03:49.714 --> 00:03:51.059 and is called fullerene. 00:03:51.850 --> 00:03:55.781 These two compounds are mixed and dissolved to become an ink. 00:03:56.413 --> 00:03:57.570 And like ink, 00:03:57.594 --> 00:04:02.020 they can be printed with simple printing techniques like slot-die coating 00:04:02.044 --> 00:04:05.855 in a continuous roll-to-roll process on flexible substrates. 00:04:06.855 --> 00:04:09.220 The resulting thin layer is the active layer, 00:04:09.244 --> 00:04:11.077 absorbing the energy of the sun. 00:04:11.905 --> 00:04:14.481 This active layer is extremely effective. 00:04:15.522 --> 00:04:18.927 You only need a layer thickness of 0.2 micrometers 00:04:18.951 --> 00:04:20.713 to absorb the energy of the sun. 00:04:21.169 --> 00:04:23.767 This is 100 times thinner than a human hair. 00:04:24.876 --> 00:04:26.845 To give you another example, 00:04:26.869 --> 00:04:29.566 take one kilogram of the basic polymer 00:04:29.590 --> 00:04:31.801 and use it to formulate the active ink. 00:04:32.502 --> 00:04:33.911 With this amount of ink, 00:04:33.935 --> 00:04:37.941 you can print a solar cell the size of a complete football field. 00:04:39.114 --> 00:04:42.798 So OPV is extremely material efficient, 00:04:42.822 --> 00:04:46.112 which I think is a crucial thing when talking about sustainability. NOTE Paragraph 00:04:47.354 --> 00:04:49.235 After the printing process, 00:04:49.259 --> 00:04:51.980 you can have a solar module which could look like this ... 00:04:52.988 --> 00:04:55.011 It looks a bit like a plastic foil, 00:04:55.035 --> 00:04:56.915 and actually has many of its features. 00:04:57.625 --> 00:04:58.775 It's lightweight ... 00:05:00.478 --> 00:05:01.628 it's bendable ... 00:05:02.458 --> 00:05:04.181 and it's semitransparent. 00:05:06.949 --> 00:05:09.329 But it can harvest the energy of the sun outdoors 00:05:09.353 --> 00:05:10.824 and also of this indoor light, 00:05:10.848 --> 00:05:13.714 as you can see with this small, illuminated LED. 00:05:14.872 --> 00:05:16.780 You can use it in its plastic form 00:05:16.804 --> 00:05:19.870 and take advantage of its low weight and its bendability. 00:05:20.938 --> 00:05:24.557 The first is important when thinking about buildings in warmer regions. 00:05:25.325 --> 00:05:28.957 Here, the roofs are not designed to bear additionally heavy loads. 00:05:28.981 --> 00:05:31.631 They aren't designed for snow in winter, for instance, 00:05:31.655 --> 00:05:35.823 so heavy silicon solar cells cannot be used for light harvesting, 00:05:35.847 --> 00:05:38.856 but these lightweight solar foils are very well suited. 00:05:40.067 --> 00:05:42.521 The bendability is important 00:05:42.545 --> 00:05:46.122 if you want to combine the solar cell with membrane architecture. 00:05:46.802 --> 00:05:50.383 Imagine the sails of the Sydney Opera as power plants. 00:05:50.932 --> 00:05:53.258 Alternatively, you can combine the solar foils 00:05:53.282 --> 00:05:55.823 with conventional construction materials like glass. 00:05:56.458 --> 00:05:58.849 Many glass facade elements contain a foil anyway, 00:05:58.873 --> 00:06:00.566 to create laminated safety glass. 00:06:01.148 --> 00:06:04.667 It's not a big deal to add a second foil in the production process, 00:06:04.691 --> 00:06:07.603 but then the facade element contains the solar cell 00:06:07.627 --> 00:06:09.489 and can produce electricity. NOTE Paragraph 00:06:11.059 --> 00:06:12.749 Besides looking nice, 00:06:12.773 --> 00:06:16.950 these integrated solar cells come along with two more important benefits. 00:06:17.595 --> 00:06:21.298 Do you remember the solar cell attached to a roof I showed before? 00:06:21.322 --> 00:06:23.991 In this case, we install the roof first, 00:06:24.015 --> 00:06:25.907 and as a second layer, the solar cell. 00:06:25.931 --> 00:06:27.931 This is adding on the installation costs. 00:06:28.508 --> 00:06:30.644 In the case of integrated solar cells, 00:06:30.668 --> 00:06:34.117 at the site of construction, only one element is installed, 00:06:34.141 --> 00:06:36.602 being at the same time the envelope of the building 00:06:36.626 --> 00:06:37.776 and the solar cell. 00:06:38.799 --> 00:06:40.829 Besides saving on the installation costs, 00:06:40.853 --> 00:06:42.775 this also saves resources, 00:06:42.799 --> 00:06:46.223 because the two functions are combined into one element. NOTE Paragraph 00:06:46.247 --> 00:06:48.144 Earlier, I've talked about optics. 00:06:48.168 --> 00:06:49.945 I really like this solar panel -- 00:06:50.366 --> 00:06:53.287 maybe you have different taste or different design needs ... 00:06:54.167 --> 00:06:55.318 No problem. 00:06:55.342 --> 00:06:56.606 With the printing process, 00:06:56.630 --> 00:07:00.905 the solar cell can change its shape and design very easily. 00:07:01.574 --> 00:07:04.088 This will give the flexibility to architects, 00:07:04.112 --> 00:07:06.024 to planners and building owners, 00:07:06.048 --> 00:07:09.721 to integrate this electricity-producing technology as they wish. NOTE Paragraph 00:07:15.322 --> 00:07:18.595 I want to stress that this is not just happening in the labs. 00:07:18.619 --> 00:07:21.367 It will take seven more years to get to mass adoption, 00:07:21.391 --> 00:07:23.631 but we are at the edge of commercialization, 00:07:24.662 --> 00:07:27.970 meaning there are several companies out there with production lines. 00:07:28.561 --> 00:07:30.417 They are scaling up their capacities, 00:07:30.441 --> 00:07:32.128 and so are we, with the inks. NOTE Paragraph 00:07:36.613 --> 00:07:37.763 (Shoe drops) NOTE Paragraph 00:07:41.004 --> 00:07:43.554 This smaller footprint is much more comfortable. NOTE Paragraph 00:07:43.578 --> 00:07:45.046 (Laughter) NOTE Paragraph 00:07:45.070 --> 00:07:47.585 It is the right size, the right scale. 00:07:48.032 --> 00:07:51.998 We have to come back to the right scale when it comes to energy consumption. 00:07:52.535 --> 00:07:55.618 And making buildings carbon-neutral is an important part here. 00:07:56.331 --> 00:07:57.482 In Europe, 00:07:57.506 --> 00:08:00.593 we have the goal to decarbonize our building stock until 2050. 00:08:01.324 --> 00:08:04.596 I hope organic photovoltaics will be a big part of this. NOTE Paragraph 00:08:05.882 --> 00:08:07.588 Here are a couple of examples. 00:08:08.123 --> 00:08:12.570 This is the first commercial installation of fully printed organic solar cells. 00:08:13.276 --> 00:08:17.029 "Commercial" means that the solar cells were printed on industrial equipment. 00:08:17.903 --> 00:08:21.289 The so-called "solar trees" were part of the German pavilion 00:08:21.313 --> 00:08:23.713 at the World Expo in Milan in 2015. 00:08:24.532 --> 00:08:26.662 They provided shading during the day 00:08:26.686 --> 00:08:28.957 and electricity for the lighting in the evening. 00:08:29.716 --> 00:08:33.272 You may wonder why this hexagonal shape was chosen for the solar cells. 00:08:33.744 --> 00:08:34.956 Easy answer: 00:08:34.980 --> 00:08:38.314 the architects wanted to have a specific shading pattern on the floor 00:08:38.338 --> 00:08:39.604 and asked for it, 00:08:39.628 --> 00:08:41.495 and then it was printed as requested. 00:08:42.276 --> 00:08:43.927 Being far from a real product, 00:08:43.951 --> 00:08:47.689 this free-form installation hooked the imagination of the visiting architects 00:08:47.713 --> 00:08:49.186 much more than we expected. NOTE Paragraph 00:08:49.830 --> 00:08:52.772 This other application is closer to the projects 00:08:52.796 --> 00:08:54.917 and applications we are targeting. 00:08:54.941 --> 00:08:57.826 In an office building in São Paulo, Brazil, 00:08:57.850 --> 00:09:01.595 semitransparent OPV panels are integrated into the glass facade, 00:09:01.619 --> 00:09:02.892 serving different needs. 00:09:03.550 --> 00:09:06.798 First, they provided shading for the meeting rooms behind. 00:09:07.479 --> 00:09:12.199 Second, the logo of the company is displayed in an innovative way. 00:09:12.644 --> 00:09:14.533 And of course, electricity is produced, 00:09:14.557 --> 00:09:16.880 reducing the energy footprint of the building. NOTE Paragraph 00:09:17.552 --> 00:09:19.398 This is pointing towards a future 00:09:19.422 --> 00:09:21.869 where buildings are no longer energy consumers, 00:09:21.893 --> 00:09:23.309 but energy providers. 00:09:23.960 --> 00:09:26.899 I want to see solar cells seamlessly integrated 00:09:26.923 --> 00:09:28.802 into our building shells 00:09:28.826 --> 00:09:31.878 to be both resource-efficient and a pleasure to look at. 00:09:32.612 --> 00:09:36.725 For roofs, silicon solar cells will often continue to be a good solution. 00:09:37.112 --> 00:09:41.628 But to exploit the potential of all facades and other areas, 00:09:41.652 --> 00:09:43.936 such as semitransparent areas, 00:09:43.960 --> 00:09:46.548 curved surfaces and shadings, 00:09:46.572 --> 00:09:51.581 I believe organic photovoltaics can offer a significant contribution, 00:09:51.605 --> 00:09:56.809 and they can be made in any form architects and planners will want them to. NOTE Paragraph 00:09:57.425 --> 00:09:58.576 Thank you. NOTE Paragraph 00:09:58.600 --> 00:10:02.015 (Applause)