0:00:01.994,0:00:04.761
You may have noticed[br]that I'm wearing two different shoes.

0:00:06.776,0:00:08.518
It probably looks funny --

0:00:08.518,0:00:10.192
it definitely feels funny --

0:00:10.192,0:00:11.872
but I wanted to make a point.

0:00:12.698,0:00:16.964
Let's say my left shoe corresponds[br]to a sustainable footprint,

0:00:16.964,0:00:20.254
meaning we humans consume[br]less natural resources

0:00:20.254,0:00:22.501
than our planet can regenerate,

0:00:22.501,0:00:27.013
and emit less carbon dioxide[br]than our forests and ocean can reabsorb.

0:00:27.532,0:00:29.568
That's a stable and healthy condition.

0:00:30.486,0:00:33.487
Today's situation[br]is more [like] my other shoe.

0:00:33.777,0:00:35.324
It's way oversized.

0:00:36.070,0:00:39.309
At the second of August in 2017,

0:00:39.309,0:00:41.574
we have already consumed all resources

0:00:41.574,0:00:43.664
our planet can regenerate this year.

0:00:44.844,0:00:48.355
This is like spending all your money[br]until the [eighteenth] of a month,

0:00:48.355,0:00:51.477
and then needing a credit[br]from the bank for the rest of the time.

0:00:51.656,0:00:53.992
For sure you can do this[br]for some months in a row,

0:00:53.992,0:00:55.939
but if you don't change your behavior,

0:00:55.939,0:00:58.436
sooner or later you will[br]run into big problems.

0:00:59.291,0:01:03.936
We all know the devastating effects[br]of this excessive exploitation:

0:01:03.936,0:01:05.409
global warming,

0:01:05.409,0:01:07.216
rising of the sea levels,

0:01:07.216,0:01:09.546
melting of the glaciers and polar ice,

0:01:09.546,0:01:12.117
increasingly extreme climate patterns

0:01:12.117,0:01:13.118
and more.

0:01:14.528,0:01:17.190
The enormity of this problem[br]really frustrates me.

0:01:18.418,0:01:21.761
What frustrates me even more[br]is that there are solutions to this,

0:01:21.761,0:01:24.114
but we keep doing things[br]like we always did.

0:01:24.599,0:01:26.477
Today I want to share with you

0:01:26.477,0:01:29.263
how a new solar technology can contribute

0:01:29.263,0:01:31.311
to a sustainable future of buildings.

0:01:32.624,0:01:36.785
Buildings consume about 40 percent[br]of our total energy demand,

0:01:36.785,0:01:38.256
so tackling this consumption

0:01:38.256,0:01:40.846
would significantly reduce[br]our climate emissions.

0:01:41.476,0:01:43.818
A building designed[br]along sustainable principle

0:01:43.818,0:01:46.202
can produce all the power[br]it needs by itself.

0:01:46.868,0:01:47.909
To achieve this,

0:01:47.909,0:01:51.509
you first have to reduce[br]the consumption as much as possible

0:01:51.509,0:01:54.402
by using well-insulated walls[br]or windows for instance.

0:01:54.773,0:01:56.971
These technologies[br]are commercially available.

0:01:57.845,0:02:00.483
Then you need energy[br]for warm water and heating.

0:02:01.130,0:02:03.994
You can get this in a renewable[br]way from the sun

0:02:03.994,0:02:05.728
through solar thermal installations

0:02:05.728,0:02:07.869
or from the ground and air[br]with heat pumps.

0:02:08.023,0:02:09.983
All of these technologies are available.

0:02:11.020,0:02:13.371
Then you are left[br]with the need for electricity.

0:02:14.001,0:02:14.997
In principle,

0:02:14.997,0:02:17.916
there are several ways[br]to get renewable electricity,

0:02:17.916,0:02:19.560
but how many buildings do you know

0:02:19.560,0:02:21.199
which have a windmill on the roof,

0:02:21.199,0:02:23.162
or a water power plant in the garden?

0:02:23.578,0:02:26.391
Probably not so many because[br]usually it doesn't make sense.

0:02:26.653,0:02:30.150
But the sun provides abundant[br]energy to our roofs and façades.

0:02:31.390,0:02:35.840
The potential to harvest this energy[br]at our buildings' surfaces is enormous.

0:02:36.763,0:02:38.566
Let's take Europe as an example.

0:02:39.206,0:02:43.641
If you would utilize all areas[br]which have a nice orientation to the sun

0:02:43.641,0:02:45.347
and they're not overly shaded,

0:02:45.347,0:02:48.378
the power generated[br]by photovoltaics

0:02:48.378,0:02:51.843
would correspond to about 30 percent[br]of our total energy demand.

0:02:52.303,0:02:54.871
But today's photovoltaics[br]have some issues.

0:02:55.746,0:02:58.276
They do offer a good[br]cost-performance ratio,

0:02:58.276,0:03:00.966
but they aren't really flexible[br]in terms of their design,

0:03:00.966,0:03:02.789
and this makes aesthetics a challenge.

0:03:03.235,0:03:05.710
People often imagine pictures like this

0:03:05.710,0:03:07.907
when thinking about[br]solar cells on buildings.

0:03:08.120,0:03:09.986
This may work for solar farms,

0:03:09.986,0:03:11.539
but when you think of buildings,

0:03:11.539,0:03:12.542
of streets,

0:03:12.542,0:03:13.572
of architecture,

0:03:13.572,0:03:14.994
aesthetics does matter.

0:03:15.520,0:03:19.067
This is the reason why we don't see[br]many solar cells on buildings today.

0:03:19.567,0:03:20.892
They just don't match.

0:03:21.861,0:03:25.394
Our team is working on a totally[br]different solar cell technology.

0:03:26.177,0:03:28.461
It's just called organic photovoltaics,

0:03:28.461,0:03:29.458
or OPV.

0:03:29.730,0:03:31.480
The term organic describes

0:03:31.480,0:03:33.995
that the material used[br]for light absorption

0:03:33.995,0:03:35.414
and charge transport

0:03:35.414,0:03:37.531
are mainly based on the element carbon,

0:03:37.531,0:03:38.726
and not on metals.

0:03:39.339,0:03:42.185
We utilize the mixture of a polymer

0:03:42.185,0:03:44.811
which is set up by different[br]repeating units,

0:03:44.811,0:03:46.864
like the pearls in a pearl chain,

0:03:46.864,0:03:49.786
and a small molecule[br]which has the shape of a football

0:03:49.786,0:03:51.131
and is called fullerene.

0:03:51.906,0:03:55.837
These two compounds are mixed[br]and dissolved to become an ink.

0:03:56.437,0:03:57.487
And like ink,

0:03:57.487,0:04:02.190
they can be printed with simple[br]printing techniques like slot-die coating

0:04:02.190,0:04:06.041
in a continuous roll-to-roll process[br]on flexible substrates.

0:04:06.855,0:04:08.244
The resulting thin layer

0:04:08.244,0:04:11.077
is the active layer absorbing[br]the energy of the sun.

0:04:12.167,0:04:14.578
This active layer is extremely effective.

0:04:15.692,0:04:19.205
You only need a layer thickness[br]of 0.2 micrometers

0:04:19.205,0:04:20.837
to absorb the energy of the sun.

0:04:21.309,0:04:23.777
This is 100 times thinner[br]than a human hair.

0:04:25.076,0:04:27.053
To give you another example,

0:04:27.053,0:04:29.733
take one kilogram of the basic polymer

0:04:29.733,0:04:31.944
and use it to formulate the active ink.

0:04:32.780,0:04:34.152
With this amount of ink,

0:04:34.152,0:04:38.008
you can print a solar cell[br]the size of a complete football field.

0:04:39.342,0:04:43.075
So OPV is extremely material efficient,

0:04:43.075,0:04:46.175
which I think is a crucial thing[br]when talking about sustainability.

0:04:47.534,0:04:49.485
After the printing process,

0:04:49.485,0:04:50.778
you can have a solar module

0:04:50.778,0:04:53.265
which can look like this ...

0:04:53.265,0:04:55.288
it looks a bit like a plastic foil,

0:04:55.288,0:04:56.908
and actually has many of its features.

0:04:57.876,0:05:00.679
It's lightweight ...

0:05:00.679,0:05:02.712
it's bendable ...

0:05:02.712,0:05:04.535
and it's semi-transparent.

0:05:07.201,0:05:09.604
But it can harvest [the] energy[br]of the sun outdoors

0:05:09.604,0:05:11.052
and also of this indoor light,

0:05:11.052,0:05:13.818
as you can see with this small,[br]illuminated LED.

0:05:15.095,0:05:17.043
You can use it in its plastic form

0:05:17.043,0:05:19.929
and take advantage of its low weight[br]and it's bendability.

0:05:21.161,0:05:24.480
The first is important when thinking[br]about buildings in warmer regions.

0:05:25.485,0:05:28.622
Here, the roofs are not designed[br]to bear additionally heavy loads.

0:05:29.201,0:05:31.837
They aren't designed for snow[br]in winter for instance,

0:05:31.837,0:05:36.048
so heavy silicon solar cells[br]cannot be used for light harvesting,

0:05:36.048,0:05:38.897
but these lightweight solar foils[br]are very well suited.

0:05:40.299,0:05:42.746
The bendability is important

0:05:42.746,0:05:46.203
if you want to combine the solar cell[br]with membrane architecture.

0:05:46.982,0:05:50.463
Imagine the cells of the Sydney[br]Opera as power plants.

0:05:51.082,0:05:53.513
Alternatively, you can[br]combine the solar foils

0:05:53.513,0:05:55.944
with conventional construction[br]materials like glass.

0:05:56.604,0:05:59.008
Many glass [façade] elements[br]contain a [foil] anyways

0:05:59.008,0:06:00.821
to create laminated safety glass.

0:06:01.388,0:06:04.865
It's not a big deal to add[br]a second foil in the production process,

0:06:04.865,0:06:07.730
but then the façade element[br]contains the solar cell

0:06:07.730,0:06:09.572
and can produce electricity.

0:06:11.265,0:06:12.783
Besides looking nice,

0:06:12.783,0:06:16.910
these integrated solar cells come along[br]with two more important benefits.

0:06:17.738,0:06:20.962
Do you remember the solar cells[br]attached the roof I showed before?

0:06:21.561,0:06:22.727
In this case,

0:06:22.727,0:06:24.221
we install the roof first

0:06:24.221,0:06:25.121
and as a second layer,

0:06:25.121,0:06:26.163
the solar cell.

0:06:26.336,0:06:28.834
This is adding on [the] installation cost.

0:06:29.058,0:06:30.828
In the case of integrated solar cells,

0:06:30.828,0:06:32.351
at the site of construction,

0:06:32.351,0:06:34.320
only one element is installed,

0:06:34.320,0:06:36.922
being at the same time[br]the envelope of the building

0:06:36.922,0:06:37.929
and the solar cell.

0:06:38.965,0:06:40.773
Besides saving on your installation costs,

0:06:40.773,0:06:42.908
this also saves resources

0:06:42.908,0:06:45.986
because the two functions[br]are combined into one element.

0:06:46.533,0:06:48.388
Earlier I talked about optics.

0:06:48.590,0:06:50.636
I really like this solar pattern,

0:06:50.636,0:06:53.287
maybe you have different taste[br]or different design needs.

0:06:54.286,0:06:55.344
No problem.

0:06:55.505,0:06:56.841
With the printing process,

0:06:56.841,0:07:00.986
the solar cell can change[br]its shape and design very easily.

0:07:01.774,0:07:04.252
This will give the flexibility[br]to architects,

0:07:04.252,0:07:06.271
to planners and building owners

0:07:06.271,0:07:09.754
to integrate this electricty-producing[br]technology as they wish.

0:07:15.563,0:07:18.289
I want to stress that this is not[br]just happening in the labs.

0:07:18.861,0:07:21.532
It will take seven more years[br]to get to mass adoption,

0:07:21.532,0:07:24.787
but we are at the edge[br]of commercialization,

0:07:24.787,0:07:28.005
meaning there are several companies[br]out there with production lines.

0:07:28.795,0:07:30.638
They are scaling up their capacities

0:07:30.638,0:07:32.555
and so are we with the inks.

0:07:41.147,0:07:43.472
This smaller footprint[br]is much more comfortable.

0:07:44.112,0:07:45.241
(Laughter)

0:07:45.470,0:07:46.675
It is the right size,

0:07:46.675,0:07:47.773
the right scale.

0:07:48.202,0:07:52.038
We have to come back to the right scale[br]when it comes to energy consumption.

0:07:52.714,0:07:55.667
And making buildings carbon neutral[br]is an important part here.

0:07:56.510,0:07:57.257
In Europe,

0:07:57.257,0:08:00.875
we have the goal to decarbonize[br]our buildings [stock] until 2050.

0:08:01.374,0:08:04.386
I hope organic photovoltaics[br]will be a big part of this.

0:08:05.452,0:08:07.368
Here are a couple of examples.

0:08:08.291,0:08:12.658
This is the first commercial installation[br]of fully printed organic solar cells.

0:08:13.481,0:08:16.826
Commercial means that the solar cells[br]were printed on industrial equipment.

0:08:18.138,0:08:21.508
The so-called solar trees are part[br]of the German pavilion

0:08:21.508,0:08:24.138
at the World Expo in Milan in 2015.

0:08:24.788,0:08:26.950
They provided shading during the day

0:08:26.950,0:08:29.391
and electricity for[br]the lighting in evening.

0:08:29.920,0:08:33.276
You may wonder why this hexagonal shape[br]was chosen for the solar cells.

0:08:33.884,0:08:35.190
Easy answer:

0:08:35.190,0:08:38.558
the architects wanted to have[br]a specific shading pattern on the floor

0:08:38.558,0:08:39.847
and asked for it,

0:08:39.847,0:08:41.774
and then it was printed as requested.

0:08:42.458,0:08:44.151
Being far from a real project,

0:08:44.151,0:08:47.974
this free-form installation hooked[br]the imagination of the visiting architects

0:08:47.974,0:08:49.477
much more than we expected.

0:08:50.092,0:08:52.577
This other application[br]is closer to the projects

0:08:52.577,0:08:54.810
and applications we are targeting.

0:08:55.260,0:08:58.038
In an office building[br]in Sao Paulo, Brazil,

0:08:58.038,0:09:01.836
semi-transparent OPV panels[br]are integrated into the glass façade,

0:09:01.836,0:09:02.909
serving different needs.

0:09:03.650,0:09:06.688
First, they provided shading[br]for the meeting rooms behind.

0:09:07.746,0:09:12.346
Second, the logo of the company[br]is displayed in an innovative way.

0:09:12.888,0:09:14.627
And of course electricity is produced,

0:09:14.627,0:09:16.760
reducing the energy footprint[br]of the building.

9:59:59.000,9:59:59.000
This is pointing towards a future

9:59:59.000,9:59:59.000
where buildings are no longer[br]energy consumers,

9:59:59.000,9:59:59.000
but energy providers.

9:59:59.000,9:59:59.000
I want to see solar cells[br]seamlessly integrated

9:59:59.000,9:59:59.000
into our building shells

9:59:59.000,9:59:59.000
to be both resource-efficient[br]and a pleasure to look at.

9:59:59.000,9:59:59.000
For roofs, silicon solar cells[br]will often continue to be a good solution,

9:59:59.000,9:59:59.000
but to exploit the potential[br]of all façades in other areas,

9:59:59.000,9:59:59.000
such as sem-transparent areas,

9:59:59.000,9:59:59.000
curved surfaces

9:59:59.000,9:59:59.000
and shadings,

9:59:59.000,9:59:59.000
I believe organic photovoltaics[br]can offer a significant contribution

9:59:59.000,9:59:59.000
and they can be made in any form[br]architects and planners will want them to.

9:59:59.000,9:59:59.000
Thank you.

9:59:59.000,9:59:59.000
(Applause)