Hello everyone.
Do you know that every minute on Earth,
you consume the equivalent of 18,000 tonnes of oil?
It means 520,000 full of cars per minute.
And that number has doubled in 40 years.
This is to tell you the immensity of the challenge of energy in the twenty-first century.
If we want to reduce our dependence on fossil fuels,
if we want to minimize our impact on global warming,
we must act on two levers at the same time:
the first is to invest massively
in the development of renewable energies;
and the second is to reduce our energy consumption.
So the question is: but how to do it
to decrease this energy consumption
without going back to the Stone Age?
One of the solutions is energy efficiency.
We must find ways
to make better use of the energy we consume.
Indeed, if we look at our energy consumption
at present, it is divided into three sectors
who each share a third of the consumption:
industry, transportation and housing.
And whatever the sector,
we have at least a third of the energy we use
which is directly lost in the form of heat
whether in the fumes,
in the chimneys, in the exhaust,
we lose a third of our energy.
The idea we had in my lab is to say:
could we do something useful
with this lost heat?
Could we turn it into electricity?
We first had to choose a sector:
we were a small research team,
the three sectors at the same time, it was a lot of work,
and so we chose to work on the industry.
The industry has a big advantage,
we have a relatively small number of factories
but each of these factories,
it is a very great source of lost heat.
So if we invent a system that allows us to transform
this heat into electricity,
we will be able to install a small number
and have a big impact.
And the technology we decided to use
to recover this heat and turn it into electricity,
it’s thermoelectricity.
Thermoelectricity, what is it?
It is a property of some materials
to transform heat directly into electricity without moving parts.
Thermoelectric materials are used
to make a thermoelectric generator,
that’s what you see in the center of the image,
and when you put this generator
between a heat source, for example smoke,
and a cold source, water or air,
the heat that, passing from one source to another,
crosses the thermoelectric generator
is partially transformed into electricity.
In practice, what does it give?
In practice, it gives that: you have the heat of the candles
which runs through the thermoelectric module that is here,
and this heat is turned into electricity
and can power the electric motor that turns this small fan.
It’s simple, it’s pretty awesome as an idea!
So you’re going to tell me: but why do not we find that everywhere?
There are two big problems with thermoelectricity right now.
The first problem is that conventional thermoelectric materials
that are found in commerce and which are the best
are extremely expensive,
several hundred euros a kilo.
So at the Institute of Mechanics, Materials and Civil Engineering,
in the team of Professor Pascal Jacques,
we wanted to try to propose a solution to this problem,
so we said to ourselves: we’re going to work on a material,
we will not try to do the best in the world but to do the cheapest.
So we started working on the FEVVL,
a material mainly based on iron,
an abundant element that does not cost much.
This material costs 50 times less than conventional thermoelectric materials
but it also produces four times less electricity.
At first glance, it looks less interesting.
Besides, when we go to a scientific conference,
we are told, “Why work on this material?
It works less well than what already exists. “
But it costs a lot less!
If we make the connection between the two, our material is actually
twelve times more interesting,
that is to say that for the same quantity of electricity produced,
a system that uses our material will cost 12 times less.
And there, it starts to become interesting.
The second problem of conventional thermoelectric materials,
it is impossible to make large quantities of them.
We are limited to a few tens, even hundreds of kilos a day
for the biggest producers.
If we want to put thermoelectric generators
in all the factories of the world,
it will be necessary to manufacture tons.
Here again, the iron-based thermoelectric material that is developed at UCL,
it has an advantage: it is iron-based
and therefore the same methods can be used as for making steel.
And steel, it’s been decades and decades
that processes have been developed to produce tons of them continuously.
Where are we now?
We worked on this material, we control its manufacture
we control its properties,
now what we want to do is show that we can use it
in an application.
For that, we are working on the Gtherm project
funded by the Walloon Region,
where we want to show in two years
that a thermoelectric system, with our material,
can recover heat and convert it into electricity
on a factory in the Liège region.
For the moment, we have shown by calculation
that, if we build a real size system,
so for a plant, we could produce 150 kilowatts of electricity.
150 kilowatts electric is enough to power 360 households.
But even better,
it’s enough to feed the Standard stadium
for 250 games a year.
And if we can help Standard, right now,
I think they will be happy.
In addition, use renewable energies
recovered in factories in the Liège region
to produce electricity,
I think this is an idea that could please the president of the Standard.
In addition, since our material is really cheap,
we have a very, very low return on investment time.
That is, if we invest
in a system with our thermoelectric material,
after barely a year, we will have recovered its stake
thanks to the decrease in the electricity bill.
If we compare with other renewable energies,
for example photovoltaics,
Well, we are close to 7 years old.
And still 7 years, it is by including all the public aid that one can have
for this type of renewable energy.
So I explained to you how a material optimized for the cost,
for mass production, could have a major impact
on energy consumption in the industry.
But that’s great with thermoelectricity,
in fact, it can apply to all sectors.
Take transportation, for example.
If we place thermoelectric generators
on all car exhausts,
we can produce electricity,
remove the alternator in cars
and therefore decrease the consumption of cars.
And if we take the housing sector,
we could take thermoelectric generators,
place them in the boilers
and so do cogeneration,
and therefore the boilers could produce their own electricity
and again, decrease the overall consumption of housing.
But if all that is possible today,
it’s thanks to two things:
to the fact that every day there are researchers like me
who get up, who go to the lab and try to achieve this dream
to have thermoelectric generators everywhere,
in all factories, in all cars,
in all the dwellings of the world.
And secondly, it’s because there are researchers who have the idea
a little crazy basically saying that we also had to consider the cost
when we were doing research and not just looking to get
the best performance.
Thank you all for your attention.
(Applause)
”
Be First to Comment