In this module we'll talk about why we need renewable energy.
Of course, at the moment,
most of our energy is coming from fossil fuels.
The problem with fossil fuels is that they are polluting source of energy.
They are also a nonrenewable source of energy, so at some point,
we'll end up using up all of the resources that are available to us.
Our problem is that we have a huge energy consumption.
In fact, we use around 15 terawatts of energy.
15 terawatts is a huge number.
And in order to satisfy our energy need,
we really need to look into the different energy resources that are available.
But first, let's take a look at the energy production at the moment.
So right now, around 80 percent of our energy is coming from fossil fuels.
A small portion is coming from uranium and then
a relatively large chunk is coming from renewable energy sources.
So you can see here we have biomass.
That's a relatively big source of energy, around 12 percent.
And this small chunk down here is all of the remaining renewable energy sources.
So let's take a look at those.
So out of the renewable,
most of it is coming from hydropower.
Hydropower is of course a really good idea
in the areas where it's possible to use hydropower.
For this reason, we see a lot of countries that have
their sole electricity production from hydropower.
So Norway is more or less an example of this.
The second largest quadrant is wind energy,
and after that we get solar in the form of solar heat and solar photovoltaics.
Lastly, we have Earth heat as well.
It is more interesting to look at the availability of energy because this
shows us how large of a percentage can we really fulfill with the different technologies.
We can see the circle here shows our current energy need.
And now by area,
you can compare it to the different energy resources that we have available.
So you can see, by far,
wind is the energy resource with the largest technical potential.
And actually you can see hydropower is a lot smaller than wind here.
And we are actually already using
a really large percentage of the hydropower that's available to us.
So the remaining resources you see here all have low technical use,
and it's important to understand that we need to use
most of these in order to fulfill our energy needs.
We can try and compare them to,
for example, fossil fuels.
So by area, you can see this is the remaining resource of fossil fuel we have.
So, from this perspective,
we can live on with fossil fuels for quite a while yet,
but you'll have to remember each of the areas for renewable energy sources are
the energy that's available every single year,
whereas the fossil circle here,
we use up the circle.
So every year, this circle will become smaller,
whereas the other technical yields of
the renewable energy sources stay the same and may even increase,
if we improve our technology.
We can also see here uranium is
a nonrenewable energy resource
that allows us to run for quite some time on uranium, if we needed to.
The one that's missing from this picture is of course the solar resource,
so the direct radiation from the sun.
And the reason it's not drawn yet is that it can't really fit in here.
So you can see by area,
this dominates all of the other and of
course this is not a representation of the technical potential necessarily,
but at least it shows us that the energy available from the sun is a huge resource,
and none of these others can really compare.
Of course we can also go in and look at almost all of these energy resources,
in some form or another,
a derivative of direct radiation.
So fossil fuel is in some ways stored solar energy.
Wind is, of course,
the movements of our atmosphere,
so that's also driven by the sun.
So the only real ones that are not included in this
is Earth heat and maybe tidal energy and uranium.
