Hello, this video corresponds to the second session of topic three about energy in MEDEAS.
In the previous session some theoretical concepts about energy was explained.
In this video how the energy part is modeled in MEDEAS will be explained.
In this session, we take a quick look at the main features of the energy module in MEDEAS
the modelling of non-renewable energy sources, the modelling of renewable infrastructures
for electricity and heat, and the different types of biomass considered in MEDEAS.
In this session, we take a quick look at the main features of the energy module in MEDEAS
the modelling of non-renewable energy sources, the modelling of renewable infrastructures
for electricity and heat, and the different types of biomass considered in MEDEAS.
In the first topic, the whole scheme of the MEDEAS model was explained.
Topic two looked at the economy module and this topic focuses only on this part of the
whole model, energy availability and energy infrastructures.
The main objective of the Energy module is to obtain the energy consumption necessary
to cover the economic demand.
For this, the required energy demand is obtained in the economic module through the energy
intensities, as explained in the second topic of this course.
The energy demand is disaggregated by five types of final energy: liquids, gases, solids,
electricity and heat.
Each demand is compared with the availability of energy.
In MEDEAS, renewable energies have priority over non-renewable energies.
Twenty-three energy sources have been modeled in MEDEAS.
Once the energy demand has been compared with energy availability, the real energy consumption
is obtained.
Apart from that, energy availability is limited in MEDEAS, in both non-renewable and renewable
sources.
The maximum extraction curves limit the non-renewable resources through Hubbert curves, while the
renewable sources are limited by the maximum potentials.
Hubbert curves and maximum potential concepts were explained in the previous session of
this topic.
This slide shows all the primary energy sources that have been modeled in MEDEAS.
They are classified by renewable and non-renewable sources and by type of final energy.
Renewable energy sources are not only considered for electricity and heat generation, Renewable
energy sources are used for the five types of final energies in MEDEAS.
For example, biofuels for traditional biomass, bioliquids and biogas are considered.
There is also a disaggregation of non-renewable energies.
For example, oil and natural gas are separated by conventional and unconventional resources.
Let's start by explaining how non-renewable energies are modeled in MEDEAS.
Oil, natural gas, coal and uranium are the four types of non-renewable primary energy
sources considered.
The modeling is based on Hubbert curves, which tells us the maximum extraction of that resource
that would be reached each year.
Also, the remaining ultimately recoverable resources (RURR) can be obtained with Hubbert
curves.
The Hubbert curves have been converted into maximum extraction curves in MEDEAS where,
based on the remaining resources, the maximum extraction of that resource is obtained.
The figure on the left shows the Hubbert curve for Laherrére 2018 for natural gas and the
figure on the right shows the natural gas extraction curve for Laherrére 2018.
In MEDEAS, the user can select the extraction curve for each energy resource.
For example, the user can select the mentioned Laherrére 2018 gas extraction curve.
This slide shows, in a simple way, how coal extraction is modeled in MEDEAS.
On the one hand, the demand for solids is obtained through the economic module, the
part of this demand covered by renewable energies is subtracted and the required demand for
coal is estimated.
On the other hand, the user chooses the maximum extraction curve from which the URR and the
maximum annual extraction are established.
Then the model compares the maximum extraction of coal with the required demand of coal and
the extraction of coal is obtained.
The coal extraction is then used to estimate when the scarcity of coal begins.
Also the real consumption and emissions derived from coal are calculated.
In this slide, the graphs with the extraction of oil and coal are shown.
It can be seen how the maximum extraction curve (the green line) limits the extraction
of the resource (the red line).
If the required demand is less than the maximum extraction, all the demand for resource will
be covered, while, if required demand is greater, the extraction of resource will be adjusted
to the maximum curve.
In the case shown in this slide, the oil is limited by its maximum extraction curve, while
coal is not limited.
Having briefly discussed the modeling of non-renewable energy sources, the modeling of renewable
energies will now be explained.
We start with renewable energies for the production of electricity and heat.
In MEDEAS, eight types of renewable energies are considered for electricity, such as hydro,
solar PV, solar CSP, onshore wind, offshore wind, geothermal, biomass and oceanic; while
for heat, three sources are considered: solar, biomass and geothermal.
Renewable energies require infrastructures to be extracted, the greater the amount of
such infrastructures, such as windmills, solar panels, etc., the greater the energy obtained,
but such equipment needs time to be set up, which is why, in MEDEAS, they are considered
as stocks and are built according to the rate of investment in infrastructures.
Several factors limit the development of these infrastructures.
One is the absolute technical potential that has been established in MEDEAS for each technology.
Another is the rate of growth, which is determined exogenously according to the different scenarios.
If the build-up of new infrastructures is slow, the technical potential might not be
reached by 2050, and if the depletion of fossil fuels is faster than the establishment for
renewable energies, shortages cannot be avoided.
However, RES development in MEDEAS is limited by two other factors: intermittency and the
contribution to the energy mix.
This might make the total renewable energy infrastructure developed by the end of the
simulation lower than that indicated by the policy, because these factors inhibit the
development of more intermittent energy during the simulation.
This slide shows, in a simplified way, the modeling of the infrastructures for the generation
of electricity.
As said before, the user defines exogenously what the defined value of the growth of renewable
energies is.
However, that growth is limited by the above mentioned aspects.
Firstly, its technical potential: when the generation of one energy source is close to
its maximum potential, the growth is limited.
Secondly, its contribution to the energy mix: for example, if electricity generation by
renewable energies is close to the total electricity demand, the growth is again limited.
Finally, the growth of renewable energies is also limited by the intermittency of some
of its sources.
The increase in the capacity of renewable energies will also depend on the time for
planning and the construction of infrastructures.
As an example of a result in MEDEAS, this slide shows the evolution of the installed
capacity of renewable energy sources for electricity, considering a scenario with a high growth
of renewable energy.
The installed capacity will grow over the next decades, especially in the solar PV and
onshore wind cases.
In 2050, the installed capacity for solar PV will be almost 20 TW.
We finish this session explaining how biomass production is modeled in MEDEAS.
Biomass is considered for both the production of liquids and gases and for its use as a
solid fuel.
The liquid fuels considered in MEDEAS are 2nd and 3rd generation biofuels derived from
food crops, the biofuels obtained from woody parts of non-food biomass residues and the
biofuels that can be obtained in "marginal lands".
The evolution of biogas is also modeled in MEDEAS, while solid fuels are used as traditional
fuel or to obtain electricity and heat as mentioned in the previous slides.
Both the growth of the different types of biomass and their maximum potential can be
defined exogenously by the user.
As an example of biomass modeling, this slide shows the production of biofuels in "marginal
lands", which refers to lands with little agricultural value.
On the one hand, the user would have to select the year in which the marginal lands will
begin to be used for biofuels and the annual growth of production.
With these variables, and with respect to the productivity of the land, the production
of the biofuels is obtained, which in turn is limited by their maximum potential.
Finally, the primary energy required to obtain this biofuel production is also calculated.
Finally, the figure on the left shows how the production of biofuels evolves (the green
line) and the primary energy that has been required to obtain this biofuel production
(the red line).
As shown in the graph, the primary energy required is much greater than biofuels production
(in fact, about 6 times more).
In addition, the figure on the right shows how the production of biofuels covers a very
small part of the total demand for liquids.
In this topic 3 about energy: In the first session we explained the great
importance of energy in the development of humanity and our societies, the current stagnation
in non-renewable energy sources production and the peak oil concept, the EROEI (energy
return on energy invested) concept and the challenge of renewable energy sources for
filling the gap left by the another energy sources.
In the second session we described the main features of energy module in MEDEAS and explained
the modelling of non-renewable energy sources, renewable infrastructures for electricity
and heat and the different types of bioenergy considered in MEDEAS.
With this, we finish the energy topic of the MOOC.