Welcome to topic 4 of the mooc “designing the energy transition: simulation models for
the design of transition paths towards a sustainable society”,
Topic 4 is entitled “energy infrastructures and land use in MEDEAS” and this session
is dedicated to land use.
This session will start by presenting the land as a general issue in the context of
the energy transition.
Second, the basis of land use modelling in MEDEAS will be illustrated.
After that, the land requeriment according to different scenarios proposed will be presented,
and finally some examples of the competition issues potentially generated by land energy
uses will be proposed.
Land is a problem in energy transition because…
As shown in the previous session, energy production, in general, and renewable energy production,
in particular, requires materials and more energy, but also land to be feasible.
Human occupation of land has increased with population growth.
In this graph, we can see that, according to united nations statistics, human population
has more than doubled in the last 60 years, and future projections predict a growing pattern.
Furthermore, land is not empty, but being increasingly occupied by human activities,
like agriculture, livestock or urban expansion, as illustrated in the graph below.
The consequence of this growing and occupation is that land is becoming a relevant constraint
for future human activities.
Unfortunately, as shown in the figure, renewable energy sources require more land to produce
the same quantity of energy than fossil fuels.
This is particularly relevant in the case of biomass, which is the most land-intensive
source of energy (around 2,000 times more land than fossil fuels per unit of energy
generated).
Then, concious management of land uses is one of the key points to guarantee a feasible
energy transition to renewables.
Taking account of this phenomenon, the MEDEAS model makes a first approach to the land requirement
of energy transition.
MEDEAS considers transformation of current marginal or crop lands to biofuels, and land
needed for electrical renewable sources.
First, using the modelled installed capacities and the power densities asssociated with the
different renewable sources to calculate land requirements for electricity from renewables.
Power density can be customized by the user according to specific coefficients in the
parameters sheet of the inputs file.
And second, the same logic is applied to calculate “marginal” and cropland area required
to meet the defined potential of the biofuel production as in the previous case, the different
variables can be customized by the user in the parameters sheet of the inputs file.
This is a first approach to have big numbers in order to consider transition feasibility
in land terms.
Following two examples of land requirements of energy transition pathways.
This is a graph illustrating results for two examples: an example using the business as
usual scenario, corresponding to the ipcc ssp2-baseline scenarios, just expanding current
patterns; and, an another one using a green growth scenario, corresponding to the ipcc
ssp2-olt scenario, showing a higher effort to develop a renewable energy mix for electricity
production, starting in 2020.
All of them consider a constant urban land.
As shown, in the case of the business as usual scenario, the transition to renewables would
require more than 275 mha of land devoted to energy purposes in 2050.
If an acceleration of the introduction of renewables is expected (green growth scenario),
then, land required would go beyond 300 million hectares.
With these figures, and since the land potentially transformable is not abundant, many issues
in the competition for land have appeared or will appear in the future.
Some of the most relevant issues associated to the competition for land will probably
be: first, the competition between energy production in solar farms (occupying fertile
land) and solar on rooftops (occupying urban land); second, in a world with famines, the
competition between land for food (croplands and pastures) and land for fuels (biofuels);
and finally, the third, the competition between land for fuels and biodiversity conservation.
To summarize with some conclusions about the topic.
We can highlight that: the transition to a system based on renewable energy needs the
construction of infrastructures that require time, materials, energy and land; transport
in MEDEAS is modeled through bottom-up policies considering the change to alternative vehicles;
mineral extraction is considered in MEDEAS.
Some critical minerals for renewable energies might reach exhaustion; static and dynamic
eroi are calculated in MEDEAS.
Fast introduction of renewable energies has the potential to lower the eroi of the whole
society; a first approach to the land use requirements of energy transition has also
been carried out in MEDEAS.
We have considered the projected patterns of marginal and crop lands used for biomass,
and also, the land requirements due to the increase in renewables for electricity according
to their power density.