vgbe energy journal 11 (2022) - International Journal for Generation and Storage of Electricity and Heat

Future Energy Systems
cations adds up to over 200 TWh in 2050.
However, this is also unlikely to meet the
total demand for power-to-X products, resulting
in an additional net import of synthetic
energy carriers of about 20 TWh in
2030 and over 350 TWh in 2050.
3.2 Boundary conditions
As shown in the previous sections, the variables
in energy system studies are subject to
a large variance the further into the future
the scenarios are. The aim of this section is
to explain some of the scatter by relating it
to individual parameters. The selection
of energy system parameters used for the
criteria-based analysis are listed in Ta -
b l e 5 . In addition, for each parameter it is
listed how much influence is to be attributed
to the respective criterion and in which direction
the influence extends. Individual
parameters and criteria are selected in the
following in order to discuss the influence of
the respective criterion in more detail. The
graphs used for this purpose include the
criterion-dependent developments of the
variables considered over the period from
2020 to 2050. In addition, their variance in
2050 is shown in the form of box plots, also
grouped by criterion. This evaluation is
based only on a subset of the above listed
studies.
3.2.1 Level of ambition
The political ambition level is clearly reflected
in the reduction of GHG emissions. This
results from the target corridor over which
this criterion is defined. F i g u r e 3 shows
this relationship graphically. Due to the
partly quite narrowly defined CO 2 corridor,
the variance of the values for the year 2050
is low, especially for high ambition. Similarly,
the renewable share is also influenced by
the ambition level and associated targets,
stricter emission targets can only be accompanied
by higher renewable electricity generation
shares. It should be noted here that
high renewable shares can result even with
low ambition. As an example, the “survivalof-the-fittest”
scenario from [27], in which
global commodity price trends result in
95 % renewable electricity generation even
without any political target. In summary,
the criterion is therefore responsible for differences
in the reduction of greenhouse
gases as well as the share of renewables in
electricity generation due to the target formulations
that are included in its definition.
Related to this are variables affecting individual
renewables, as well as CO 2 prices.
Ambition thus affects almost all energy system
variables considered.
3.2.2 Openness of the model
Tab. 5. Influence of criteria on energy system variables. Higher expression of the criterion leads to
higher (+), lower (-) or constant (o) manifestation of the respective energy system variables.
GHG emissions in Mt CO2e
Characteristic
Renewable share of gross electricity production o ++ - o o o + +
Photovoltaics share of gross electricity production - + o - - o o o
Wind turbines share of gross electricity production - o o + o + o +
Photovoltaics share of renewables - o o o - o o o
Wind turbines share of renewables - o o ++ o + o o
Onshore share of total wind turbines ++ - o o o o o o
Gross electricity consumption - + o o - o o o
Installed capacities of renewables - + o o o o + +
Installed capacities of gas-fired power plants -- + o - o o o o
Installed capacities of conventional power plants -- o o - o o o o
Installed capacities of photovoltaics -- ++ o - o o o o
Installed capacities of wind turbines o ++ o + o o + +
Installed capacities of offshore wind turbines - + - o o o + +
CO 2 emission allowance costs + ++ - - o o + ++
GHG emissions - -- - - - -- -- -
800
600
400
200
High Mid Low
0
2020 2030 2040 2050
Society
Ambition
High
ambition
Certainty
Grid
Trade
Medium
ambition
Openness
Sector
Speed
n=13 | 8 | 15
Low
ambition
Fig. 3. Expected development of the greenhouse gas emissions (left) and boxplots of the 2050
variance (right), both in context of the scenarios level of ambition.
GHG emissions in Mt CO2e
800
600
400
200
0
High Mid Low
2020 2030 2040 2050
The effect of the openness criterion initially
appears to have a larger effect on variables
related to wind power, for both types of
wind turbines, offshore and onshore. More
development-open models correlate with a
higher expression of the technology’s variables,
for example, installed capacity or the
respective shares of the total power generation.
However, the apparent correlation is
not necessarily due to causality, but may be
due to bias in the studies. Based on the definition
of the criterion, it is noticeable that
the developments specified therein are less
predetermined in the direction of wind power.
For example, the “persistence” and “unacceptance”
scenarios from ISE(2020) favor
photovoltaics over wind turbines. In addition,
the given development also correlates
with whether a trend is presented.
Since trend studies, in turn, are often associated
with a lower ambition level, this correlation
is particularly evident in emissions
(F i g u r e 4 ), as its results are similar to
the impact of the scenarios ambition (F i g -
u r e 3 ). Nevertheless, more open models
should be used, as they allow for a purely
fact-based decision and reduce the potential
for biases.
Open
model
Some
limitations
n=16 | 6 | 3
Predefined
development
Fig. 4. Expected development of the greenhouse gas emissions (left) and boxplots of the 2050
variance (right), both in context of the openness of the energy systems model.
38 | vgbe energy journal 11 · 2022