IEEE Power & Energy Magazine - July/August 2018 - 27

Distribution of Energy-Related CO2
Emissions in 2015
Total = 754 Million Metric Tons

Final Energy Consumption (Twh)

3,000
2,500

27%

28%

2,000
17%

30%

29%

31%

30%

21%

19%

18%

17%

18%

21%

18%

16%

39%

33%

34%

31%

33%

30%

1996

2008

2009

2010

2011

2012

2013

2014

2015

1,500
17%
1,000
500
0

28%

18%

Electricity
44%

LowTemperature
Heat
18%
Industrial
Processes
17%

Mobility
21%

(a)

(b)

Low-Temperature Heat Fossil Fuels

Low-Temperature Heat Others

Industrial Process Heat Others

Electricity

Mobility Fossil Fuels

Industrial Process Heat Fossil Fuels
Mobility Others

figure 2. The (a) development and share of the final energy consumption by sectors and (b) distribution of energy-related
CO2 emissions by sector in 2015. (Source data: BMWI Energy Data, 2017.)

here, the model distinguishes between two kinds of different
structures: open and closed systems.
When considering the technology of an open system, the
model has the option to increase or decrease the specific
penetration of the technology as long as it doesn't violate
the set expansion potential. for example, onshore wind turbines can be installed as long as the total installed capacity
is below the cumulative technical potential (approximately
180 gWel in germany that, starting from 2015, is roughly
5 gWel per year). likewise, the model could also decide
not to install any onshore wind turbines, such that the total
amount of onshore wind power decreases over the years
through retirements. While the installed capacity of each
technology can increase or decrease in open systems (i.e.,
renewable energy resources, power plants, and thermal and
chemical storage facilities), in closed systems, the technologies are not limited by technical constraints but by others.
for example, the cumulative deployment of technologies
for space heating and domestic hot water supply is limited
by the total number of buildings in germany. here, the
assumption is that every building is equipped with one heat
generator. Whenever this technology reaches the end of its
expected lifetime, the model can decide whether to install
a heat generator of the same type or choose a different one.
This means that the model can optimize the share of each
technology available within the closed system, but it can't
change the exogenously fixed number of technologies in
each closed system.
Conventional lignite and hard coal power plants, nuclear
power plants, oil-fired power plants, gas turbines (gTs), combined heat and power (ChP) plants as well as gas-fired and
steam power plants are implemented as generators. renewable
july/august 2018

energy can be supplied in the model using wind turbines (onshore
and offshore), photovoltaic systems, and hydropower plants.
Biomass can be used either directly or after conversion into a
secondary energy carrier. for example, wood can be burned
in boilers to provide process heat for industrial applications
and for the generation of low-temperature heat in the building
sector. Biogas systems (gasification systems with subsequent
synthesis into hydrogen, methane, or liquid fuels) and biodiesel
systems are implemented as possible systems for the conversion
of biomass. electrical energy-storage systems in the form of
stationary and mobile batteries (in vehicles) or pumped-storage
power plants are implemented as storage systems. hydrogen
and thermal hot water storage systems in different orders of
magnitudes are considered as well.
energy demand is divided into four groups, according to
the different fields of use: mobility, intrinsic electricity applications, heat for buildings (residential, nonresidential, and industrial buildings), and process heat in the industry. The mobility sector is mapped in detail concerning passenger cars and
trucks, with seven vehicle classes each. The energy demand of
aviation, shipping, and fuel-based railway traffic is considered
in the balance, without temporal resolution. The basic electricity load is mapped using load profiles based on the data of
european transmission grid operators reduced by the weatherrelated electric load for heating systems. The load for heating
systems is calculated model endogenously and is not included
in the basic load. Table 1 summarizes the main components of
the energy system considered in remod-D.

Comparative Findings and Discussion
in the following section, the results of three cost-optimized
scenarios are analyzed in detail. The scenarios differ from
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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - July/August 2018