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Supply and demand
An initial orientation to the supply and demand options in the model PyPSA-Eur-Sec can be found in the description of the model PyPSA-Eur-Sec-30 in the paper Synergies of sector coupling and transmission reinforcement in a cost-optimised, highly renewable European energy system (2018). The latest version of PyPSA-Eur-Sec differs by including biomass, industry, industrial feedstocks, aviation, shipping, better carbon management, carbon capture and usage/sequestration, and gas networks.
The basic supply (left column) and demand (right column) options in the model are described in this figure:
Electricity supply and demand
Electricity supply and demand follows the electricity generation and transmission model PyPSA-Eur, except that hydrogen storage is integrated into the hydrogen supply, demand and network, and PyPSA-Eur-Sec includes CHPs.
Unlike PyPSA-Eur, PyPSA-Eur-Sec does not distribution electricity demand for industry according to population and GDP, but uses the geographical data from the Hotmaps Industrial Database.
Also unlike PyPSA-Eur, PyPSA-Eur-Sec subtracts existing electrified heating from the existing electricity demand, so that power-to-heat can be optimised separately.
The remaining electricity demand for households and services is distributed inside each country proportional to GDP and population.
Heat demand
Heat demand is split into:
- urban central: large-scale district heating networks in urban areas with dense heat demand
- residential/services urban decentral: heating for individual buildings in urban areas
- residential/services rural: heating for individual buildings in rural areas, agriculture heat uses
Heat supply
Oil and gas boilers
Heat pumps
Air-to-water heatpumps are used in urban central bus.
They have coefficient of performance (COP) based on either the external air or the soil hourly temperature.
Ground-source heat pumps are only allowed in rural areas because of space constraints.
Only air-source heat pumps are allowed in urban areas. This is a conservative assumption, since there are many possible sources of low-temperature heat that could be tapped in cities (waste water, rivers, lakes, seas, etc.).
Resistive heaters
Large Combined Heat and Power (CHP) plants
A good summary of CHP options that can be implemented in PyPSA can be found in the paper Cost sensitivity of optimal sector-coupled district heating production systems.
PyPSA-Eur-Sec includes CHP plants fuelled by methane, hydrogen and solid biomass from waste and residues.
Hydrogen CHPs are fuel cells.
Methane and biomass CHPs are based on back pressure plants operating with a fixed ratio of electricity to heat output. The methane CHP is modelled on the Danish Energy Agency (DEA) "Gas turbine simple cycle (large)" while the solid biomass CHP is based on the DEA's "09b Wood Pellets Medium".
The efficiencies of each are given on the back pressure line, where the back pressure coefficient c_b is the electricity output divided by the heat output. The plants are not allowed to deviate from the back pressure line and are implement as Link objects with a fixed ratio of heat to electricity output.
NB: The old PyPSA-Eur-Sec-30 model assumed an extraction plant (like the DEA coal CHP) for gas which has flexible production of heat and electricity within the feasibility diagram of Figure 4 in the Synergies paper. We have switched to the DEA back pressure plants since these are more common for smaller plants for biomass, and because the extraction plants were on the back pressure line for 99.5% of the time anyway. The plants were all changed to back pressure in PyPSA-Eur-Sec v0.4.0.
Micro-CHP for individual buildings
Optional.
Waste heat from Fuel Cells, Methanation and Fischer-Tropsch plants
Solar thermal collectors
Thermal energy storage using hot water tanks
Small for decentral applications.
Big water pit storage for district heating.
Retrofitting of the thermal envelope of buildings
Co-optimising building renovation is only enabled if in the config.yaml the option :mod:`retro_endogen: True`. To reduce the computational burden default setting is
System Message: ERROR/3 (<stdin>, line 117); backlink
Unknown interpreted text role "mod".System Message: ERROR/3 (<stdin>, line 121)
Unknown directive type "literalinclude".
.. literalinclude:: ../config.default.yaml
:language: yaml
:lines: 134-135
Renovation of the thermal envelope reduces the space heating demand and is optimised at each node for every heat bus. Renovation measures through additional insulation material and replacement of energy inefficient windows are considered.
In a first step, costs per energy savings are estimated in :mod:`build_retro_cost.py`. They depend on the insulation condition of the building stock and costs for renovation of the building elements. In a second step, for those cost per energy savings two possible renovation strengths are determined: a moderate renovation with lower costs and lower maximum possible space heat savings, and an ambitious renovation with associated higher costs and higher efficiency gains. They are added by step-wise linearisation in form of two additional generations in :mod:`prepare_sector_network.py`.
System Message: ERROR/3 (<stdin>, line 129); backlink
Unknown interpreted text role "mod".System Message: ERROR/3 (<stdin>, line 129); backlink
Unknown interpreted text role "mod".Settings in the config.yaml concerning the endogenously optimisation of building renovation
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Unknown directive type "literalinclude".
.. literalinclude:: ../config.default.yaml
:language: yaml
:lines: 136-140
Further information are given in the publication
Mitigating heat demand peaks in buildings in a highly renewable European energy system, (2021).
Hydrogen demand
Stationary fuel cell CHP.
Transport applications (heavy-duty road vehicles, liquid H2 in shipping).
Industry (ammonia, precursor to hydrocarbons for chemicals and iron/steel).
Hydrogen supply
Steam Methane Reforming (SMR), SMR+CCS, electrolysers.
Methane demand
Can be used in boilers, in CHPs, in industry for high temperature heat, in OCGT.
Not used in transport because of engine slippage.
Methane supply
Fossil, biogas, Sabatier (hydrogen to methane), HELMETH (directly power to methane with efficient heat integration).
Biomass
Biomass supply
Biomass supply potentials for each European country are taken from the JRC ENSPRESO database where data is available for various years (2010, 2020, 2030, 2040 and 2050) and scenarios (low, medium, high). No biomass import from outside Europe is assumed. More information on the data set can be found here.
System Message: WARNING/2 (<stdin>, line 5); backlink
Duplicate explicit target name: "here".The desired scenario can be selected in the pypsa-eur-sec configuration. The script for building the biomass potentials from the JREC ENSPRESO data base is located here. Consult the script to see the keywords that specify the scenario options.
The configuration also allows the user to define how the various types of biomass are used in the model by using the categories : biogas, solid biomass, and not included. Feedstocks categorized as biogas, typically manure and sludge waste, are available to the model as biogas (that is upgraded to biomethane). More details below.
Feedstocks categorized as solid biomass, e.g. secondary forest residues or municipal waste can be used directly or converted to gas or liquid fuels. More details below.
Feedstocks labeled as not included are ignored by the model. A typical use case for biomass would be the medium availability scenario for 2030 where only residues from agriculture and forestry as well as biodegradable municipal waste are considered as energy feedstocks. Fuel crops are avoided because they compete with scarce land for food production, while primary wood, as well as wood chips and pellets, are avoided because of concerns about sustainability . See the supporting materials of the paper for more details.
Solid biomass conversion and use
Solid biomass can be used directly to provide process heat up to 500 C in the industry. It can also be burnt in CHP plants and boilers associated with heating systems. These technologies are described elsewhere [link to heat and industry sections].
Solid biomass can be converted to syngas if the option is enabled in the config file. In this case the model will enable the technology BioSNG both with and without the option for carbon capture [link to technology data]. Liquefaction of solid biomass can be enabled allowing the model to convert it into liquid hydrocarbons that can replace conventional oil products. This technology also comes with and without carbon capture [link to technology data].
Transport of solid biomass
System Message: WARNING/2 (<stdin>, line 5); backlink
Duplicate explicit target name: "here".The transport of solid biomass can either be assumed unlimited between countries or it can be associated with a country specific cost per MWh/km. In the config file these options are toggled here. If the option is off, use of solid biomass is transport. If it is turned on, a biomass transport network will be created between all nodes. This network resembles road transport of biomass and the cost of transportation is a variable cost which is proportional to distance and a country specific cost per MWh/km. The latter is estimated from the country specific costs per ton/km used in the publication “The JRC-EU-TIMES model. Bioenergy potentials for EU and neighbouring countries”.
Biogas transport and use
Biogas will be aggregated into a common European resources if a gas network is not modeled explicitly, i.e., the gas_network option is set to false. If, on the other hand, a gas network is included, the biogas potential will be associated with each node of origin. The model can only use biogas by first upgrading it to natural gas quality [link to tech description] (bio methane) which is fed into the general gas network.
Oil product demand
Transport fuels, agriculture machinery and naphtha as a feedstock for the chemicals industry.
Oil product supply
Fossil or Fischer-Tropsch.
Industry demand
Based on materials demand from JRC-IDEES and other sources such as the USGS for ammonia.
Industry is split into many sectors, including iron and steel, ammonia, other basic chemicals, cement, non-metalic minerals, alumuninium, other non-ferrous metals, pulp, paper and printing, food, beverages and tobacco, and other more minor sectors.
Inside each country the industrial demand is distributed using the Hotmaps Industrial Database.
Industry supply
Process switching (e.g. from blast furnaces to direct reduction and electric arc furnaces for steel) is defined exogenously.
Fuel switching for process heat is mostly also done exogenously.
Solid biomass is used for up to 500 Celsius, mostly in paper and pulp and food and beverages.
Higher temperatures are met with methane.
Transportation
Land transport
Aviation
Shipping
Carbon dioxide capture, usage and sequestration (CCU/S)
Carbon dioxide can be captured from industry process emissions, emissions related to industry process heat, combined heat and power plants, and directly from the air (DAC).
Carbon dioxide can be used as an input for methanation and Fischer-Tropsch fuels, or it can be sequestered underground.