Types of energy system components
This document provides details on the component models and their implementations.
The description of each component type includes a block with a number of attributes that describe the type and how it connects to other components by its input and output interfaces. An example of such a block:
| Type name | BoundedSink |
| File | energy_systems/general/bounded_sink.jl |
| Available models | default |
| System function | bounded_sink |
| Medium | medium/None |
| Input media | None/auto |
| Output media | |
| Tracked values | IN, Max_Energy |
The available models listed are subtypes to the implementation of a component, which each work slightly differently and might use different parameters. An example is the difference between a condensing gas boiler and a traditional one. Note: At the moment there is no argument for the model, as each component currently only has one implemented model. In the future this will be extended to include a default model (when no argument is provided) and additional optional models.
Of particular note are the descriptions of the medium (if it applies) of the component type and its input and output interfaces. The Medium is used for components that could handle any type of medium and need to be configured to work with a specific medium. The attributes Input media and Output media describes which input and output interfaces the type provides and how the media of those can be configured. The syntax name:value lists the name of the parameter in the input data that defines the medium first, followed by a forward slash and the default value of the medium second, if any. A value of None implies that no default is set and therefore it must be given in the input data. A value of auto implies that the value is determined with no required input, usually from the Medium.
The Tracked values attribute lists which values of the component can be tracked with the output specification in the input file (see this section for details). Note that a value of IN or OUT refers to all input or output interfaces of the component. Which these are can be infered from the input and output media attributes and the chosen medium names if they differ from the default values.
The description further lists which arguments the implementation takes. Let's take a look at an example:
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
max_power_profile_file_path |
String |
Y/N | profiles/district/max_power.prf |
Path to the max power profile. |
efficiency |
Float |
Y/Y | 0.8 | Ratio of output over input energies. |
static_temperature |
Temperature |
N/N | 65.0 | If given, sets the temperature of the heat output to a static value. |
The name of the entries should match the keys in the input file, which is carried verbatim as entries to the dictionary argument of the component's constructor. The column R/D lists if the argument is required (R) and if it has a default value (D). If the argument has a default value the example value given in the next column also lists what that default value is. Otherwise the example column shows what a value might look like.
The type refers to the type it is expected to have after being parsed by the JSON library. The type Temperature is an internal structure and simply refers to either Float or Nothing, the null-type in Julia. In general, a temperature of Nothing implies that any temperature is accepted and only the amount of energy is revelant. More restrictive number types are automatically cast to their superset, but not the other way around, e.g: . Dictionaries given in the {"key":value} notation in JSON are parsed as Dict{String,Any}.
Boundary and connection components
General bounded sink
| Type name | BoundedSink |
| File | energy_systems/general/bounded_sink.jl |
| Available models | default |
| System function | bounded_sink |
| Medium | medium/None |
| Input media | None/auto |
| Output media | |
| Tracked values | IN, Max_Energy |
Generalised implementation of a bounded sink.
Can be given a profile for the maximum power it can take in, which is scaled by the given scale factor. If the medium supports it, it can either be given a profile for the temperature or use a static temperature.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
max_power_profile_file_path |
String |
N/N | profiles/district/max_power.prf |
Path to the max power profile. |
static_power |
Temperature |
N/N | 4000.0 | If given, sets the power of the input to a static value. |
scale |
Float |
Y/N | 4000.0 | Factor by which the max power values are multiplied. Only applies to profiles. |
temperature_profile_file_path |
String |
N/N | profiles/district/temperature.prf |
Path to the profile for the input temperature. |
static_temperature |
Temperature |
N/N | 65.0 | If given, sets the temperature of the input to a static value. |
General bounded supply
| Type name | BoundedSupply |
| File | energy_systems/general/bounded_supply.jl |
| Available models | default |
| System function | bounded_source |
| Medium | medium/None |
| Input media | |
| Output media | None/auto |
| Tracked values | OUT, Max_Energy, Temperature |
Generalised implementation of a bounded source.
Can be given a profile for the maximum power it can provide, which is scaled by the given scale factor. If the medium supports it, it can either be given a profile for the temperature or use a static temperature.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
max_power_profile_file_path |
String |
N/N | profiles/district/max_power.prf |
Path to the max power profile. |
static_power |
Temperature |
N/N | 4000.0 | If given, sets the power of the output to a static value. |
scale |
Float |
Y/N | 4000.0 | Factor by which the max power values are multiplied. Only applies to profiles. |
temperature_profile_file_path |
String |
N/N | profiles/district/temperature.prf |
Path to the profile for the output temperature. |
static_temperature |
Temperature |
N/N | 65.0 | If given, sets the temperature of the output to a static value. |
Bus
| Type name | Bus |
| File | energy_systems/connections/bus.jl |
| Available models | default |
| System function | bus |
| Medium | medium/None |
| Input media | None/auto |
| Output media | None/auto |
| Tracked values | Balance |
The only implementation of special component Bus, used to connect multiple components with a shared medium.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
connection_matrix |
Dict{String,Any} |
N/N |
General fixed sink
| Type name | Demand |
| File | energy_systems/general/fixed_sink.jl |
| Available models | default |
| System function | fixed_sink |
| Medium | medium/None |
| Input media | None/auto |
| Output media | |
| Tracked values | IN, Load, Temperature |
Generalised implementation of a fixed sink.
Can be given a profile for the energy it requests, which is scaled by the given scale factor. Alternatively a static load can be given. If the medium supports it, it can either be given a profile for the temperature or use a static temperature.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
energy_profile_file_path |
String |
N/N | profiles/district/demand.prf |
Path to the input energy profile. |
static_load |
Float |
N/N | 4000.0 | If given, ignores the energy profile and sets the input energy to a static value. |
scale |
Float |
Y/N | 4000.0 | Factor by which the energy profile values are multiplied. Only applies to profiles. |
temperature_profile_file_path |
String |
N/N | profiles/district/temperature.prf |
Path to the profile for the input temperature. |
static_temperature |
Temperature |
N/N | 65.0 | If given, sets the temperature of the input to a static value. |
General demand
| Type name | Demand |
| File | energy_systems/general/fixed_sink.jl |
Alias to FixedSink. |
General fixed supply
| Type name | FixedSupply |
| File | energy_systems/general/fixed_supply.jl |
| Available models | default |
| System function | fixed_source |
| Medium | medium/None |
| Input media | |
| Output media | None/auto |
| Tracked values | Out, Supply, Temperature |
Generalised implementation of a fixed source.
Can be given a profile for the energy it can provide, which is scaled by the given scale factor. If the medium supports it, it can either be given a profile for the temperature or use a static temperature.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
energy_profile_file_path |
String |
N/N | profiles/district/energy_source.prf |
Path to the output energy profile. |
static_supply |
Float |
N/N | 4000.0 | If given, ignores the energy profile and sets the output energy to a static value. |
scale |
Float |
Y/N | 4000.0 | Factor by which the energy profile values are multiplied. Only applies to profiles. |
temperature_profile_file_path |
String |
N/N | profiles/district/temperature.prf |
Path to the profile for the output temperature. |
static_temperature |
Temperature |
N/N | 65.0 | If given, sets the temperature of the output to a static value. |
Grid connection
| Type name | GridConnection |
| File | energy_systems/connections/grid_connection.jl |
| Available models | default |
| System function | bounded_source, bounded_sink |
| Medium | medium/None |
| Input media | None/auto |
| Output media | None/auto |
| Tracked values | IN, Out, Draw sum, Load sum |
Used as a source or sink with no limit, which receives or gives off energy from/to outside the system boundary.
If parameter is_source is true, acts as a bounded_source with only one output connection. Otherwise a bounded_sink with only one input connection. In both cases the amount of energy supplied/taken in is tracked as a cumulutative value.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
is_source |
Boolean |
Y/Y | True |
If true, the grid connection acts as a source. |
Other sources and sinks
Photovoltaic plant
| Type name | PVPlant |
| File | energy_systems/electric_producers/pv_plant.jl |
| Available models | default: simplified |
| System function | fixed_source |
| Medium | |
| Input media | |
| Output media | m_el_out/m_e_ac_230v |
| Tracked values | OUT, Supply |
A photovoltaic (PV) power plant producing electricity.
The energy it produces in each time step must be given as a profile, but can be scaled by a fixed value.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
energy_profile_file_path |
String |
Y/N | profiles/district/pv_output.prf |
Path to the output energy profile. |
scale |
Float |
Y/N | 4000.0 | Factor by which the profile values are multiplied. |
Transformers
Combined Heat and Power plant
| Type name | CHPP |
| File | energy_systems/electric_producers/chpp.jl |
| Available models | default: simplified |
| System function | transformer |
| Medium | |
| Input media | m_gas_in/m_c_g_natgas |
| Output media | m_heat_out/m_h_w_ht1, m_el_out/m_e_ac_230v |
| Tracked values | IN, OUT |
A Combined Heat and Power Plant (CHPP) that transforms combustible gas into heat and electricity.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
power |
Float |
Y/N | 4000.0 | The maximum design power. |
electricity_fraction |
Float |
Y/Y | 0.4 | Fraction of the input chemical energy that is output as electricity. |
min_power_fraction |
Float |
Y/Y | 0.2 | The minimum fraction of the design power that is required for the plant to run. |
min_run_time |
UInt |
Y/Y | 1800 | Minimum run time of the plant in seconds. Will be ignored if other constraints apply. |
output_temperature |
Temperature |
N/N | 90.0 | The temperature of the heat output. |
Electrolyser
| Type name | Electrolyser |
| File | energy_systems/others/electrolyser.jl |
| Available models | default: simplified |
| System function | transformer |
| Medium | |
| Input media | m_el_in/m_e_ac_230v |
| Output media | m_heat_out/m_h_w_lt1, m_h2_out/m_c_g_h2, m_o2_out/m_c_g_o2 |
| Tracked values | IN, OUT |
Implementation of an electrolyser splitting water into hydrogen and oxygen while providing the waste heat as output.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
power |
Float |
Y/N | 4000.0 | The maximum design power. |
min_power_fraction |
Float |
Y/Y | 0.2 | The minimum fraction of the design power that is required for the plant to run. |
heat_fraction |
Float |
Y/Y | 0.4 | Fraction of the input electric energy that is output as heat. |
min_run_time |
UInt |
Y/Y | 1800 | Minimum run time of the plant in seconds. Will be ignored if other constraints apply. |
output_temperature |
Temperature |
N/Y | 55.0 | The temperature of the heat output. |
Fuel boiler
| Type name | FuelBoiler |
| File | energy_systems/heat_producers/fuel_boiler.jl |
| Available models | default: simplified |
| System function | transformer |
| Medium | |
| Input media | m_fuel_in |
| Output media | m_heat_out/m_h_w_ht1 |
| Tracked values | IN, OUT |
A boiler that transforms chemical fuel into heat.
This needs to be parameterized with the medium of the fuel intake as the implementation is agnostic towards the kind of fuel under the assumption that the fuel does not influence the behaviour or require/produce by-products such as pure oxygen or ash (more to the point, the by-products do not need to be modelled for an energy simulation.)
The current implementation includes functionality to model a PLR-dependant thermal efficiency , however the efficiency curve is not customizable without code changes until a system for functions-as-parameters is in place.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
m_fuel_in |
String |
Y/N | m_c_g_natgas |
The medium of the fuel intake. |
power |
Float |
Y/N | 4000.0 | The maximum design power. |
min_power_fraction |
Float |
Y/Y | 0.2 | The minimum fraction of the design power that is required for the plant to run. |
min_run_time |
UInt |
Y/Y | 1800 | Minimum run time of the plant in seconds. Will be ignored if other constraints apply. |
output_temperature |
Temperature |
N/N | 90.0 | The temperature of the heat output. |
max_thermal_efficiency |
Float |
N/Y | 1.0 | The maximum thermal efficiency if no is used. |
is_plr_dependant |
Boolean |
N/Y | False | Toggle if is used or not. |
Heat pump
| Type name | HeatPump |
| File | energy_systems/heat_producers/heat_pump.jl |
| Available models | default: carnot |
| System function | transformer |
| Medium | |
| Input media | m_el_in/m_e_ac_230v, m_heat_in/m_h_w_lt1 |
| Output media | m_heat_out/m_h_w_ht1 |
| Tracked values | IN, OUT, COP |
Elevates supplied low temperature heat to a higher temperature with input electricity.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
power |
Float |
Y/N | 4000.0 | The maximum design power. |
min_power_fraction |
Float |
Y/Y | 0.2 | The minimum fraction of the design power that is required for the plant to run. |
min_run_time |
UInt |
Y/Y | 1800 | Minimum run time of the plant in seconds. Will be ignored if other constraints apply. |
fixed_cop |
Float |
N/N | 3.0 | If given, ignores the dynamic COP calculation and uses a static one. |
input_temperature |
Temperature |
N/N | 20.0 | If given, ignores the supplied temperature and uses a static one. |
output_temperature |
Temperature |
N/N | 65.0 | If given, ignores the requested temperature and uses a static one. |
Storage
General storage
| Type name | Storage |
| File | energy_systems/general/storage.jl |
| Available models | default: simplified |
| System function | storage |
| Medium | medium/None |
| Input media | None/auto |
| Output media | None/auto |
| Tracked values | IN, OUT, Load, Load%, Capacity |
A generic implementation for energy storage technologies.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
capacity |
Float |
Y/N | 12000.0 | The overall capacity of the storage. |
load |
Float |
Y/N | 6000.0 | The initial load state of the storage. |
Battery
| Type name | Battery |
| File | energy_systems/storage/battery.jl |
| Available models | default: simplified |
| System function | storage |
| Medium | medium/m_e_ac_230v |
| Input media | None/auto |
| Output media | None/auto |
| Tracked values | IN, OUT, Load, Load%, Capacity |
A storage for electricity.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
capacity |
Float |
Y/N | 12000.0 | The overall capacity of the battery. |
load |
Float |
Y/N | 6000.0 | The initial load state of the battery. |
Buffer Tank
| Type name | BufferTank |
| File | energy_systems/storage/buffer_tank.jl |
| Available models | default: simplified |
| System function | storage |
| Medium | medium/m_h_w_ht1 |
| Input media | None/auto |
| Output media | None/auto |
| Tracked values | IN, OUT, Load, Load%, Capacity |
A short-term storage for heat of thermal carrier fluids, typically water.
Model simplified:
If the adaptive temperature calculation is activated, the temperatures for the input/output of the BT depends on the load state. If it is sufficiently full (depends on the switch_point), the BT can output at the high_temperature and takes in at the high_temperature. If the load falls below that, the output temperature drops and reaches the low_temperature as the load approaches zero.
If the adaptive temperature calculation is deactivated, always assumes the high_temperature for both input and output.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
capacity |
Float |
Y/N | 12000.0 | The overall capacity of the BT. |
load |
Float |
Y/N | 6000.0 | The initial load state of the BT. |
use_adaptive_temperature |
Float |
Y/Y | False |
If true, enables the adaptive output temperature calculation. |
switch_point |
Float |
Y/Y | 0.15 | Partial load at which the adaptive output temperature calculation switches. |
high_temperature |
Temperature |
Y/Y | 75.0 | The high end of the adaptive in-/output temperature. |
low_temperature |
Temperature |
Y/Y | 20.0 | The low end of the adaptive in-/output temperature. |
Seasonal thermal storage
| Type name | SeasonalThermalStorage |
| File | energy_systems/storage/seasonal_thermal_storage.jl |
| Available models | default: simplified |
| System function | storage |
| Medium | |
| Input media | m_heat_in/m_h_w_ht1 |
| Output media | m_heat_out/m_h_w_lt1 |
| Tracked values | IN, OUT, Load, Load%, Capacity |
A long-term storage for heat stored in a stratified artificial aquifer.
Model simplified:
If the adaptive temperature calculation is activated, the temperatures for the input/output of the STES depends on the load state. If it is sufficiently full (depends on the switch_point), the STES can output at the high_temperature and takes in at the high_temperature. If the load falls below that, the output temperature drops and reaches the low_temperature as the load approaches zero.
If the adaptive temperature calculation is deactivated, always assumes the high_temperature for both input and output.
| Name | Type | R/D | Example | Description |
|---|---|---|---|---|
capacity |
Float |
Y/N | 12000.0 | The overall capacity of the STES. |
load |
Float |
Y/N | 6000.0 | The initial load state of the STES. |
use_adaptive_temperature |
Float |
Y/Y | False |
If true, enables the adaptive output temperature calculation. |
switch_point |
Float |
Y/Y | 0.25 | Partial load at which the adaptive output temperature calculation switches. |
high_temperature |
Temperature |
Y/Y | 90.0 | The high end of the adaptive in-/output temperature. |
low_temperature |
Temperature |
Y/Y | 15.0 | The low end of the adaptive in-/output temperature. |