PV and CSP source node

PV and CSP source nodes can generate multiple different resources simultaneously. The standard approach would be to include electricity and heat from solar power, both via solar PV and concentrated solar power. The implementation of the node is hence similar to that of NonDisRES but uses dictionaries for the fields cap, profile, opex_var and opex_fixed to facilitate multiple Resources (both electricity and heat outputs). The type is also used to enable a specialized constructor that samples the Tecnalia_Solar-Energy-Model module.

Introduced type and its field

The CSPandPV is a subtype of AbstractNonDisRES (the same is the case for NonDisRES) and is thus implemented as equivalent to a RefSource. Hence, it utilizes the same functions declared in EnergyModelsBase.

Standard fields

Standard fields (of an AbstractNonDisRES) being reused are given as:

• id:
  The field id is only used for providing a name to the node. This is similar to the approach utilized in EnergyModelsBase.

• output::Dict{<:Resource, <:Real}:
  The field output includes Resources with their corresponding conversion factors as dictionaries. In the case of a PV and CSP energy source, output should always include your electricity resource and a heat resource. In practice, you should use a value of 1.
  All values have to be non-negative.

• data::Vector{Data}:
  An entry for providing additional data to the model. In the current version, it is not applicable. We intend to change this in future releases to enable investments.

  Constructor for `CSPandPV`

  The field data is not required as we include a constructor when the value is excluded.

Additional fields

CSPandPV nodes alter the types of some fields compared to a AbstractNonDisRES:

• cap::Dict{<:Resource,<:TimeProfile}:
  The installed capacity corresponds to the nominal capacity of the node for each of the produced resources.
  If the node should contain investments through the application of EnergyModelsInvestments, it is important to note that you can only use FixedProfile or StrategicProfile for the capacity, but not RepresentativeProfile or OperationalProfile. In addition, all values have to be non-negative.
• profile::Dict{<:Resource,<:TimeProfile}:
  The profiles are used as a multiplier to the installed capacity to represent the maximum actual capacity in each operational period for each of the produced resources. The profiles should be provided as OperationalProfile or at least as RepresentativeProfile. In addition, all values should be in the range $[0, 1]$.
• opex_var::Dict{<:Resource,<:TimeProfile}:
  The variable operating expenses are based on the capacity utilization through the variable :cap_use for each of the produced resources. Hence, it is directly related to the specified output ratios. The variable operating expenses can be provided as OperationalProfile as well.
• opex_fixed::Dict{<:Resource,<:TimeProfile}:
  The fixed operating expenses are relative to the installed capacity (through the field cap) for each of the produced resources and the chosen duration of a strategic period as outlined on Utilize TimeStruct.
  It is important to note that you can only use FixedProfile or StrategicProfile for the fixed OPEX, but not RepresentativeProfile or OperationalProfile. In addition, all values have to be non-negative.

Mathematical description

In the following mathematical equations, we use the name for variables and functions used in the model. Variables are in general represented as

$\texttt{var\_example}[index_1, index_2]$

with square brackets, while functions are represented as

$func\_example(index_1, index_2)$

with parantheses.

Variables

Standard variables

The PV and CSP source node types utilize all standard variables from the AbstractNonDisRES node type. The variables include:

• $\texttt{opex\_var}$
• $\texttt{opex\_fixed}$
• $\texttt{cap\_inst}$
• $\texttt{flow\_out}$
• $\texttt{emissions\_node}$ if EmissionsData is added to the field data.
• $\texttt{curtailment}[n, t]$: For CSPandPV, this variable is the sum of curtailed energy (as rate) of source $n$ in operational period $t$.
  

Additional variables

CSPandPV replaces the variables $\texttt{cap\_use}$ and $\texttt{curtailment}$ variables with the following variables

• $\texttt{solar\_cap\_use}[n, t, p]$: The capacity usage of source $n$ in operational period $t$ for resource $p$.
• $\texttt{solar\_curtailment}[n, t, p]$: Curtailed capacity of source $n$ in operational period $t$ for resource $p$ with a typical unit of MW.
  The curtailed resources specifies the unused generation capacity of sources. It is currently only used in the calculation, but not with a cost.

Constraints

The following sections omit the direct inclusion of the vector of PV and CSP source nodes. Instead, it is implicitly assumed that the constraints are valid $\forall n ∈ N^{\text{CSPandPV}\_source}$ for all CSPandPV types if not stated differently. In addition, all constraints are valid $\forall t \in T$ (that is in all operational periods) or $\forall t_{inv} \in T^{Inv}$ (that is in all strategic periods). Finally, all constraints are valid $\forall p \in outputs(n)$ (that is in all output resources).

Standard constraints

CSPandPV nodes utilize specialized constraint functions that extend the standard approach to accommodate multiple resources with per-resource tracking. These constraints are:

• constraints_capacity:

  \[\texttt{solar\_cap\_use}[n, t, p] \leq capacity(n, t, p)\]

  \[\texttt{solar\_cap\_use}[n, t, p] + \texttt{solar\_curtailment}[n, t, p] = profile(n, t, p) \times capacity(n, t, p) \qquad \forall p \in outputs(n)\]

  \[\sum_{p \in outputs(n)} \texttt{solar\_curtailment}[n, t, p] = \texttt{curtailment}[n, t]\]

  constraints_capacity_installed

  The function constraints_capacity_installed is not used and the node thus currently does not support investments.

• constraints_flow_out:

  \[\texttt{flow\_out}[n, t, p] = \texttt{solar\_cap\_use}[n, t, p] \times outputs(n, p) \qquad \forall p \in outputs(n) \setminus \{\text{CO}_2\}\]

• constraints_opex_fixed:

  \[\texttt{opex\_fixed}[n, t_{inv}] = \sum_{p \in outputs(n)} opex\_fixed(n, t_{inv}, p) \times capacity(n, first(t_{inv}), p)\]

• constraints_opex_var:

  \[\texttt{opex\_var}[n, t_{inv}] = \sum_{t \in t_{inv},\, p \in outputs(n)} \texttt{solar\_cap\_use}[n, t, p] \times opex\_var(n, t, p) \times scale\_op\_sp(t_{inv}, t)\]

• constraints_data:
  This function is only called for specified data of the node, see above.

Additional constraints

CSPandPV nodes do not add additional constraints.