Economics
Introduction¶
The economics module evaluates the expenditures and revenues of the energy management system (EMS) for a simulation.
The expenditures of the EMS are divided into capital expenditures (CapEx) and operating expenditures (OpEx). CapEx covers debt payments for acquisition costs, while OpEx covers ongoing expenses for operating, maintenance, insurance and staff salaries. The total expenditures for the EMS are calculated by adding up CapEx and OpEx. Revenues for the EMS are generated, when CHP units produce excess electricity that is sold to the power grid.
Equations¶
Capital expenditures (CapEx)¶
\[ C_{CapEx} = \frac{ANF}{8760 \frac{h}{a} / \Delta t} \cdot C_{purch} \cdot f \]
\[ ANF = \frac{(1 + i)^n \cdot i}{(1 + i)^n - 1} \]
\[ C_{purch} = C_{chps} + C_{boilers} + C_{storage} + C_{compressor} + C_{flare} + C_{cooler} \]
| Symbol | Description | Unit |
|---|---|---|
| \(C_{CapEx}\) | Capital expenditures for a single simulation step | € |
| \(C_{purch}\) | Total purchase costs for equipment | € |
| \(C_{i}\) | Individual purchase costs for equipment | € |
| \(ANF\) | Annuity factor | a-1 |
| \(i\) | Bank interest rate | a-1 |
| \(n\) | Payback time in years | - |
| \(\Delta t\) | Time difference of a simulation time step | h |
| \(f\) | Factor (15%) for additional costs due to planning, permit, certificate and reserve | € |
Operating expenditures (OpEx)¶
\[ C_{OpEx} = C_{electr} + C_{maint} + C_{insur} + C_{staff} \]
\[ C_{electr} = P_{el,demand} \cdot p_{el,price} \cdot \Delta t \]
| Symbol | Description | Unit |
|---|---|---|
| \(C_{OpEx}\) | Operating expenditures for a single simulation step | € |
| \(C_{electr}\) | Total electricity costs of the EMS for electricity purchased from the power grid | € |
| \(C_{maint}\) | Total maintenance costs | € |
| \(C_{insur}\) | Total insurance costs | € |
| \(C_{staff}\) | Total costs due to staff salaries | € |
| \(P_{el,demand}\) | Power demand of EMS for a single simulation step | kW |
| \(p_{el,price}\) | Electricity purchase price | € \(\cdot\) kWh-1 |
| \(\Delta t\) | Time difference of a simulation time step | h |
Total expenditures¶
\[ C_{total} = C_{CapEx} + C_{OpEx} \]
| Symbol | Description | Unit |
|---|---|---|
| \(C_{total}\) | Total expenditures of the EMS for a single simulation step | € \(\cdot\) h-1 |
| \(C_{CapEx}\) | Capital expenditures | € \(\cdot\) h-1 |
| \(C_{OpEx}\) | Operating expenditures | € \(\cdot\) h-1 |
Revenues¶
\[ R_{electr} = P_{el,excess} \cdot p_{el,price} \cdot \Delta t \]
| Symbol | Description | Unit |
|---|---|---|
| \(R_{electr}\) | Revenue of the EMS for sold electricity to power grid (for single simulation step) | € \(\cdot\) h-1 |
| \(P_{el,excess}\) | Excess power of the EMS for a single simulation step | kW |
| \(p_{el,price}\) | Electricity selling price | € \(\cdot\) kWh-1 |
| \(\Delta t\) | Time difference of a simulation time step | h |
Source code documentation¶
mod economics