Data View, Branch: Demand Sites and Catchments, Category:
Cost, Tabs: Capital Costs, Fixed Operating Costs, Variable Operating Costs,
Fixed Benefit, Variable Benefit.Costs
For each individual item (such as demand nodes, transmission links, treatment plants and reservoirs), costs can be entered as capital, fixed operation, and variable operation costs. These variables can be accessed by right clicking on an item in the Schematic View. The dropdown menu provides a list of all the variables associated with the item. These variables can also be accessed by navigating through the Data View screen to the item of interest, then clicking on the Cost tab.
Cost variables include:
Capital Costs - the principal of the loan, in dollars. Capital costs represent the investment in project construction and are often financed. WEAP provides the LoanPayment function for calculation of the annual payment on a loan. This feature can be used in the expression builder, and includes variables such as the principal value, length of loan and year to initiate payments, and interest rate. For example, for a wastewater treatment plant built in 2005 for $50,000,000 and financed with a 30-year loan at 5% interest, the expression would be LoanPayment(50000000, 2005, 30, 5%).
Fixed Operating Costs - costs from annual operations and management that are not a function of the volume of water produced, transmitted, or consumed by an item. For example, the labor cost of running the wastewater treatment plant does not vary according to how much wastewater is treated. Therefore, labor would be a fixed annual cost.
Variable Operating Costs - costs from operations and management that are represented as per unit of water produced, transmitted, or consumed by an item. The quantities of water subject to these costs can include demand site supply inflows, reservoir releases, river headflow, flows in river reach transmission links and return flow links, groundwater pumping, wastewater treatment plant inflows (outflows may differ if in-plant losses occur), flows into tops of diversions from rivers, and flow requirements (total flow at that point). For example, processing costs at a wastewater treatment plant, including chemicals, filters and energy costs, will vary according to the volume of wastewater treated. Therefore, these costs are considered variable operating costs and entered as a cost per volume of water (e.g., cubic meter) treated.
Benefits
Benefit variables can be accessed in a similar manner as the cost variables. You can right click on an item in the Schematic View or by navigating the Data View. Three types of benefits can be modeled in WEAP:
Fixed Benefit--this value represents the total annual benefit produced by an item that is not a function of the volume of water produced, transmitted, or consumed by an item.
Variable Benefit--benefit expected per unit of water produced, transmitted, or consumed by a model item. Use the BlockRate function to model a tiered pricing structure, where the unit cost of water supplied to each consumer can increase with increasing consumption.
Electricity Revenue--this variable is available for the case of reservoirs and run-of-river hydropower plants, where revenue produced by electricity generation can be calculated as a separate variable. Electricity revenues are entered per unit of electricity generated.
Entered on:
Data View, Branch: Demand Sites and Catchments, Category:
Cost, Tabs: Capital Costs, Fixed Operating Costs, Variable Operating Costs,
Fixed Benefit, Variable Benefit.
Or
Entered on:
Data View, Branch: Supply and Resources \ Groundwater,
Category: Cost, Tabs: Capital Costs, Fixed Operating Costs, Variable Operating
Costs, Fixed Benefit, Variable Benefit.
Or
Entered on:
Data View, Branch: Supply and Resources \ River \ "river
name" \ Reservoirs, Category: Cost, Tabs: Capital Costs, Fixed Operating
Costs, Variable Operating Costs, Fixed Benefit, Variable Benefit, Electricity
Benefit.
Or
Entered on: Data View, Branch: Supply
and Resources \ River \ "river name" \ Reaches, Category: Cost,
Tabs: Capital Costs, Fixed Operating Costs, Variable Operating Costs,
Fixed Benefit, Variable Benefit.