Utility Rate

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To view the Utility Rate page, open a case with residential or commercial financing, and then click Utility Rate in the main window's navigation menu.
ico-minus-16x16Overview

The Utility Rate page allows you to choose the rate structure for distributed energy projects with residential or commercial financing. Those projects may both purchase electricity from and sell electricity to an electric service provider. Solar Advisor assumes that projects with utility or commercial third party financing sell all of the electricity they produce at a fixed or escalating rate negotiated through a power purchase agreement. For such projects, Solar Advisor calculates an electricity sales price as a result, and ensures that it covers project costs and meets financial constraints

Note. A project's financing type is defined in the Technology and Market window.

The utility rate is the price per kilowatt-hour available to distributed energy projects for electricity sold or purchased by the project. Solar Advisor displays electricity payments and revenue in the project cash flow, and accounts for them in the net present value reported in the Metrics table, but not in the levelized cost of energy (LCOE) calculations.

To choose the utility rate structure:

1.In the rate type list, choose a rate type.

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Solar Advisor allows two options for modeling the utility rate: utility flat rate and utility time-of-use rate.
ico-minus-16x16Utility Flat Rate

For the utility flat rate option, a single rate applies to every hour of the year. If you specify a non-zero escalation rate, Solar Advisor escalates the utility rate annually. The flat rate option assumes net-metering, where electricity is purchased and sold by the project at the same rate.

Rate Information

Flat Rate ($/kWh)

The electricity price for sales and purchases of electricity under a net-metering agreement in dollars per kilowatt-hour.

Rate Escalation (%/yr)

The annual rate of increase of the electricity price above the inflation rate defined on the Financing page.

In some cases, it may be useful to assign a different flat utility rate to each year in the analysis period. (The analysis period is defined on the Financing page.) For example, you could model a flat rate that increases every five years by assigning one value to years 1 through 5, a second one to years 6 through 10, and so on.

To enter the flat rate as an annual schedule:

1.Choose Utility Flat Rate for the rate type.

The "Value" label is blue indicating that the single value mode is active for the variable.

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2.Click the button with the "Sched" label to change the mode to schedule and activate the Edit button.

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3.Click Edit.
4.In the Edit Schedule window, type values for each year in the analysis period. Use the horizontal scroll bar to move through the years.

To delete a value, select it and press the Delete key on your keyboard.

Note. You must type a value for each year. If you delete a value, Solar Advisor will clear the cell, and you must type a number in the cell or Solar Advisor will consider the schedule to be invalid.

5.When you have finished editing the schedule, click Accept.
ico-minus-16x16Utility Time-of-use

The utility time-of-use (TOU) option allows you to apply a TOU schedule in order to define electricity prices that vary with the time of day and month. Solar Advisor stores time-of-use schedules in a library, so you can either choose a schedule from the library, or create your own schedule.

Schedule Library

Choose schedule from library

Solar Advisor includes schedules for four U.S. regions. You can choose a schedule from the library to automatically populate the time-of-use periods rates and the schedule matrices. See the instructions below for details.

Time-of-Use Periods

Each time-of-use schedule can have up to nine periods, each with a different electricity price and annual escalation rate.

Period (1-9)

The period number and color corresponds to the number and color in the schedule matrix.

Name

The name of the time-of-use period. The name is a description of the period to help you identify the different periods. Solar Advisor does not use the name.

Rate ($/kWh)

The electricity price in dollars per kilowatt for the time-of-use period.

Esc (%/yr)

The annual escalation rate that applies to the electricity price for the time-of-use period.

Weekday Schedule

The time-of-day and month-of-year matrix that assigns the time-of-use periods to a given schedule that applies to the five working days of the week: Monday through Friday. Solar Advisor assumes that the year begins on Monday, January 1, in the hour ending at 1:00 a.m.

Weekend Schedule

The time-of-day and month-of-year matrix that assigns the time-of-use periods to a given schedule that applies to the two weekend days of the week: Saturday and  Sunday. Solar Advisor assumes that the year begins on Monday, January 1, in the hour ending at 1:00 a.m.

To choose a schedule from the library

1.In the Schedule Library list, click a schedule name.

Schedules with "SAM/" in the name are predefined schedules that you cannot modify. Schedules with "USER/" in the name are schedules that you can modify in the library manager. See Working with Libraries for details.

2.Click Apply Schedule.

Solar Advisor displays the time-of-use schedule in the weekday and weekend schedule matrices, using colors and numbers that correspond to those in the list of Periods 1 through 9 in the time-of-use periods list.

You can modify values and times for the schedule. See the instructions for creating your own schedule below for details.

To create your own schedule

1.In the Schedule Library list, click a schedule name for a schedule similar to the one you want to create, if applicable.
2.In the time-of-use periods list, type a name, rate, and escalation rate for up to nine periods in the time-of-use schedule.

See the descriptions in the table above for details about the variables.

3.In the weekday schedule matrix, use your mouse to select the blocks to which Period 1 applies, and type a '1' to populate the blocks.

The block color changes to match the Period 1 color and the number 1 appears in the block.

4.Select the squares for the next period, type the period's number, and repeat until the schedule is complete.
5.Repeat Steps 3 and 4 in the weekend schedule matrix to define the weekend schedule.