4.2.3 Utility Costs: Ratchets

90.1-2019

Ratchets allow the modeling of tariffs that include some type of seasonal ratcheting. Ratchets are most common when used with electric demand charges. A ratchet is when a utility requires that the demand charge for a month with a low demand may be increased to be more consistent with a month that set a higher demand charge.

The time period over which the ratchet is calculated is defined by inputs for “Season From” and “Season To.” Ratchets take the hourly metered values as calculated in the parent tariff and determine a peak quantity for each billing period. If a season is specified, the ratchet may compute the demand for a specific season, such as summer. In addition, the ratcheted demand may be adjusted by an offset or multiplied by a fraction. A value is calculated for each billing period for use in associated tariff and block-charge.

 

Ratchet Name

Applicability

All projects using custom utility rates

Definition

A unique identifier for the ratchet being defined calculated. The name is used in identifying the output results and in associating all of the charges and other objects that are affected by the ratchet. Along with the name of the ratchet, the associated tariff also needs to be specified.

Units

Text

Input Restrictions

None

Baseline Building

Same as proposed

 

Season From

Applicability

All projects using custom utility rates

Definition

This input is the name of the season that is being examined. The maximum value for all of the months in the named season is what is used with the ratchet multiplier fraction and ratchet offset value. This is most commonly summer or annual.

Units

List: Summer, Winter, Spring, Autumn, Annual, Monthly

This input also requires a descriptor for Seasonal Schedule that defines the months for each season

Input Restrictions

None

Baseline Building

Same as proposed

 

Season To

Applicability

All projects using custom utility rates

Definition

This input is the name of the season that the ratchet applies to. This is most commonly winter or annual. The ratchet only applies to the months in the names season.

Units

List: Summer, Winter, Spring, Autumn, Annual, Monthly

This input also requires a descriptor for Seasonal Schedule that defines the months for each season

Input Restrictions

None

Baseline Building

Same as proposed

 

Ratchet Multiplier Fraction

Applicability

All projects using custom utility rates

Definition

This is the value by which the peak demand in the months defined under Season From are multiplied to calculate the minimum demand applicable to months defined under Season To. The higher of the actual month demand or this calculated value is used to specify the demand for the applicable month. If both ratchet multiplier and ratchet offset are defined, the multiplier is applied to the offset demand or energy value, which then determines the minimum demand or energy for a month.

Units

Text

Input Restrictions

None. Default is 1.

Baseline Building

Same as proposed

 

Ratchet Offset Value

Applicability

All projects using custom utility rates

Definition

An offset may be defined that can either be added (in case of a positive offset) or subtracted (in case of a negative offset) from the calculated demand. The demand offset value (in kW) needs to be defined, which would be applied to the peak demand. If both ratchet multiplier and ratchet offset are defined, the multiplier is applied to the offset demand or energy value, which then determines the minimum demand or energy for a month.

Units

Number

Input Restrictions

None

Baseline Building

Same as proposed