Power Supply and Generation

The Independent Power Producer ("IPP") Generation metric illustrates the portion of generation portfolio and mix of resources that is not provided by Hawaiian Electric. The Power Supply and Generation performance metrics of Weighted Equivalent Availability Factor (“WEAF”), Weighted Equivalent Forced Outage Rate – Demand (“WEFORd”), and Weighted Equivalent Forced Outage Factor (“WEFOF”) measure the reliability of the Hawaiian Electric power plants. The data collection and metrics calculations are made in accordance with the formula provided in the North American Electric Reliability Corporation Generating Availability Data System (“NERC GADS”) Appendix F, which can be found on the NERC website using the link below:

NERC GADS Appendix F

Independent Power Producer ("IPP") Generation

The IPP Generation metric is the percent of the total net generation provided by IPPs (both renewable and non-renewable). This metric illustrates the portion of generation portfolio and mix of resources that is not provided by Hawaiian Electric. The renewable energy contributions by customer-sited resources are not included in this calculation. The charts below show the results for Hawaiian Electric on a consolidated and island region basis. View the Hawaiian Electric Amount of Renewable Energy Generation Curtailment metric.

Hawaiian Electric

Oahu

Maui County

Hawaii Island

Please click the button below for historical data (in Excel format).

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Weighted Equivalent Availability Factor ("WEAF")

WEAF measures the percentage of time that a fleet of generating units is available to generate electricity. It is weighted for the size of generating units such that larger units have a greater influence on the calculated value than smaller units. Generally speaking, higher WEAF values are better than lower values. However, in instances where returning a unit to service as expeditiously as possible (following an outage) is not required to maintain adequate system reliability, utility management may choose not to incur premium expenses to do so. In these situations, where adequate excess capacity is available, returning a unit to service in an economic manner will take precedence, and may result in lower WEAF values. View the calculation formula for WEAF.

Oahu and Hawaii Island calculate and report a quarterly year-to-date WEAF for their respective utility fleets as a whole. Maui County calculates a consolidated quarterly year-to-date WEAF value for its Maui, Lanai and Molokai divisions.

Please click the button below for historical data (in Excel format).

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Weighted Equivalent Forced Outage Rate – Demand (“WEFORd”)

WEFORd is a measure of the portion of time a fleet of generating units is in demand but is unavailable to operate due to forced outages and forced deratings. It is one measure of a fleet's reliability. The formula for WEFORd provides more weight to forced outages and forced deratings that occur during periods where the generation is needed and less weight during periods where they are less needed. WEFORd is also weighted for the size of generating units such that larger units have a greater influence on the calculated value than smaller units. Lower WEFORd values are normally better than higher values. However, in instances where returning a unit to service as expeditiously as possible (following an outage) is not required to maintain adequate system reliability, utility management may choose not to incur premium expenses to do so. In these situations where adequate excess capacity is available, returning a unit to service in an economic manner will take precedence and may result in higher WEFORd values. View the calculation formula for WEFORd.

Oahu and Hawaii Island each calculate and report WEFORd for their respective utility fleets as a whole. Maui County calculates a consolidated WEFORd value for its Maui, Lanai and Molokai divisions.

Hawaiian Electric reports WEFORd annually. The parameter, D, is defined as Service Hours ("SH") divided by the number of unit actual starts. For baseload units, which operate 24 hours a day, seven days a week, and frequently, for 52 weeks a year, the parameter, D, will be zero for shorter periods, such as months or quarters. On occasion, it may be zero in a year. In order to avoid this "divide by zero" problem, longer time periods are appropriate for WEFORd. Please refer to Note #2 in NERC GADS, Appendix F, page F-39.

Below are the Hawaiian Electric WEFORd metrics for the past five years:

Weighted Equivalent Forced Outage Factor (“WEFOF”)

WEFOF is a fraction of a given operating period in which a generating unit is not available due to forced outages and forced deratings. It is an indication of the reliability of a generating fleet. It is weighted for the size of generating units such that larger units have a greater influence on the calculated value than smaller units. Lower WEFOF values are normally better than higher values. However, in instances where returning a unit to service as expeditiously as possible (following an outage) is not required to maintain adequate system reliability, utility management may choose not to incur premium expense to do so. In these situations where adequate excess capacity is available, returning a unit to service in an economic manner will take precedence, and may result in higher WEFOF values. View the calculation formula for WEFOF.

Oahu and Hawaii Island calculate and report quarterly year-to-date WEFOF for their respective utility fleets as a whole. Maui County calculates a consolidated quarterly year-to-date WEFOF value for its Maui, Lanai and Molokai Divisions. Hawaiian Electric will report WEFOF on a quarterly year-to-date basis.

Maui County began calculating WEFOF starting in 2014. In 2013 and prior Maui County calculated Forced Outage Rate ("FOR") using the equation FOR = Forced Outage Hours / (Forced Outage Hours Operating Hours) * 100%. FOR is not weighted by the size of the generating units nor does it consider forced deratings.

Please click the button below for historical data (in Excel format).

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Losses and Unaccounted For Energy

Losses and Unaccounted For Energy measures the amount of energy that is lost as heat or through other means (such as theft) or used by Hawaiian Electric between the point where energy generated at power plants enters the grid to the point of measurement at customer's meters. Losses and Unaccounted For Energy is calculated as follows:

• N = Net-to-system energy, in GWh
• S = Sales, in GWh
• C = Company use, in GWh
• L = Losses and Unaccounted For Energy, in GWh
• N – S = L + C
• L = N – S – C
• L, as percentage of net-to-system energy = (L / N) x 100

A lower percentage means lower loss due to heat, company use, and theft. The chart below shows the quarterly results for Hawaiian Electric on an island system basis.

Please click the button below for historical data (in Excel format).

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