Table of Contents

• 1.0 HECO IRP-4
• 1.1 Observations
• 1.2 Summary of observations regarding generation plants
• 2.0 Independent Power Producer info
• 3.0 Carbon intensity data
• 4.0 PUC Docket documents
• 2009-0155_1
• 2009-0176_1
• 2009-0195_1
• 5.0 HECO System Overview
• 6.0 Putting it all together
• 6.1 Power plant data
• 6.2 Simulation data generation

1.0 HECO IRP-4

Available at: http://www.heco.com/vcmcontent/IntegratedResource/IRP/PDF/HECO_IRP4_Plan2009_2028_Final_Report.pdf

1.1 Observations

Page 131, Table 6.3-2: Provides HECO Unit Performance Data, which specifies the generators (Honolulu 8,9; Waiau 3-10; Kahe 1-6) their fuel types, and their generation capacity.

Page 241, Section 10.2.2: Time of Use rates specify peak hours (M-F, 5pm-9pm), mid-peak (M-F 7am-5pm, Sat/Sun/Holidays 5pm-9pm), off-peak (Daily 9pm-7am, Sat/Sun/Holidays 7am-5pm).

p. 257: Dispatchable generating units include: steam boilers, diesel generators, and combustion turbines. Perhaps these correspond to "baseload", "cycling", and "peak" generators? Although this is incorrect, because Waiau 9-10 is listed as Diesel but also identified as a combustion turbine.

There appears to be an additional category, "emergency standby status" (see below).

p. 62: Combustable Oil product types: residual oil, diesel fuel, coal.

p. 85: HECO's existing combustion turbines: Waiau Units 9 and 10. Can start in 20 minutes. Also reference to 29.5 MW of an unidentified "distributed generation units" can start up in a few minutes. p. 89-90: Spinning reserve: the amount of reserve capacity that is immediately available from units that are connected to the system and are operating below their maximum rated levels. Spinning reserve is set at 180 MW (so that loss of one combined-cycle unit can be covered). Kalaeloa 2-on-1 unit (AES ?) has a total output of 180MW, Kahe Unit 6 is next largest with 134MW.

p. 204: Waiau 3 and 4 are to be placed on emergency standby status.

p. 83 combustion turbines can start up in 20 minutes; cycling steam units require 1-2 hours. There is also a "minimum shutdown time" for a generating unit.

p. 85: Waiau 9 and 10 are Oahu's existing combustion turbines.

p. 125: combustion turbines (CT) are used for mid-range and peaking purposes and steam boilers are used for base load generator.

p.174 Waiau 3 and 4 appear to be exceptionally "dirty", and that is a motivation for their retirement.

p. 214 Baseload generating units: Kahe 1-6, Waiau 7-8.

1.2 Summary of observations regarding generation plants

Here's a table summarizing what IRP-4 appears to reveal about the generation plants:

Where LSFO is low-sulfur fuel oil, which is the dregs left over after oil has been refined for jet fuel, gasoline, and diesel.

Note that the gross represents the total generation of the plant, while net subtracts the power requirements of running the plant. Thus the Net figures should be used to calculate whether or not there is adequate power production to meet demand, while the Gross numbers should be used to calculate carbon intensity (since the carbon is emitted regardless of whether the power actually makes its way to customers).

2.0 Independent Power Producer info

HPower burns Oahu municipal waste and produces power. Carma (see below) provides CO2 emission data.

Kalaeloa Partners burns LSFO in two combined cycle turbines, and uses the waste heat to power a steam turbine. They use treated waste water instead of drinking water, and also provide heat to Tesoro's refinery. Blurb in Hawaii Business, Blurb from PSEG, one of the owners.

AES Hawaii is the old coal-burning plant in the State. AES Wikipedia page. SourceWatch claims CO2 emissions of 1,624,335 tons for 2006, different page says 1,634,000 tons for 2007. This 2008 Greenhouse Gas Emission Reduction Task Force Meeting minutes notes a presentation by AES indicates that they report emitting 1.2 - 1.4 million tons of CO2/yr.

3.0 Carbon intensity data

This CARMA site seems to be a good resource for CO2, MW capacity, and carbon intensity data. They even provide CSV and XML export of the data, and an API.

The following table summarizes the Carma data for Oahu power plants:

4.0 PUC Docket documents

Documents reviewed: 2009-0104, 2009-0155, 2009-0162, 2009-0164, 2009-0176, 2009-0195, 2009-0290.

2009-0155_1

p. 5: Kahe 3, 4 and Waiau 7, 8 are "combustion engineering boilers".

2009-0176_1

p. 3: Kahuku Power (formerly North Shore Power) will be a 30 MW wind farm operational around January 1, 2011. HECO will pay approximately $200/MWh. It should save approximately 100,000 barrels of fuel oil per year.

2009-0195_1

p. 4 Waiau 7 is a 90MW steam unit manufactured by Combustion Engineering.

5.0 HECO System Overview

Googling on "HECO System Overview" unearthed the HECO System Overview powerpoint presentation with several slides of interest. The first slide presents the firm generation plants on Oahu, along with their classification as baseload, cycling, or peak. A portion of this slide is displayed next:

The next image shows the Yearly Load Profile:

The daily demand curve:

And the historical minimum and peak demands:

6.0 Putting it all together

6.1 Power plant data

We can combine all of the above to create a integrated table with data about all primary Oahu power plants, as long as we make a few assumptions:

• The Carma data lists a single carbon intensity for all Waiau power plants of 1,971, but Waiau contains both cycling and peaking plants. To deal with this, we will adjust the cycling plant carbon intensity downward to 1,800 and the peaking plants upward to 2,400. This latter figure was chosen so that the peaking plants would have the greatest carbon intensity of all.

• Plants have an "overhead", in terms of the electricity they generate that is consumed by themselves. This is determined as (Gross MW - Net MW), or estimated when Gross MW is not available (as in the case of HPOWER, AES, and Kalaeloa).

• We will assume that Kahe 7 is constantly running at nearly full capacity as the source of "spinning reserve", even though those MW are not used in the grid. All other baseload plants are assumed to run at the "overhead" level if they are not actively involved in power generation.

• Since Waiau 3 and 4 are scheduled for emergency backup purposes, we will eliminate them as power plants for the purposes of the simulation.

With these assumptions, we get a table like this:

6.2 Simulation data generation

We can employ the following procedure to generate the simulation data for any given day. The simulation data is generated at 15 minute intervals.

• Generate the daily demand curve for the given day. The daily demand curve will indicate (a) the total power to be generated for any given 15 minute period, and (b) how that total amount of power will be divided among baseload, cycling, and peaking generation plants.

• For each 15 minute interval, first choose which baseload power plants to use (other than Kahe 7), and decide how much power must be generated by each in order to satisfy the baseload requirements. Second, if this interval includes cycling power, choose which cycling power plants will satisfy this and how much power is contributed by each of them. Third, do the same for peaking power.

• Calculate the carbon generated by each plant for this 15 minute interval as: Carbon Intensity of Plant * MW generated * .25 hours.

Here is a hypothetical entry for the daily demand curve table:

And the following table indicates a hypothetical selection of power plants for generation of this power, and the resulting lbs of carbon output during this 15 minute interval:

In summary, for this 15 minute period, the plants generated 1304 MW of energy (1100 for the grid, and 204 for overhead and spinning reserve), which produced a total of 612,132 lbs of carbon.