Questions from Mayor Rob Burton and reply from TCL
Mayor’s Letter to the Bidders, August 15, 2009
On behalf of the Council of the Town of Oakville, I write to seek the answers to the following questions about the OPA proposal you have filed for the SWGTA RFP.
If you are unable at this time to answer any particular question, would you be kind enough to indicate at what time you would anticipate being able to answer such question?
1. Emissions in grams/second of each of the criteria pollutants, NOx, SO2, PM2.5, VOCs, CO when operating with and without duct-firing.
2. Average emissions in grams/second of each of the criteria pollutants, NOx, SO2, PM2.5, VOCs, CO during start-up.
3. Average emissions in grams/second of each of the criteria pollutants, NOx, SO2, PM2.5, VOCs, CO during shut-down.
4. Estimated number of start-ups per year.
5. What consultations did you undertake with the surrounding community and what changes to your proposal resulted from your consultation?
6. How tall will your tallest buildings be?
7. How tall will your stacks be?
8. How frequently do you expect your proposed plant to produce a visible plume?
9. With what frequency and range will your proposed plant be capable of producing fogging or icing?
10. What buffers or set backs from your property edges are you planning to use?
11. What measure of noise level and at what frequencies do you expect your proposed plant to generate at your property edges?
12. What hazard warning signals and mitigation will you have for plume related fog, showers, sleet or icing on public roads or rails?
Thank you for your information.
Response from TransCanada, September 14, 2009
From: Chris Breen
To: mayor@oakville.ca
Date: 09/14/2009 04:38 PM
Subject: Oakville Generating Station
Dear Mayor Burton,
Thanks for your patience while awaiting a response to your letter. In response to your questions:
Questions #’s 1,2 & 3 – Emissions
The proposed OGS will be an intermediate facility, which falls in between a base load and peaking facility. OGS is expected to start and stop to meet system and market demands which will vary from season to season and from year to year. The facility is designed to provide dispatchable firm supply to the meet the needs of the Ontario electricity system as well as provide critical local capacity to underpin the transmission capacity to the southwest GTA and may be dispatched to meet either of these important needs.
| VOC | Each Gas Turbine including duct burner (g/s) |
Diesel Generator (g/s) | Auxiliary Boiler (g/s) |
|---|---|---|---|
| 1,3 Butadiene | 1.53E-04 | 9.34E-05 | NA |
| Acetaldehyde | 1.42E-02 | 1.83E-03 | NA |
| Acrolein | 2.28E-03 | 2.21E-04 | NA |
| Benzene | 4.45E-03 | 2.23E-03 | 1.87E-04 |
| Butane | 1.87E-01 | NA | 1.87E-01 |
| Dichlorobenzene | 1.07E-04 | NA | 1.07E-04 |
| Ethane | 2.76E-01 | NA | 2.76E-01 |
| Ethylbenzene | 1.14E-02 | NA | NA |
| Formaldehyde | 2.59E-01 | 2.82E-03 | 6.67E-03 |
| Hexane | 1.60E-01 | NA | 1.60E-01 |
| PAH | 7.82E-04 | NA | NA |
| Pentane | 2.31E-01 | NA | 2.31E-01 |
| Propane | 1.42E-01 | NA | 1.42E-01 |
| Propylene | NA | 6.16E-03 | NA |
| Propylene Oxide | 1.03E-02 | NA | NA |
| Toluene | 4.65E-02 | 9.77E-04 | 3.03E-04 |
| Xylenes | 2.28E-02 | 6.81E-04 | NA |
The NOx and CO emissions of a combustion turbine vary with load. When the unit is warming up, operating under no load or light load, emissions are higher than when the unit is operating at a steady state full load. For modeling purposes, all start-ups were assumed to be cold starts which result in the 3 maximum start-up emissions rates as compared with hot or warm starts.
Duct burners are utilized in the heat recovery boilers for additional steam generating capacity. They are required to ensure the full capacity of the proposed OGS is available under all ambient operating conditions and they provide incremental peaking capability. For the purposes of assessing the maximum impact of the proposed OGS, it was assumed that the duct burners were in operation whenever the turbines were at full operating conditions.
The following table represents the emission rates of conventional pollutants used in modelling the relevant operating scenarios. These inputs are consistent with the requirements of the OPA RFP.
| Contaminant | Each Gas Turbine including duct burner (g/s) | Diesel Generator (g/s) | Auxiliary Boiler (g/s) | ||
|---|---|---|---|---|---|
| Start- Up | Full Operation | Shut-Down) | |||
| PM10 | 1.7 | 2.3 | 1.3 | 0.02 | 0.16 |
| NOx | 23 | 29.0 | 26 | 4.2 | 0.83 |
| SO2 | 0.16 | 0.21 | 0.16 | 0.69 | 0.01 |
| CO | 441 | 12 | 370 | 0.28 | 1.7 |
Please note that we have assumed the estimate of Total Particulate Matter (TPM) as the estimate for PM10 emissions and PM2.5 emissions given that there is no way to differentiate the PM size for natural gas combustion of this nature. The use of the TPM number to represent PM10 or PM2.5, is in fact this is an overestimate in both cases and thus a conservative approach.
Question #4 – Start Ups As you likely know, we can only estimate the number of start ups per year as we do not know when we will be called into service by the Independent Electricity System Operator. According to the OPA and the Ministry of Energy, the proposed facility is expected to run anywhere from 15-40% of the time in a given year. Typically operation would be during periods when power demand is highest, primarily the hours between 7 a.m. and 10 p.m.. With this said we estimate 260 start ups per year.
Question #5 – Consultations in Oakville We have held two open houses. We hosted a project website http://www.transcanada.com/company/oakville.html with a telephone number and email address through which we posted project information and answered public inquiries. This site also hosts a video produced to explain what type of plant we hope to build and why. We offered to meet with every local community group we became aware of in Oakville however only three groups accepted our offer. Our consultation process remains ongoing as we await the decision of the OPA.
Question #6 – Building Height Our tallest building will be 28 meters.
Question #7 - Stack Height Our gas turbine stack heights will be 62.5 meters. Our cooling tower will be no taller than 27 meters.
Questions #8, 9 & 12 – Plume, Fogging and Icing Our modelling assumes operations 24 hours a day, 7 days a week, whereas in reality, the plant is expected to run between only 15% and 40% of the time. Based on this conservative modelling approach, plume is expected to be visible 5 – 9% of the time. Fogging is not expected to exceed 20 hours per year with less than 5 hours per year over Cornwall Road. Icing is not anticipated to exceed 2 hours per year. The cooling tower plume and icing study results were based on the SACTI model and local meteorological data which is the Ministry of the Environment accepted model. The results will ultimately be reviewed by applicable regulatory agencies and the public as part of the permitting process.
Question #10 – Buffers and Setbacks The setback requirements will be dictated by the applicable zoning bylaw and TransCanada has developed a plant design which will conform to the existing bylaw. We will use elevations, landscaping and anchored barriers as buffers from the road and rails surrounding the property.
Question #11 – Noise We do not measure noise level at the property edges as there are no receptors (residents, businesses, etc.) there. As per Ministry of the Environment limitations, our plant will not exceed 50 dBA during the day or 45dBA during the night when measured from the nearest receptor.
The illustration below provides more detail regarding the results of our noise studies.
Thanks,
Chris Breen Public Sector Relations
TransCanada Corporation
www.transcanada.com
416.605.3524