Appendix F: Technology Lead Times
Time has a cost, so the time it takes from project conception to commercial operation has a significant effect on the viability of any electricity generating plant project. In this report only costs that are incurred from the beginning of design and construction are included in the electricity unit costs for the different technologies.
F.1 Project Stages
All projects, no matter what the technology, follow a similar process but the timings do differ. Three main stages in the process can be identified.
The first stage consists of a large number of activities that include: scoping, investigation, feasibility studies, consultation, conceptual design and a decision made to apply for resource consents.
The second stage is the preparation of the appropriate documents, further consultation and the application for resource consents and perhaps dealing with appeals. Once resource consents are granted and the outcome of any appeals determined the developer can then decide whether or not to proceed; this is when the third stage begins. This stage includes finalising the detailed design, procurement, construction and commissioning.
Usually infrastructure issues such as electricity transmission, gas transmission, and coal supply and transport also need to be considered. An adequate water supply is also required.
F.1.1 Stage 1, Pre-Consent Studies and Consultation
This stage is primarily concerned with resource, community and environmental issues.
Fuel and water resources that are required need to be defined, investigated and secured. If these are readily available then this may not be a large issue but changes in land use to fit a project's requirements may be. The necessary land also needs to be secured.
Running in parallel with these studies it will be necessary to undertake pre-feasibility studies of options (these having been identified earlier in scoping studies) and a preliminary environmental reconnaissance followed by feasibility studies. The latter stage generally involves local and regional councils and community interest groups.
Where an extension of a mine or new mine is required this could be done in parallel with the power station development. In this case, all three project stages would need to be gone through for the mine. Timing would need to ensure that the mining consents were obtained before the commitment to proceed with stage 3 of the power station development.
The preferred power station option is selected by consideration of all the factors by the developer, after which information on this option can be released for public consultation. Some detail design and detailed investigations can be carried out often involving the relevant community groups. Following this, sufficient information should be available to proceed to the next stage.
F.1.2 Stage 2, Application for Consents and Approvals
This stage involves preparation of all the necessary documentation for resource consents and other required approvals, including an assessment of the environmental effects and resolution of adverse effects, and submitting them to the appropriate authorities.
Consideration of the resource consent application needs to follow the process and timing set out in statute. Additional time may be needed to supply more information if requested by the consent authorities and to deal with appeals. Familiarity and experience by the consent authorities in dealing with energy matters may reduce the time taken.
F.1.3 Stage 3, Design, Build and Commission
Once consents and approvals have been obtained final design, procurement, construction and commissioning can follow. Depending upon how the process has been managed, many activities can be run in parallel so that once approvals are given construction may start straight away.
The whole process is depicted in Figure F1
Figure F1: General Investigations Programme
Full size version of Figure F1 [11 KB GIF]
F.2 Infrastructure
Some general comments can be made about infrastructure issues such as, electricity transmission, gas transmission, coal supply and transport, water supply and waste disposal, but most are site specific.
F.2.1 Gas Fuelled Plant
For gas fuelled plant it would be expected that it would be situated within a reasonable proximity to existing gas supply line and electricity transmission system that have sufficient capacity.
F.2.2 Coal Fuelled Plant
Coal fired plant has a more complex set of issues.
Should Southland and the West Coast be considered it would be likely that a power station would be situated close to the mine so transport issues should be small. Electricity transmission appears to be the major infrastructure issue and could be the limiting factor on the size of the plant.
For coal plant situated in the northern Waikato region, coal may be sourced from several mines so coal transport would have to be addressed. Coal could come from existing and new mines. Electricity transmission may be assisted by the proposed Transpower upgrades from Huntly to Otahuhu expected to be commissioned in June 2005, noting that a more significant upgrade is targeted for 2010.
Should a coal fired plant in the Marsden Point region be considered, it is likely that it would be situated close to the port so the coal transport route would be short. Electricity transmission should not be an infrastructural issue for anything up to a 500MW plant.
If coal is imported or is transported over a significant distance, then a number of territorial authorities may be involved in consenting. This should not add to the overall time for consenting, but it would add to the resource needed for preparing consent applications and for progressing them.
F.3 Gas Fuelled Electricity Generation
Gas turbine based projects lend themselves to modular construction techniques which lead to more standardised designs and shorter construction periods than for coal based ones.
F.3.1 Open Cycle Gas Turbines
These are the simplest of the technologies considered, available in modules and have the shortest project times. Major issues are likely to include air discharges, noise (particularly in an urban environment), and perhaps water supply and waste disposal.
F.3.2 Combined Cycle Gas Turbines
These are more complex than open cycle gas turbines but are generally still modular in nature. In this case, the gas turbine, heat recovery steam generator (HRSG), and steam turbine all need to be matched. Cooling requirements are more complex.
Major issues are similar to the open cycle gas turbine but in addition there is a requirement for more or larger cooling towers, and the effects of spray drift, the visual plume, and effluent discharge need to be addressed.
F.4 Coal Fuelled Electricity Generation
Coal plant designs can be standardised but require more customisation, principally to deal with the differing characteristics of the coal being fired. Because of the complexity and extra plant needed, a coal based project takes a lot longer than a gas based one. An extension to a mine or a new mine and coal transport may also be part of an overall project which would add to the complexity and issues to be addressed, particularly if several consenting authorities are involved. This part of the project would run in parallel with the power plant part. The power plant would generally be expected to be on the critical path, so the mine should not add to the time to commissioning. However in some cases a new mine may extend the overall project time.
Coal has the same major issues that are associated with operating combined cycle gas turbine plant (water supply, noise, air discharges), but also there may be coal mining issues (dust, noise, effluent disposal and land remediation), coal transport and storage issues (dust, noise), and additional issues stemming from the operation of the plant (fugitive dust emissions, ash disposal; and effluent from flue gas desulphurisation may also need to be addressed).
If coal is imported, then coal unloading and storage issues at the port may need to be addressed as well.
F.5 Project Duration
The times for each stage for key different technologies are set out in Figure F1. With respect to gas turbines, times for advanced open cycle plant should be the same as for standard open cycle plant, and times for advanced combined cycle plant should similarly be the same as for standard combined cycle plant.
With respect to coal plant, times for subcritical and supercritical plant should be the same. Also, whether plant is for lignite, sub-bituminous or bituminous coal should not have any significant effect on times, and whether or not flue gas desulphurisation (FGD) is installed should not make any difference.
The times are approximate and indicative only. A number of activities can run in parallel particularly in the design area so the times shown are those that add to the overall project time. Delivery from vendors can vary depending upon demand for their equipment at the time. How urgently the buyer requires the plant can also affect delivery times. The greatest uncertainty in the timing is with stage 2, the consent and approval stage.
Table F1: Project Times| Technology | Duration (Months) |
| Total | Pre-Consent Activities | Consents and Approvals* | Constn and Comming** |
| Likely | Min | Max | Min | Max | Min | Max | Min | Max |
| Open cycle gas turbine | 33 | 23 | 41 | 5 | 6 | 6 | 17 | 12 | 18 |
| Combined cycle gas turbine | 57 | 38 | 77 | 6 | 24 | 6 | 17 | 26 | 36 |
| Coal plant supercritical with FGD | 79 | 60 | 109 | 12 | 36 | 12 | 22 | 36 | 51 |
From Figure F1 it can be seen that an open cycle gas turbine may take over two and a half years from the initial idea to commercial operation, a combined cycle over four and a half years and over six and a half years for a coal fired station. These estimated times are those for a greenfield site and a project that runs reasonably smoothly. Reductions in time may be possible where there are existing facilities, but such reductions are not likely to be significant.
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