Evidence by Paul Cedric Botha on Behalf Of

Before the Hearings Commissioners at Palmerston North

in the matter of: Notices of Requirement by the New Zealand Transport Agency under section 168 of the RMA for the construction, operation, maintenance and improvement of approximately 11.5km of new State Highway between Ashurst and Woodville to replace the closed section of State Highway 3 through the Manawatu Gorge and associated works, known as the Te Ahu a Turanga Manawatu Tararua Highway Project (‘the Project’)

to: Palmerston North City Council

Manawatu District Council

Tararua District Council

applicant: New Zealand Transport Agency

submitter: Meridian Energy Limited

Statement of Evidence by Paul Cedric Botha on behalf of

Meridian Energy Limited

Date: 15 March 2019

Introduction and experience

1. My full name is Paul Cedric Botha. I am a chartered mechanical engineer (CEng). I hold a bachelor’s degree in mechanical engineering and a master’s degree in energy studies. I am a member of the Institute of Mechanical Engineers (MIMechE) and a member of the Institute of Acoustics (MIOA).

2. I have worked in the wind energy industry for a continuous period of over 29 years. I have worked on wind energy projects in numerous countries including; New Zealand, Australia, the United Kingdom, the USA, China, the Philippines and Sri Lanka.

3. I am currently a director of Roaring40s Wind Power Limited.

4. Previously I held the role at Meridian Energy Limited (Meridian) as a Wind Technical Strategy Manager from 2003 to 2018. During that time, I was responsible for designing the layout of Meridian’s wind farms, including Te Apiti being the subject to this hearing, White Hill in Southland, West Wind and Mill Creek near Wellington, Te Uku east of Raglan and Projects Hayes, Central Wind, and Hurunui. In my role at Meridian I also undertook wind speed analysis and provided wind energy estimates of potential wind sites throughout New Zealand. I have undertaken similar roles while employed in the UK and working in several other countries with an international wind energy consultancy. These activities are now a key focus of Roaring40s Wind Power Limited.

5. I have been involved with wind turbine acoustics for 27 years which commenced at the time the first wind farms were commissioned in Wales, UK. While working for a wind farm consultancy I prepared numerous noise impact assessments for proposed wind farm developments and gave expert evidence at planning enquiries in Australia. At Meridian I was responsible for the noise impact assessments undertaken for Meridian wind farm developments and gave acoustics evidence to the Environment Court.

6. While in the UK I completed various investigations into wind farm sound and those reports were used in the development of the UK wind farm planning document ETSU-R97. I was a member of the committee which developed NZS6808:1998 and again on the committee which reviewed that document and compiled the 2010 version of that same New Zealand Standard.

7. I have attended a number of the International Conferences on Wind Turbine Noise held every two years and presented papers at a number of these. I have also presented wind turbine acoustics papers at the New Zealand Wind Energy Association conference and the International Symposium on Sustainability in Acoustics. I had a paper published in Acta Acustica United with Acustica, Vol 99 (2013) 537 544 titled “Ground Vibration, Infrasound and Low Frequency Noise Measurements from a Modern Wind Turbine”.

8. I confirm I have read the Code of Conduct for Expert Witnesses contained in the Environment Court Practice Note 2014 and agree to comply with them in giving evidence in this proceeding. Except where I state that I am relying on the evidence of another person, this written evidence is within my area of expertise. I have not omitted to consider material facts known to me that might alter or detract from the opinions expressed in this evidence.

9. In presenting this evidence I have also read the evidence prepared on behalf of Meridian by Tony Kyte of BBO, Christopher Jones of RCP and Lindsay Daysh of Incite.

10. I make this statement in support of Meridian’s request that should the Notice of Requirement decision be recommended that the conditions be imposed to appropriately address adverse effects arising from the new State Highway between Ashurst and Woodville bisecting an existing and operational wind farm and is required for Meridian to carry out its electricity generation business.

11. This statement of evidence provides:

(a) Background;

(b) Explanation of wind farms and design;

(d) Effects of the proposed NZTA Project:-

a. Temporary and construction effects;

b. Post construction effects;

i. Impact on wind flow, lifecycle loads on turbine and reduced output;

ii. Civil works, access and crane platform requirements;

iii. Buffer/setback;

iv. Plantings;

v. Incompatible uses;

c. Repowering;

(e) Health and Safety;

(f) Recommended mitigation; and

(g) Questions raised in Third Minute from the Hearing Panel.

Executive Summary

12. In summary, the proposed highway construction, through the Te Apiti wind farm, is going to impact the day to day operation of 31 of the 55 Te Apiti turbines located to the south of the Saddle Road. These impacts will largely be due to the proposed NZTA construction access routes off Saddle Road and through the wind farm.

13. Twenty-five of the turbines are connected to underground electrical feeders which are proposed to be modified in some way, having part of the electrical feeder relocated under the proposed highway. The re-configuration of these feeders is going to result in the direct loss of energy production and wind farm revenue.

14. Sixteen turbines and one of the two wind farm meteorological masts will be impacted long-term as their locations place them on the south side of the proposed highway, resulting in modified long- term access for day to day service and possibly separate over- dimensional load access. The increased wind farm access track lengths will have an impact on the on-going operational budget of the wind farm.

15. At least one turbine is proposed to be removed which will have a direct impact on the amount of renewable electricity generated from the Te Apiti wind farm. This impact will be long-term and beyond the life of the current operational turbine’s lifetime as the re-powering opportunity will be lost too. Since the proposal by NZTA is an outline, and includes an indicative alignment only, it is unsure whether further turbines may need to be removed. Such certainty will only be obtained once detailed engineering is completed along with the final alignment and design.

16. NZTA have yet to provide Meridian with over-dimensional wind farm access track routes, with sufficient design detail, that shows suitable access to turbines TAP01, TAP02 and TAP08.

17. The highway alignment has not been finalized however the indicative alignment shows cut batters of up to 34 m deep being located very close to existing wind turbine locations. The presence of those deep cuts through the wind farm are going to result in changes to the wind flow conditions (wind speed, turbulence intensity, inflow angle, wind shear and wind veer) with a reduction in the turbine lifetime and a reduction in wind turbine output.

18. Large spoil sites are proposed within the wind farm site and while the filling of valleys can have a beneficial effect, the height of those spoil sites has the ability to reduce the wind turbine wind speed and consequently the generation output of the wind farm.

19. Trees have the ability to both reduce the lifetime of the turbines and decrease the energy production through their impact on the wind flow conditions. The extensive tree planting proposed in the NOR application would have an impact on a significant number of turbines. There remains uncertainty around what planting is still being proposed by NZTA and therefore its impact on the long-term output of the Te APiti wind farm however I do note NZTA has agreed by Memorandum dated 1 March 2019 not to carry out planting to offset or compensate for terrestrial ecology on the Te Āpiti Wind Farm site1.

20. Meridian’s current consent for the Te Apiti wind farm allows for the 55 turbines to be located within 100 m of their consented locations. Meridian would like to continue to maintain the flexibility granted in that consent and therefore considers that a 60 m construction buffer be added to the 100 m turbine location allowance to create a turbine contingency zone of 160 m from the original consented locations.

Background

21. The Te Apiti wind farm gained a resource consent in 2003 (see Appendix A) and wind farm construction commenced that same year after wind turbine and balance of plant procurement had been completed. Construction of the $190 million wind farm was completed in 2004 and it was fully commissioned in that same year. The wind farm comprises of 55 wind turbines, each of 1.65 MW capacity, originally manufactured by NEG-Micon of Denmark which was later purchased by the world’s largest wind turbine supplier Vestas.

1 See para [22], Pre-Hearing Meetings Report on behalf of the New Zealand Transport Agency 1 March 2019

22. The Te Apiti wind farm is located over 1,150ha of farmland owned by four separate land owners (including Meridian). Approximately 21km of roads were built within the site so as to allow the transportation of oversized loads and for the ongoing maintenance and servicing of the turbines.

23. The turbines have a rotor diameter of 72 m and a hub height of 70 m. The electrical output from each wind turbine generator is at 690 V and that is stepped-up to 22 kV (22,000 V) via a transformer in the base of each turbine. The 55 turbines are connected via 8 underground electrical feeders (circuits) each terminating at the centralized sub-station on the Saddle Road. Here the entire wind farm electrical output is transformed to 110 kV via a large transformer and an overhead line connects the Te Apiti wind farm to the Transpower sub-station in Woodville. Te Apiti was New Zealand’s first transmission connected wind farm.

24. A wind turbine extracts the kinetic energy in the wind and converts that into electrical energy. In the case of Te Apiti, the electrical output is supplied to the national grid at Woodville. The theoretical power in the wind is a function of the cube of the wind speed, the swept area of the turbine and the density of the airflow. The actual output from a turbine includes a factor which is a function of the aerodynamic efficiency of the turbine’s rotor and blades. As the wind speed incident on a wind turbine increases, the power output of the turbine increases significantly more quickly until the turbine reaches its rated output, which in the case of Te Apiti is 1.65 MW. At that point the Te Apiti turbines control their electrical output by pitching (feathering / rotating) their blades. The turbines maintain constant electrical power output as wind speeds increase further, until their maximum operational wind speed is reached, in this case a 25 m/s (90 km/h) average wind speed.

25. The New Zealand Government issued carbon credits to Meridian for the Te Apiti wind farm since it was a carbon neutral power development and in 2005 Meridian sold 655,000 tonnes of these credits to HSBC and the Dutch government.

26. The annual expected output from the Te Apiti wind farm is 305 GWh per year which is the equivalent of 39,000 average New Zealand homes. This generation volume leads to expected revenues of between $21m and $30m per annum, depending on wholesale market prices. I have used Woodville average spot prices for 2017 and 2018.

27. As noted above I was responsible for designing the layout of Te Apiti wind farm. I am very familiar with the site and I spent a significant amount of time at Te Apiti wind farm during my employment at Meridian. I recently undertook a specific site visit to visualize where the proposed highway was to bisect the wind farm.

Explanation of processes in the design and layout for wind farms

28. The design of a wind farm incorporates a number of criteria. The wind conditions are key, and these include the wind speed distribution, the wind direction distribution, wind shear (rate of wind speed increase with height above ground level) turbulence intensity (gustiness) inflow angle and wind veer (change of direction with height). The spacing between the turbines is a critical factor too, as the presence of a wind turbine creates a disturbed flow behind it (down-wind) which is often referred to as the turbine wake. That wake alters the wind flow conditions, primarily the wind speed and the turbulence of the down-wind airflow and needs to be considered when placing one turbine down- wind of another. At a high level, wind farm design incorporates this impact in terms of inter-turbine spacing expressed as a multiple of the turbine’s rotor diameter (D). The Te Apiti turbines are placed at approximately 5D (350 m) down-wind by 3D (210 m) cross-wind. The prevailing wind directions at Te Apiti are predominately from the north-west (315°) and the secondary direction is from the south-east (120°).

29. Other important criteria in the design of a wind farm include exclusion zones identified for factors including cultural, ecological, landscape, archeological, noise, shadow flicker and telecom interference impacts which are identified and assessed through the resource consent process. Finally, the turbines need to be in locations to which suitable access can be gained through the construction of new wind farm access tracks and have ground conditions suitable for the installation of a suitable foundation designed for the specific turbine.

30. At the time of consenting Te Apiti, the choice of wind turbine had not been finalised. The consent application requested that each turbine be allowed to be placed within 100 m of the co-ordinates included in the consent application. This request was to allow for final turbine micro-siting which needed to be considered as part of the final turbine selection and construction issues arising. Construction issues included geotechnical conditions, final crane pad location, suitable turbine access, foundation design and proximity to slopes, proximity to the gas pipe line, proximity to the Saddle Road and the two houses within the wind farm. The impact of moving one turbine has the potential to impact on a number of other turbines within the wind farm and therefore the requirement to be able to micro-site the turbines within 100 m was critical. This requirement was reflected in the conditions of consent with the clarification that none of the four turbines closest to Ashurst could not be moved any closer to Ashurst. Those are the turbines with operational numbers of TAP01 to TAP04. These are shown in Figure 1.

31. During the construction of Te Apiti, all 55 wind turbines were placed at locations different to the exact locations consented, however, the majority of movements were reasonably small and all within the 100 m allowance. Turbines were moved between distances of 1 m and 80 m from their consented locations, 35 of the turbines were moved distances less than 10 m while 3 moved more than 50 m.

32. At the time the Te Apiti wind farm was designed, it was intended to maximise the number of turbines within the site and therefore maximise the electrical generation from the wind farm. Based on the constraints at the time, there was no opportunity to install more than 55 turbines within the site boundary.

NZTA proposed route/corridor

33. The Project is summarized within the NZTA NOR application at Section 4 of the executive summary and I do not repeat it. Nonetheless the key points as to where it interacts with the existing Meridian wind farm are that 17 of the 55 turbines (31%) are directly impacted long-term, 16 turbines being located to the south of the proposed highway and one turbine planned to be removed. In addition to the long-term impact, 25 of the turbines (45%) are connected to electrical feeders that are going to require modification due to the proposed highway. Finally, 31 of the turbines (56%) located to the south of the Saddle Road and will have their access tracks impacted in some way as a result of the proposed NZTA temporary access routes through the wind farm. I also note that there is a high level of uncertainty with the NZTA proposal as detailed design is yet to occur and it is possible that more than one turbine may need to be removed.

34. While the proposed highway impacts numerous turbines, the greatest impacts to the wind farm is where the proposed route bisects the four “north-south” ridges in the south-west of the wind farm on which the turbines are located. Starting in the West, these four ridges are the locations of the following wind turbines:

 TAP01 - TAP02 - TAP03  TAP05 – TAP06

 TAP08 – TAP09  TAP21 – TAP22 – TAP23

Figure 1. Te Apiti turbine numbering including proposed NZTA alignment

35. As the road alignment has not been finalized, the drawings provided by NZTA to Meridian are continually changing. While it is possible to identify the likely impacts of the proposed highway on the operation of the wind farm, it is impossible to quantify the actual extent of those impacts until such time there is more certainty on the proposed road alignment. From very early discussions with NZTA, Meridian made it clear that access to each turbine had to be sufficient to transport over-dimensional loads. The turbines also had to have daily access for possible service crews which may pose safety issues if the daily access points were off the proposed highway.

36. NZTA have proposed an underpass (north of turbine TAP24) which would give daily service access to all turbines located to the south of the proposed highway. The new wind farm track between turbines TAP22 and TAP02 (via TAP08) was originally promoted as a wind farm service track suitable for 4WD service vehicles and would give access to turbines TAP08, TAP02 and TAP01. Over- dimensional access to turbines TAP01 and TAP02 was planned to be via a new over-dimensional track off the highway shown in Drawing A03 (Pg45 of 95 of NOR Section 4). Over-dimensional access to turbine TAP08 was also proposed to be off a new access off the highway, however that is now not included in the NOR detail, Drawing A04 (Pg46 of 95 of NOR Section 4). Another good example of lack of detail due to continually changing alignment is that the same drawing shows a 16 m to 22 m cut at chainage 7200 - 7300, which starts immediately adjacent to turbine TAP09 and cutting through its hard-standing area. This has previously not been the case in drawings provided to Meridian. Meridian is yet to receive drawings, which it is able to review and agree, that access to turbines TAP01, TAP02 and TAP08 can be gained. Overall the lack of information provided and the failure to update drawings which address Meridian’s concerns in relation to their wind farm assets, has made the assessment of the effects on Meridian’s Te Apiti wind farm difficult to quantify.

Effects

37. I note taking the above matters into account the following effects arise:

Temporary and construction effects

38. There is going to be significant disruption to the day to day operation of the Te Apiti wind farm during the period of the construction of the proposed highway and to minimize the overall impact it would need to be very carefully managed. Examples include the ability for Meridian to continually have large vehicle access to all turbines that are ultimately going to end up on the south side of the proposed highway. Any relocation of electrical cable feeders will require entire feeders to be turned off any time work is going to be undertaken on the feeder. Those outages need to be scheduled with the System Operator. This will require identification of the time and date for isolating the feeder and again the time and date of bringing it back in service. While they can be scheduled at reasonably short notice, depending on the power outage, this will require careful management as there are significantly more variables at play rather than day to day wind farm operations. The fiber optic communications to each turbine is required for them to operate and be remotely controllable. Any changes to the electrical cable re-routing will need to be accompanied by the fiber re-routing. Temporary NZTA construction access points will disrupt the day to day operations of the wind farm, depending on the final locations of these access tracks and which turbines are being worked on. The delay in getting access to turbines and taking them out of service for NZTA construction requirements will all contribute to lost energy production and consequently reduced wind farm revenues which may be significant.

Post construction effects

Impact on wind flow, lifecycle loads on turbine and reduced output

39. I believe that the introduction of a highway through the Te Apiti wind farm only brings about negative effects on the wind farm operation. These include the potential reduction in wind farm output, decreased turbine lifetime due to increased turbulence, more difficult access for day to day wind farm operations and the restriction on future wind farm re-powering. While it may be suggested that the new highway will give better access for repowering, the Saddle Road was used for the original construction and has subsequently been improved. Furthermore, a large number of the turbines remain to the north of the Saddle Road and will require continued access off that road.

40. NTZA has proposed a number of spoil sites which will be used for the disposal of excess material excavated along the proposed route. While it is possible that filling in some of the valleys adjacent to some turbines may offer a benefit in terms of wind flows, (reduced inflow angle) it is also possible that increasing the terrain height upwind of turbines can reduce the wind speed incident on the wind turbine and increase the turbulence intensity. Meridian will need to have an ability to limit the height and absolute extents of spoil sites within the wind farm boundary. I have indeed experienced a case where a contractor filled a spoil site to the extent that it created a hill in front of a turbine. The result was that the higher level of the spoil site needed to be re-worked due to impacts on the wind flow at the turbine.

41. There are proposed spoil sites, north and south of turbines TAP01 and TAP02, North of TAP08, East of TAP09, North of TAP24 and TAP27, South of TAP40 and North of TAP47 and TAP50. Beyond these turbines there are other turbines which could be impacted to a lesser degree. These are shown in Drawings A03, A04, A05 and A06 (Pages 45 to 48 of 95 of NOR Section 4).

42. The proposed highway features box cuts within the wind farm of up to 34 m deep between two turbines (TAP02 and TAP03), at chainage 6100. Other significant cut and fills are:

 Chainage 5500, cut depth of 29 m upwind of TAP01

 Chainage 6600, cut depth of 25 m south-west of TAP06

 Chainage 7200, cut depth of 22 m north-east of TAP08 and south of TAP09

 Chainage 7600, cut depth of 18 m north of TAP24

 Chainage 9100, fill of 13 m north-east of TAP47

43. There is also a large cut north of TAP50 at chainage 9800, however the drawing showing the plan and long section of the highway at this point (drawing number LC-08 page 67 of 96 of NOR Section 4) does not include the correct Long Section detail but rather repeats the information from drawing LC-07.

44. These large cut features are going to induce increased turbulence intensity, increase inflow angle and impact the wind shear and veer of the wind into the turbines, all of which impact the operational life of the wind turbines. The large cut features also have the ability to reduce the incident wind speeds and consequently the energy output of the wind farm. Accordingly, the effects on renewable energy production and operational costs are likely to be significant.

45. Meridian have a resource consent which is not time-bound and the business case for the project assumed re-powering of the wind farm. Any impacts caused by the construction of the proposed highway not only impact the current operational turbines but will indeed impact the production of any future re-powering of the wind farm and efficiencies.

Civil works, access and crane platform requirements

46. The wind turbines will continue to require suitable access for regular service vehicles and less frequent large loads including cranes and turbine component delivery vehicles. The access roads need to be designed to certain standards to allow for the movement of these oversized vehicle movements. Adjacent to each turbine is a large flat area or hard-standing, on which suitable cranes can be located to install or dismantle turbine components and undertake any major servicing. These too need to be maintained for the life of the wind farm. I note that for some turbines it is proposed to have separate service vehicle access tracks and large load access tracks which is going to bring about an increased road maintenance requirement, due to the increased wind farm site access roading. Maintaining two tracks to a number of turbines is not an optimum solution for wind farm operations.

Buffer/setback

47. Meridian and NZTA have discussed a potential buffer around each turbine and permitted turbine location, outside of which NZTA can undertake earthworks without the need to consult Meridian on those works. Any works within a 60 m radius of the existing wind turbines or permitted locations would require Meridian’s specific sign-off. I understand that the derivation of the 60 m was a figure derived by way of civil and geotechnical engineering advice. The 60 m was considered to give protection to the integrity of the ground supporting the wind turbine foundations. It won’t in all cases provide full integrity to the ground supporting the crane hardstand areas and doesn’t in any way reflect the zone impacting the wind conditions. The issue with the 60 m buffer zone as proposed by NZTA is that it may give protection to the current location of the wind turbines but not to the consented locations and their 100 m allowable movement. I understand that the Officers Report supports Meridian’s submission seeking a setback of 160 m from the existing wind turbine locations.2

48. On re-powering, Meridian has permission to locate the turbines within 100 m of their consented locations, the therefore the 60 m construction buffer should be applied to the 100 m turbine contingency zones allowed for in the Te Apiti conditions of consent. If Meridian re-powers the Te Apiti site with similar sized wind turbines which meet the conditions of consent, the conditions allow for turbines with individual maximum capacity of 1.75 MW each and a maximum blade tip height of 116.6 m. The turbines need to be located within 100 m of their consented locations.

49. Given that the wind farm access tracks have already been constructed along the suitable ridgelines and that the electrical underground reticulation and electrical sub-station have been designed for a wind farm of about 90 MW it is likely that this existing infrastructure will be used in any repowering and within 100 m of the turbines existing locations. These wind farm infrastructure assets have a design life greater than the turbines.

50. When the turbines reach the end of their design-life, an option available to Meridian is to replace the existing turbines with similar sized machines. It is extremely likely that when the wind turbines are replaced, the turbine towers and the foundation-tower connection will need to be replaced due to the fatigue loading experienced over the life of the turbines. On this basis it is likely the most efficient solution will be to construct a new turbine foundation with foundation connection suitable for the new turbines and making use of the existing hard-standing area.

2 See para [613] and [651] s42A Officer’s Planning Report

51. The reduction in the ability to micro-site wind turbines when the Te Apiti turbines are replaced will impact the future energy output from the wind farm. A good example is the western most ridge of the Te Apiti wind farm on which turbines TAP01, TAP02 and TAP03 are located. The highway is proposed to bisect this ridge between turbines TAP02 and TAP03. In any re-powering scenario, TAP01 can only move northwards as the ridge drops off steeply to the south. Moving TAP01 northwards, requires TAP02 and TAP03 to move in that same direction to maintain the separation distances between each. Assuming this is done twice (after years 20 and 40), TAP02 will move approximately 40 m closer to the proposed highway and will have its foundation close to the edge of the proposed 60 m construction buffer zone shown on the NOR drawings. The turbine hard standings would need to be modified accordingly to allow access to the new turbine locations.

52. From a practical re-powering perspective, I think the 60 m construction buffer indicated is insufficient and would need to be increased in order to allow Meridian to sensibly repower Te Apiti with similar sized wind turbines. In order not to restrict Meridian’s current ability to re-power turbines with new turbines located within 100 m of their consented locations the construction buffer zone would need to extend out to 160 m from the consented turbine locations.

Plantings

53. As stated above, the theoretical power available in the wind is a function of the wind speed cubed. Wind speeds are increased as they flow over the crest of ridges or funneled through gorges. Two very good examples of wind speed enhancements due to large scale topographical funneling are through the Cook Strait and over the Saddle between the Tararua Ranges and the Ruahine Ranges. It is one of the reasons that 73% of New Zealand’s current wind generation is located in these two regions. Wind turbines are sited to maximise their output while taking into account other siting constraints.

54. The presence of vegetation, trees, forests etc. slows the wind down and at the same time increases the turbulence intensity of the wind downwind of that vegetation. A good example of this is hedge rows or wind breaks that farmers regularly plant to afford wind protection from the prevailing wind directions. Here vegetation is planted with the purpose of slowing the wind down and affording protection on the down-wind side. Another good example is the edge of forestry blocks in windy areas where the upwind edges of the forestry generally increase in height from the upwind forestry boundary.

55. The reduction of wind speeds due to the presence of trees has a direct impact on the energy produced by the wind farm and therefore the revenue generated and consequently its commercial viability. Wind farm operators generally set in place land agreements with the owners of the land on which turbines are sited and these agreements require the landowner to gain permission prior to any tree planting. The potential for energy reduction is under the control of the wind farm operator. This is indeed the case at the Te Apiti wind farm too. By way of example, a copy of the Bolton Wind Power Easement agreement is attached as Appendix B. Clauses 2 (f) and 5.1 are those which restrict the planting of trees. Likewise, similar planting restrictions are also placed over all other titles at Te Apiti wind farm. I note that this Easement also restricts the stockpiling of any soil, which I discussed in paragraphs 40 and 41 in relation to spoil sites.

56. In addition to the direct loss of energy production due to tree planting, the increased turbulence has an impact on the lifetime of the turbines. Increased turbulence has a direct impact on the fatigue loading on a wind turbine and therefore the turbine’s operational life. Turbines are designed with a maximum allowable turbulence intensity and in extreme cases, the introduction of trees could increase the turbulence intensity resulting in wind conditions beyond the design capability of the wind turbines.

57. NZTA did agree with Meridian, as outlined in the Pre-Hearing meeting report paragraph 22(a) not to plant trees to offset or compensate for adverse effects of terrestrial ecology within the Te Apiti wind farm site as originally proposed in the NOR document, and in particular, the proposed plantings shown in drawing Figure 6.A.9 in the Terrestrial Ecology report (Page 620 of 1130 NOR Volume 3).

58. I confirm that planting as originally proposed in the NOR would have an impact on a significant number of wind turbines and will result in a long-term loss of energy production and shortened turbine lifetimes due to increased turbulence intensity. I support Meridian’s request that these planting not be undertaking within the wind farm site.

59. I note Meridian is well advanced with assessing and modelling adverse effects of planting trees on wind farms sites. This is because Meridian is currently investigating options as to offsetting its carbon emissions. As noted within Meridian’s Integrated Annual Report it is stated that going forward, Meridian intends to offset carbon emissions by native forestry projects on the Waitaki and Waiau rivers i.e. as opposed to locating native forestry projects on its operational wind farms.3

60. I also note that there is ongoing discussion with respect to amenity plantings on the edges of the proposed highway and in particular cut and fill batters. I support Meridian’s request that all planting within the road corridor should be restricted to a maximum mature height of 1.5 m.

Incompatible uses

61. One of the Te Apiti turbines, which has direct access off the Saddle Road, has been setup as a location where visitors can stop and see the turbine up close. This location provides suitable parking and Meridian has provided some public information at this turbine (TAP43). Here visitors are able to stand directly below the wind turbine and experience the turbine up close while also affording good views of the balance of the wind farm. This is a very popular stopping point for people travelling the Saddle Road.

62. It is highly likely that people will stop on the proposed new highway to have a look at the turbines as they drive through. I believe that road users will stop in the wind farm access ways to get a closer look at the turbines, just as they currently stop in access ways on the Saddle Road, despite the signage to a visitor turbine. If wind turbine viewing bays are included, they will need to restrict people from wanting to walk across farmland to the closest turbine and restrict people from wanting to cross the highway to get a better view on the other side.

63. I observe that the designation boundary is much wider than the width of the proposed highway itself. The wider the designation boundary, the greater the impact on the future potential of the Te Apiti wind farm site to provide renewable energy. I support Meridian’s view that the designation boundary be minimised after highway construction and that there is future allowance for turbine blades to overhang the designation boundary provided that the turbines don’t impede the airspace above the highway itself.

3 See page 27, Meridian Energy Limited Integrated Report 2018

Repowering

64. Wind farm repowering has become more popular world-wide as a large number of turbines approach the end of their design life. Repowering is simply using the same wind farm site for ongoing wind power generation and this can be done using either similar sized turbines or through the utilisation of larger wind turbines. I will only consider the use of similar sized turbines as Meridian has ongoing consent for that activity. Repowering a wind farm would make as much use of the existing infrastructure as possible but would need to replace components which have reached the end of their useful operational life. Repowering will involve a number of steps including:

(a) Determine which turbine will be used to replace the existing operational wind turbines. After the turbine has been selected the foundation solution (including size and location) will need to be determined along with an electrical connection solution. This is likely to allow some construction activity to commence prior to the existing turbines being removed and therefore maximise wind farm generation output while the repowering programme was underway.

(b) The new foundations would be constructed including excavation, reinforcing steel placement, locating the turbine holding down bolts and electrical ducts set in place. The concrete would be centrally batched (mixed) on site and delivered to each of the new foundations.

(c) On completion of the foundations, the hard standing area, to be used for the cranes and component deliveries would need to be checked for size and strength at both the old and the new turbine locations. A large crane would be used to dismantle an existing turbine, the individual components being transported off-site. Once an old turbine was dismantled, ideally the same crane will be used to install a new turbine. The transport of the old turbine components off-site and the new turbine components on to site would require the use of over-dimensional transporters and each turbine would require approximately 8 such loads (3 blades, nacelle, hub and 3 section tower).

(d) Once a new turbine was installed, it would be electrically connected to the underground feeder. Old turbines would be removed and new turbines installed on an electrical feeder one at a time, such that when those new turbines are installed the electrical feeder can be connected and the new turbines can commence generation once commissioned.

(e) Once the turbines were commissioned and operational, site rehabilitation works and compliance requirements would be completed as required and in accordance with the any conditions of consent.

65. If in the future the wind farm was going to be re-powered by fewer than 55 wind turbines, having a new highway bisecting an already completed wind farm will create optimization constraints at that time. The highway, and airspace above it, will become an exclusion zone the length of the wind farm and of width equal to the highway width plus at least a blade length either side, i.e. highway width plus a rotor diameter. Using the current Te Apiti turbine diameter of 72 m as an example, the exclusion zone through the wind farm will be wider than 100 m. Not only does the highway restrict the area available to optimise turbine locations but due to the nature of the terrain with “north-south” ridges, the bisecting of these ridges restricts what can be done of the remaining portions of the ridge. The elevated ridges within the Te Apiti wind farm are the locations suitable for wind turbine placement and as the proposed highway runs east-west through the wind farm, it cuts through at least five ridges which are most suited to wind turbine placement.

Health and Safety

66. There are going to be significant health and safety issue to address. I am familiar with Meridians strong focus on H&S and the risks in working on a wind farm and with electricity. While I have no direct experience with NZTA’s H&S requirements they are in a different industry and may have a slightly different focus. I have heard from the Meridian Te Apiti wind farm site manager that during the NZTA investigations phase, there have been a number of concerns with NZTA meeting Meridian’s site requirements. During construction, all the NZTA construction traffic will need to pass through the operational wind farm and adhere to Meridian’s requirements. Te Apiti wind farm service technicians will also need to pass through the NZTA construction zone in order to access turbines to the south of the proposed highway.

Recommended conditions

67. I have read the statement from Mr Daysh and I agree with the proposed conditions outlined in Attachment A of his evidence.

Questions raised in Third Minute from the Hearing Panel

68. The Hearings Panel raised a number of questions with NZTA in the panels third minute. I have given my response to a selected number of these.

69. Question on Volume 2, Page 36. The question has been raised with respect to alternative locations for the turbine that is proposed to be removed. As stated above in paragraph 32, when Te Apiti was designed, it was optimised for the maximum number of turbines within the site boundary and for the given constraints. In saying that, one constraint that has changed since the original construction is the removal of the residential dwelling on the Bolton land. The original presence of that dwelling created an exclusion zone for noise received at that dwelling. It is possible that a suitable location may exist for that turbine. From a very high level assessment on site, the high point between turbines TAP45 and TAP40 could be considered, however this appears to be within the designation boundary and could only be assessed once the road alignment was finalized. The location would also need to be assessed for access suitability and how it could be electrically connected to the electrical feeders. Another solution could be to relocate TAP05 further south by approximately 100 m however this is still within the designation, will have extremely difficult access.

70. Two question were raised on Section 3A Technical Reports, one in relation to Landscape, Page 67, paragraph 310 on whether tree planting has been designed to avoid effects on the wind farm. The other is in relation to the terrestrial ecology report, Page 33, paragraph 87(a) in relation to plantings in specified zones within the wind farm. I have addressed the impacts with respect to trees on the wind flows and consequential impact of harnessing that energy in paragraphs 53 to 60. Plantings in these areas will have a detrimental impact on the long-term operation of the wind farm. Again, I note that NZTA had agreed with Meridian not to undertake those plantings, due to Meridian’s concerns on the impact, and the only remaining planting issue being discussed, was the height limitation on planting within the road corridor. As stated above, if these road-side amenity plantings were limited to a mature height 1.5 m they would be acceptable.

Dated: 15 March 2019

______P C Botha

Appendix A. Resource consent decision

Appendix B. Bolton Wind Farm Easement Agreement