The turbines turn at TrustPower's Mahinerangi wind farm, in
the hills about 70km west of Dunedin. TrustPower's
Mahinerangi hydro storage lake can be seen in the distance,
to the south of the turbines. Photo by Stephen Jaquiery.
Lee Stream farmer Peter Doherty still considers the wind
turbines he can see from his farm gate "a blot on the
But he concedes that after having TrustPower's Mahinerangi
wind farm as a neighbour for a little more than a year the 12
turbines are "growing on him" a little.
"I've got used to it ... You have to, don't you?
"They are still not appealing, but I don't take as much
notice of them now."
Other neighbours are not quite as forgiving. Robert Reid says
the turbines annoy him every time he looks at them, and that
is every day unless he is off his farm.
Asked what goes through his mind when he sees them, he
replied: "How could anybody be so bloody stupid to put that
in our landscape?"
Although small, the wind farm, which lies to the north of
TrustPower's Mahinerangi hydro storage lake, is Otago's
largest. The last of its turbines were commissioned in April
last year and in the 12 months since, it quietly worked away,
generating 111GWh of electricity - enough to power about
13,700 average homes.
The wind farm got off to a promising start, producing 9% more
electricity than expected in the first eight months of
operation. But reduced wind speeds in the first few months of
this year brought generation over a full year back to 5.7%
above expectations, TrustPower community relations manager
Graeme Purches said.
At the time the wind farm was being proposed, TrustPower said
it was attracted to the Mahinerangi site because of steady
winds experienced in the area.
Since its commissioning, the total average availability of
wind for the wind farm had been 98.31%, he said. While the
turbines began generating when wind speeds reached 4 metres
per second (m/sec) the ideal wind speed was 9 m/sec. The
average wind speed for the first 12 months was 9.33 m/sec.
The best month for winds was July last year, when the average
wind speed was average 11.9 m/sec. During that month, 15GWh
was produced, Mr Purches said.
However, wind speeds this year had been lower. So far the
average had been 7.9 m/s, while the average for last year the
average was 9.33 m/s.
"This year we have seen 20% lower wind speeds in April
compared to the same month last year, and 7% lower winds in
The lowest average winds were recorded in December - 5.8 m/s
- while the next two worst months were April this year (8.6
m/s) and October (8.2 m/s).
One turbine was out of production in May. Mr Purches said
Vesta, the company which supplied the turbines, identified an
issue with parts in overseas turbines which it believed might
lead to a reliability risk.
"Out of our 12 turbines, only two were identified to have any
risk based on serial numbers of turbines and batch numbers of
parts used in each turbine, and ... Unit 8, it was shut down
as a precaution."
The wind farm attracted determined opposition during the
resource consent process.
The four red aviation hazard lights which wink throughout the
night remain one of the main irritations for neighbours.
Mr Reid, fellow Lee Stream farmer Lindsay Brown, and another
person who did not want to be named, all said they had been
assured at the Environment Court hearing that the lights
would be shielded and would not be able to be seen from the
ground, but that was not correct.
Mr Reid said he understood the local consultation committee
established when the wind farm was first proposed had raised
the issue with TrustPower.
Reflections from the turbine blades, particularly when the
sun was low, and the constant movement of the blades were
Mahinerangi farmer and wind farm objector Peter Doherty
walks on Lee Flat Rd beside his farm. More than 12 months
on, he takes a more relaxed view of the neighbouring wind
farm. Photo by Craig Baxter.
Mr Brown said the turbines could be seen from
"I think you can see them from the bloody moon".
Because of their visual impact, Mr Brown suggested the
resource consent requirements should be different for wind
"We're not talking about the impact of a line of trees on a
hilltop or the colour of a house roof. The impact of wind
farms is a quantum leap away from that."
Based on TrustPower's figures, the wind farm had produced at
30% capacity over the first year, Mr Reid said.
"It makes a mockery of wind farms being such an efficient way
to generate electricity.
"What's the use of having something that is only 30%
TrustPower has consent for a further 88 2MW turbines or 66
larger 3MW turbines at Mahinerangi.
Mr Doherty said while he had "just about got used to" 12
turbines, he did not want to think about what a wind farm of
80 to 100 turbines would be like.
"The place would look like a picket fence."
2007: TrustPower granted consent by Clutha District
Council and Otago Regional Council for "development
envelope"on 1723ha site north of Lake Mahinerangi, about 70km
west of Dunedin. Consent allows for up to 100 turbines
producing 200MW of electricity annually, and 37km of internal
2007: Consents appealed to Environment Court by
Contact Energy and the Uplands Landscape Protection
Society2008: Environment Court hears appeal. TrustPower
abandons the envelope approach and states it will provide
exact locations for its turbines. Environment Court dismisses
appeals but asks TrustPower to re-examine project, saying it
is not confident 100 turbines will fit on 1723ha. High Court
orders Uplands Protection Society to pay $50,000 in costs.
2009: Uplands Protection Society says it cannot pay
2010: TrustPower announces 12 3MW turbines from
Denmark will be installed in stage one. Total value of stage
one $75 million.
Construction begins in September with formation of roads and
2011: Tower and turbine components arrive at Port
Chalmers by ship and are trucked to Mahinerangi. The first
two turbines begin generating in February and by April, all
12 are operating. TrustPower says future expansion of the
wind farm is on hold, pending decision on who will pay for
the upgrade of the Cook Strait electricity cable.