Errol Kelly (Servants of society rather than masters of nature, May 8) argues wind farms destroy non-renewable landscapes simply by being there, so they can never be sustainable.
If only it was this simple. Landscapes are dynamic. They change over time with both natural and human influences, and so are non-renewable in themselves.
Some changes will have a greater impact than others.
The principle of sustainable management, which is at the heart of the Resource Management Act, recognises that using or modifying a resource does not necessarily destroy it.
A wind farm does introduce a change into the landscape, but it leaves broad landforms, environments and ecosystems intact.
Of the land a wind farm occupies, 97 to 99% remains in its existing state. More often than not, the land stays in productive agricultural use.
But within the wind farm, areas with high natural values can be left unaffected or even protected and restored.
In exchange, we see some wind turbines on a ridgeline or hillside.
If a better form of electricity generation comes along, the turbines can be dismantled at the end of their lifetime, fully reversing their visual effect.
In the meantime, generating electricity from wind will not produce harmful greenhouse gases.
There are some environments in which wind farms should not be built as they are too precious to all of us - our national parks might top the list.
But what about modified environments? Perhaps a hillside that contains a mixture of tussock, pasture and forestry? White Hill wind farm, southeast of Mossburn in Southland, fits this description and receives strong public support.
What about proposed wind farm sites that are grazed and have been subject to decades of human modification? While such environments retain some natural values, these may not be actively protected or managed.
Meridian's Project Hayes and TrustPower's Mahinerangi Wind Farm fall into this category.
There seems to be an assumption that if these wind farms are not built, the sites will magically restore themselves.
But the sites are working farms, so that isn't going to happen.
Left as is, there is no guarantee such environments will even be maintained in their current condition.
So we can leave a site as is and hope for the best, or develop it in a way that that will cause some changes but also result in better management of the local environment and benefits for the wider environment.
No-one claims wind energy has no impacts, but wind energy has far fewer effects on far fewer people than any other form of electricity generation - something we need to consider as we face the consequences of low lake levels and increasing electricity prices.
As we head into winter, demand is increasing and, to meet this demand, additional electricity is being generated with coal at Huntly and diesel at Whirinaki.
Restricted electricity supply is not a problem that affects just North Islanders.
The HVDC cable, which links the North and South Islands, has had no northwards flow at all for the past week.
Spot power prices in the South Island are three times higher than this time last year.
If consumers are unwilling to reduce their demand (which appears to be the case), then new generation in the South Island is required.
Mahinerangi and Hayes are part of the solution.
Sometimes, we have to make a choice between the view from our window and what will be best for the environment and our future.
The RMA gives us a process for assessing a proposed development, its benefits and impacts.
Reassuringly, the RMA's principle of sustainable management ensures that wind farms built in New Zealand will, indeed, be sustainable.
Wind energy is proven, mature and accepted around the world.
In New Zealand, it is making an increasingly important contribution to our electricity supply and it will continue to do so from appropriate places.
- Fraser Clark is the chief executive of the New Zealand Wind Energy Association.
