(The author is a Reuters columnist. The opinions expressed are his own)
By Gerard Wynn
LONDON, Sept 4 (Reuters) - A U.S. study has found that wind farm developments do not lower house values, a concern often flagged in objections to planning applications, but bigger less easily measured concerns remain.
How, for instance, can you gauge the impact of placing a group of steel turbines in what locals often describe as familiar, treasured landscapes?
UK precedent shows landscape sways onshore wind planning decisions on a case by case basis. If you cannot measure that impact and people's attachment to wildlife and historical sites these things become random elements in planning decisions and thus potential pitfalls for developers.
But the comprehensive report, by the Lawrence Berkeley National Laboratory (LBNL, a government body), can add some rigour to local energy development decisions, by allaying property concerns among local communities.
The findings are also relevant to other energy projects where growth in residential areas may be greater than onshore wind, including electricity transmission pylons and shale gas.
The LBNL report aimed to add to the present understanding of impacts on house values by collecting more data, from 51,276 house sales, closer to wind turbines than previous studies.
The authors applied various models to correct for non-wind farm influences on values, including trends in the wider housing market and house location.
The context for the study was rapidly rising wind power deployment in the United States, which is expected to continue, including in more populated areas such as New York, New England, the Mid-Atlantic and upper Midwest.
They compared house values, as measured by sale price, before and after the announcement of a proposed nearby wind farm, and before and after construction.
"Regardless of model specification, we find no statistical evidence that home values near turbines were affected in the post-construction or post-announcement/pre-construction periods."
Possible explanations for the small/zero impact may include: a "fear of the unknown" anticipation which ebbs rather quickly; a minimum distance between wind turbines and homes; and self-selection of house buyers who accept wind turbines more readily.
The LBNL study did not review or analyse the actual role of house value impacts in local objections to wind farm developments.
Britain is a crowded country with rapidly growing wind power capacity and a formidable planning system, and so offers a useful case study to put the role of house price concerns in context among other possible objections.
British planning data show that more than a third of total onshore wind applications have been rejected to date, at 7.1 gigawatts refused compared with 13.6 GW approved. (See Chart 1)
In addition to direct refusals, another 4.3 GW of applications were withdrawn, possibly because of expected refusal, and a further 1.6 GW of applications were not formally submitted, possibly because of expected delays or rejection.
The total of refused/ withdrawn/ unsubmitted proposals, at 13 GW, almost equals total approvals, indicating a significant barrier to development.
Planning officials weigh applications according to impacts on the economy, landscape, the historic environment, wildlife and the living conditions of residents, as well as national policy on renewable energy and sustainable development.
One way to examine planning decisions and local objections is to focus on the largest of the UK's 3,104 formal and informal onshore wind planning applications.
The biggest was for a 652 megawatt (MW) wind farm on the Isle of Lewis in the far northwest of Scotland, a remote area with strong wind resources.
The planning application was refused in 2008 on the basis of its impact on a local bird reserve; it received some 11,022 individual representations (including 5,698 from the island), of which just 98 were in support.
In its planning refusal, the Scottish government summarised four categories of public objection to the project: turbine and construction noise; impact on landscape and visual amenity; adverse impact on tourism; and ecological impacts.
The local government found potential for both house price increases, as a result of demand from workers on the project, and decreases, for homes closer to turbines.
The second biggest proposed onshore wind project was a 371 MW wind farm in Shetland, another group of islands off the north coast of Scotland; the government approved the project after 2,772 public objections and 1,109 comments in support.
"The objections raised concerns on a number of subjects including habitat, wildlife, visual impact and infrastructure. Ministers are of the view that these issues will be appropriately addressed by way of mitigation and, where impacts remain, these are outweighed by the economic benefits and renewable energy generation which the Development will bring," said the planning approval statement, in April last year.
House prices were not a top concern.
The third biggest UK wind farm proposal was for a 350 MW project in southern Scotland.
A summary of the public enquiry found that there could be "unavoidable significant impacts on the visual amenity" for at least 162 properties, but the plan was still approved on the basis of benefits including meeting renewable energy targets.
Visual amenity is the enjoyment locals get from a particular view or experience of a landscape.
A recent planning briefing note for British lawmakers, "Planning for onshore wind farms", confirmed that landscape could equally be the basis for refusing an application, or be over-ruled on the basis of other benefits. (Editing by Keiron Henderson)