Ten major studies in three countries of 1.3 million property transactions over 18 years of data have found no connection between wind farms and property values. Yet the fear of property value loss persists and is exploited by anti-wind campaigning groups in their attempts to turn local populaces against wind developments.
By comparison, only two moderately reliable studies with some statistical significance found property value impacts, and they are both challenged in different ways. Five other often referenced studies are merely case studies with no statistical significance, done by appraisers who show strong evidence of bias, and in one case there is clear evidence that they ignored the reality of the property they appraised.
The evidence that wind farms don’t harm property values is robust, methodologically sound and from reliable organizations. The evidence that wind farms harm property values is much weaker, methodologically challenged at best and usually from much less reliable organizations.
Respect the people and their concerns
Whether it is a home or a vacation property, people who buy or own rural property have deep emotional drivers attached to it. For some older people, it is the home they have been in for decades. For others, it is a rural idyll, the fantasy of a hobby farm or country estate. For others, it is an escape from the vertical canyons, concrete, steel and noise of the city. For most of them, it represents a very large percentage of their finances, with all of the attendant concerns that it might turn to dust as happened in the US with the subprime mortgage collapse in 2008. It is worthwhile to respect the deep emotions involved in this subject. Anti-wind advocacy groups certainly do, and while some are directly motivated by fears of falling properties, many broader groups are using those fears to directly motivate grassroots organizations to form to fight wind turbines.
Property values show no long-term correlation to wind turbine presence
There have been several major reports released in 2013 and 2014 that substantially add to the evidence base for wind farms and property values.
Most recently, the largest and longest duration study was released by the Center for Economics and Business Research (Cebr) in the UK. They were commissioned by RenewableUK, the industry body for wind and marine energy generation, which in many minds will reduce the merit of the study, however, it covers over one million property transactions in counties with wind farms over 18 years, making it the study with by far the largest statistical base and longest perspective. The methodology and statistics are sound. Their findings?
Our analysis of the raw house price data for transactions completed within the vicinity of the wind farms yielded no evidence that prices had been affected by either the announcement, construction or completion of the wind farms for six out of seven sites.
In fact, the analysis shows that on average, house prices near wind farm sites grew faster for the periods between the start of construction and mid-2013 (0.8% annual growth) than at the wider county-level (0.5% annual growth). One site did see a noticeable downturn following the announcement that a wind farm would be built; however once the turbines were erected, local house price growth returned to the county-wide norm.
As can be seen from a key graph, the average house prices within five kilometres of wind farms track the county averages very closely over the eighteen years. What’s also of relevance to the discussion is that house prices dropped in 2008 and have continued downward. Once again, the visibility of wind farms makes them lightning rods for concerns that are actually caused by other things.
As a side note, Cebr excluded two wind farms from the statistical analysis because they had too few properties within five kilometres of them for statistical validity. This is interesting because the transactions near those wind farms — 470 and 2,384 respectively — are greater than the total transactions in virtually all of the studies finding harm to property values, casting those studies even more deeply into doubt.
The most substantive is the 2013 update of the 2009 Lawrence Berkeley National Laboratory (LBNL) study, described below in detail.
Pertinent points are extracted here:
We collected data from more than 50,000 home sales among 27 counties in nine states. These homes were within 10 miles of 67 different wind facilities, and 1,198 sales were within 1 mile of a turbine—many more than previous studies have collected. The data span the periods well before announcement of the wind facilities to well after their construction. We find no statistical evidence that home values near turbines were affected in the post-construction or post-announcement/pre-construction periods.
This major study controlled for significantly more variables and concerns than previous studies and found no impact on property values from wind farms.
The LBNL also collaborated with the University of Connecticut on an assessment of property value impacts near wind farms in the US state of Massachusetts in 2013, publishing their results in January 2014. They spread the net even wider:
To determine if wind turbines have a negative impact on property values in urban settings, this report analyzed more than 122,000 home sales, between 1998 and 2012, that occurred near the current or future location of 41 turbines in densely- populated Massachusetts communities.
The results of this study do not support the claim that wind turbines affect nearby home prices. Although the study found the effects from a variety of negative features (such as electricity transmission lines and major roads) and positive features (such as open space and beaches) generally accorded with previous studies, the study found no net effects due to the arrival of turbines in the sample’s communities. Weak evidence suggests that the announcement of the wind facilities had a modest adverse impact on home prices, but those effects were no longer apparent after turbine construction and eventual operation commenced. The analysis also showed no unique impact on the rate of home sales near wind turbines.
In January 2014, a Canadian study assessed the impacts of the Melancthon wind farms near Orangeville, Ontario — at one point the largest in Canada — on home and farmland property values over another 7,004 property transactions. The study’s conclusions:
The results of the hedonic models, which are robust to a number of alternate model specifications including a repeat sales analysis, suggest that these wind turbines have not significantly impacted nearby property values. Thus, these results do not corroborate the concerns raised by residents regarding potential negative impacts of turbines on property values.
Also in 2013, the University of Rhode Island performed an assessment specifically of property transactions in that US state. They covered 48,554 property transactions over thirteen years, both near and far from the twelve large and mid-sized wind turbines constructed in ten sites between 2006 and 2013.
Across a wide variety of specifications, the results indicate that wind turbines have no statistically significant impact on house prices. For houses within a half mile of a turbine, the point estimate of price change for properties within 1⁄2 mile relative to properties 3-5 miles away 3 is -0.2%. So our best estimate is wind towers have no virtually effect on prices of nearby properties.
The best study in this field prior to 2013 was funded by the US Office of Energy Efficiency and Renewable Energy. They mandated the Lawrence Berkeley National Laboratory to study the concern and the report was delivered in 2009. Here’s what they found:
The present research collected data on almost 7,500 sales of single- family homes situated within 10 miles of 24 existing wind facilities in nine different U.S. states. The conclusions of the study are drawn from eight different hedonic pricing models, as well as both repeat sales and sales volume models. The various analyses are strongly consistent in that none of the models uncovers conclusive evidence of the existence of any widespread property value impacts that might be present in communities surrounding wind energy facilities.
It is worth noting and debunking the arguments used against the study, as they have been recycled constantly:
- The claim: it doesn’t agree with what is obviously happening around the person observing. The reality: statistics have never had much success in convincing someone who believes something and receives sufficient evidence to support their confirmation bias.
- The claim: the Lab is government-funded. The reality: the bona fides and independence of the LBNL are top-notch and questioning them indicates the rhetorical or intellectual disposition of the questioner.
- The claim: the study excluded 34 statistical outliers. The reality: statistical studies of any size do this to eliminate unrepresentative data and 34 exclusions on a sample size of 7,500 is miniscule. This study is accurate and has not been manipulated.
The next study is the 2007 study by the Royal Institute of Chartered Surveyors (RICS) in conjunction with Oxfords Brookes University. These are serious, respectable and trusted institutes as well; RICS traces its history to chartering in 1792 and is a pre-eminent standards setting body world-wide. The researchers assessed property transactions within five miles (8 kilometers) of three wind farms from 2000 to 2007. This provides geographical, distance and time-frame perspectives. They eliminated transactions where significant other factors would impact prices: a large open cast slate mine, very expensive properties, very cheap properties and sea view properties. This was to provide a clear view of specifically wind turbines’ impact on property values. This left them with 919 transactions, which is statistically valid. Their findings:
Despite initial evidence that there was an effect, when they investigated more closely, there were generally other factors which were more significant than the presence of a wind farm. Insofar as there was any impact on prices, the results seem to show that it is most noticeable for terraced and semi-detached houses, with there being a significant impact on properties located within a mile of a wind farm. The effect seems much less marked – if at all – for detached houses.
Regarding the terraced and semi-detached houses:
The view of the estate agents was that proximity to a wind farm simply was not an issue. What they did say, though, was that the properties close to one of the wind farms – St Eval – were, in fact, ex-Ministry of Defence properties, and so less desirable than similar properties.
To paraphrase, while people blamed wind turbines for property value decreases, other factors were much more significant, and detached homes, the dominant form of real estate near wind farms showed no price impacts. Unfortunately, RICS has removed this survey from their available publications on their website and appear to not be standing by the results of their research.
The third major study worth assessing is the Renewable Energy Policy Project’s (REPP) 2003 study. While the oldest, it also assessed the largest pool of data prior to 2013, more than 25,000 property transactions in the USA. They looked at every home within 5 miles (8 kilometers) of ten greater than 10 MW wind developments that came online between 1998 and 2001. They gathered sales data for the control regions near the wind turbines but outside of the 5 mile (8 kilometer) boundary to ensure that they could assess differences accurately. They gathered six years worth of data covering the years leading up to and following the wind farms’ online dates. It is worth noting that while this is by far the largest study with the least statistical adjustment of data, the creator of the study, REPP, is an organization whose public and stated goal is to accelerate the use of renewable energy. As such, while the study design is arguably very good and sample size the largest, it is the only one that might be possible to discount due to source. What REPP found:
- For 8 of the 10 of the wind projects, property values increased faster inside the five mile limit than outside of it over the six years.
- For 9 of the 10 wind projects, property values increased faster within the five mile limit after the wind projects came online than they had before.
- For 9 of the 10 wind projects, property values increased faster within the five mile limit after the wind projects came online than in the comparable communities.
Not only did this massive study not find negative impacts on real estate values, it found exactly the opposite: wind turbines have a slight positive impact on real estate values.
A fourth study is also worthy of a closer look: “Wind Farm Proximity And Property Values: A Pooled Hedonic Regression Analysis Of Property Values In Central Illinois” by Jennifer L. Hinman in partial fulfilment of a Master in Applied Economics with Illinois State University in 2010. Ms. Hinman’s study evaluated 3,851 residential property transactions from January 1, 2001 through December 1, 2009 from McLean and Ford Counties, Illinois around the 240-turbine, Twin Groves wind farm (Phases I and II) in eastern McLean County, Illinois. Ms. Hinman’s study found no correlation between a working wind farm and decreased property values, in fact saw more rapid price increases nearer to the wind farm as was observed in the REPP report. Her study most clearly shows that there is a statistical correlation between fears about a wind farm before it is erected, temporarily depressing property values, and that this temporary dip is rapidly eliminated once the wind farm is in operation.
A University of New Hampshire study published in December 2012 assessed another 4,600 property transactions and found:
While this study does not exclude the possibility of isolated cases of property value impacts attributable to the Lempster Wind Power Project, this study has found no evidence that the Project has had a consistent, statistically‐significant impact on property values within the Lempster region. This is consistent with the near unanimous findings of other studies—based their analysis on arms‐length property sales transactions—that have found no conclusive evidence of wide spread, statistically significant changes in property values resulting from wind power projects.
Two correlation graphs from this study paint a clear picture.
Note that distances are in kilometres.
Basically, there’s no variance on home prices due to distance from wind turbines, and a huge correlation to size of dwellings.
A preliminary Australian study indicates that this is also true south of the equator. While the sample size of sales transactions is low, they found that 40 of 45 sales transactions had no evident reduction in value in close proximity to wind farms and that properties that were in sight of wind farms found no reduction in value.
What is the evidence that shows negative impacts?
There is a statistically valid, methodologically sound, peer-reviewed study which contradicts the preponderance of evidence above, and is worth detailed assessment as a result. Martin Heintzelman and Carrie Tuttle did a study of 11,331 property transactions over 9 years in three counties in Northern New York, 461 of which were within three miles of wind turbines. They found that two of the three counties had significant property value decreases while the third had positive indicators. For context, this study is relatively equivalent in terms of organizational respect and depth to Ms. Hinman’s study from Illinois State University; credible but not from a world-class organization such as the Berkeley Lab or RICS. A significant failing of the study that makes it difficult to trust compared to other studies is the short time frame of the data for the two counties with negative impacts. Their wind farms became operational in 2008 and 2009, basically in the last year of the data set. The county with positive impacts went live in 2006, in the middle of the data set, providing a much richer analysis space. There are several other significant differences between the two counties that showed negative results and the county with positive results as well.
- The two counties with negative impacts (Franklin and Clinton) had significantly fewer transactions — 210 between them — than the county with some positive impacts (Lewis) which had 251 transactions by itself.
- The two counties with negative impacts had significantly higher resales of properties than the county with positive impacts, 75 to 65.
- The two counties with negative impacts are adjoining to one another with the third county two hours drive away, effectively in another community conversation region and making it possible for other local impacts to be masked; three completely separate or three completely co-located regions would have eliminated this oddity.
- The two counties with negative impacts had fewer wind turbines on average than the county with positive impacts (221 between them to 194 in Lewis).
This region also has a robust set of anti-wind activist groups. The 2011 anti-wind documentary, Windfall , is from upstate New York, and Lisa Linowes, a long term anti-wind advocate with ties to astroturf-supporters such as the Heartland Institute and the Koch brothers was the sole technical advisor to the movie and has been active in the area. Despite the largest county with the longest history of wind energy and the most transactions having positive indicators for property values, the authors focused their conclusions dominantly on the negative counties. The authors state in their initial preamble, since revised, that they did not believe it possible that wind turbines didn’t negatively affect property values. They found the results they expected, ignoring the significant oddities in their results. This study can only be considered of moderate reliability due to the challenges.
A German study is also worth assessing briefly. It covers 1,405 transactions near a wind farm of nine wind turbines in Germany. It found lower property values near wind farms, regardless of whether the wind turbines could be seen or not. It is weak as it does not have control values from other areas, does not assess other potential causes of hedonic impact and has a limited transaction base. At best it is an interesting outlier from the preponderance of evidence of only moderate reliability.
There are four anecdotal sets of property value appraisals by property value appraisers — McCann, Gardner, Lansink and Reardon — in Canada, the USA and Australia that are often mentioned. They variously use case studies, paired sales analysis and an apparently invented statistical method in one case. They cover a few dozen property transactions at most with little in the way of methodological rigor or control. They all show strong evidence of pre-existing bias in their statements. Given the tiny sample sizes and poor methodological rigor, they cannot be considered reliable as evidence. One Australian report by a property appraiser, Peter Reardon, follows in the footsteps of weak anecdotal assessments in Canada and the USA, looking at three sales near wind farms and pairing them with properties elsewhere. It has the typical weaknesses of poor methodology and rigor, but a statement from a purchaser of one of the two properties which apparently suffered property value impacts came into my hands via a correspondent. It’s worth looking at what they say about the property that they purchased. Netting it out, it was grossly overpriced for reasons having nothing to do with the nearby wind farm, and everything to do with the property itself.
As you know the property had been on the market since September 2010 at no time did we see it advertised at $320,000. We spoke to the agent when it was priced at $299,000 which we thought was grossly over valued even for a lifestyle block let alone a grazing block, having as you stated not only one but two 330KV lines transversing the block along with the associated easement restrictions (some 50 double sided pages of conditions and and terms), it is divided by the duel carriage Hume Highway and two truck parking bays (North & South), with the associated noise and litter problems, it has no 240V power access on the block (and we know what that costs). That’s the lifestyle detractions of the block. Now Grazing- the block has over 30% water logging and drainage problems, covering both sides of the highway-in fact many times we saw the agents vehicle parked on the edge of the road- presumably inspections by “foot” The block had poor boundary fencing on the southern side, the carrying capacity of the block is app. 2.5 DSE per Ha. We therefore came to the value of $205,000 (2500 per Ha.) This was allowing some $8000 for “proximity” to the Highway- having purchased her brother’s property some 12 months before at app. $2400Ha.(carrying capacity of6 DSE per Ha.) (no agent involved in this transaction! ) We had to increase this offer by some $20,000 to secure this deal. I think Real Estate Agents are no different in the country to their city cousins- raising unrealistic expectations of the value of property especially in a difficult market. It would seem that people want sub-division prices for undeveloped land, not allowing for development and approval costs. Having also sold the mentioned 80Ha block on the Collector Rd we know the demands of financing lifestyle blocks in recent years. This block does have 240V power available as per Council Sub-division regulation.
The anecdotes about property value loss represent real people telling the truth as they see it, which is to say, from a limited perspective in both space and time. What they are observing is accurate – lower sales prices than they expected – but their interpretation of the reasons appears to be flawed. However, decisions on policy and legislation must be made on the most robust evidence. The evidence related to property value and wind farms is clear: the only impact that wind farms have is that host properties are worth more after the wind turbines are installed. Nearby properties are unaffected.