Rooftop and Building Integrated Wind Turbines are a Failure Says NREL

By Paul Gipe

The National Renewable Energy Laboratory (NREL) concludes in a new report that rooftop-mounted and building-integrated wind turbines are a failure, though readers would be hard pressed to find that statement in so many words.

One needs to be thoroughly grounded in the purpose of renewable energy technology and especially in wind energy to successfully read between the lines and parse the sometimes lawyerly prose. Those who do are ultimately rewarded with a conclusion that the wind industry reached long ago—wind turbines in, on, or near buildings are simply a bad idea.

Unfortunately, there’s no mention in the report of Venger’s embarrassing project on a medical building in Oklahoma, or Cleanfield, Canada’s contribution to disastrous rooftop Vertical-Axis Wind Turbine (VAWT) development, or UGE’s installations at Lincoln Field in Philadelphia or the true nadir of rooftop VAWT hustle, UGE’s two turbines inside the Eiffel Tower in Paris. (See A Tale of Two Turbines and Eiffel’s Tower.)

NREL twists itself into knots trying to spin the results to something other than embarrassing failures. Take this statement from the summary.

“In general, the BEWT [NREL’s coinage for Built Environment Wind Turbine] industry has experienced mixed results, with some positive project outcomes and several negative outcomes for stakeholders. We see that projects with positive outcomes usually share the following commonalities.” [Emphasis added.]

“Mixed results? Indeed, the installations all failed at a wind turbine’s most fundamental task—reliably delivering cost-effective electricity. When you drill down to how NREL identifies projects with “positive outcomes” in the subsequent bullet points, you find that if the project goals “include some education or marketing component” and if the project does “not rely solely on energy production” as a measure of success and there was some resulting mention in the press, NREL declared the project a “success.” In other words, they called a project a success if the developers solely met their public relations objectives. This is the very definition of greenwashing.

Yes, you read that right. If developers set out to install a greenwashing project and they got some favorable mention in the press, NREL labeled the project a success. Oy vey!

We can only hope that NREL was under political pressure to produce a report that didn’t damn the rooftop wind turbine market out of hand and that the authors were gritting their teeth the entire time they were writing the report. If not it calls into question just what NREL is doing with its time.

Fortunately, the authors did sneek some doozies into the report that escaped the censors.

For example, the most “successful” of the greenwashing projects was 12 West in Portland. The project uses four Skystream turbines on the roof of the LEED-certified green building.

The architects that designed the building estimated that the four turbines would generate a total of 9,500 kWh per year or only 1% of the buildings consumption. In the end the turbines produced only 5,500 kWh and these are turbines on relatively tall towers (45 feet) for rooftop wind turbines.

But it gets better. The installation of the four turbines cost $240,000 or $60,000 for each 3.7 meter diameter, 2.1 kW wind turbine—or something less than $30,000 per kW of installed capacity. For comparison, commercial wind turbines cost $2,000 to $4,000 per kW of capacity.

So, let’s see, that’s $240,000 for 5,500 kWh per year. That gives you an average cost of generation of $44 per kWh. Note that this is not the cost of energy. This is simply a metric used to judge relative cost-effectiveness. Commercial wind turbines at good sites should deliver about $0.40-$0.50 per kWh. The 12 West turbines cost about 100 times that of a commercial wind turbine at a good site. And this is the only project NREL studied where the turbines are typically operating. Ouch!

NREL calculated that this project, after including the federal tax subsidies, would pay back its investment in 40 years. I find that estimate optimistic. In real terms, the project will never pay for itself.

Despite all this, NREL called the installation a “success” because the objective of the architects that designed the project was to “elevate the visibility of the building.” It did that so in the eyes of NREL—or those pushing for this study—this was a success.

It just keeps going downhill when you dig deeper. NREL notes that the “wind turbines were part of a larger project: the design and construction of a 23-story LEED Platinum-certified mixed-use apartment and office building.” That will set off alarm bells for anyone who has followed the whole “let’s put them on a building” flim-flam. The architects used the wind turbines to win LEED points. They didn’t really care if they worked—as wind turbines—only that they spun in the wind to call attention to the building. 12 West could be the poster child for what’s wrong with LEED. See LEED Leads to Bad Wind.

And if you think that it’s just NREL that’s been snookered by the lure of building-mounted wind turbines, take a gander at another example in the report: NASA. Yes, that NASA, the people who put a man on the moon.

In late 2014, NASA completed installation of four UGE (Urban Green Energy) VAWTs on Building 12 at the Johnson Space Center in Houston. The four 1 kW wind turbines cost $100,000 not including electrical infrastructure. That’s $25,000 per kW of installed capacity.

In March of 2015, the turbines generated a whopping 0.12 kWh. (Yes, the decimal is in the right place.) From the manufacturer’s power curve and the wind speeds at the time, the turbines should have produced 7.8 kWh. Let’s see, that’s overestimating the generation by a mere 65 times.

And for NASA, the embarrassment continues. NASA selected the turbines, VAWTs, because of “wildlife impacts and wind speed requirements.” That is, they bought into the hype that VAWTs are more “bird friendly” than conventional wind turbines (they are not), and that VAWTs are better at low wind speeds than conventional wind turbines (they are not).

It’s one thing if a group of architects mount some wind turbines on one of their buildings as a promotional tool, it’s something quite different if one of the premier organizations in the United States buys into some hocus pocus that rooftop VAWTs are the wind business’ answer to solar panels.

NREL has done a valuable service, whether intentional or not (and I hope it was intentional) by including such gems in its report. It would have been better, though, if NREL had simply stated boldly and unequivocally that rooftop or building-integrated wind turbines are a really stupid idea.