Why aren’t there more small wind turbines on buildings?

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Solar panels and batteries are common elements of a microgrid. Wind turbines, on the other hand, are more of a rarity.

Large wind turbines can be found in microgrids built on islands or in remote blustery locales. But smaller rooftop wind turbines, befitting a city skyline, are rare. Solar panels are the more common sight.

Cities can be plenty windy. So what’s the problem?

Rooftop wind turbines placed on buildings are inefficient because they are in “the shadow of the winds,” said Alexander Suma, founder and CEO of IBIS Power, a renewable energy company in the Netherlands. Turbulence around the rooftop makes energy production inefficient.

His company has devised a system called PowerNest — a modular unit that combines solar, wind and energy management in an architecture that Suma said overcomes the turbulence problem and maximizes renewable energy production.

1 + 1 =3

“The goal is to generate as much energy as possible on the limited roof space because big buildings, high buildings, they are basically the biggest energy users inside a city grid. On a small footprint, they have the highest demand,” Suma said in a recent interview with Microgrid Knowledge.

Designed for flat roofs, PowerNest requires that the building be at least five stories, a height where the best winds begin. The unit has internal wind turbines and solar panels on the top. It is placed on the building roof.

It looks like a simple box from the outside, but its success lies in its use of aerodynamic shaping, he said. “Imagine an airplane with square wings. It wouldn’t take off. The wings look very simple, but there is a lot of intelligence behind that shape.”

PowerNest works to remove the turbulence around a building by capturing the wind, then bending it inward, accelerating it and guiding it through the wind turbine.

The wind/solar combination is important, Suma said, because solar alone often can’t meet the building’s energy demand — there is not enough roof space. Plus, solar generates less energy in northern climates during the winter. The wind also cools the solar panels. The unit uses bifacial solar panels and employs internal solar reflections. 

PowerNest

PowerNest installation. Photo courtesy of IBIS Power

All of this leads to renewable energy generation that is multiple times the norm from rooftop renewables, especially in cities with good wind and solar climates, according to Suma.

“It’s not just solar and wind stuck together,” said Timothy Vail, founder and principal at Blue Mountain Technologies and contract consultant with IBIS Power. “The word synergism really comes to mind because the louvers on the PowerNest not only direct the airflow and optimize the vertical axis wind turbines, but it also cools the solar panels that are overhead. And so it takes double advantage of that situation. And it really is the first and only time I’ve seen two distinct technologies put together and not just be one plus one. This is one plus one equals three.”

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PowerNest moving into US market

Founded in 2012, IBIS Power installed its first commercial unit in Europe in 2019 and is now completing its fifth installation with eight more in the works in the Netherlands and Belgium. The company is currently eyeing medium- to high-rise buildings in the US, attracted by the nation’s growing push for local energy, electrification and decarbonization of urban buildings. Suma said he’s initially focusing on Boston, New York and Philadelphia, where he sees strong interest in sustainability, good wind and solar potential and building stock of the right size and density. Electricity costs are also high in these cities, which makes energy alternatives more cost-competitive.

The PowerNest is not a microgrid, in and of itself, but is microgrid ready — able to connect to pair with a microgrid controller and serve as a component of a building nanogrid.

Others pursuing small wind for microgrids

IBIS Power isn’t the only company that sees potential in pairing small wind turbines and microgrids.

Bergey Wind, a long-time small wind turbine producer, has touted their use in off-grid hybrid microgrids as a way to reduce the use of diesel, increase renewables and spare wear and tear on batteries.

Newer to the market, California-based Air Voltaics is pushing small to midsize wind turbines for microgrids for similar reasons. The company also points out that wind turbines demand less space than solar panels. Together with solar panels, they create more reliable energy supply.

Last year, FlowGen, a wind turbine technology company based in Switzerland, and microgrid developer CleanSpark inked a deal to pair their technologies. CleanSpark was granted exclusive distribution rights for FlowGen’s small wind turbine solutions (under 1 MW) in North America and South America. 

Will these companies drive more small wind turbine use in microgrids? So far it’s been a tough sell, with solar plus storage holding the spotlight. As always, we’re interested in our readers’ thoughts. Please post your comments below, on our LinkedIn Group, or on Twitter @Microgridnews.

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About Elisa Wood

Elisa Wood is the chief editor of MicrogridKnowledge.com. She has been writing about energy for more than three decades for top industry publications. Her work also has been picked up by CNN, the New York Times, Reuters, the Wall Street Journal Online and the Washington Post.

Comments

  1. Hello Elisa Wood,
    The very simple answer and very ugly truth is that our world is control freak central with politics involved. If I owned a town, this what my town would look like,

    — ALL buildings/dwellings (residential/commercial/government) empty walls would be covered with solar panels as well as wind turbines of all shapes and sizes on roof tops, bridges, any other tall structures.

    — meters replaced with battery packs and build battery farms next to any substation(s) in the town, excess can be sold to the Feds

    — the hospital would be a complete self-sustaining micro-grid (battery packs for ER rooms only for example) as well as fire/police station(s)

    — teach all residents to install/maintain the microgrid(s)

    — solar panel installation training is around 40 hours

    — teach in schools about skills for microgrids required hands on!!!

    — born in Zaandam, The Netherland, used wind power for several 100 years

    Thank you

    John Schoen

    faradmotion@outlook.com (website not active)

    615-293-8469

    Hoping for a world wide free power grid powered by people’s microgrids power from all over the planet, ditto for the internet!!! Have a great day.

  2. I not only have a small wind turnie on my two story Arlungton, VA office building, but have spec’d small turbines on over 300 buildings all over the world. Wind is ideal paired with solar and batteries since most wind (aside from
    shoreline) mostly blows at night and during stormy weather when the sun does not shine. Pairing solar with wind allows the downsizing of the battery bank since there is auxiliary charging. Wind speed can be quite ideal on buildings tall and small. The biggest barruer is not wind speed or technology, but zoning and building codes. Limits on height of anythingbon building roofs, njoise issues (even though most turbines cannot actually be heard (or barely heard), or burdensome interconnection rules beyond that of solar pv. The real barrier is basic education of building owners, community bgroups and local gopvernments, and local government building code and zoning officials. – — Scott Sklar, President, The Stella Group, Ltd., Arlington, VA 22201 E-mail: solarsklar@aol.com
    Website: http://www.TheStellaGroupLtd.com, The Stella Group, Ltd.. is a global strategic technology optimization owner’s rep firm for clean energy users and companies, with a focus on system standardization, modularity and web-enabled diagnostics.

  3. John’s Comments are valid.
    There’s also power & reliability issues. A windturbine gives power to the cube of its diameter so doubling the diameter gives eight times the power. A 60m windturbine gives 27,000 times the power of a 2m turbine. If a turbine has an MTBF of 20 years, that’s 1,350 2m turbines failing and needing to be fixed each year for one 60m turbine.
    A solar panel has no moving parts.
    There were a lot of small turbines installed around the UK a few years ago, a lot of them are stationary now.

  4. “Cities can be plenty windy. So what’s the problem?”
    As mentioned in the article shadowing by buildings, turbulence on roofs and gusty winds tend to cause vibrations at mounting points that can well be heard throughout the building that has the turbine no matter how small, mounted to the roof.

  5. Alden M Hathaway says:

    Hi Elisa:

    I’m Alden Hathaway, and am the father of Tripp Hathaway formerly of Hannah Solar Government Services who has contributed to your articles in the past. (I think you know him, don’t know if you know me) Although he is currently serving his country on deployment with the SC National Guard, I am reaching out to recommend Jenny Marquez of ARC Industries, a Providence RI manufacturer of small wind turbines. I am President of the Cranberry Isles Community Solar Association and we are considering ARC Industries turbines to supplement our solar and better level out the demand curve minimizing batteries for backup.

  6. I am Sukumaran and the patented innovator of the RADIAL REACTION WIND TURBINE ENGINE / POWERPLANT.
    Your article sounds very similar to what I have been promoting to the Singapore HDB and others worldwide.
    My wind turbine is suitable for roof tops because it does not have a tower and is connected to 2 generators.
    It is a boxed in housing with open ‘In’ and ‘ exit’. it has a single spiral blade and an aerofoil profiled roof and floor.
    Due the convergent / divergent duct of the blade and the aerofoils placement, differential pressures are created within the housing. It works based on Bernoulli’s Principle. I hope that you did not get this idea from my LinkedIn posting to Officials and others in general.