6 Considerations for Wind

11/01/2014 | By Jennie Morton

Learn about the breezy benefits of this renewable power source

Geothermal heating and cooling? Hidden beneath your feet. Rooftop solar array? Placed out of sight. A utility-scale wind turbine? Visible from miles away.

You don’t need gale-force winds to invest in a turbine. This form of renewable energy is breezing its way onto schools, hotels, office parks, and college campuses. As long as you have available land and an eye for a long-range payback, wind can help you secure clean energy in your own backyard.

Spinning with Success
Imagine long white blades stretched across a blue sky and gracefully rotating in the wind. It paints a pretty picture, but turbines aren’t for architectural interest. These renewable energy generators can significantly offset the amount of electricity your facility normally draws from the grid.

“There’s no silver bullet for renewable power – we can’t meet all of our energy goals with one technology. You have to use what’s most appropriate and feasible for the particular resource of your location, and wind can deliver for many regions,” explains Trevor Atkinson, sales and business development manager for Northern Power Systems, a turbine manufacturer.

INFORMATION AND IMAGES COURTESY OF NORTHERN POWER SYSTEMS

Case Study #1: McGlynn Elementary and Middle School

This municipality-owned turbine at the McGlynn Elementary and Middle School was identified as an opportunity for energy independence by Medford, MA.

Installed in February of 2009, the congested city site was predicted by AWS Truepower to have an average wind resource of 4.6 m/s (10.3 mph), but in actuality has experienced winds of 4.3 m/s (9.6 mph). As a result, the annual energy output has been lower than anticipated but well within expectations for this type of urban installation.

The low height profile of the 37-meter tower and quiet permanent magnetic direct-drive (PMDD) operation ensure that the school’s neighbors are not adversely affected. A web monitoring program tracks energy output, carbon emission offsets, cost savings, and other historical data that can be accessed online by classrooms and the community.

“The opportunity with wind for schools is not only to educate tomorrow’s leaders about energy and the environment, but also to gain real savings that can translate to teacher positions, arts programs, facility improvements, and even other renewable energy projects,” noted Michael J. McGlynn, mayor of Medford at the time of installation.

The city obtained incentives from numerous sources, such as the Massachusetts Renewable Energy Trust LORI grant, Massachusetts Energy Consumers Alliance grant, Clean Energy Choice grants through the National Grid GreenUp Program, annual renewable energy credits, state appropriation general laws, and Chapter 312 of the Acts of 2008.

Whether adding a wind turbine to an existing property or a new development, you need to extensively research your options before committing to an installation. To ensure a successful project, do your homework using these six factors:

1) Understand Your Goals
Before you even consider wind, take care of efficiency projects first. There’s no sense in adding renewable generation if it will only lull you into wasting power elsewhere in your facility.

“You need to understand your load and how you can improve it,” Atkinson stresses. “If you’re generating your own power, you don’t want to be throwing away your green energy on incandescent lighting and leaky windows.”

Once you get your energy usage as lean as possible, determine what goals you want a wind turbine to satisfy.

“Do you want to be 100% powered by renewable energy or just 10%? Do you want to create a microgrid so you reduce power quality issues? Do you want to earn LEED credits? Do you simply want to put up a green flagpole to announce your company is sustainable?” Atkinson asks. “Each of these goals directly impacts the size of the turbine you need.”

Beyond diversifying their energy sources, the majority of owners use wind to manage their utility spend. It’s key to know how much your building is consuming so you can appropriately match the turbine output, says Adam Miller, founder of Summit Design + Build. Even better, use submetering throughout your facility. This will lay the groundwork for ROI if you can concretely say your wind generation in a given year will satisfy 100% of your lighting needs or 85% of your HVAC consumption.

2) Calculate Your Wind Resource
Wind resource is the amount of wind your site receives annually. Sure, you can step outside and feel the direction of a stiff breeze by licking your finger and sticking it in the air, but that’s only good for movie characters, not real life.

“If you’re going to spend seven figures on a turbine, you want to make sure the wind is going to be there,” says Ari Killian, project manager for Summit Design + Build.

Note that the viability of wind power is dependent on geography, adds Killian. Solar is likely to have an edge in southern and western states, but wind is more prevalent in the plains and coastal areas. And even if your region has strong wind throughout the year, performance varies on a daily basis, even more so than sunny days.

“Wind speeds can fluctuate between 20 to 25% each year, whereas solar is within 2 to 3%,” Atkinson explains.

There are two ways a commercial property can assess its wind resource. The most common is to use national weather data.


“There are a number of online databases that utilize hundreds of weather stations. While they are a pay-for service, you can put in your building location and it will give you a highly accurate assessment of your wind resource,” says Atkinson. “For a single distributed-scale turbine project that’s 100, 200, or even 300 kW, the online data is extremely reliable. We’re talking about a nominal 3 to 4% accuracy range from what is measured on-site to what was predicted.”

The other option is to install a wind tower that uses anemometry to document wind speeds, says Miller. This is the same technology a wind farm developer uses to study the microclimate of a potential site. These feasibility studies are an added expense and typically run for several years, but they may save you from installing a wind turbine that ultimately won’t meet your goals.

“Every year you collect data, you radically reduce the uncertainty of your wind resource,” emphasizes Atkinson.

INFORMATION AND IMAGE COURTESY OF NORTHERN POWER SYSTEMS

Case Study #2: Wausau East High School

Wisconsin’s first high school renewable energy center is proud to have this turbine complement textbook lessons on renewable power.

Installed in 2009, the gearless design offers 24/7 monitoring capabilities and students can access power data through web portals. The information is used across curricula and throughout all grade levels to track wind speed, historical data, and energy efficiency.

The school is projected to save almost half a million dollars on utility bills and has thus far offset more than 208 metric tons of carbon emissions. The site’s five-year wind resource has averaged 4.23 m/s (9.9 mph).

The educational benefits of the wind system to the students was the primary motivation and purpose for this renewable energy installation. The project was funded with support from the Walter Alexander Foundation, Focus on Energy, and the Wisconsin Public Service Response Rewards.

3) Determine Your Siting
Given how large these structures are, you need to carefully consider where on your property to place the turbine.

Even if you have the land space required, you can’t just plop these anywhere, Killian stresses. There’s the view of your neighbors to consider, adjacent structures, bird safety, airport traffic, power lines, and even landscaping such as tall trees.

Your municipality will have zoning guidelines you need to follow, or if you’re a pioneer in your community, your project may become the test case.

“In Chicago, for example, the zone requires a radius that is 10% larger than the turbine’s aerial footprint,” Miller explains. “If your turbine hub is 150 feet and you have another 80 feet for the blades, that’s 230 feet plus 10%, which is a 250-foot radius. Obviously you need a very large area. At the same time, you have to make sure this extra buffer doesn’t spill over your property line.”

Your manufacturer or a consultant can help you navigate siting considerations, including any topographical barriers that could complicate the project, adds Atkinson.

4) Check Grid Connectivity and Metering
Connecting a wind turbine to the grid, as with any other renewable energy source, can make utility providers wary. Safety and connection stability aside, you need to investigate pay rates. The optimal arrangement is for your local power provider to allow net metering.

“The utility will install a meter that runs both ways,” Killian explains. “When the turbine is generating excess power your facility can’t use, the meter will spin the other way.”

What this means is that when you dump clean energy onto the grid, you receive credit for it at the same rate you would normally purchase it. The utility receives a source of green energy and what you produced doesn’t go to waste.

Be cautious that not every utility is on board with net metering. You need to have this conversation before you commit to your project, says Ryan Gilchrist, assistant director of business development for Urban Green Energy (UGE), a provider of building-integrated turbines. There could also be expensive utility upgrades you have to make to enable such an arrangement, which could negatively impact your margins if you don’t account for them at the project’s onset.

“Even if your utility offers this option, there’s no universal net metering thresholds among states or even within utility regions,” Atkinson explains. “Some may have allowances of 100 kW, some are only 50. Some could be unlimited while others are up to 20 MW. It’s all over the map, so know what your state or region will permit.”

There are also arrangements that are less than favorable for building owners. A growing number of states have mandated that utilities offer net metering, but without this enforcement, some utility regions may still offer an avoided rate.

“You may pay 10 cents per kW but only get 2 or 3 cents for your wind energy. In these situations, the economics are terrible and may impede an attractive payback,” cautions Atkinson.

5) Look for Independent Verification
Not sure if the reputation and quality of your manufacturer’s claims are valid? Greenwashing can stain even the most promising products, so keep a sharp eye out for independent verification.

“You want to make sure the machine has third-party verification or reports that validate how the turbine will behave, particularly with acoustics and power curve,” Atkinson says.

There are two certifying bodies for wind turbines:

The International Electrotechnical Commission (IEC) offers comprehensive wind turbine metrics. These includes design requirements, acoustic noise measurement techniques, measurement of mechanical loads, and communications for monitoring and control of wind power plants.

The Small Wind Certification Council (SWCC) applies to small and medium turbines and has been adopted by the American Wind Energy Association (AWEA). It

covers rated annual energy output, power, and sound level. Certified turbines must also satisfy durability and safety requirements.

Power curves, annual energy performance curves, and measured sound pressure levels are provided for all models. Note the standard only verifies test results rather than conducts them, and towers and foundations are not within its scope.

“I would also urge any prospective investor to get project references from a manufacturer’s clients,” adds Atkinson.

6) Anticipate Maintenance Service and Warranty
Your car needs periodic oil changes and so will your turbine eventually. These units are not maintenance-free and preventive upkeep is key to preserving your investment for years on end.

Like your roof, wind turbines are offered with a warranty, though these vary by manufacturer. Two years is average for a utility-scale turbine and smaller ones may offer up to five years of coverage, says Atkinson. These generally cover parts for failures, though not always labor for those repairs.

Maintenance can be purchased as a separate contract through your vendor or you can connect with an independent firm that specializes in maintenance services. Expect one or two yearly visits for scheduled maintenance.

BALLOGG PHOTOGRAPHY

Case Study #3: TESTA PRODUCE

This utility-scale turbine at Testa Produce was one of the first installed in Chicago. It helps to power a LEED Platinum freezer/cooler distribution facility with over 90,000 square feet of office and warehouse space.

The 260-foot unit was installed in April 2011 and generates 880,000 kWh annually, roughly 30% of the building’s power. One of the project’s challenges was securing code approval, as zone requirements had to be written from scratch to cover installations in the Windy City.

Blown Away by ROI
There’s no denying that the price tag of a wind turbine may make some building owners blanch, but most would be surprised to know they only need to wait a decade or so to reap free energy.

“Make no doubt, these turbines pay for themselves in 10-15 years, which is faster than geothermal or solar,” Miller says. “Our clients aren’t speculative developers that are going to turn around and immediately sell the property. These are businesses that are building facilities that will last 100 years, which allows owners to take a long-term view with ROI and payback.”

“There’s three legs to the wind ROI stool – wind resource, utility rates, and incentives and grants,” Atkinson adds. “You don’t have to be in a super windy spot or in a high utility region. If you can get those three metrics to align and optimize your upfront costs, wind can work out very nicely.”

Beyond local and state funding, owners can turn to federal incentives such as the Investor Tax Credit, which offers a 30% credit for expenditures on small wind turbines that are 100 kW or less or 10% for microturbines that are 2 MW or less. Take note that these expire in 2016, so time is limited for eligibility.

Beyond your utility bill, look for soft benefits. Intrigued onlookers may turn into potential customers or business investors.

“There’s an enormous public relations opportunity with wind, especially free advertising if your company logo is painted on the tower,” says Miller. “A wind turbine is showing a commitment by a corporation that they’re all in with sustainability. It’s a real statement when your company invests in a high-profile feature like this.” “We’ve had many commercial customers tell us their foot traffic increased by 20 to 30% after they installed a turbine simply because people were curious,” adds Atkinson.

Jennie Morton jennie.morton@buildings.com is senior editor of BUILDINGS.

 


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