September 2018 Issue of Wines & Vines
 
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Wind Turbine Electricity Generation

Scheid Family Wines expands sustainability efforts with renewable resource

 
by Cynthia Bournellis
 
 

Wind is not just something that you can feel against your skin, hear when it howls, or see the effects of its devastation. Wind also is one of the fastest-growing sources of electricity in the world. In the United States, wind energy ranks fourth in electricity production, behind natural gas, coal and nuclear energy, according to the California Energy Commission (CEC).

In California, wind plays a crucial role in the state's electricity portfolio and Renewable Portfolio Standard (RPS). According to the CEC, electric utilities are required to source 50% of retail sales from renewable sources by 2030. Further data from the CEC shows that commercial-scale wind projects generated a net 13,500 gigawatt-hours of electricity in 2016, about 6.81% of the state's gross system power; and wind energy accounted for 39% of California's renewable energy production for the RPS.

While hundreds of homes and farms are using small turbines to produce electricity, others are going big time. Most impressive is a wind-turbine installation in California's Salinas Valley in Monterey County. In August 2017, a huge turbine was erected at Scheid Family Wines in Greenfield to improve overall efficiency by supplementing the electricity delivered through the Pacific Gas & Electric (PG&E) grid with an on-site, emission-free renewable energy source.

Scheid has been farming wine grapes in Monterey County since 1972 and today has 4,000 acres of sustainably certified vineyards and a large state-of-the-art winery in Salinas Valley. The new wind turbine is a major element in Scheid's sustainability-practices program.

Salinas Valley whirlybirds
The Scheid wind turbine may very well be the first large-scale project in the U.S. to be installed on a winery property and was put in by Foundation Windpower LLC, a developer, owner and operator of utility-scale wind projects. This is the third Foundation installation in Salinas Valley, including a turbine at Taylor Farms, a food-processing plant in Gonzales, and another at the city of Soledad's wastewater-treatment plant. Foundation Windpower has 20 sites throughout California, with the oldest installed in 2010 in the city of Tracy, at the base of the Altamont Pass.

Wind turbines require sites that 1) have a good wind regime to generate significant energy and 2) are in a non-residential area, according to Bob Lewis, founder of Foundation Windpower. "There has to be enough wind to run the turbines, which are state-of-the-art and are the same size as those used on wind farms."

The Scheid turbine is a utility-scale 1.85-megawatt generator designed for high-wind environments. These massive structures are built to last 25 years but potentially can run 30 years or more.

Winds in the Salinas Valley blow, on average, 13.5 miles per hour, making conditions favorable to wind-energy generation, particularly during the summer afternoon hours of noon-6 p.m. (Monday through Friday). These hours are defined by PG&E as "peak electrical demand" hours and result in higher electricity costs and an increase in greenhouse gases. "The turbine offsets this expense and impact," Lewis says.

Turbines begin spinning and generating electricity when the wind blows at 7-9 mph, Lewis notes, produce full power at 34 mph, and generally shut off and enter a survival mode when the wind exceeds 56 mph.

The wind above my vines
Scheid ripped out 6 acres of Pinot Noir vines (to be replanted later) to clear, grade and excavate the site for the turbine. The first phase of construction involved excavating at a depth of up to 35 feet from the surface to construct a foundation 15 feet in diameter. The subsurface soil was prepared for both the foundation and pad, and any remaining soil was returned to the center of the foundation pursuant to the foundation design. Construction lasted two weeks, followed by 30 days of inactivity to allow the foundation's concrete to cure.

The second phase, which took four weeks, involved the delivery and assembly of the tower, rotor, transformer and nacelle (a cover housing that houses all of the generating components in a wind turbine). Each piece was shipped and then assembled on-site using cranes. The finished turbine sits on less than one-half acre; the additional area is required for delivery and construction of the structure. Next, electrical work was performed to connect the wind-turbine generator to two transformers and an underground transmission line. The distance from the wind turbine to the circuit box is 1,000 feet.

Assembly and installation by Foundation Windpower using General Electric equipment included two transformers. One transformer, located at the base of the turbine, increases the generator's 690 volts (V) to 12.47 kilovolts (kV) for delivery of electrical energy through underground conductors to the step-down transformer. The step-down transformer delivers 12.47 kV-480 V and is located near Foundation's protection switchgear adjacent to Scheid Family Wines' main switchgear. Foundation's switchgear provides a 52G turbine breaker operated by relays and a DC battery system. The switchgear also includes PG&E's manual disconnect switch.

The wind turbine can be seen, not heard, for miles. The center line of the turbine hub is 264 feet above ground. Three propeller blades are each 132 feet long, and the top arch of the propeller blades is 396 feet above ground level. The props turn at approximately 19.5 rpm. The turbine operates on an automatic basis whenever sufficient wind is present, 24 hours per day, seven days per week. Sound at the base of the turbine is approximately 70 decibels and less than 50 decibels at 1,000 feet.

Netting it out
The contract between Scheid Family Wines and Foundation Windpower is called a Power Purchase Agreement in which Foundation Windpower owns, operates and maintains the turbine, in addition to providing power to the winery operations. Scheid pays a fee that includes a discount below what PG&E would charge.

The turbine is connected to the energy meter at the winery and provides power for main winery operations. The turbine operates in parallel with PG&E. This means that when the wind is not blowing, Scheid is drawing energy from PG&E. When the turbine is operating, the energy that is not used from PG&E remains in the utility grid and Scheid receives credits from Foundation Windpower at the same rate that PG&E would have billed Scheid during that time period.

Maintenance is included in the Power Purchase Agreement, and costs range from 3% to 5% of the total installation cost of $4 million to $5 million. "Foundation Windpower is monitoring the turbine generation remotely 24/7," Lewis says. If there is an issue, we have a team of technicians available to access and repair any problem. Preventive maintenance is also performed throughout the life of the turbine."

Windfall in savings
The turbine went online Sept. 15, 2017. Based on a wind-energy savings analysis from Scheid for the period from September 2017 through January 2018, Scheid has realized $28,854 in energy savings via the wind turbine. A full year, however, is required to determine the reduction in PG&E demand charges.

"After evaluating our electrical cost savings from the wind turbine project and due to the growth in our business, comparing year-over-year costs is not reflective of the savings from wind-power utilization," says Tony Stephen, Scheid Family Wines chief planning officer. "Based on current performance, we estimate electricity savings from the turbine to exceed $50,000 per year."

In keeping with its sustainability practices, the cost to replant the 6 acres of Pinot Noir vines that were ripped out for the turbine installation was $3,500 per acre, including materials-because Scheid reused the original trellis and end posts.

Industrialization and wildlife coexisting
Before construction, Foundation Windpower conducted an analysis that included potential impact of the turbine on birds and other wildlife, plants and aesthetics (scenic vistas, intact landscapes and scenic routes), using data from Ventana Wildlife Society, California Department of Fish and Wildlife, California Natural Diversity Database, the U.S. Fish and Wildlife Service and the California Native Plant Society's Electronic Inventory of Rare and Endangered Vascular Plants.

At a time when the Migratory Bird Treaty Act of 1918 is turning 100, the industrialization of landscapes is top of mind. Turbines-as well as oil spills and power lines-can pose a threat, especially to birds. In the Salinas Valley, the king of birds is the federally endangered California condor. There are roughly 90 birds in Central California, according to Mike Stake, senior wildlife biologist for Ventana Wildlife Society in Monterey County. Ventana is credited with the successful recovery of the breeding population of bald eagles in Central California and currently is doing the same for the condors.

"I visited the [Scheid] site several years ago, and based on my opinion about the condors' potential to collide with these structures, I recommended that Foundation Windpower do a study," Stake recalls. While Stake says that collision is a problem for golden eagles at some wind facilities, concerns over condors have intensified because of their large size. The California condor is North America's largest land bird, with a wingspan of 9.5 feet. Adults weigh approximately 22 pounds. Their size-coupled with the valley's propensity toward high winds and fog-could compromise their ability to navigate these turbine structures.

The California condor range in Central California includes the Carmel Highlands on the north, San Simeon on the south, and extends east across the Salinas Valley to Pinnacles National Park in the Gabilan Range of San Benito and Fresno counties. This rugged terrain gives them the uplift they need to sustain flight. Although the Salinas Valley is not considered ideal condor habitat, they regularly fly across the valley to the ranges on either side, making their crossing as high as 5,000 feet or more above the ground.

The condors seek out a direct path to get from one side of the valley to the other. Condor flights tend to be lower and more frequent in the southern Salinas Valley. For example, condors typically fly several thousand feet above the valley floor in Gonzales and Soledad, but flights are often below 1,000 feet near King City.

Per a contract with Foundation Windpower, Stake began conducting data analysis of condor locations to study their movement patterns at the Scheid site in 2015. The goal was to determine whether the condors fly low enough at the site to be at risk for collision. Stake focused primarily on the east side of Salinas Valley, close to the foothills, where condor traffic is higher than in other areas.

Ventana has been tracking condor movement since 1997, first with VHF radio transmitters attached to the birds' wings. In 2003, they began using satellite tags. Roughly one-quarter of the condor population in this area has been tagged. The tags are run by solar power to collect location fixes (GPS coordinates) and position the birds within several meters of where they are. The GPS is coordinated to the bird, and each bird is given a specific number as an identifier. The GPS communicates with a satellite and collects the birds' locations, which are stored inside the tag. Once a condor flies near a cell tower, the data is uploaded to a server at Ventana's office.

The GPS takes into account the condors' horizontal positions relative to the satellite and their vertical positions relative to the ground. "Their vertical position is key to all of this because it lets us see how high above ground the birds are flying," Stake says. Average altitude is also measured to determine potential collisions. The condors' locations are then plotted onto a Google Earth map to determine how many birds are flying close to the wind-development site.

Findings from the condor study
The 2015 study occurred over one month. It included 1.5 million data points on condor movement already collected in 2003 up through the end of the one-month study. The results showed that California condors, on average, are flying 1,000 feet or more over the Scheid property in Greenfield, where they tend to fly higher than they do in the southern part of the valley. "Based on our study, we did not find any birds [condors] flying within rotor tip height (maximum height that the turbine blade swings upward) at Scheid," Stake reports.

Ventana's study of condors over time shows that even though today's condor populations are much bigger and more birds are flying over the Salinas Valley, they are still flying quite high, are continuing on a straight path, and do not seem to be approaching the three turbines in Salinas Valley. When the condors fly near King City and closer to the ground, biologists have become more concerned about wind-energy developments.


Cynthia Bournellis is a certified California Wine Appellation Specialist with honors, journalist, and wine industry professional. You can read more about her journeys through wine on her blog, frombehindthetastingbar.com.

 
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