The Answer is Blowin' in the Wind

By Jessica Binns

Before a wind farm can be established, extensive research must be conducted to ensure that enough power will be generated to justify developing the property. The process involves installing 200-foot-tall meteorological towers that measure such data as wind speed, direction and temperature. For Renewable Energy Systems, headquartered in Kings Langley, England, this information was captured on data cards through wireline dial-up modems attached to the towers, a process that Dr. Andrew Oliver, VP of technology, describes as a "real administrative burden."

RES did not employ a team of field technicians to retrieve the data cards. Instead, it would establish a relationship with someone who either owned the property where the test site was located or simply took interest in the project, and pay the individual to trek out to the remote location once a month to collect and mail back the data cards to RES' regional research offices.

"Sometimes our contact would send the data card back to us promptly, and sometimes they'd forget to send it right away," says Oliver. "Sometimes the card would get corrupted, or it would get lost in the mail. In truth, we wanted to maintain the card system but gather data more frequently, so that if a wind tower was zapped by lightning we wouldn't lose a month's worth of data."

When the stresses of not being able to analyze wind data in a timely manner got to be too much, RES began to research wireless solution options and discovered the Raven, a powerful wireless modem offered by AirLink Communications of Hayward, Calif., which was acquired earlier this year by Sierra Wireless of Vancouver. Featuring AirLink Embedded Operating System (ALEOS), packet-level diagnostics, over-the-air firmware updates, and remote monitoring and configuration capabilities, the Raven was a considerable improvement. With the wireless modem, RES can now instantly tweak settings, remotely reset a device that has been knocked offline, perform onboard diagnostics and monitor the performance of the carrier network.

With more than 800 turbines in the alone, producing in excess of 1,100 megawatts each year, RES is a leader in harnessing wind energy. The company has helped governments and utilities, among other industries, develop this sustainable and financially attractive energy solution and unobtrusively integrate wind farms into the surrounding environment. RES also controls the single largest wind farm in the world, a sprawling site located in King Mountain, --a state better known for its oil production.

Setting up the new wireless system proved to be a challenge. RES contacted AirLink partner Mobile Electron, an M2M and wireless data systems integration consulting company, headquartered in Lutz, Fla., for help with configuring the solution. David Schwarz, senior VP of Mobile Electron, says his team recommended the line of Raven modems because each one is tailored to different cellular carrier technologies, such as GSM, CDMA, GPRS and EDGE.

"A lot of times when we start to analyze a customer's requirement, it almost becomes a real estate analogy: location, location, location," says Schwarz. "We initially tried to deploy the appropriate Raven modem in the area where any given carrier might have the preferred, prevailing service footprint, which is critical to the end-to-end solution." The wireless modem system is an IP-based solution, says Schwarz, and has greatly improved the transmission of data to RES regional offices. What's more, RES can be notified of problems with the meteorological towers much more quickly than before.

RES collects wind data by using a Campbell Scientific data logger attached to each tower. The system is set up to retrieve historical data on demand; workers send a query from their office computers to the data logger via the Raven modem, which is assigned a static IP address. "This company that is on the forefront of sustainable energy completely utilizes M2M technology to accomplish what could be a time-consuming process," says Schwarz. "There is a dramatic impact on the productivity of personnel. Running a wireline out to these remote sites could take six months and cost a lot of money. And if the site doesn't prove suitable for wind farming, RES can just pack up and go--there's no infrastructure involved."

There were significant drawbacks to not having robust data under the dial-up modem system. "Losing a month's worth of information adds to the uncertainty of how much wind production there would be at the site," Oliver says. "Bottom line, it comes down to what the banks are willing to lend you. If there's more uncertainty, they'll lend you less."

Beyond the unreliability of collecting the data cards, the dial-up modems themselves were not economical in terms of power consumption. The old modems utilized solar batteries and were run in a circuit switch, which meant that RES offices could not connect to multiple modems at one time. "We'd have a window of time when the remote systems would shut off so as to not drain the power supply," Oliver says. "Sometimes the modems would search for a signal for hours."

The cost savings from the AirLink solution include reduced long-distance phone bills, since the new modems are wireless, says Oliver, and the elimination of expenses related to the freelance technicians who previously retrieved and mailed in the data cards. But the payoffs, such as "reduced operational inefficiencies," are more significant.

"We can be more proactive in our business," Oliver explains. "Someone came in the other day and said, 'I'd like to know [how much energy] a wind farm would have produced today.' It was the hottest day of the year in . [The client] wanted to know by 8 a.m. the next morning, and we were able to tell him. There's no way we could have done that before. We wouldn't have been able to get the data cards back to the office in time."

Finding a solution that was also environmentally friendly is especially satisfying. "Many times you find the alternative communications capability of a wireless network and these types of modem solutions are preferred in that they are noninvasive," says Schwarz. "RES, in analyzing locations for proposed wind farms, and in monitoring wind on test sites, is looking to do as little damage and disruption as possible to the surrounding property. The modems run off DC power, solar panels and rechargeable battery packs."

RES has more than 60 test sites in the and roughly 48 have been transitioned to the AirLink solution. Retroactively outfitting the towers with the new modems is a relatively simple process that takes a few minutes, says Oliver. If a technician needed to visit a test site, the Raven modem was installed during that trip. Today, all new sites are built with the Raven modems, and all previous tower installations that can be retrofitted have been.

Because many of RES' test sites are so remote and characterized by difficult terrain, some cannot be transitioned to the AirLink solution. "To the extent that we can use the wireless modems, we are," says Oliver. He admits that lightning can still damage the Raven, just like the old dial-up modems; but the difference now is that RES will have received all of the data prior to the weather event instead losing 30 days of critical information.

RES currently maintains 15 percent of the wind energy market share and hopes to increase that number to 20 percent. With streamlined data collection operations, thanks to AirLink's Raven wireless modem, that goal is closer than ever.  //