Wind Utility Owners, Operators and Field Technicians: What’s in Your Data Communication Tool Box?
n recent years, the use of wind power generation has increased as a viable energy solution. With this increase, owners, operators and field technicians are looking for the best ways to maintain wind turbines and prevent failure.
In recent years, the use of wind power generation has increased as a viable energy solution. With this increase, owners, operators and field technicians are looking for the best ways to maintain wind turbines and prevent failure. An important factor in wind power generation is the maintenance, upkeep and monitoring of the entire system because wind power application decisions are cost-oriented; failure or system damages can result in millions of dollars of unexpected expense.
Technicians and operators need to be able to troubleshoot the various mechanical, hydraulic and speed control systems; converter issues and components. There is also a need to diagnose problems within the generators and equipment as quickly as possible to prevent further issues from arising. The faster operations and maintenance (O&M) can detect problem signals the sooner that loss can be mitigated and potential disasters avoided. With these issues being a central focus of wind energy, it is easy to see why quality control analysis through the use of data collection and transmission is critical in the process of maintaining wind turbines and wind farms. There are several communication system options that enable people to make the best decisions because they are provided with dependable data transmission for condition monitoring, supervisory control and data acquisition (SCADA), meteorological (MET) tower diagnostics and productivity reporting. (See Different Communication Technology Solutions table.)
A common solution for wind turbine monitoring is a wired or cable solution. Many operators, however, are finding that installing additional wire is not feasible—usually because of remotely located turbines and the high costs associated with installing and running additional wire. It’s sometimes not possible to run wire back to the O&M office.
Wireless technologies have recently become an option for various monitoring and control applications in the renewable industries. Satellite systems, for example, have broadband capabilities and tend to be reliable, but have monthly recurring costs. Cell phone systems also function similarly to satellite systems, use an existing network of communication devices and have monthly charges. If users are within range of a cell tower, cell phone systems are a simple solution for sending data back to the O&M office. The monthly recurring costs associated with satellite or cell phone systems, however, can become a burden on an operating budget.
|Different Communication Technology Solutions|
Operators also can now choose Frequency Hopping Spread Spectrum (FHSS) radios to send critical data to the O&M office without the added cost of fiber installation and without the monthly or reoccurring fees that tend to accompany cellular and satellite solutions. This class of wireless radios has proven its reliability in the military, oil and gas, water and wastewater industries and is now available as a solution for monitoring and data transmission in wind turbines. Especially useful for installation in remote locations and difficult environments, the radios can transmit real-time data up to 60 miles line-of-sight reliably.
|Radio up tower.|
Real World Example— Southwestern U.S.
A wind power company in the Southwestern U.S. along the Texas and New Mexico border needed a vibration monitoring solution for dozens of turbines. In this case, the property owner and site operator did not want the contracting company to use their existing fiber optic network. They also didn’t have the bandwidth or the ability to use their existing fiber optic network to set up the system. It became a question of how to get vibration-sensing data from the turbine back to the O&M office if they couldn’t use the existing fiber optic network the site operator installed.
Fiber optic networks usually are installed at the same time as the turbines. The fiber optic networks consist of large webs of fiber optic cable that continuously send and receive data. They provide high throughput and are industrially prepared for this type of application, but in this particular case the company did not have the option to use fiber. It began looking at several wireless providers and settled on one that offers FHSS wireless data radios.
There is a class of FHSS wireless data radios that has proven to succeed in the most difficult environments. In this particular installation, all the turbines sat on top of a mesa, which offered a clear line of site. Both pier-to-pier communication and point to multi-point communication was easily achieved. Each of the turbines, however, is composed of a mast some 200 hundred feet tall by 15 to 20 feet in diameter and is made of corrugated steel. This could easily have created an issue with line of sight. There was a concern that radio frequency (RF) would reflect off the turbines like a mirror.
Operators should always work with a wireless company that provides path studies or lender radios to ensure the products will work before they purchase them. In this situation, the tests showed the wind turbines would not be an issue. When the wind power company performed the path study, it compared multiple radios and was able to determine which ones performed despite the potential obstruction of the wind turbines. One of the radios in the comparison lost data each time a blade passed through the arc link, so the company went with the solution that did not have link issues.
The chosen radio provider took the potential obstruction into consideration before installing the radios. In this case, it conducted a study using a digital elevation level to indicate potential problems. That was only one way, however, to account for the huge obstruction, so it was a bit of a variable. The radio provider did additional testing by climbing to the top of a cell and setting up a radio inside the housing. The signal successfully transmitted through the turbine back to the O&M office.
The deployment of these radios has been such a success that 11 different sites are planned for installation in the next year and a half. The company is looking to install 450-500 more radios across the country.
|Example of wind farm network topology. Each dot represents a wind turbine generator—the red square represents the master and the blue dot represents a repeater.|
A Model for Long-term Success
Many data communication technology companies, such as FreeWave Technologies, believe that with every network communication application, owners, operators and field technicians need to take the necessary steps to define the technologies they need and why. The importance of mission-critical data transmissions is growing and organizations that count on data communications for operational success—where failure and downtime are not an option—need to examine every possibility and option available. The following information provides a brief outline of suggested starting-point recommendations for the decision-making process.
System Needs and Long-term Goals
First and foremost, one of the most critical steps to instituting a reliable and comprehensive communication network system is to understand the current and future needs of the system’s requirements. Compiling a set of standards and requirements provides an overview of where the system’s capabilities currently are and gives insight into what the system’s needs will be. It is imperative to involve experts in the field and all stakeholders because of the various perceptions and ideas that people will bring to the table.
|Wind turbines outfitted with wireless transceivers.|
Second, it is important to understand the organization’s long-term communication goals. What is the company trying to achieve with this communication network? Do these goals align with the future needs of the system? Is the company going to need this communication infrastructure to be shared for different applications? How do the long-term goals of the communication network apply and compare to the long-term goals and vision of the company in general? Failure to completely understand all of these considerations in the short-run will increase the odds of future complications and can even lead to a system failure.
Once long-term goals are established and everyone has mapped out future system requirements needs, it is time for the detailed data communication network planning stages. How frequently, for instance, does the data acquisition need to be conducted for the organization? There are many options to consider:
- On-demand, hourly, daily, on exception, changes in status, etc.;
- How the data will be delivered;
- Raw data or data packet sizes;
- Large or small data packets;
- Data streamed, polled or reported by exception;
- Latency or performance requirements; and
- Deciding which communications aspects are important to ensure so the application or component does not take too long to complete a user task.
Know the Market
Competition brings out the creative nature of everyone involved. When considering installing or adding to the data communication network, it is important to pay attention to what the competitors and neighbors are doing. This information will provide a better understanding of what they are trying to achieve and how the overall market landscape is changing. Most importantly, the focus should be on core competencies. Make choices based on individual needs and goals and not what competitors or neighbors are doing. When entering into a new realm of possibilities, always verify the performance of the supplier, contractor and manufacturer. Don’t blindly trust market buzz or advertising; get as much information as possible and confirm the credentials of the technology partner. The name of the game in communication networks is reliability, so make sure all needs are met in order to reach set goals.
|Radios enable communication systems by providing dependable data transmission for condition monitoring, SCADA, MET tower, productivity reporting.|
Selecting the Appropriate Technology
Selecting the technology that best fits the requirements is an important consideration now that the overall goals and system requirements need to be determined. As with any big decision, time should taken to learn about the various technology options. Learn the advantages and limitations and how each option could play into the future development of the communication system. It is beneficial to be a skeptic because one size does not fit all with communication networks. Each system is different because of its location or topography, data speed requirements, performance or polling times, and backward compatibility issues. Since every communication network is unique, the option of hybrid networks might offer the best technical approach for diverse needs and requirements.
The budget usually plays a large role in determining what kind of technology will be introduced for a wind farm’s communications network. Obviously, cost is an important factor for many decision-makers. Consider a communication network an investment in technology as a capital expenditure since it is an upfront investment for the future, or, in other words, it is an expenditure that creates future benefits. In addition, it is crucial to consider the operating expenditures because there are recurring charges to consider based on the technology options chosen.
Lastly, there are various maintenance, repairs and service charges to be taken into consideration to avoid going over budget. Financing is a viable option for these new communication technology assets being introduced into the company; a depreciation method—tax deduction—can be used to recover the costs of these assets. By mapping out these budgetary considerations, a snapshot can be made of the benefits and savings accrued by making certain choices.
For wind energy owners, operators and field technicians, it is imperative to examine the best ways to maintain wind turbines and prevent failure—through the utilization of effective and reliable data communication technologies. The key to building a successful data communication network is to examine all the available tools in the communication tool box. The options are endless with continuously improving wireless data radios, communication technologies, firmware and software, plus the option of hybrid solutions to optimize communications requirements. Clearly, as wind energy owners, operators and field technicians learn of more successful wireless installations, they are beginning to view FHSS wireless radios as a viable option for monitoring and reporting the status of wind turbine equipment and activity.