By: Zack Smith
Industrial wireless’s reliable cost-effective nature makes perfect sense in utility-scale solar.
Many solar industry veterans have a bad taste in their mouth about industrial wireless integration. Why? A few years ago, wireless technology wasn’t considered robust or reliable enough for industrial environments. A lost data connection could potentially cost millions each minute of downtime.
Seven years before working at Affinity Energy, I sold wireless. At that time, technology was definitely not mature enough to be used in critical environments. But now, I trust wireless to provide 100% uptime.
Today’s wireless connections are considered reliable and redundant enough to perform in industrial atmospheres. Of particular benefit are large solar environments where miles of cable can be expensive to install and maintain.
An Outdated Fear of Industrial Wireless
Integration of wireless in industrial environments like manufacturing or utility-scale solar is fairly new. Perhaps this is the reason some solar owners believe wireless is unreliable and should only be used in non-critical applications. Others are worried about data security implications.
Unreliability and insecurity may have been characteristics of wireless connections in the past, but today’s industrial-grade radios have just as much (if not more) security capability and encryption as a wired switch, and their reliability is unparalleled.
4 Key Benefits of Industrial Wireless in a Solar Environments
From a cost standpoint, the advantage of wireless over wired is overwhelming. Many solar owners take the low cost to be an indicator of poor reliability but it’s simply a reflection of material and installation savings. You save a lot on labor costs when you aren’t paying for miles and miles of trenches and conduit.
Here are a few examples:
- Industrial manufacturing: Charlotte Pipe and Foundry wanted to connect compressors sprawled around their plant to their data acquisition server. To run conduit to all the compressors and back to the server, they received quotes from $50,000 to $70,000. Affinity Energy did it wirelessly for just $4,000.
- Utility-scale solar: When designing a solar project, someone forgot to include the drawings that included 400 feet of Ethernet. Unfortunately, that greatly exceeds the length of Ethernet cable. The owners were considering a fiber-optic cable, quoted at tens of thousands of dollars. We proposed to bridge the gap wirelessly at less than $1,000.
It seems like solar was built for wireless. Because of their size and geography, solar plants are very friendly to industrial wireless connectivity, probably more so than any other industrial application. With acres of wide open space and minimal obstacles, it’s easy for an integrator to easily point radios across a solar field to each other.
Consider the time devoted to wired in a new construction schedule. Installing wireless radios is considerably faster than digging trenches, laying cable, and covering it all back up again. To put the time-savings into perspective, I installed and configured a fully-integrated 80MW site in less than two weeks, whereas fiber-optic cable would have taken months to install.
In a wired infrastructure, there are many points of failure, mostly from accidental cable cutting. Due to the simplified network of industrial wireless, there are actually less points of failure than in a wired infrastructure. The worst possible scenario in a wireless situation is if a radio happens to go bad (a rarity). In which case, a new radio can be installed in as little as 30 minutes.
4 Solar Wireless Options
If you’re convinced you need wireless implementation across your solar farm, there are a few wireless radio options. With these options, there are tradeoffs of bandwidth and range.
- Bandwidth: The amount of data that can flow wirelessly. The smaller the bandwidth, the less data you can receive to your data acquisition console. Sites that require a lot of raw data transmission should opt for an option with high bandwidth. Usually the more bandwidth you have, the less range you get.
- Range: The distance wireless can travel effectively across a given area. If a solar site spans giant open fields over hundreds of acres, you’ll need something with higher range. Usually the further range you have, the less bandwidth you get.
900MH radios have small bandwidth, but great range and punchthrough power, able to connect through difficult obstacles like tree lines. The 20-40-mile line-of-sight radius is so strong in fact, that directional antennas aren’t required. Affinity Energy recently integrated 900MH industrial wireless radios at an 80MW site with great success. Because the site was only interested in receiving processed data, high bandwidth wasn’t necessary. Dozens of 5MW and 10MW sites use 900MH radios and haven’t skipped a beat.
2.4GH radios are extremely common in residential environments, but also have applicability in industrial as well. In my opinion, these are the best bang for your buck. With 2.4GH, you get three times the bandwidth from 900MW, but sacrifice a bit on distance. 2.4GH radios have a 10-mile line-of-sight and you must be pickier about which direction your antennas are pointing, especially on larger solar sites.
3.6GH radios have even more bandwidth than a 2.4GH, with less range. They’re still good for up to 5-7 miles, which is fine for a 5MW site up to a 20MW site. A lot of solar owners like 3.6GH because nobody else uses it, which means the lines are pretty clear. Overall, it’s a pretty good tradeoff for range and bandwidth.
5GH radios are fairly common now in both residential and commercial. These babies are so powerful that airports utilize them for terminal Wi-Fi. These radios give you maximum bandwidth, but I wouldn’t install these radios in any site bigger than 5MW, even with directional antennas.
Don’t Fear Wireless…Embrace It!
To those who don’t have a lot of confidence in wireless, understand that wireless technology has come a long way in the past few years.
Wireless is an obvious solution to many of the problems traditional to wired solutions. If you want to save money during construction and increased ability to diagnose problems in your solar environment, industrial wireless is for you.
Zack Smith is an accomplished Field Services Manager at Affinity Energy, and as a Certified Control Systems Technician (CCST) with 20 years of experience, has responsibility for managing a dedicated team of field engineers and field technicians. Upon his honorable discharge as a member of the U.S. Navy Submarine force, Zack pursued a career in industrial automation at manufacturing companies Sandvik and Delphi Automotive, and became an expert in programming industrial automation machinery and robotics. After spending six years as Head Applications Engineer at an industrial automation supplier, he joined the Affinity Energy team in 2010. Zack’s contributions include major enhancements to SCADA systems at Carolinas Healthcare System, Chesapeake Bay Bridge and Tunnel, and the University of Virginia, along with numerous utility-scale PV integrations.