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Snowmaking Automation

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No doubt, snowmaking automation is the wave of the future. An automated system can start up, adjust to changing conditions, and shut down much more quickly. It can make better quality snow. It requires less labor. And it can provide better management data, and faster. But can it do all this well enough to justify the cost? That’s the big question.


There are so many variables involved, it’s not easy to make cost comparisons or estimate efficiency gains. Full automation might be as simple as an on/off valve for a line of fixed-flow stick guns, or as complex as a mix of multi-flow low-e and fan guns, with or without hydrant regulation, all controlled via computer that manages sequencing, prioritizing, and pressure regulation. And there are many levels of automation in between.


One difficulty in trying to measure the impact of automation is the lack of good data on current onhill operations at many areas. “At Ratnik, we have come up with a model that shows the cost and ROI analysis,” says president Ron Ratnik. “You can start earlier, and do better snowmaking. But there is very little data to show the financial benefits and the value of better quality. And it’s hard to measure the impact once areas phase it in.”


But that’s changing. “Resorts are getting a better handle on snowmaking costs and operating statistics,” says Joe VanderKelen, president of SMI. “That allows them to make the business case for investments in new technology. A computer on the desk might only monitor power and water flow in the pump house, but that’s a great start. It allows you to estimate benefits.” (The Snowmaking Efficiency Index can help in that regard; see “Are You Snow White or Faux Green?” SAM, November 2010).


PUMP HOUSE CONTROLS
One place automation can clearly pay for itself is in the pumphouse, where VFDs and PLCs cut energy use and increase efficiency throughout the system. “It’s easier to track savings with water pumps and air,” says Rick Chapman, outside sales for Trask-Decrow Machinery. “We can look at a certain pumping level, can determine what the power draw is with a VFD, and show the savings. There are more variables with snowmaking guns—the air temperature, humidity, wind, and so on.”


Plus, those savings can qualify for energy rebates and paybacks from local power companies, and pump house automation complements any steps taken onhill. For these reasons, it makes sense to automate the pumphouse first, as many areas already have.


The efficiencies and cost savings are real. “We’ve had some pump houses improve 60 to 70 percent,” says Joe Cousins, president of Torrent Engineering. “Used to be, pumps were operated on/off manually. Since areas lacked staff, the snowmakers would turn on pumps before they needed them, and then leave them on after they were no longer needed. A computer can make those moves at the right moment.”


There are other benefits, as well. “Automation extends the life of the equipment,” Cousins says. “It eliminates human error, and equipment lasts longer. Ninety percent of the failures we see are the result of human error. There are a lot of savings from that alone.”


In addition, with pressure controlled by the VFD, “snowmakers on the hill see more constant pressure. It’s not just dollars and cents, it’s also what they can do on the hill,” Chapman says.


Smaller pumps and compressors can be automated by the VFD itself, Chapman adds. “It’s very basic, but serves the purpose. It starts and stops pumps and controls the pressure. And that’s what some of the smaller areas are looking for. It gets them rebates from the power company and keeps them more efficient.”


AUTOMATION ON THE HILL
Out on the hill, resorts can apply automation in several ways. Automation might perform any combination of the following functions, on any type of compatible gun—air/water, low-e tower, or fans—depending on existing infrastructure:


• starting and stopping


• adjustment of air and water valves


• draining of guns and waterlines


• gun and plant communications


• data collection and management


• remote control by manager


• remote control by computer


Again, depending on the guns’ configurations, starting, stopping, and adjustment of the guns can be accomplished in three ways: individually by each gun, by a master/slave relationship where one gun controls several neighbors, or by a central computer. Areas can choose from a menu of options and set their own priorities for which steps to automate.


A system with several automated steps and a central control system might manage all pumps and guns and make adjustments as necessary, all from a single location. It can alert the operator (a person or computer) to any faults, which can then be addressed immediately. Such systems can also be flexible: an operator (person) can override or reset the operating parameters for individual guns or a line of guns to suit a particular need, either from a central point or out on the hill at an individual gun.


Alas, a fully automated system costs more than most areas can justify.


DOING IT PIECEMEAL
Areas are addressing the cost issue by upgrading in stages. The first step is often a move to fixed towers, either low-e or fans, which shortens setup time and makes the system more efficient—even without automating any of the process. “A lot of the benefit is becoming more efficient with your technology,” says Snow Economics president Charles Santry. “Then, resorts can go automated once they get their feet wet and are comfortable with it.” Other snowmaking suppliers echo that sentiment.


“Focus on priority trails,” advises TechnoAlpin CEO Geir Vik. “Those make the most sense first, both for season startup and resurfacing through the season. Automated systems make that easier and save on cost and labor.”
Another cost-saving tactic with both low-e and fan guns on fixed towers is to link them in a master/slave setup. That way, one weather station can serve five to 15 guns, depending on the local conditions. Fixed guns means you have “a lot of money tied up on a few runs, but that’s effective on high-use trails,” says Vik.


LINE AUTOMATION
Line flooding is another step areas have taken toward automation. A single valve is used to start or stop an entire line or trail, typically with fixed-flow guns.


“It’s really simple to start pods of five to 20 guns at once by flooding a trail through a valve at the base of the trail,” says Santry. “You only need three valves and air. For automation, you add a PLC in a valve house, and you amortize the whole expense over several guns.” Valves can be operated manually, remotely from a computer, or via touch screen.


Turbocristal has had success with controlling the air on a line of fixed-flow guns. “At Jiminy Peak, they put an air valve at the bottom of a trail, and it operates the whole system,” says sales manager Ismael Fréchette. “At a certain temperature, it cuts airflow in half, so the snowmakers can shut down compressors.” And air, he notes, is the most expensive component. Add a simple weather station to the air valve and it can be operated automatically. “That’s an inexpensive way to put some automated components in and get involved in automation,” he adds.


FULL COMPUTER CONTROL
Control software and system-wide communications are the tool that allows an automated system to really increase efficiency and reduce labor. It enables a computer, or a person, to manage the guns in groups or individually. The computer, or manager, can see and adjust the operating parameters to maximize production of each individual gun, and manage the overall system. “For example, by monitoring energy use, you can do automatic load shedding. If you’re about to enter a higher-cost bracket, you can get a warning. You can program the computer to shed loads as you have pre-defined, and shut off equipment you least need at the moment,” says Vik.


In addition, the software stores data and can create performance reports and graphs that help managers understand system performance.


Many areas have already started down this path. “In North America, there about 75 areas using our SmartSnow software,” says VanderKelen. “For example, Wisp [Md.] has been using it for 10 to 12 years. Bear Creek [Penn.] has been doing it for four or five years now, and just added more guns to their system. All are doing a portion of their system that way.”


Several suppliers, including Johnson Controls, Ratnik, Areco, Turbocristal, SMI, and TechnoAlpin, provide software systems. These have gone through years of refinement in other parts of the world, particularly Europe, where automated systems are common. “The software all does the same thing,” says Ratnik. There are some differences, including the style of reports and onscreen navigation, but “there are more differences in the auto-mation hardware and valves,” he says.


Areco’s Ed Dietzel agrees, adding, “how easy is it to use? That’s an important consideration. Our software package is pretty straightforward and simple, and as basic as possible. It’s fairly visual and graphic. Some are more intuitive than others. That’s where the differences are.”



CENTRAL OR DISTRIBUTED CONTROL
One point of difference is how automated controls are handled—whether centrally (the main computer sends out commands and makes the adjustments) or distributed (with automatic controls on each gun). TechnoAlpin, among others, favors the distributed approach. “Even if the communications go down, the guns operate on the last information they received,” says Vik. “All our guns function in fully auto mode without talking to the computer.


“The difference between central and distributed control is like the use of computers in many businesses. They used to have a mainframe; now, everyone has a desktop. That makes the system more flexible and secure, and keeps cost down.”


Johnson Controls might argue with that. Its systems are centrally controlled so that the computer can make sure the entire system (whether a trail, a pod, or the whole mountain) always functions at its most efficient.


In Johnson’s system, says engineer Jean Petit, “Based on where you want to make snow, the computer reads the data and decides how many guns it can feed. If the wet bulb and pumping capacity allows 30, and you want 50, the system will choose 30—the most efficient 30. If someone wants less than the system maximum, the computer will optimize pump and air use. Each gun is adjusted optimally, and the same with pumping.


“You need to have very good gun curves, to know just how much air/water will be needed. Then the computer will rank guns by maximum snow production and go with those that have the highest production. We optimize everything.” Still, an operator can override the system, to alter snow quality or target a specific trail, for example.


“Automation equals optimization of resources. When we talk about efficiency, automation is the answer,” he says.


And that’s why automation continues to make inroads. “People are realizing that automation is a path they will have to take,” says Fréchette. “We have lots of RFPs from resorts about the possibilities. The continuing challenge of getting areas open earlier will lead to changes.


“Automation is everywhere in all types of industries. And it’s going to be the way to operate snowmaking production, too—eventually.”