A Look at Robots in Alternative Energy
by Bennett Brumson
, Contributing Editor
Robotic Industries Association Posted 11/01/2010
“Alternative energy companies were very small and doing everything manually. With government funding available and the push towards alternative energy, companies are producing in much greater volume but cannot support that volume with manual processes,” says Christopher Blanchette, National Distribution Account Manager with FANUC Robotics America Inc. (Rochester Hills, Michigan) “Alternative energy companies are looking to automate quickly and to design an assembly process with hard automation would slow them down because the market changes so quickly.”
Alternative energy systems evolve at a rapid pace, making hard automation unsuitable for these applications, professes Erik Nieves, Technology Director of Yaskawa America Inc.’s Motoman Robotics Division (West Carrollton, Ohio) “Alternative energy technology is rapidly evolving and end-user requirements in that industry change almost monthly. The environment is too dynamic to build a tool for a specific purpose.”
“Manual labor in solar cell manufacturing is not applicable due to the precision required. Alignment of devices relative to each other is critical.”
Nieves suggests that a robot’s most important task in manufacturing alternative energy systems is material handling. “Robotics use in alternative energy component manufacturing is biggest in material handling, but not simply moving parts from point A to B as in consumer goods. Material handing in renewable energy is part of the assembly process and requires much greater precision than typical applications.”
Tim Noppe, general manager at Applied Manufacturing Technologies Inc. (AMT, Orion, Michigan) has a similar assessment to Nieves. “The products and processes end-users in alternative energy use are evolving. End-users might make type A parts until they see needed improvements, then go on to type B.” Products change so rapidly that the volume of production is not sufficient to justify dedicated automation. “End-users might need to build both part types on any given day, even side-by-side,”
The rapidly changing nature of alternative energy systems lends itself to robotics, says Noppe. “Many end-users AMT encounters are automation neophytes. They are very smart about how to convert one form of energy into another but they do not know how to manufacture things yet.” Furthermore Noppe says, “End-users need simple and robust operation and do not know what is necessary to operate and maintain a robotic work cell.”
Simulation assists end-users to scale-up production as demand for alternative energy systems increases, says Noppe. “Simulation helps end-users understand how to meet production needs and possible impacts when they vary. As demand changes, simulation is used to plan expanded manufacturing capability as companies get more funding.” Citing a plausible hypothetical situation, Noppe says, “If an end-user needs to make six units per week now but must to ramp up to 600 a day, simulation helps model increased production and design a system to be easily expandable at low capital costs.”
Quickly handling delicate silicon wafers for use in solar panels is important to end-users of Adept Technology Inc. (Pleasanton, California), says Rush LaSelle, Adept’s Director of Global Sales and Marketing. “Robots are more consistent and gentle than people and can provide higher throughput with better yield when handling wafers and solar cells. Components like thin film solar panels are too big and awkward to be handled manually.” LaSelle adds, “In emerging technologies where processes might not be mature, the flexibility afforded by robotics is attractive because a robot can be retooled or redeployed whereas hard automation is frequently scrapped.” A wafer is a thinly sliced piece of silicon used in solar panels to act as a semiconductor and helps convert sunlight into electricity.
Robot vision has a vital role in alternative energy work cells, says LaSelle. “Vision is used for both robot guidance and inspection in the manufacture of solar products and is a tremendous driver in the adoption of robotics in a variety of alternative energy manufacturing areas. Vision provides quality control and reduced costs associated with fixturing in processing larger substrates and products such as wind turbines.”
Manipulating solar wafers is also crucial to Yves Crepel, World Solar Market Specialist at Stäubli Corp. (Duncan, South Carolina), who says, “Securely loading and unloading processes is the most important reason to use robotics for the manufacturing processes of photovoltaics. Fabricating solar cell wafers involves applying a coating using a plasma deposition process requiring extremely high precision.” Crepel says required repeatability of handling solar cells is 0.03 mm. Due to the risk of breaking fragile wafers, this application is impossible to do manually.
Silicon ingots are expensive enough for manufacturers to glean as much as feasible from them. “In the solar market, accuracy requirements drive getting as much out of an ingot of silicon as possible. To achieve this, wafer manufacturers slice silicon thinner and thinner, making them more fragile,” explains ABB Inc.’s (Auburn Hills, Michigan) Charles Miller, Vice President of Sales. “Wafers cost $5 to $6 a piece and are a recipe for disaster when handled manually at high speeds. Robotics handles wafers very well.”
While the silicon portion of a solar cell is lightweight and fragile, solar panels become heavier and larger as they move through the assembly process. “Beyond silicon, robots are used to handle large glass components and do edge deletion where the robot is holding a laser or the glass,” Miller elaborates.
“Robots are used extensively to precisely place strings relative to each other in a straight line while wires are attached together and laid out precisely across the strings,” points out Blanchette. “Strings are stacked, laminated, and electrically connected. That assembly process can be quite sophisticated because the components are very large at that point.” Robots are used to laminate and precisely solder solar panels.
Solar arrays are made up a panel that converts sunlight into electricity. Several panels can be robotically linked or stringed together to transmit its power through wires to a central source for storage into batteries.
Silicon dust is generated when forming ingots, notes John Dauber, North American Sales Manager for Camfil Farr APC of Jonesboro, Arkansas. “We provide equipment to remove silicon and glass dust when making solar panels. Silicon dust is hazardous and needs to be sucked away and filtered by high efficiency particulate air (HEPA) filters.”
Robotics have a role in two major aspects of wind turbine manufacturing. “ABB does work in both wind turbine blades and towers. We see more interest in welding turbine towers as well as painting towers and turbine blades,” confirms Miller. “Robotics have cut the time of painting, sanding and polishing turbine blades from days to hours. That allows more production in the same manufacturing space.”
Miller goes on to say, “A manufacturer of turbine towers we worked with sold their manufacturing capacity for a year and a half in advance because of bottlenecks and quality issues in the welding of towers. They looked at ways to use robotics to get a higher yield.” Miller contends that the manufacturer needed to increase their productivity in the most cost-effective way possible. “The turbine tower maker was turning down orders and risking creating new competitors because they could not meet the lead time.” Robotics was part of their solution, Miller concludes.
FANUC’s Blanchette agrees, saying, “Robots are used to weld the structural components for turbine towers due to their significant geometry. Robots are used to deburr the edges of gears, trim and grind blade flash, and precisely drill and cut blade roots.” Blanchette says because turbine blades have very large and contoured surfaces, robots are necessary to prepare finishes. “The distribution of paint must be very uniform over the entire blade surface. If not, blades could have balancing problems.” Properly applying paint over turbine blades cannot be accomplished manually.
Blanchette observes that the wind turbine industry wants to automate their processes because they need more consistent quality in production. “Wind turbine makers do not want parts in the nacelle breaking down because a significant effort is required to get someone up there to replace parts. The wind industry has a need for more reliable quality parts and to reduce variation in parts produced.”
KMT Robotic Solutions Inc. of Auburn Hills, Michigan integrates robots for drilling and cutting of turbine blade’s root end, says Roberta Zald, KMT’s Director of Business Development. “A robotic approach to root end processing offers benefits that hard automation cannot. These include less set-up time and more throughput.” Zald says robots afford “The ability to process a range of blade sizes on the same equipment with greater flexibility to run batch sizes of one and to adjust for design changes all in a smaller footprint and lower capital cost.”
Go With the Flow
Like wind turbines, hydroelectric turbines use robotics when fabricating parts, reports Whitney Moon, Market Development Manager with Genesis Systems Group LLC (Davenport, Iowa) “Genesis does welding of wicket gates in hydroelectric plants. Robots are used because cycle times are very long and monotonous if done manually.” Moon says consistency is the primary reason for end-users to utilize robotics for welding wicket gates. “Wickets are subject to a great deal of stress. If the welds have inconsistencies, voids, or if contaminants become trapped, structural problems could result.”
Wickets act as louvers to regulate the amount of water flowing over hydroelectric turbines. Moon describes them as being like louvers in venetian blinds to block varying amounts of light entering a room.
Hydroelectric wickets are too large for successful manual welding, argues Moon. “Wickets are huge pieces of metal, 10 to 15 feet long, three feet wide and six to 10 inches thick. They need to be rotated to access all of the wicket and welds are very large requiring the part to be held in a way that gravity brings the weld into the seam rather than drip onto the floor.” Moon believes only flexible robots with multiple axes of motion are able to reach all areas of parts where hard automation might not be able to.
LaSelle has a similar take on the role of robotic welding in hydroelectric turbines as Moon. “Robotics are frequently used in wind and hydro turbine manufacturing in the handling of large and cumbersome parts for welding, trimming and part finishing. Batch sizes for these systems tend to be small enough that the cost of a robotic system compared to the significantly higher expense of a custom designed machine is much more attractive and provides similar levels of performance.”
Additionally, LaSelle says, “Cost drivers are equally crucial where the production process is capital-intensive enough where batch sizes can be as low as one. Small batch sizes are frequently the case in wind and hydroelectric generation systems.” Wind and hydroelectric systems change rapidly and product life cycles are short enough that robotics are increasingly adopted due to the inability of hard automation to adapt to changes in production processes, LaSelle declares.
On the Road
While the infrastructure to refuel automobiles powered with batteries or fuel cells is very minuscule, engineers with foresight see the day when these types of vehicles will establish parity with gasoline and diesel.
Again, Adept’s Rush LaSelle: “Robots are used in a wide variety of applications such as high accuracy assembly and handling of hazardous materials in battery and fuel cell production. Robots commonly multitask in a work cell, combining assembly of fuel cells with screw-driving processes.” As with other applications in alternative energy system manufacture, robots improve quality, consistency while reducing the footprint required to produce these products, says LaSelle.
Batteries contain hazardous materials such as lead and lithium and robotics help remote people from them during assembling says Blanchette. “Robotics take people out of hazardous environments where lithium, lead and other hazardous chemicals are. With vision-enabled robotics, work cell design can be simpler than hard automation with less touching of parts and greater flexibility to handle more products without significant tooling changes.” Integration costs and time are thus reduced.
According to Blanchette, robots are performing tasks in battery manufacture such as stacking active materials, welding bus bars together, and assembling battery cases. “Batteries for electric vehicles are much larger and heavier than conventional car batteries. People cannot package these batteries manually and need robotics for these tasks.”
Fueling the Fuels of the Future
Funding from the United States Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) has risen to $2.36 billion in fiscal year 2011. Information on obtaining alternative energy funds can be found at http://eere.energy.gov/financing/, https://www.fedconnect.net/FedConnect/ and http://www.fbo.gov/.
Twenty-First Century Power
As alternative energy technology changes, so does the manner robots are integrated to manufacture these systems. “In the past five years, the biggest change in alternative energy system manufacturing has been the migration from custom assembly lines to modular work cells. Integrators must come up with modular work cells but they do not know exactly what products a particular end-user will make in that work cell,” asserts Blanchette. Look to see more alternative energy equipment integrated in a modular way.