Early versions of mobile elevating work platforms (MEWPs), were introduced about seventy years ago to serve as an effective substitute for ladders and scaffolding. Today this category of machines includes boom lifts, scissor lifts, compact crawlers etc., which are used indoors and outdoors for a remarkable variety of use applications.
Historically the most common type of power came from diesel engines. Recently however Europe introduced “Stage V” standards which are anticipated to drive up the cost of maintenance for diesel equipment. In the US concern about diesel engines’ emissions and noise have driven innovation in the categories of electric and hybrid machines.
Demand for greener machines has been driven in part by environmental legislation but also to reduce the equipment’s total cost of ownership (TCO). Fully electric machines have virtually no maintenance costs compared to diesel. With the improving efficiency and popularity of lithium-ion powered machines, their costs are coming down while costs for diesel equipment remains the same or continue to go up.
Battery technology continues to improve every year. Companies like Tesla push the technical limits & efficiency of battery technology while reducing the costs of purchase and maintenance.
For MEWPs traditional lead-acid batteries offer the advantage of low initial cost, almost universal availability and, in some cases the additional weight of these old-school batteries can be an advantage for stability. Initial equipment purchase cost is very similar between diesel machines and their lead-acid equivalents.
Lithium-ion batteries’ advantages include lighter weight, more energy in the same physical space and long duty cycles. The industry may have been slow generally to adopting Lithium-ion batteries because there a premium on initial purchase price. Fully electric scissor lifts are quite popular in particular because they are used indoors so often. The lack of fumes and noise is a great advantage in general but especially in indoor public spaces.
Hybrid machines were developed to take advantage of the flexibility of a small diesel engine with a generator along with battery power. These units can offer the same effectiveness as a rough terrain diesel unit. JLG’s 340AJ is an 25-hp diesel articulating boom lift can climb steep grades and move at 3 plus mph. JLG’s battery-powered equivalent is the H340AJ.
“Each of these four-wheel-drive lifts weighs 9,700 to 9,800 lbs, moves at 3-plus mph and can climb 45 percent grades. The H340AJ is termed a hybrid because, though its motive power is from electric motors, its eight 12-V batteries are charged by an onboard 11-hp diesel engine. The H340AJ is an example of JLG’s “series hybrid” machines — primarily electric but with a recharging diesel engine — whereas the company’s “parallel hybrid” machines rely principally upon a diesel engine but have an electric motor to boost performance or to take over when operated indoors. Outdoors, the electric motor kicks in automatically whenever the lift encounters rolling resistance. An example of a parallel hybrid is the JLG H800AJ articulating boom.” *
What does the future have in store for MEWPs?
As technology continues to evolve fully electric solutions will likely outpace other solutions. According to Micro Negri, product manager coordinator for JLG
Technology is continuously developing, and obviously, JLG is following this closely. We anticipate that lithium batteries will become more affordable, and that the technology will become more accessible, therefore, there will be less need and demand for hybrid models. This will be because the performance of a lithium-ion operated machine is equal to a conventional diesel-powered machine.
As our customers continue to adopt more “green” solutions, we believe that all of the ingredients for electrification are in place. JLG
* https://compactequip.com/aerial-lifts/the-rise-of-hybrids-technologies-and-trends-in-electric-bi-energy-and-variously-styled-mobile-elevating-work-platforms/
