Munich, Germany—The market for renewable wind energy is moving up, way up.

Last year, developers installed about 2,400 MW of generating capacity in the U.S., a gain of 1,524 turbines, according to the Dept. of Energy and the American Wind Energy Association.

The explosive growth has translated into an average annual increase of 23% in generating capacity over the last five years. This special edition of "Kicking Tires" covers the latest tools of the trade.

Europe-based Liebherr Group used Bauma to unveil the world's tallest telescoping crane, whose eight-section hydraulic boom stretched more than 100 meters over the huge outdoor exhibit area in Munich.

The nine-axle all-terrain crane's pendant rigging and two giant lateral arms made the rig appear as if it were about to set sail, or take off in flight. Crowds of people swarmed in to have a look.

In another booth (about a 20-minutes' walk away), U.S.-based Manitowoc Crane Group took the wraps off a part-all-terrain crane, part-tower crane that seemed to defy conventional technology. The spider-looking thing rose into action amid great fanfare at the end of the weeklong Bauma show's second day on April 24.

Wind-power cranes, challenged by the growing size of turbines, represent huge engineering feats in themselves.

Five years ago, wind turbines stood at an average 80 meters tall. Today, they average 100 meters, and engineers think they will rise again to 120 meters within the next five years. The new wind cranes are anticipating this future growth.

Machines designed to tackle the challenge with safety and speed mean big money for contractors doing the work. The cranes need to be able to lift turbine nacelles, which weigh about 80 metric tons, to heights above 100 meters at radii between 18 and 25 meters.

That means you need a high-capacity, stable crane with lots of lateral bracing to handle the tight quarters.

These kinds of problems are a crane engineers' dream. Or a nightmare.

Liebherr's bracing arms, which roughly triple the capacity of the telescopic boom, became the subject of a patent dispute around the time of the 2004 Bauma Exhibition.

A federal administrative court in Germany ruled that Liebherr violated a superlift patent for held by competitor Terex-Demag, but both companies settled, according to sources, on a mutual handshake agreement to share each others' lateral bracing refinements.

How civilized.

Manitowoc's Grove division, which also builds a similar superlift wing, took an entirely different route.

Tudor Van Hampton This crane's designers thought outside the boom.

Its crane took lateral loads via four trusses that radiated from the top of the mast at 90° angles. Pendants connected the trusses to the crane's outriggers at ground level, effectively using them as counterweight and reducing the need to schlep more components to the jobsite. A five-section telescoping turret mounted atop the mast provided reach.

Liebherr's all-terrain crane, which can reach a hook height of 170 meters with extra jibs, beat its prior record holder, the 84-meter-tall LTM-1500, which it introduced in 1998 at the triennial Bauma convention. It has since sold over 100 of those machines.

At its base, the LTM-11200's boom measured about 1.6 meters in diameter, big enough for a small service mechanic to climb inside to inspect the works. And the rig was decked out with plenty of amenities, like a cab which, using the magic of hydraulics, gently descends to the ground to greet the user. Price: About $6.5 million.

Later in the day, Manitowoc's GTK-1100, which can reach a height of 140 meters, slowly telescoped into to the sky as a harmonica player blew a psychedelic tune with whah-whahs and echo effects.

Imagine a cross between Kraftwerk's "Electric Café," Peter Frampton's "Do You Feel Like We Do" and Doobie Brothers' "China Grove."

Admittedly, it was a freaky reveal. But the odd music set an appropriate tone for a mixed-up-looking machine that is going places. Two units sold on the first day, according to Glen Tellock, president of Manitowoc's crane division. Its average price: About $5 million.

What's to come next? Who knows. But after seeing some truly spectacular-looking cranes at this year's Bauma, the next show in 2011 is sure to blow away the crowd, yet again.