Often derided as a blot on rural landscapes, wind turbines got bigger and stronger than ever anyway. The next generation are even larger and designed to withstand an Arctic battering. 

The granddaddy of them all is a machine with rotors that cut a 164 meter (538 foot) swath made by a Vestas Wind Systems venture with Mitsubishi Heavy Industries. A single blade is 80 meters, about the entire wingspan of an Airbus A380 jumbo jet. In the intensely competitive wind turbine business, it's rare for executives to allow a close-up look of what they're developing, lest they tip off rivals. Vestas allowed Bloomberg News to visit and photograph the prototype units this month.

As they got bigger, the units became more efficient, boosting global installations 23 percent last year to a record 63.5 gigawatts, which at full tilt would be about as much as what flows from 63 nuclear reactors. Wind is now the most installed form of low-carbon energy. While few people outside the industry noticed, the trend lifted shares and profit of manufacturers from their crash during the financial crisis. Vestas is due to report its fifth consecutive increase in quarterly profit on Friday, overcoming a slump that forced it to cut 3,000 jobs since 2011.

A job not for the acrophobic. An employee closes the nacelle hatch of a Vestas V136 wind turbine, 140 meters off the ground. The blade adds another 80 meters to the structure's height.

Photographer: Chris Ratcliffe/Bloomberg

Even the plunge in crude prices since  2014 has failed to derail industry growth.

"The doubling of turbine size this decade will allow wind farms in 2020 to use half the number of turbines compared to 2010," said Tom Harries, an industry analyst at Bloomberg New Energy Finance. "This means fewer foundations, less cabling and simpler installation -- all key in slashing costs for the industry."

The average turbine installed in Europe was 4.1 megawatts last year, 28 percent larger than in 2010, according to the London-based researcher, which expects 6.8 megawatts to be the norm by 2020. Harries said Siemens has hinted it's working on a 10 megawatt turbine.