Manufacturing study questions green credentials of solar panels

Many solar panels are made using "spectacularly inefficient" manufacturing techniques that could undermine their environmental benefits, according to new research from the Massachusetts Institute of Technology (MIT).

The study, released last week, found that many of the cutting edge processes used to make computer chips, solar cells and nanomaterials use an "alarming" amount of energy compared to established manufacturing techniques.

While many of the manufacturing techniques used by heavy industries have been widely criticised by environmentalists for their inefficiency, the MIT study found that new manufacturing systems are anywhere from 1,000 to one million times bigger consumers of energy, per pound of output, than more traditional industries.

The study cites the fast-expanding solar industry as a prime example of a modern manufacturing sector where a focus on price and quality has led to energy efficiency being ignored.

It warns that "the inherent inefficiency of current solar panel manufacturing methods could drastically reduce the technology's lifecycle energy balance - that is, the ratio of the energy the panel would produce over its useful lifetime to the energy required to manufacture it".

The report also warned that energy use across the solar sector could increase still further as manufacturers began to deploy so-called vapour-phase processing, which relies on the creation of vacuum chambers during solar cell manufacture. The method is less energy efficient than liquid-phase processing that deposits coating onto semiconductors using a liquid solution.

Professor Timothy Gutowski of MIT's department of mechanical engineering, who led the research, said that there was an urgent need for modern manufacturing industries to increase their focus on energy efficiency or risk seeing their environmental claims undermined.

"The seemingly extravagant use of materials and energy resources by many newer manufacturing processes is alarming and needs to be addressed alongside claims of improved sustainability from products manufactured by these means," he warned.

Gutowski added that the study's figures were likely to be conservative as his team did not assess the energy required to make the raw materials or maintain the environment of the plant, such as the air conditioning and filtration for clean rooms used in semiconductor processing.

He concluded that many of the manufacturing processes could be improved and made more energy efficient, but only if modern manufacturing industries realised the "significant energy cost".

The study follows the launch of a campaign earlier this year urging the solar industry to act early to address concerns over some of the toxic components found in solar panels.