Apple has revealed plans to build a giant 20MW solar array to help power its North Carolina data centre, as part of its latest efforts to reduce the firm’s environmental footprint.

The computing giant unveiled the plan in a facilities 2012 report launched this week, which claimed that once built the system will be the largest user-owned onsite solar array in the US.

The array will be installed on 100 acres of land surrounding Apple’s recently opened Maiden data centre in North Carolina, which the company claims has already been built to demanding energy efficiency standards.

The report failed to detail how much Apple was investing in the project, or when the array would be completed, saying only that it was making “major leaps” to ensure a large proportion on the Maiden facility is run using renewable energy.

Apple said it was also building a fuel cell installation adjacent to the data centre, which is expected to be the largest non-utility fuel cell installation operating in the US once completed later this year.

The 5MW facility will be powered by biogas and could provide more than 40 million kWh of baseload renewable energy annually, the company said.

IT companies are under pressure to reduce the environmental impact of data centres, which often require vast amounts of energy to power and cool servers. According to some estimates between two and three per cent of global carbon emissions are a direct result of the IT industry.

A number of high profile firms are now pursuing strategies to reduce their carbon emissions. For example, Google has invested heavily in renewable energy technologies, while Facebook recently announced it would look to shift from coal to renewable energy to power its giant data centres.

Apple’s latest green energy plans could serve to improve its reputation with environmental groups, after Greenpeace excluded the company from its Cool IT Leaderboard ranking technology firms’ environmental efforts.

The company said its Maiden data centre already holds a platinum certificate under the US Green Building Council’s Leadership in Energy and Environmental Design (LEED) scheme. Most notably, the facility uses a chilled water storage system and outside air cooling system, which combined allow Apple to switch off its chillers more than 75 per cent of the time.

The building also uses variable-speed fans to match air flow to server requirements and a white roof to maximise solar reflectivity.

In addition, the company report reveals that the building was constructed with 14 per cent recycled materials, diverted 93 per cent of construction waste from landfills, and sourced 41 per cent of purchased materials within 500 miles of the site.