US supermarket giant Walmart has announced plans to install up to 400 new solar power plants at its facilities in the next four years.

The store, which has more than 10,000 stores around the world under different brands – including Asda in the UK – has set a goal to produce or buy seven billion kWh of renewable energy by 2020 and be supplied by 100% green power.

The installations will vary in size, depending on the store or facility.

Smaller systems are expected to provide up to 20% of the facility’s electricity requirements and larger systems will provide up to 30% of power.

Kim Saylors-Laster, Vice President of energy at Walmart said: “These projects bring us closer to fulfilling our commitment to double the number of on-site solar energy projects in US stores, Sam’s Clubs and distribution centres – thereby reducing our energy expenses and generating clean energy in local communities.”

The supermarket has so far installed around 260 solar projects in the US, saving more than $5 million on its energy bills.