Silicon Valley startup Bloom Energy announced a service under which customers pay only for the electricity consumed rather than buying its fuel cell energy servers.

The Sunnyvale, California-based company's Bloom Box weighs about 20,000 pounds, and cost $800,000.

According to the company, customers can continue to buy Bloom Boxes as a capital purchase or choose to sign up for the Bloom Electrons service.

Bloom Electrons service allows customers the flexibility to purchase electricity provided by the Bloom Box without incurring any other costs, the company said. The service allows customers to lock in their electricity rates for 10 years, delivering significant savings. Customers can immediately save up to 20 percent on their energy bills.

Bloom Energy created this program in collaboration with Credit Suisse and Silicon Valley Bank.

Initially, over 20MWs (200 systems), the equivalent of powering 20,000 American homes, will be deployed at customer sites to provide clean, reliable power, it said.

Bloom manages and maintains the Bloom Box systems on the customers’ sites and the customers pay only for the electricity consumed. This allows immediate cost savings with no initial investment, making onsite clean, reliable, affordable energy more accessible, it said.

Bloom Energy said companies such as Walmart, Staples, Coca-Cola, Caltech, Kaiser Permanente and BD among others have signed up for Bloom Electrons service.

Bloom Electrons is about providing universal access to clean, reliable, affordable energy. Empowering our customers to buy energy on their terms is another significant step on our journey to change the way energy is generated and consumed in the world, said KR Sridhar, principal co-founder and chief executive of Bloom Energy.

To date, the Bloom Energy fleet has provided customers over 40 million kilowatt-hours and eliminated about 45 million pounds of carbon-dioxide emissions, it said.

Founded in 2001, the company can trace its roots to the NASA Mars space program. For NASA, the company's management team were charged with building technology to help sustain life on Mars using solar energy and water to produce air to breath and fuel for transportation. They soon realized that their technology could have an even greater impact here on Earth and began work on what would become the Bloom Energy Server.

The Bloom Energy Server, known as the Bloom Box, contains ceramic wafers made of a sand-like powder. Each Bloom Energy fuel cell is capable of producing about 25W... enough to power a light bulb. For more power, the cells are sandwiched, along with metal interconnect plates into a fuel cell stack. A few stacks, together about the size of a loaf of bread, is enough to power an average home.

According to the company, the Bloom Energy Server converts air and nearly any fuel source - ranging from natural gas to a wide range of biogases - into electricity via a clean electrochemical process, rather than dirty combustion. Even running on a fossil fuel, the systems are around 67 percent cleaner than a typical coal-fired power plant. When powered by a renewable fuel, they can be 100 percent cleaner.

Each Bloom Energy Server provides 100 kilowatts of power, enough to meet the basel­oad needs of 100 average homes or a small office building - day and night, in roughly the footprint of a standard parking space.