Nate Lewis (left) will direct a $122-million research project to make fuel directly from sunlight. Credit:

The US Department of Energy has launched an 'artificial photosynthesis' initiative with the ambitious goal of developing, scaling up and ultimately commercializing technologies that directly convert sunlight into hydrogen and other fuels.

The Joint Center for Artificial Photosynthesis (JCAP) will receive US$122 million over five years, and will be jointly led by the California Institute of Technology (Caltech) in Pasadena and the Lawrence Berkeley National Laboratory in Berkeley, California. Announced on 22 July, JCAP is the second of three Energy Innovation Hubs that US energy secretary Steven Chu plans to establish this year.

The hubs aim to get basic science out of the lab and into the real world. "We have to scale up from the nanoscale to the macroscale," says Nate Lewis, a Caltech chemist who will direct the JCAP programme, which will ultimately employ 150–200 people in two buildings at Caltech and the Berkeley lab.

We have to scale up from the nanoscale to the macroscale. ,

Existing photovoltaic cells capture photons and produce electricity, which can be used to split water molecules and produce hydrogen. With artificial photosynthesis, photons from the Sun would drive a 'wireless' chemical conversion process to generate fuels. The most likely fuel is hydrogen, which can be used as it is or converted into other liquid fuels as a replacement for petroleum.

Caltech and the Massachusetts Institute of Technology in Cambridge are already leading a similar effort, known as 'Powering the Planet', that was funded with a $20-million, 5-year grant from the National Science Foundation in 2008. But Lewis says that project focuses more on basic science questions at each step of the process, such as how to boost the number of photons captured by a given material or increase the efficiency of a given catalyst.

By contrast, JCAP aims from the outset to build a solar-fuel system that will ultimately prove commercially viable. Potential advances in electrolysis and photovoltaic solar panels would be welcome but incidental, says Lewis. "That's the dividing line that we drew intellectually." Lewis adds that the centre will compare materials and processes used by competing researchers to determine which scientific avenues look most promising.

Chu initially proposed eight energy hubs, but Congress authorized the energy department to move forward with three. The first energy hub, which focuses on advanced nuclear reactors, was announced in May. A third hub aimed at energy-efficient buildings will follow in the coming months. Chu has called the energy hubs 'Bell lablets' after the famous Bell Laboratories in Murray Hill, New Jersey.

Earlier this year in its fiscal 2011 budget, the energy department requested $34 million for a fourth hub, focusing on batteries and electricity storage, but Congress has yet to approve it.