Solar energy stored efficiently

Jun 26, 2005

Pilot solar power-plant delivers promising results

For the first time solar energy has been successfully used in a pilot-plant to create storable energy from a metal ore. In a project funded by the EU, the Paul Scherrer Institute (PSI) with the Swiss Federal Institute of Technology Zurich (ETHZ) together with other research institutes and industrial partners, have reached an important milestone.

A 300-kilowatt pilot installation to create zinc using solar temperatures of over 1200 degrees Celsius successfully came into operation in Israel. The solar-reactor technology is Swiss developed, by the PSI and ETH Zurich, and forms the heart of the plant.

Reducing zinc oxide to zinc is a useful way of chemically storing the sun's energy in a transportable form, for later use. Zinc can be used in zinc-air-batteries or be used to produce hydrogen by reacting it with water vapor. In both cases the zinc recombines with oxygen and zinc oxide is produced, which can be reused in the solar reactor to produce zinc once more.

"After extensive trials with reactor-prototypes at the PSI solar-oven we have, with our project partners from Sweden, France and Israel, begun to successfully operate a 300-kilowatt pilot-plant at the Weizmann Institute of Science (WIS) in Rehovot near Tel Aviv", explains Christian Wieckert from PSI, Scientific Coordinator of the project.

The aim is sixty-percent efficiency

The first trials of the solar power-plant have used thirty-percent of available solar energy and produced forty-five kilos of zinc an hour, exceeding projected goals. During further tests this summer a higher efficiency is expected. Industrial size plants, for which this is a prototype, can reach efficiency levels of fifty- to sixty-percent. The success of this solar chemistry pilot project opens the way for an efficient thermo-chemical process whereby the sun's energy can be stored and transported in the form of a chemical fuel. In this process the zinc is combined with coal, coke or carbon biomass which acts as a reactive agent, yet in this reactor only a fifth of the usual amount of agent is used. The sun's rays are concentrated on this mixture by a system of mirrors and the zinc forms as a gas which is then condensed to a powder.

The research into high-temperature solar-chemistry at PSI and ETHZ combines fundamental physics and chemistry research with solar-chemical reactor technology. The long-term goal is the development of fuels by means of clean, universal and sustainable energy sources. "Solar fuels can be used as an environmentally friendly energy provider and thereby be part of the solution to climate change", says Aldo Steinfeld, Professor from the Institute of Energy Technology at the ETH Zurich and leader of the Solar Chemistry Laboratory at PSI.

Source: Paul Scherrer Institut

Explore further: ORNL scientists generate landmark DOE hydropower report

Related Stories

Researchers enable solar cells to use more sunlight

Feb 25, 2015

Scientists of the University of Luxembourg and of the Japanese electronics company TDK report progress in photovoltaic research: they have improved a component that will enable solar cells to use more energy of the sun and ...

Cheap solar cells made from shrimp shells

Feb 18, 2015

The materials chitin and chitosan found in the shells are abundant and significantly cheaper to produce than the expensive metals such as ruthenium, which is similar to platinum, that are currently used in ...

Recommended for you

Improving geothermal energy

59 minutes ago

Generating electricity from the hot rocks deep underground is clean, safe and renewable - and it's about to take a step forward in Utah.

Amazon unveils new business marketplace

1 hour ago

Amazon announced Tuesday it was launching a new business marketplace, in a move aimed at bringing the online giant's expertise to wholesaling.

Taking the hassle out of parking

2 hours ago

It's a pain we all know: trying finding a parking spot in a crowded lot, from shopping centers to medical complexes to the airport. A Rice University team of senior electrical and computer engineers designed ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.