An Effective and Low-cost Solution for Storing Solar Energy
August 25, 2016 | EPFLEstimated reading time: 2 minutes
Solar energy can be stored by converting it into hydrogen. But current methods are too expensive and don’t last long. Using commercially available solar cells and none of the usual rare metals, researchers at EPFL and CSEM have now designed a device that outperforms in stability, efficiency and cost.
How can we store solar energy for period when the sun doesn’t shine? One solution is to convert it into hydrogen through water electrolysis. The idea is to use the electrical current produced by a solar panel to ‘split’ water molecules into hydrogen and oxygen. Clean hydrogen can then be stored away for future use to produce electricity on demand, or even as a fuel.
But this is where things get complicated. Even though different hydrogen-production technologies have given us promising results in the lab, they are still too unstable or expensive and need to be further developed to use on a commercial and large scale.
The approach taken by EPFL and CSEM researchers is to combine components that have already proven effective in industry in order to develop a robust and effective system. Their prototype is made up of three interconnected, new-generation, crystalline silicon solar cells attached to an electrolysis system that does not rely on rare metals. The device is able to convert solar energy into hydrogen at a rate of 14.2%, and has already been run for more than 100 hours straight under test conditions. The method, which surpasses previous efforts in terms of stability, performance, lifespan and cost efficiency, is published in the Journal of The Electrochemical Society.
Enough to power a fuel cell car over 10,000km every year
“A 12-14 m2 system installed in Switzerland would allow the generation and storage of enough hydrogen to power a fuel cell car over 10,000 km every year”, says Christophe Ballif, who co-authored the paper. In terms of performance, this is a world record for silicon solar cells and for hydrogen production without using rare metals. It also offers a high level of stability.
High voltage cells have an edge
The key here is making the most of existing components, and using a ‘hybrid’ type of crystalline-silicon solar cell based on heterojunction technology. The researchers’ sandwich structure – using layers of crystalline silicon and amorphous silicon – allows for higher voltages. And this means that just three of these cells, interconnected, can already generate an almost ideal voltage for electrolysis to occur. The electrochemical part of the process requires a catalyst made from nickel, which is widely available.
“With conventional crystalline silicon cells, we would have to link up four cells to get the same voltage,” says co-author Miguel Modestino at EPFL.“So that’s the strength of this method.”
A stable and economically viable method
The new system is unique when it comes to cost, performance and lifespan. “We wanted to develop a high performance system that can work under current conditions,” says Jan-Willem Schüttauf, a researcher at CSEM and co-author of the paper. “The heterojunction cells that we use belong to the family of crystalline silicon cells, which alone account for about 90% of the solar panel market. It is a well-known and robust technology whose lifespan exceeds 25 years. And it also happens to cover the south side of the CSEM building in Neuchâtel.”
The researchers used standard heterojunction cells to prove the concept; by using the best cells of that type, they would expect to achieve a performance above 16%.
Suggested Items
Siemens’ Breakthrough Veloce CS Transforms Emulation and Prototyping with Three Novel Products
04/24/2024 | Siemens Digital Industries SoftwareSiemens Digital Industries Software launched the Veloce™ CS hardware-assisted verification and validation system. In a first for the EDA (Electronic Design Automation) industry, Veloce CS incorporates hardware emulation, enterprise prototyping and software prototyping and is built on two highly advanced integrated circuits (ICs) – Siemens’ new, purpose-built Crystal accelerator chip for emulation and the AMD Versal™ Premium VP1902 FPGA adaptive SoC (System-on-a-chip) for enterprise and software prototyping.
Vicor Power Orders Hentec Industries/RPS Automation Pulsar Solderability Testing System
04/24/2024 | Hentec Industries/RPS AutomationHentec Industries/RPS Automation, a leading manufacturer of selective soldering, lead tinning and solderability test equipment, is pleased to announce that Vicor Power has finalized the purchase of a Pulsar solderability testing system.
Lockheed Martin Successfully Transitions Long Range Discrimination Radar To The Missile Defense Agency
04/23/2024 | Lockheed MartinThe Long Range Discrimination Radar (LRDR) at Clear Space Force Station in Clear, Alaska, completed DD250 final acceptance and was officially handed over to the Missile Defense Agency in preparation for an Operational Capability Baseline (OCB) decision and final transition to the Warfighter. In addition, prior to this transition, the system has started Space Domain Awareness data collects for the United States Space Force.
US Department of Defense Selects Intel Foundry for Phase Three of RAMP-C
04/23/2024 | IntelThe U.S. Department of Defense (DoD) has awarded Intel Foundry Phase Three of its Rapid Assured Microelectronics Prototypes - Commercial (RAMP-C) program.
Real Time with... IPC APEX EXPO 2024: AI Implementation at Omron
04/18/2024 | Real Time with...IPC APEX EXPOEditor Nolan Johnson and Omron Product Manager Nick Fieldhouse discuss the company's focus on AI implementation to enhance customer experience and results. They address programming challenges and how AI can help customers achieve better outcomes with less experience. Omron's AI is compatible with existing systems, facilitating easy upgrades.