science

Feeding solar electricity directly from its own panels into overhead lines, on a fully-electrified rail network, would be more cost-effective for the state-owned company than buying that green power from the grid, according to a new study.

German solar company Polarstern sees many performance-enhancing effects when photovoltaic systems are combined with green roofs. These are provided by cooling, dust absorption and reflective behavior, which are favored by the plants on the roof.

Scientists in the UK have explained the mechanism behind chlorine used to boost the efficiency of cadmium telluride thin-film solar cells. With new understanding of the chemical processes at work in the manufacturing process, the group hopes to be able to push for cell efficiencies beyond 25%.

An international research team has conducted a techno-economical comparison between lithium-ion and lead-acid batteries for stationary energy storage and has found the former has a lower LCOE and net present cost. Through their analysis, which was performed assuming the use of the batteries in connection with a 10 kW, grid-tied PV system, the scientists concluded that lithium-ion batteries are the most viable solution.

Scientists in the United States used machine learning to analyze maintenance reports, performance data and weather records from more than 800 solar farms located across the country. The analysis allowed them to determine which weather conditions have the biggest impact on PV generation, and to suggest the most effective ways to boost the resilience of PV installations to extreme weather events.

NREL researchers developed a system that uses heated silica particles for thermal energy storage. The baseline technology is designed for a storage capacity of up to 26,000 MWh and is claimed to have a cost of of between $2 and $4 per kWh.

Conceived by Swiss researchers, the battery shows good stability over 50 cycles, with an average energy efficiency of 68% and a water-splitting voltage efficiency of 64.1%. According to its creators, the device produces pure hydrogen that only needs to be dried and compressed for optimal storage.

Scientists in the U.S. discovered a promising new battery chemistry based on chlorine and table salt. Batteries based on this chemistry can achieve at least six times the energy density of today’s lithium-ion batteries, according to the group that created it. The prototype battery could already be suitable for small devices such as hearing aids, and with further work could be scaled up to larger applications.

U.S. researchers have proposed a new approach to fabricate solar thermophotovoltaics (STPV) with higher power densities. The novel technique consists of reducing the distance between the emitter and the solar cell to a nanoscale.

Scientists have demonstrated a zinc-ion battery that overcomes many of the challenges for this technology. By working with a highly-concentrated salt solution as the electrolyte, the group was able to achieve stability over more than 2,000 cycles combined with a strong electric performance. The group says that its work opens up “a viable route to developing aqueous batteries for emerging electrochemical energy storage applications.”