News & Views in 2018

Perovskite solar cells are noted for their high performance and ease of synthesis, but are still plagued by concerns over their stability. Researchers are now demonstrating why higher performance and increased stability go hand-in-hand — and how to continue improving both.

The efficiency of perovskite solar modules is limited by the difficulty in fabricating uniform and high-quality perovskite films. Now, a modified doctor blade method with a surfactant-controlled drying process has been shown to enable high-speed deposition of large-area and uniform perovskite films.

The effectiveness of fuel taxation towards reducing gasoline usage in vehicles has been a subject of debate. Using data from Sweden, which has one of the highest gasoline taxes in the world, research now demonstrates a potential consumer preference for gasoline even at price parity with ethanol.

The energy density of aqueous organic flow batteries is generally low primarily because of the low solubility or instability of charge-storing organic molecules. Now, a phenazine-derived molecule is shown to have both high solubility and long-term stability, leading to an exceptionally high capacity in an aqueous flow battery.

The performance of enzymatic biofuel cells is greatly hindered by the poor electron transfer between enzyme catalysts and electrode surfaces. Now, an efficient electrical connection is made by coupling conventional direct and mediated electron transfer mechanisms, leading to much improved power density and stability.

Many consumers encounter electric vehicles for the first time at car dealerships when they are looking to buy a new vehicle. Now, research shows that interactions with sales personnel have an important and often detrimental influence on the purchase of electric vehicles, presenting a critical barrier to their wide-spread adoption.

Wind facilities have generally deployed turbines of the same power and height in regular uniform arrays. Now, the modern generation of turbines, with customer-selectable tower heights and larger rotors, can significantly increase wind energy’s economic potential using less land to generate cheaper electricity.

Capturing CO₂ directly from the air could lead to negative emissions, but more efficient technologies are still required. Now, researchers use a multi-stage cycle based on amino acids and organic salts to capture CO₂ from air, which can be released with concentrated solar power.

Various approaches have been adopted to enhance the performance of alkaline water electrolysers, such as improving catalyst efficiency or increasing operating temperatures. Now, magnetic hyperthermia is demonstrated as another potential route to enhance overall water splitting catalytic activity.

Photovoltaic electricity is increasingly competitive with conventional electricity generation, and cost analyses are now being developed for early-stage technologies. A recent techno-economic analysis looks at thin-film tandem photovoltaics to inform research directions.

Membrane technologies for carbon capture can offer economic and environmental advantages over conventional amine-based absorption, but can suffer from limited gas flux and selectivity to CO₂. Now, a membrane based on enzymes embedded in hydrophilic pores is shown to exhibit combined flux and selectivity that challenges the state of the art.

Quantitative scenarios from energy–economic models inform decision-making about uncertain futures. Now, research shows the different ways these scenarios are subsequently used by users not involved in their initial development. In the absence of clear guidance from modellers, users may place too much or too little confidence in scenario assumptions and results.

Battery charging and discharging regimes mostly attempt to maximize potential profit by following price signals. Combining a technical understanding of batteries with financial theory, researchers now present a framework that allows optimization of economic benefits considering both potential revenues and battery degradation.

Thermoelectric devices convert heat flows into electricity. Researchers recently demonstrated that thermoelectric materials can be produced in good quality by 3D printing, enabling a low-cost production process in the near future.

Analysts and markets have struggled to predict a number of phenomena, such as the rise of natural gas, in US energy markets over the past decade or so. Research shows the challenge may grow because the industry — and consequently the market — is becoming increasingly volatile.

New and emerging energy consumption patterns driven by the rise of prosumers may lead to under-recovery of network costs under current network charges, so new tariffs are being sought. A study using detailed household consumption data now illustrates the potentially disproportionate impact of different tariffs on household budgets.

In current solar cells, any photon energy exceeding the semiconductor bandgap is lost before being collected, limiting the cell performance. Hot carrier solar cells could avoid these losses. Now, a detailed experimental study and analysis shows that this strategy could lead to an improvement of the photoconversion efficiency in practice.

Realization of rechargeable batteries with alkali metal anodes is challenged by their high reactivity and dendritic growth. Now, an alloy-based, artificial solid electrolyte interphase is shown to allow smooth metal deposition, enhance interfacial charge transfer, protect against parasitic reactions and offer extra energy storage.

Documenting the emissions and net energy of a crude supply could be essential to meeting national emission and energy security targets. Using data from hundreds of fields worldwide, a well-to-refinery study presents a high-granularity profile of China’s crude oil supply in terms of emissions and energy return on input.

Protonic ceramic fuel cells (PCFCs) are a potential alternative to solid oxide fuel cells at temperatures below 600 °C, but they suffer from low power output and poor chemical stability. Now, PCFCs with a power density of over 500 mW per cm² at 500 °C and long-term stability are demonstrated using optimized perovskite-based electrolyte and electrodes.