Nanowerk May 10, 2021 The water-droplet/solid-based triboelectric nanogenerator, has so far generated peak power densities of less than one watt per square metre, due to the limitations imposed by interfacial effects. An international team of researchers (China, USA – University of Nebraska, Hong Kong) has developed a droplet-based electricity generator (DEG) using polytetrafluoroethylene (PTFE) film on an indium tin oxide substrate plus an aluminium electrode. When the spreading water connects the two electrodes, all the stored charges on the PTFE can be fully released to generate an electric current. As a result, both the instantaneous power density and energy conversion […]
Category Archives: Energy
Carbon-neutral ‘biofuel’ from lakes
Science Daily March 31, 2021 Although the greenhouse gas methane is less well known and much rarer in the atmosphere, its global warming potential is 80 to 100 times greater per unit. Methane from lakes and water reservoirs makes up about 20% of global natural methane missions. Researchers in Switzerland outline the potential and theoretical possibilities for using methane from lakes and other freshwater bodies for sustainable energy production. The feasibility of up-scaled adsorption-driven technologies to capture and refine aqueous Biogenic CH4 is mostly generated from biomass produced through atmospheric CO2 uptake. Its exploitation in freshwaters can thus secure large […]
No losses: Scientists stuff graphene with light
EurekAlert November 16, 2020 Researchers in Russia developed a technique to achieve 90% energy conversion from the pump laser field to the surface plasmon polaritons (SPPs) on the base of the hybrid optoplasmonic multi‐level scheme of near‐resonant interaction with semiconductor quantum dots (QDs) placed in the proximity of a graphene surface. Using numerical simulations and semiclassical approach for the light–matter interaction they found that maximum efficiency of SPP generation is achieved in strong coupling conditions for a stationary regime of SPP‐QD interaction. The technique can be used for converting energy in solar cells, and nano and bio-object detection…read more. TECHNICAL […]
Building walls that will make summer heat waves more bearable
Phys.org September 28, 2020 A team of researchers in South Korea propose Phase Change Material (PCM) wall device using bubble injection method for the application of PCM in building envelopes. The density difference between PCM and bubbles causes the upward movement of the bubbles and flow in the liquid PCM destroying temperature stratification in the PCM and heat penetration across the PCM is reduced. With the application of the bubble injection method, 11% more latent heat energy was stored in the PCM, 28% less heat penetrated across the PCM wall and the average flow rate inside the liquid PCM with […]
Faster, more efficient energy storage could stem from holistic study of layered materials
Science Daily August 25, 2020 An international team of researchers (USA – Oak Ridge National Laboratory, Georgia State University, Tulane University, Drexel University, Portugal) integrated theoretical data from computational modeling of experimental data to pinpoint potential locations of a variety of charged ions in titanium carbide, the most studied MXene phase. MXenes are a class of two-dimensional materials constructed in layers that are only a few atoms thick. They were able to form links between theory and different types of materials characterization, ranging from very simple to very complex over a wide range of length and time scales. The study’s […]
Efficient Off-Grid Power, After the Sun Sets
Optics and Photonics August 19, 2020 An international team of researchers (USA – Stanford, Israel) analyzed the basic thermodynamics of a heat engine, with the hot side under the roof and the top of the roof radiating thermal energy out into the environment. They developed models to maximize the amount of electrical power generated for various temperature gradients. The team’s design for a nighttime power generator would occupy a rooftop area of 1 m2. It incorporates a radiative emitting panel, a state-of-the-art TEG made of metal alloy, and a heat sink, with radiation shields and insulative pegs to reduce radiative […]
Engineers develop new fuel cells with twice the operating voltage as hydrogen
EurekAlert June 17, 2020 Researchers at Washington University have developed high-power direct borohydride fuel cells that operate at double the voltage of conventional hydrogen fuel cells. They pioneered a reactant identifying an optimal range of flow rates, flow field architectures and residence times that enable high power operation ensuring proper fuel and oxidant distribution and the mitigation of parasitic reactions. They demonstrated a single-cell operating voltage of 1.4 or greater, double that obtained in conventional hydrogen fuel cells, with peak powers approaching 1 watt/cm2. Doubling the voltage would allow for a smaller, lighter, more efficient fuel cell design. Their approach […]
Using the ‘shadow effect’ to generate electricity
Techxplore May 21, 2020 Researchers in Singapore used Kelvin Probe Force Microscopy to experimentally validated that a shadow-effect energy generator (SEG) scavenges the illumination contrast that arises on the device from shadow castings, and generates a direct current, simply by placing a part of the generator in shadow. The SEG is capable of harvesting energy from illumination contrasts arising under weak ambient light. Without any optimization, the generator has a power density of 0.14 μW cm−2 under indoor conditions 0.001 sun, where shadows are persistent. It performs 200% better than that of commercial silicon solar cells under the effects of […]
Fossil fuel-free jet propulsion with air plasmas
Science Daily May 5, 2020 Researchers in China propose a prototype design of a propulsion thruster that utilizes air plasma induced by microwave ionization. They used a microwave air plasma jet thruster using high-temperature and high-pressure plasma generated by a 2.45 GHz microwave ionization chamber for injected pressurized air. They measured the lifting force and jet pressure at various settings of microwave power and the air flow rate and demonstrated that, given the same power consumption, its propulsion pressure is comparable to that of conventional airplane jet engines using fossil fuels. A carbon-emission free thruster could potentially be used as […]
Pentagon awards contracts to design mobile nuclear reactor
Defense News March 9, 2020 Project Pele is run through the Strategic Capabilities Office within DDR&E of DOD, involves the development of a safe, mobile and advanced nuclear microreactor to support a variety of Department of Defense missions such as generating power for remote operating bases. Under the program the Pentagon issued three contracts to start design work as part of a two-step plan. The system should be safely and rapidly moveable by road, rail, sea, or air and quick to set up and shut down, with a design which is inherently safe. If the testing goes well, a commercially […]