A liquid-state pyroelectric energy harvester is described and a remarkable capacity to convert a thermal gradient into electrical energy is demonstrated.

Increasing the sustainability of energy generation can be pursued by harvesting extremely low enthalpy sources: low temperature differences between cold and hot reservoirs are easily achieved in every industrial process, both at large and small scales, in plants as well as in small appliances, vehicles, natural environments, and human bodies. This paper presents the assessment and efficiency estimate of a liquid-state pyroelectric energy harvester, based on a colloid containing barium titanate nanoparticles and ferrofluid as a stabilizer. The liquid is set in motion by an external pump to control velocity, in a range similar to the one achieved by Rayleigh–Bénard convection, and the colloid reservoir is heated. The colloid is injected into a Fluorinated Ethylene Propylene pipe where titanium electrodes are placed to collect electrical charges generated by pyroelectricity on the surface of the nanoparticles, reaching 22.4% of the ideal Carnot efficiency of a thermal machine working on the same temperature drop. The maximum extracted electrical power per unit of volume is above 7 mW/m3 with a ΔT between electrodes of 3.9 K.

Hydrogen is a versatile energy storage medium with significant potential for integration into the modernized grid.

Advanced materials for hydrogen energy storage technologies including adsorbents, metal hydrides, and chemical carriers play a key role in bringing hydrogen to its full potential.

The U.S. Department of Energy Hydrogen and Fuel Cell Technologies Office leads a portfolio of hydrogen and fuel cell research, development, and demonstration activities, including hydrogen energy storage to enable resiliency and optimal use of diverse domestic energy resources.

Today, the technology around generating and storing efficient and sustainable energy is rapidly evolving and hydrogen technologies offer versatile options. This perspective provides an overview of the U.S. Department of Energy's (DOE) Hydrogen and Fuel Cell Technologies Office's R&D activities in hydrogen storage technologies within the Office of Energy Efficiency and Renewable Energy, with a focus on their relevance and adaptation to the evolving energy storage needs of a modernized grid, as well as discussion of identified R&D needs and challenges. The role of advanced materials research programs focused on addressing energy storage challenges is framed in the context of DOE's H2@Scale initiative, which will enable innovations to generate cost-competitive hydrogen as an energy carrier, coupling renewables, as well as nuclear, fossil fuels, and the grid, to enhance the economics of both baseload power plants and intermittent solar and wind, to enhance resiliency and avoid curtailment. Continued growth and engagement of domestic and international policy stakeholders, industry partnerships, and economic coalitions supports a positive future outlook for hydrogen in the global energy system.

U.S. ethanol production capacity increased more than threefold between 2002 and 2008. We study the effect of this growth on corn acreage. Connecting annual changes in county-level corn acreage to changes in ethanol plant capacities, we find a positive effect on planted corn. The building of a typical plant is estimated to increase corn in the county by over 500 acres and to increase acreage in surrounding counties up to almost 300 miles away. All ethanol plants are estimated to increase corn production by less than their annual requirements.