Zero-emission vehicles are getting bigger and flying higher, so this week we take a look at carbon-free aviation and a proposed charging network for medium and large electric trucks. We also check out an innovative, industrial-scale energy storage system.
Flying with Hydrogen Fuel
The electric aircraft industry is beginning to soar, but the fuel source—batteries—suffer from a poor power-to-weight ratio, limiting zero-emission planes to relatively short flights with few passengers. ZeroAvia thinks the solution is hydrogen, but if the thought of hydrogen-based flight brings up images of an early 20th-century disaster, relax—we’re talking about fuel cells, not dirigibles.
ZeroAvia recently flew a modified airplane with a 260kW (350hp) powertrain driven by hydrogen fuel cells, as part of the UK’s HyFlyer initiative, a project designed to move electric aircraft away from batteries and toward fuel cells. ZeroAvia’s founder and CEO, Val Miftakhov, believes that hydrogen is the best option for zero-emission flight. Batteries are much heavier and more volatile than fuel cells. Although hydrogen has an explosive reputation, its ignition point is much higher than that of lithium-ion batteries (or even jet fuel, for that matter), and because hydrogen is so light, it tends to disperse rather than collect. Furthermore, an electric powertrain driven by a fuel cell is twice as efficient as an internal combustion engine. Miftakhov suggests that hydrogen can be produced on-site through hydrolysis by building solar arrays on the unused space at airports. (While they’re at it, how about solar carports over the parking lots?)
Miftakhov says that the main obstacle of hydrogen-powered flight is the lack of standards, not the technology. At this point, the authorities haven’t established parameters and testing methods, so ZeroAvia is working with regulators to establish specifications and procedures for testing and certifying fuelcell aircraft. That’s one benefit of being a pioneer in an industry: you have an opportunity to become the standard by which others are measured.
ZeroAvia plans to have a 10- to 20-seat aircraft available by 2023. Miftakhov says that its design is scalable and believes that within two decades, a hydrogen-powered 200-seat craft capable of flying more than 3,000 miles (4,800km) will be feasible.
High-Speed EV Charging Network
Interstate 5 (I-5) stretches nearly 1,400 miles (2,250km) up and down the West Coast. As a major trucking route through Washington, Oregon, and California, the highway is a significant source of pollution, so the three states launched the West Coast Clean Transit Corridor Initiative, a plan to develop a high-speed charging network for medium-duty and heavy-duty trucks. The group’s report, released in June 2020, includes feedback from electric utilities and industry consortia regarding electric vehicle technology, electrification programs, and truck traffic.
The consortium found that clean air policies continue to be a significant driver of vehicle electrification, and similar policies and incentive programs regarding charging infrastructure would expedite the transition to electric trucking. The trucking companies noted that fast-charging stations available to the public would help the industry to go electric, and recommended placing 27 high-speed DC charging stations at roughly 50-mile intervals along Interstate 5. Each station would include 10350kW charging ports, each of which could accommodate medium-duty vehicles such as cargo vans and shuttle busses. That phase would be completed by 2025 and the second phase would upgrade 14 of those sites with 10additional 2MW charging ports, each sufficient for heavy-duty vehicles like tractor trailers.
Thermal Energy Storage
As part of its “Future of Storage” initiative, Siemens Energy has partnered with EnergyNest to offer thermal energy storage systems for industrial customers. EnergyNest developed a thermal battery made of inexpensive, abundant materials that can store heat from multiple sources, such as concentrated solar power (CSP) systems, industrial heaters powered by excess photovoltaic and wind energy, and waste heat from other processes. The stored heat can then be used either to heat a building directly or to create steam that generates electricity through traditional turbines. In both cases, the need to burn natural gas for heat or to drive a turbine is reduced or eliminated.
Heat is stored in a proprietary concrete-like material, which EnergyNest says is less expensive than molten salts. The battery elements are arranged into modular containers that become part of a complete, scalable thermal battery system. Since the system has no moving parts and no chemical reactions, the company estimates its lifespan to be 30 to 50 years.
I contacted Christian Thiel, CEO of EnergyNest, who elaborated, “Excess (or low-cost) electricity from renewables will heat the thermal battery system via an electric industrial heater, which is directly connected to the thermal battery. We have already applied the same system with our technology pilot in Masdar City, Abu Dhabi, in 2015. By electrifying industrial heat such as high-quality process steam, we enable our customers to take advantage of excess or low-cost renewable electricity for replacing their heat production, which in most cases is currently done via burning natural gas. This not only saves [natural gas] costs but directly translates into significant CO2 savings by not having to burn natural gas.”
Interested in the science behind this thermal battery? Check out this article from the Journal of Energy Storage.
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