Many viable solutions for climate change will likely involve pairing advanced technology with legacy applications. For example, going driverless might be good for the planet, as autonomous vehicles such as the MQ-4C Triton unmanned aircraft system (UAS) and driverless cars produce fewer emissions than traditional manned options. In a similar vein, electric planes might make the most sense for counteracting climate change in the area of regional air travel.
Electric Planes for Short Hops
Vancouver-based Harbour Air plans to operate the world’s first all-electric seaplane fleet, and as the Canadian Broadcasting Commission notes, Harbour Air has already conducted test flights with its electric-powered planes. Once they are certified as airworthy and ready for passenger flights, the airline plans to start using them on its regular commercial routes, which include short regional flights between Vancouver and the British Columbia capital, Victoria, for example.
The airline already uses small propeller planes to connect up and down the Pacific Northwest coast, flying regularly between Seattle, Vancouver, Whistler and the Gulf Islands. The existing commercial itinerary is perfect for electrification.
The world’s largest electric plane flew in May of 2020 just a little further south down the coast from Vancouver, BC. The BBC reports that the nine-seater modified Cessna test plane made aviation history above a field in central Washington State, flying for 30 minutes above Grant County International Airport and becoming the first commercial airplane to be powered for takeoff and flight exclusively by electricity.
Weight and Power Limit Battery-Powered Flights
The reason why shorter routes are more suitable to electric planes is that they are comfortably within the range of the on-board batteries needed to power the flights. Battery-powered flight is limited by the battery power itself, and in terms of energy density, batteries fall way behind aviation fuel. This means that even if enough battery power could be placed on board a typical commercial jet liner, the jet could only fly for 1,000 km (621 miles) rather than its usual range of 15,000 km (9,320 miles).
However, despite the relative lack of power and reduced range, electric flight could offer the benefits of cost savings and reduced emissions. A significant portion of global air travel is short haul, over distances suitable for electric planes, and the 30-minute modified Cessna flight cost only $6 compared to between $300 and $400 for a similar flight using conventional aviation fuel.
Autonomous Handling, Higher Altitude and Longer Flights for Lower Emissions?
Staying up in the air for a lot longer could also help to reduce emissions, as the MQ-4C Triton shows. Used for surveillance and reconnaissance, the MQ-4C Triton’s advanced technology includes a 360-degree sensor payload that is well protected against environmental conditions frequently encountered at high altitudes and over marine environments.
What goes up must come down, but keeping the vehicle in the air for longer can reduce its emissions and fuel costs, as takeoff and landing are the most fuel-hungry parts of flight, according to Center for Climate and Energy Solutions. As an autonomous aircraft system, the MQ-4C Triton has a flight duration of around 24 hours.
Flying stats show that the MQ-4C Triton does differ from traditional manned flights considerably in terms of emissions. This is due to its design, which utilizes a smaller fuselage on a bigger wingspan to create better flying efficiency. Autonomous flight capabilities also help, as pre-programming a flight lets the on-board system fly with much greater efficiency than a human pilot could achieve, and at altitudes around 50,000 feet (15.24 km), where it is easier to cruise without guzzling fuel.
Compared to the equivalent manned system, this UAS not only uses less fuel but also emits 34 times less carbon dioxide. One standard flight uses the equivalent of a 55,922-mile (nearly 90,000 km) car journey, while fuel consumption for its manned counterparts rockets to the equivalent of almost 2 million miles for a similar flight.
Hybrid Options for Reduced Emissions
Because commercial air travel requires flights over longer distances, but usually not for 24 hours at a stretch, UAS commercial flights may not be the way forward. Instead, researchers are exploring hybrid options that combine traditional fuel engines with advanced electric plane technology. For example, MIT News has reported on a hybrid electric plane concept that uses a gas turbine to create electric power for the propulsion system.
In their turbo-electric concept, a gas turbine powers an electric generator, which in turn powers the propellers or fans on the airplane wings. Because the gas turbine exhaust can be contained in this system, it can be passed through an emissions control system that scrubs out harmful nitrogen oxide particles, one of the major sources of pollution from airplanes. Furthermore, airplane electrification using this approach would not add as much extra weight as batteries would.
Another tactic that can help reduce emissions is replacing traditional surveillance methods that involve manned flights with the MQ-4C Triton and only calling in manned aircraft once a target is located and accurately mapped. With this approach, the gas-guzzling airplane would only need to fly out when it’s necessary and wouldn’t have to spend time in the air searching.
While we might not be spending 24 hours on a UAS flight in the future, it’s likely that we will be able to leverage electric power for certain flights, rather than relying exclusively on fossil fuels.
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