Electric Aircraft CO2 Emission Calculator

Description

This calculator estimates the CO2 emissions from a battery-powered electric aircraft.

Below are some values for reference.

• Jet liners have L/D around 15.
• Helicopters have L/D around 5.
• The Joby S4 eVTOL has a mass of about 2200 kg.
• A kilogram weighs about 2.2 lbs (on earth).
• Electric cars have a propulsive efficiency of about 0.9 from battery to wheel. Presumably an aircraft rotor would have similar efficiency, but then have further losses converting rotor power to thrust.
• 0.386 kg/kWh for batteries changed on the US electric grid
• 1.013 kg/kWh for batteries charged by burning coal
• 0.008 kg/kWh for batteries charged by wind turbines

Equations

The following equations are used to estimate the CO2 emissions \( e \) from the lift/drag ratio \( L/D \), total aircraft mass \( m_t \), battery to propulsion energy efficiency \( \eta_{b-p} \), grid to battery energy efficiency \( \eta_{g-b} \) and grid CO2 emissions per unit energy \( e_g \). Other relevant values include the battery energy used \( E_B \) and the grid energy consumed \( E_G \) to fly 1 km. These equations assume a constant speed flight and exclude energy required in the cabin for avionics, air conditioning, etc. In reality, takeoff and climb may consume much more energy, causing substantially higher emissions.

We are working on a new article regarding the feasibility of electric aircraft and flying cars. Please check back later.