# Electric Aircraft CO2 Emission Calculator

 Lift/drag ratio - Total aircraft mass $$kg$$ Propulsion efficiencypropulsive energy / battery energy consumed - Grid efficiencybattery energy / grid energy consumed - Grid CO2 emission $$gCO2/kWh$$ CO2 emission 383.8 $$g/km$$ CO2 emission 617.7 $$g/mile$$

## 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.

$E_B = D * 1 km / \eta_{b-p}$ $D = m_t*9.8\frac{m}{s^2}/(L/D)$ $E_G = E_B / \eta_{g-b}$ $e = E_G * e_g$

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

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