Physics of Sustainable Energy

What is meant by the term sustainable?

Anything we can use for the next ~1000 years and not significantly deplete

What is 1kWh in J?

1kWh = 3.6×10⁶J

Why is gas a much greener option than coal?

Hydrogen to carbon ratio

• Coal: H/C = 4/1

• Gas: H/C = 1/1

Moles of CO2 released

• Coal: 2.0 mol CO2/MJ

• Gas: 1.2 mol CO2/MJ

Energy per kilogram released

• Coal: 24 MJ/kg

• Gas: 55 MJ/kg

How do you calculate power per unit area?

Power per unit area = mass/area x calorific value

What are 2 equations for power?

P = Fv

P = IV

What is the equation for electrical potential?

V = E/d

What is the equation for electrical energy?

E = qV

What is Wein’s law?

λ_peak= 0.0029/T

What is Stefan’s law?

P = σAeT⁴

What is the equation for the first law of thermodynamics?

ΔU = Q + W

What is the equation for maximum efficiency of a Carnot engine?

What is embodied energy?

The sum of all the energy required to produce any goods or service considered as if the energy was incorporated or embodied in the product itself