energy systems: terms and issues

energy

capacity to do work

power

energy’s rate of change with respect to time

1kJ is enough to

raise 1 cup of water by 1ºC

1TJ is enough for

an airliner to cross the Atlantic

20-80W

laptop power consumption

cost of 1 kWh in Québec

8 cents

solar flux of Earth

1361 W/m²

solar flux of Earth at surface

500-1000 W/m²

rooftop solar panel wattage

150 W/m²

total human energy supply

19 TW

total anthropogenic CO2 radiative forcing (flux and then total)

2.2 W/m² → 310 TW

primary energy

source where it first comes into the economy e.g. energy content of crude oil

final energy

energy at point of sale to the end user e.g. energy content of gasoline

useful energy

fraction of the primary energy that turns into useful work-doing e.g. the car’s mechanical power

efficiency

unitless between 0 and 1

efficacy

something valuable from using energy

energy systems

production, storage, and distribution

good energy system involves

renewable sources, accessible, reliable, resilient, efficient, and low cost

renewable energy is better because

no extraction races, decentralized production, sustainable, no GHGs, less pollution and land impacts

by 2060, primary energy demand projected to grow by

1/3

per capita primary energy projected to peak by

2030

mix of energy inputs by 2060 should be

renewable and nuclear