Energyand

Sustainability

Energy

How much energy do you need?

How much energy do you use?

EnergyHow much energy do you need?• Energy from food

= 2,000 Calories / day= 8,000 BTUs / day

• Energy for all of the other things you do

= (Take a guess) _____________ BTUs ?

How much?

Total annual energy consumption in the United States (2011)

97.3 quadrillion BTUs

~ 1017 BTUs

~ 1020 Joules

(1 BTU = 1055 Joules)

How much?Total U.S. energy consumption

= 97 x 1015 BTUs / year

Then your energy consumption / day is

97 x 1015 BTUs / year(316,000,000 people) (365 days / year)

= 840,000 BTUs / person / day( + 8,000 BTUs from food )

How much?

So, if you are a typical U.S. resident, you will use about 848,000 BTUs of energy today

Food: 8,000 BTUs

For all other things:840,000 BTUs

How can this be?

U.S. Energy Uses

SectorElectric Power 40%Transportation 28%Industry 21%Res & Commercial 11%

Total (97 quads) 100%

Your energy use = Direct use + Indirect use

U.S. Energy Sources

U.S. Renewable Energy

Renewables are ~ 9% of U.S. Total Energy Consumed

Source (quads)Hydroelectric 3.2Wood 2.0Biofuels 1.9Wind 1.2Waste 0.5Geothermal 0.2Solar / PV 0.2Total (quads) 9.1

Oil 35%Natural Gas 24%Coal 28%Nuclear 6%Hydro 6%Renewable 2%Total 510 quads

= 200,000 BTUs / person / day

World Energy Consumption

Personal Consumption

BTUs / person / day

United States840,000

Australia718,000France

498,000Japan

440,000Mexico

157,000China

130,000Brazil

84,000India

36,000Parts of Africa

7,000

Population

0 500 1000 1500 20000

2,000,000,000

4,000,000,000

6,000,000,000

8,000,000,000

10,000,000,000

Human Population of Planet Earth (Bil-lions)

Year

Population

1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 20500

2

4

6

8

10

Human Population of Planet Earth (Billions)

Year

Bill

ions

of P

eopl

e

How much energy do we have left?

Energy Reserves

Estimated world reserves of fossil fuels (in quadrillion BTUs):

Years leftQuads at current

consumed consumptionReserves per year rate

Oil 6,370 178 36Natural gas 6,390 121 53Coal 20,250 143 142

Are there any other problems?

The Carbon Problem

Fuels:Oil 35%Natural Gas 24% 87%Coal 28%Nuclear 6%Hydro 6%Renewable 2%510 Quadrillion BTUs / year

The Carbon Problem

The Carbon Problem

Green Strategies ConservationEfficiencyGeothermalSolar• Passive• Photovoltaic

Fuel cellsTidalWindWavesHydroelectricNuclearBiomass