Sustainability - Exam 2

G (Giga)

10⁹

T (Tera)

10¹²

k (kilo)

10³

M (Mega)

10⁶

1 C

2 lb CO2/day = 1 kg/day

1 w

3.8 L/day = 1 gallon/day

1 D

2000 Calories = 8.4 MJ/day

efficiency

desired energy output / energy input

amount of heat released when a unit mass of fuel is completely burned

heating value of fuel

Quad

10¹⁵ BTU

direct conversion efficiency

useful energy out / direct energy in

Mcf

1000 cubic feet of natural gas

MMcf

one million cubic feet of natural gas

Roman numeral L

50

Roman numeral C

100

Roman numeral D

500

Roman numeral M

1000

n (nano)

10^-9

mu (micro)

10^-6

P (peta)

10¹⁵

mpg-e

miles/gallon gasoline energy equivalent

mpg-eE

miles/gallon gasoline energy equivalent efficiency

1 hectare

2.47 acres, so roughly 2.5 football fields

1 acre

roughly 1 football field

1 horsepower =

745.7 Watts

SI Unit of energy

Joules

Imperial units of energy

calories, therms (BTU)

SI units of power

watts (J/s)

Imperial units of power

horsepower

EJ

10¹⁸ J

De

energy for electricity

Dp

primary energy used to make electricity

Dff

energy in fossil fuel

DnC

energy not associated with carbon emissions (renewable)

HSPF =

heating season performance factor = heat produced (BTU) / electrical energy used (Wh)

HSPF (definition)

(heating season performance factor) measures the heating efficiency of a heat pump over an entire heating season

SEER

seasonal energy efficiency ratio - measure of an air conditioner's cooling efficiency over an entire cooling season

AFUE

annual fuel utilization efficiency - a rating for furnaces and boilers and measures how efficiently they convert fuel into usable heat over an entire heating season

actual power (kW)

the amount of power converted into useful output

apparent power (kVA)

the total amount of power consumed in a system

load factor

average demand / peak demand

converting kW into kVA

actual power (kW) / power factor (pf) = apparent power (kVA)