RE Calculations of Many Kinds

Background: Peter & David Schwartzman (a son and father team) have created this page to encourage more mathematical/scientific discourse in the needed transition from a fossil-fuel based economy to a renewable energy driven one.

(A) Energy from Power (info popup)This calculator converts power to energy for power used over a period of time.×

Power:       in W
Time:         in days

Energy:       in kWh

(B) How many wind turbines or how big a solar array do you/we need? (info popup)Assuming that people use a certain amount of electricity at home, one can calcuate how big a solar array or wind turbine farm is needed.×

Population
(of house/city)

Electricity Required:       in MWh (for residential use only)
Number of Wind Turbines:       each 1.6 MW
Size of Solar Array:       in acres in sq. ft

(Assumptions: Per capita residential electricity use in USA: 4,348 kWh/yr; Capacity factors: Wind = 35%; Annual Solar Production = 357 MWh/acre. Since sun and wind resources are not available 24/7, it is advisable that a mix of the two sources be installed.)

(C) Energy from Photovoltaics

Number of Panels: 
Panel Rating:         in W
Hours of full sun/day:   hrs
(If you don't know: link. Note: One "full sun" hour is equal to 1 kWh/m2 per day.)

Energy Produced:
in kWh (annually)


(Assumptions: Derating factor = 0.77)

(D) Energy from Wind

Number of Turbines:    
Size (MW) of Turbines:   in MW
Capacity Factor:         (If you don't know: link)

Energy Produced:
in MWh (annually)

(E) Carbon Dioxide Reduction using RE (info popup)In our 2021 published study, we determined how much CO2 emissions could be reduced through a deliberate effort to shift to renewable energy. We share are "calculator" here. Notice, it matters which fossil fuel is displaced and, most surprising to many, natural gas is the fossil fuel most warranting reduction (due to the methods currently used for extraction which emit a tremendous amount of methane--a powerful greenhouse gas--inadvertently). ×

Energy produced by RE:
in MWh
(this RE displaces non-RE energy)

CO2 emissions averted when RE displaces said energy:
Oil (conventional):   in tonnes of CO2
Coal:         in tonnes of CO2
Natural Gas:     in tonnes of CO2
Equivalent car driving:   in miles

(Assumptions: CO2-equivalent emissions (tonnes/TJ) from Oil (76), Coal (106), and NG (110) (these value compare to 3 for wind and solar energy, if these RE forms come from RE infrastructure built with fossil fuels--or 0 otherwise); car used gets 22 mpg. Note: CO2-equalivalent emissions take into account other greenhouse gas emissions due to the extraction, refining, transportation, and use of a fossil fuel. For more information, see Schwartzman & Schwartzman's (2021) AIMS Energy article: link)

(F) Creating RE from FF (as discussed in Schwartzman & Schwartzman's 2011 report, "A Solar Transition is Possible": link) (info popup)In our 2011 report, we computed how much renewable energy was feasibly creating using fossil fuel (and existing RE) as investments for the build out of new RE infrastruture. We provide our calculator here. Notice, that with conservative values used in the model, RE production can easily double current overall global energy production levels in 20 years or less.×

RE produced globally in 2020: 7,344 TWh (s1)
FF consumed in 2020: 147,378 TWh (s2)
(s1, link; s2, mod. from link)

REOI (Return on Investment):   
(ratio of RE produced to FF invested to make new RE (over lifetime of RE))
Lifetime of RE:      years
% of FF invested to make RE:      %
% of RE reinvested to make new RE:     %

Total RE produced in 2030:   in TW
Total RE produced in 2040:   in TW

R* (ratio of RE produced in 2040 to Total global energy use in 2020)


(Note: Year 1 is 2020.)