Arthur Williamson
• We have become dependent on fossil fuel
• We are using fossil fuel at an unsustainable rate
• Burning fossil fuel is producing greenhouse gases which lead to climate change which may become intolerable
The great Nuclear
reactor in the sky
Earth300K
Radiation from sunAt 6000K
Re-radiation from earth to space at 0K
Energy input from sun =1.3 x 1017 watts
Energy reaching earth’s surface = 1.0 x 1017 watts = 100 000 TW
Intensity at earth’s surface = 1000 watts/square metre
What Happens To It?
• Reflection back into space 25%
• Absorbed (to low temp thermal) 67%
• Evaporation 32%
• Wind and Waves 0.25%
• Photosynthesis 0.03%
• Total energy = 3 x 1020 J/yr
• Average power =10TW
• Fraction that is oil = 33%
SOLAR ENERGY SOLAR ENERGY FALLING ON EARTH FALLING ON EARTH
IS IS
10 000 TIMES10 000 TIMES
MANKIND’S NEEDSMANKIND’S NEEDS
Energy falling on NZ
160W/square metre
130 000 000 PJ/yr
Primary energy 750 PJ/yr
Consumer energy 550PJ/yr
Average energy per day for each month (kWh/square metre)
For ChristchurchMonth Horizontal
surface
40 deg inclination
January 5.98 5.47
February 5.45 5.53
March 3.98 4.76
April 2.80 4.14
May 1.78 3.18
June 1.38 2.74
July 1.51 2.78
August 2.53 4.07
September 3.29 4.18
October 4.86 5.21
November 6.27 5.92
December 6.98 6.18
Mean Value 3.9 4.5
• Transport 38%
• Industrial 30%
• Residential 12%
Primary energy (NZ)
• Oil 33%
• Gas 32%
• Hydro 10%
• Geothermal 11%
• Coal 7%
• Wood 5%
• Other 2%
Consumer Energy by Fuel(NZ)
• Oil 53%
• Electricity 25%
• Gas 7%
• Wood 6%
• Coal 6%
• Geothermal 3%
Electricity sources
• Hydro 56%
• Gas 30%
• Geothermal 7%
• Coal 4%
• Other 3%
• WIND
• HYDRO POWER
• SOLAR THERMAL ENERGY
• PHOTOVOLTAIC
• PHOTOSYNTHESIS
Windflow turbines
• WIND
• HYDRO POWER
• SOLAR THERMAL ENERGY
• PHOTOVOLTAIC
• PHOTOSYNTHESIS
• WIND
• HYDRO POWER
• SOLAR THERMAL ENERGY
• PHOTOVOLTAIC
• PHOTOSYNTHESIS
150 MW Kramer Junction
Mojave Desert California
SOLAR1
Now abandonned
Power Tower Spain 11 MW
Sandia 25kW Stirling engine
ELECTROLYSIS
PHOTOTHERMAL
PHOTOCHEMICAL
WATER SPLITTING
• WIND
• HYDRO POWER
• SOLAR THERMAL ENERGY
• PHOTOVOLTAIC
• PHOTOSYNTHESIS
25mw SOLAR PV Spain 2008
1.5MW South Germany cadmium telluride
Small scale systems Arthur’s Pass
• WIND
• HYDRO POWER
• SOLAR THERMAL ENERGY
• PHOTOVOLTAIC
• PHOTOSYNTHESIS
Factors to be considered
• Low overall effectiveness- 0.1%
• Choice of plant type -oil,cellulose, starch, sugar
• Method of conversion
• Competition with food
PHOTOSYNTHESIScycle times
• COAL AND OIL 100 MILLION YR
• TREES 30-50 YR
• CROPS ANNUAL
• ALGAE CONTINUOUS
CONVERSION OF BIOMASS
• DIRECT COMBUSTION
• CONVERSION TO ALCOHOL
• EXTRACTION OF VEGETABLE OIL
• FERMENTATION TO BIOGAS
CONVERSION OF BIOMASS
• DIRECT COMBUSTION
• CONVERSION TO ALCOHOL
• EXTRACTION OF VEGETABLE OIL
• FERMENTATION TO BIOGAS
CONVERSION OF BIOMASS
• DIRECT COMBUSTION
• CONVERSION TO ALCOHOL
• EXTRACTION OF VEGETABLE OIL
• FERMENTATION TO BIOGAS
CONVERSION OF BIOMASS
• DIRECT COMBUSTION
• CONVERSION TO ALCOHOL
• EXTRACTION OF VEGETABLE OIL
• FERMENTATION TO BIOGAS
Yields
• Beet alcohol 5000L/ha yr
• Canola Diesel 1000L/ha yr
EROEIEnergy Return on Energy Invested
• Trees as fuel for combustion 30
• Gorse 30
• Beet alcohol 1.5?
• Canola for diesel 1.5?
• PETROL / ALCOHOL 2 000 000 ha
• DIESEL/BIODIESEL 6 000 000 ha
CONTEXTto feed 4 000 000
• TO FEED 4 000 000
• If we were vegan ABOUT 500 000 ha
• For meat and 3 veg ABOUT 1 500 000 ha
• HOW MUCH HAVE WE GOT?
• ABOUT 13 5000 000 ha
What if we opt for a wood fired thermal power plant
• This could run as baseload
• So we need 1000MW continuous
• Area required = 300 000 -500 000 ha