renewable energy prof. peter seligman, d.eng. inspired by sustainable energy – without the hot air...
TRANSCRIPT
Definitions:
Renewable: we can continue indefinitely
Sustainable: we can do it for a long time but eventually will have to come up with something different.
Zero carbon: we may run out in the foreseeable future but it’s still worth doing.
How much energy do we use?from ABARES
Australian Bureau of Agricultural and Resource Economics
abare-brs.gov.au
Primary energy:
Domestic: 5.8 exajoules per annum
Export: 13.8 exajoules per annum
Exajoule = 1018 Joule
Our domestic primary energy use:
Domestic: 5.8 exajoules per annum
= 5.8 x 1018 joules or watt seconds
divide by 3.6 x 106 = 1.6 x 1012 kWh/annum
divide by number of people: 22 x 106
= 73,200 kWh/annum/person
divide by hours in a year: 365 x 24= 8360 Watts/person
Our domestic primary energy use:
8360 Watts/personx by 24/1000
= 200 kWh/person/day
UK/Europe = 125 kWh/person/day
Primary energy: 8000 watts/person
Heating 80% efficientElectricity generation 30% efficientTransport 20% efficient
Average efficiency 50%
End-use energy: 4000 watts/person
Where do we use energy?• Personal
– Food – Electricity – Gas– Petrol– Flying– Stuff we buy– House construction
• Public– Factories– Offices– Shops– Hospitals– Schools– Universities– Public transport– Sporting facilities– Street lighting– Cinemas, theatres– Construction
About a quarter of our energy use is personal:
1000 watt/person
Three quarters of our energy use is public:
3000 watt/person
Elec industrial
Elec commercial
Elec domestic
Elec Misc
Fuels other than elec generation
Distribution of total energy use
Electricity use
National average electricity generation 25 GWover 22 million people:
1100 watts/person
Output of a 1 kW solar panel
• 1000 watts nominal peak in bright sunlight• 800 watts under realistic conditions
(temperature and inverter efficiency)• 400 watts taking into account night time• 320 watts taking into account sun angle• 160 watts taking into account cloud• 40 watts each for a 4 person family
Role of domestic solar PV• Elec. price rises due to distribution, not
wholesale price• Increase distribution costs due to aircons• Each $1500 aircon adds $7000 to
infrastructure cost• PV can provide power locally when it is
most needed (best facing NW at steep angle)
Renewable energy system
• Wind• Solar• Geothermal• Wave• Utility scale energy storage• High voltage DC (and AC) links
How much power from the wind?
5 turbine diameter separation between turbines 2 watt/m2
2 – 3 turbine diameters in non-prevailing wind directions
Typically: 4.5 watt/m2
Land is still suitable for farming
Wind Power
• Turbines now up to 7.5 MW
• Technologically mature
• Capacity factor 30%
• Average output 2.3 MW per turbine
Turbine technology• Enercon E126 turbines• 7.5 MW• Gearless design • 138m hub height• 127m blade diameter
A question of storageWind power in South Australia and Victoria
From Wind farming in South Australia
Large scale solar - California 1984345 MW peak: 75 MW average
http://www.itas.fzk.de/deu/tadn/tadn013/image37.jpg
Torresol Gemasolar Molten Salt Solar
• solar power at night• “Baseload” “Dispatchable” solar – better than coal
How much power from the sun?
Solar radiation: 1000 watts/m2
• Taking into account night-time and cloud160 watts/m2
• Taking into account 15% efficiency24 watts/m2
• Taking into account shading and access4.5 – 15 watt/m2
Geothermal resources in Australia
• Hot Dry Rocks• Heat build-up in radioactive granite
+ residual heat from earth’s core • Typical power flow 50 – 100 millwatts/m2
• Not renewable but usable over 400 years• Could supply about 800 watts per person
(end use)
How much power from waves?
• 2000 km of Australian south coast• 100 – 160 kW/linear metre• Extraction efficiency: 5 – 10%• Could supply about 900 watts per person
(end use)
Tidal power?
• North West Australia10 metre tides: 150 watts per person (end use)
• Port Phillip Bay 10 watts/Melbournian
High Voltage DC links• Low loss power transmission over long
distances• No current due to line capacitance• No eddy current losses is wires• Lower peak voltage (or higher average
voltage)
High voltage DC links
• 1700 km in the Congo, built 1982• Longest 2100 km, China• Highest power: 6400 MW, China and India
• Basslink: 300km cable, 600 MW
http://en.wikipedia.org/wiki/List_of_HVDC_projects
More HVDC details
• May use monopole (earth return)
• DC is the only practical solution to undersea cables
• Power loss: 2% / 1000km, 1.5% in converters
http://www.utilities-me.com/article-690-electricity-highway-powers-through-china/
AC-DC-AC Converter
http://www.energy.siemens.com/hq/pool/hq/power-transmission/HVDC/HVDC-Classic/TSQ-Valvehall-b.jpg
Resource Watts/person Proportion of resource
Hydro 73 Existing
Geothermal 682 Currently measured resource fully used
Wave 18 3% of coastline
Solar 909 0.06 % of country
Wind 909 0.13% of country compatible with farming
Total 2600 (end use
UK, Europe)
An energy strategy for Australia
Transport• Biofuels from algae?• Unwanted CO2 as feedstock for algae.• Hydrogen• Ammonia – NH3 ?!• Electrification of road transport• Use of transport batteries for large scale
energy storage