Renewable Energy Prof. Peter Seligman, D.Eng

Inspired by Sustainable Energy – without the hot air by David MacKay FRS Google: withouthotair

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 = Joule

Our domestic primary energy use: Domestic: 5.8 exajoules per annum = 5.8 x joules or watt seconds divide by 3.6 x 10 6 = 1.6 x kWh/annum divide by number of people: 22 x 10 6 = 73,200 kWh/annum/person divide by hours in a year: 365 x 24 = 8360 Watts/person

Our domestic primary energy use: 8360 Watts/person x by 24/1000 = 200 kWh/person/day UK/Europe = 125 kWh/person/day

Primary energy: 8000 watts/person Heating 80% efficient Electricity generation 30% efficient Transport 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

Our energy use Private 1000 watts (ten 100 watt globes)

Our energy use Public 3000 watts (thirty 100 watt globes)

Total end-use energy Per person: 4000 watts (forty 100 watt globes)

Distribution of total energy use

Electricity use National average electricity generation 25 GW over 22 million people: 1100 watts/person

Distribution of electricity use

How much power can a 1000 watt photovoltaic system produce? = 160 watts average

How much power per person? = 40 watts average (remember we use 4000 watts each)

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)

We can’t solve a big problem by thinking small

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/m 2 2 – 3 turbine diameters in non-prevailing wind directions Typically: 4.5 watt/m 2 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 storage Wind power in South Australia and Victoria From Wind farming in South Australia

Large scale solar - California MW peak: 75 MW average

Andasol 1 to 3 Granada Spain 50 MW turbines 20MW average courtesy Ferrostaal AG.

Molten salt storage

Torresol Gemasolar Molten Salt Solar solar power at night “Baseload” “Dispatchable” solar – better than coal

Gemasolar in Spain MW turbines 12.5MW average

Large scale solar courtesy Ferrostaal AG.

Liquid salt storage tanks courtesy Ferrostaal AG.

How much power from the sun? Solar radiation: 1000 watts/m 2 Taking into account night-time and cloud 160 watts/m 2 Taking into account 15% efficiency 24 watts/m 2 Taking into account shading and access 4.5 – 15 watt/m 2

How much of Australia? 200 km square 4.5 watt/m watt/person

Geothermal energy from hot dry rocks sen.asn.au/renewables/geothermal

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/m 2 Not renewable but usable over 400 years Could supply about 800 watts per person (end use)

Geothermal resources in Australia

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 Australia 10 metre tides: 150 watts per person (end use) Port Phillip Bay 10 watts/Melbournian

Supply, demand and curtailment From BZE Zero Carbon Australia Stationary Energy Plan

Nullarbor pumped seawater electricity storage Bunda cliffs From Google Earth

200 GWh battery

Okinawa pumped seawater electricity storage

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

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 china/

AC-DC-AC Converter Classic/TSQ-Valvehall-b.jpg

Transformer for High voltage DC power line Courtesy Siemens AG

Wiring diagram for Oz

ResourceWatts/personProportion of resource Hydro73Existing Geothermal682Currently measured resource fully used Wave183% of coastline Solar % of country Wind % of country compatible with farming Total2600 (end use UK, Europe) An energy strategy for Australia

Transport Biofuels from algae? Unwanted CO 2 as feedstock for algae. Hydrogen Ammonia – NH3 ?! Electrification of road transport Use of transport batteries for large scale energy storage

Efficiency and waste

Why do we need to do this? We don’t have a Planet B! (Madeleine Trau – 8 years old)

Beyond Zero Emissions

ZCA2020 Available online and in print from MEI: or…