Ecologically Sustainable Energy

Transcription

1 Ecologically Sustainable Energy Equals Efficient Use of Renewable Energy Dr Mark Diesendorf Institute of Environmental Studies, UNSW 1

2 The Fossil Fuel Problems By far the biggest source of global GHG emissions. Large source of air and water pollution, and land degradation Peak oil about now, followed by peak gas and peak coal before

3 Federal Govt s Main Solution : Coal Power with Capture & Burial of CO 2 (CCS) May not be commercially available before 2025 (MIT, 2007) Risks of escape of buried gas Will cost more than wind power and bioenergy from crop residues Necessary and cheaper at NW Shelf gas fields 3

4 Coalition s Back-up Solution : Nuclear Power Technology of 1970s, still has all the old problems: Proliferation of nuclear weapons Superb terrorist target Rare but devastating accidents Still no long-term dump for high-level nuclear wastes Chernobyl More expensive than wind power and some bioelectricity 4

5 Is Nuclear Power Part of the Greenhouse Solution? Too slow to build, so it s not a short-term solution Emits increasing amounts of CO 2 as uranium ore grade decreases, so it s not a long-term solution Therefore, based on existing technologies, nuclear power is a dead-end alley, a diversion from genuine action. 5

6 Ecologically Sustainable Energy The efficient use of renewable energy sources Only sustainable energy and backed up with gas can achieve a large reduction in greenhouse gas emissions from energy before

7 To substitute for fossil fuels, we must consider all 3 types of energy use Electrical and mechanical Electric motors & drives, lighting, electrolysis, refrigeration, air conditioning Heating Hot water, space heating, industrial process heat Transportation Passenger vehicles, freight In practice, electricity, a high-grade form of energy, is also used for some heating and transportation. It would be more efficient to use less electricity for heating and more for transportation. 7

8 Bioenergy, Rocky Point, Qld Concentrated solar Wind, Albany, WA Energy efficiency Wind Biomass Solar, Geothermal Solar-efficient homes, Christie Walk, Adelaide Sustainable Energy Mix 8 PV solar tiles, Sydney

9 Sustainable Energy Systems A mixture of different technologies with different properties Together can provide an energy system just as reliable as fossil fuels Can be ecologically sustainable More local employment too! 9

10 Cleaner Energy Mix: Direct Local Jobs per Unit of Electricity Generated Source of electricity Relative number of job-years per kwh in Australia Coal electricity + coal mining 1 Wind power with 50% Australian content Bio-electricity with 50% Australian content Wind power with 80% Australian content 2 3 Approx. 3.5 (mostly rural) Principal source: MacGill, Watt & Passey (2002) 10

11 Energy Efficiency The Cheapest and Fastest Technologies e.g. Residential Solar efficient design in new buildings & retrofits Insulation of buildings Efficient heating & cooling Efficient appliances, equipment & lighting Solar hot water with efficient shower heads & taps Christie Walk, Adelaide City 11

12 Micro-Economics of Sustainable Energy Mix Efficient energy use saves money and can pay for much of the additional costs of renewable energy Sustainable energy is least-cost & fastest greenhouse solution. 12

13 Solar Hot Water Solar boosted by instantaneous gas has lowest GHG emissions and highest price Solar-electric, gas and electric heat pump hot water have next lowest emissions Potential savings in Aust: 4.6 GW of coal power stations, 7 Mt per year of CO 2 13

14 Wind Power Wind could generate 10% of Australia s electricity by 2020 and 20% by 2030 Global capacity at end 2008: 121 GW 20% of electricity achieved in Denmark, increases planned Changes to transmission network are needed Large-scale dispersed wind + gas turbines can substitute for coal in electricity grid --> base-load Albany wind farm, Western Australia. 14

15 Wind Power: Alleged Adverse Impacts Either untrue or exaggerated Wind farm, Copenhagen Harbour

16 Large-Scale, Dispersed Wind is not Intermittent Single wind turbines are intermittent (they switch on and off frequently in low winds) Multiple wind farms, located in geographically separated locations, are not intermittent. In general, their total output varies slowly. At windy sites, about 2600 MW of wind power can substitute for the electricity generation of a 1000 MW coal power station, which can be retired or deferred. Wind-hydro combinations are as reliable as fossil fuels. In absence of hydro, wind can be made as reliable as fossil fuel by adding some gas turbine capacity. Since gas turbines have low capital cost and are operated infrequently, they provide reliability insurance with a low premium. 16

17 Bioelectricity from Crop Residues Could supply 6 8% Australia s electricity by 2020, 20% by 2030 Residues & organic wastes cheapest & fastest. Either direct combustion or gasification and combustion. Price depends on transportation distance Generates base-load power Biomass residues don t compete with food Estimated global capacity in 2006 is 45 GW Burning sawmill & sugar cane residues at Rocky Point, Qld 17

18 Bioelectricity from Dedicated Crops Generally more expensive than residues Seek multiple economic and environmental benefits Oil mallee yields electricity, eucalyptus oil, activated charcoal Reduces dryland salinity and erosion, improves landscape 18

19 Geothermal: Conventional Potential in NZ, Iceland, USA, Japan In 2005, 2.6 TWh/y or 6% of NZ electricity generation Could increase to 8 TWh/y or 20% of 2005 generation by 2050 Geothermal can provide residential & industrial heat, thus reducing demand for electricity 19

20 Geothermal: Hot Rock Under development in France, Australia & USA In Australia, huge potential in central Aust. Base-load power In theory, low water use and low pollution First electricity expected in

21 Solar Photovoltaic (PV) Global capacity at end 2008: 16 GW Annual production 2008: about 6 GW Electrical storage is still expensive so PV is daytime power: intermediate- & peak-load Just as important as base-load Technological advances will reduce cost of PV panels Needs R&D funding and market stimulus 21

22 Solar Photovoltaic (PV): New Technologies under Commercial Development Thin film (e.g. Sliver cells and crystalline silicon on glass) cells Dye sensitised cells Building integrated PV becoming more popular 22

23 Solar Thermal Electricity (Concentrated Solar Thermal Power) Revival post-2004: new 64 MW trough in Nevada; 11 MW power tower and 50 MW trough in Spain; 1 MW trough in Arizona Thermal storage in water, rock bed, graphite, molten salts, ammonia Thermal storage needs additional solar collectors Thermal much cheaper than electrical storage Base-load (24-hour) power: 10 MW commencing Cloncurry Qld, 2010 Old 354 MW system in California 23

24 Solar Thermal Electricity: Diverse Systems Big dish ANU Power tower or central receiver CLFR at Liddell Power station, NSW CLFR = Compact Linear Fresnel Reflector 24

25 Hydro and Marine Power Technology Status Additional Aust. potential Hydro Commercial, 8% of Low electricity (conservation areas, drought) Tidal barrage Commercial Low? Ocean current (water turbine) Wave Experimental Several different prototypes Low-medium? High, but long-term 25

26 Gas as a Transitional Fuel Peak oil is upon us; peak gas is coming Cogeneration of electricity and heat, especially in industrial & commercial sectors Gas back-up for solar hot water, solar space heating & solar thermal electricity Back-up for wind power with peak-load gas turbines, in absence of hydro Post-2050, gas gradually replaced by solar (both PV and STE) and biofuels produced sustainably 26

27 Possible Scenario for Electricity, Gas Coal Hydro Solar Biomass Wind Marine Geothermal Solar Biomass Wind Gas Coal Hydro

28 Matching Demand and Supply for daily Electricity Demand Continuous balancing act; cannot do it with inflexible base-load alone Conventional Peak: Hydro & gas turbines Intermediate: Coal & gas combined cycle Base: Coal, nuclear Renewable Hydro, gas turbine burning biofuel Solar PV, biomass Biomass, wind, solar thermal + thermal storage, geothermal,. 28

29 Substituting Solar Hot Water & Intermediate- Load Gas for Base-Load Coal Base-load is artificial construct to justify inflexibility of coal & nuclear. Coal-fired off-peak hot water artificially boosts demand for base-load coal power. Shut down this component of coal power and substitute with solar, gas & electric heat pump hot water and intermediate-load electricity. 29

30 Typical Current Electricity Prices by Source ($/MWh) Depend on siting, project scale, discount rate (here 8% real), subsidies 30

31 Principal Govt Policies Needed to Drive Sustainable Energy Stronger greenhouse targets Expanded Renewable Energy Target to 25% electricity by renewable heat target Gross feed-in tariffs for small systems & net feed-in tariffs for renewable energy power stations Carbon price with no exemptions apart from border adjustments Meanwhile, ban new conventional coal power Upgrade transmission system for renewable energy Mandatory Energy Performance Standards, ratings and labelling for all buildings and appliances

32 Resources for the Climate Action Movement 2009 UNSW Press 2007