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- Количество слайдов: 22
Sustainable Energy Supply? Global Sustainability problem Jens Tjell, DTU-Environment Kaliningrad, 2009 Typical citizens of advanced industrialized nations each consume as much energy in six months as typical citizens in developing countries consume in their entire DTU Environment Technical University of STRONG life MAURICE Denmark
Our energy use, what’s the problem? Fossil fuels contain carbon, Burning produces CO 2: CH 2 + O 2 → CO 2 + H 2 O CO 2 is a green house gas! Problem: we burn far too much!! DTU Environment Technical University of Denmark
What is the person energy consumption? Examples: • US and Canada: ~80000 k. Wh/p/y • Russia: ~60000 k. Wh/p/y) • Denmark: ~40000 k. Wh/p/y • Ethiopia, Nepal, Bhutan: <300 k. Wh/p/y
Present worldwide commercial energy production Fossil Fuels provide ~85% Does not include firewood etc used by half of the world population
Oil prices Oil price currently ~100 US $ a Barrel* Economy may force us to utilize other sources, or promote energy savings. *12/08 < 50 US$ Is the oil price really that high?
World crude oil production, past and prediction. Fossil Fuels are running dry!
Proven-In-Place Natural Gas Reserves. Most in politically unstable regions
Present much debated technical fix on CO 2 removal. Potential: large, expensive.
Alternative: Solar energy? Potential: Enormous House with photovoltaic panels Prices for installation: 1958 -$2, 000 / watt 1970 - $100 / watt 2002 - $5 / watt 2008 - $3 / watt Large proposed solar power station, Arizona, USA (heat to electricity) DTU Environment Technical University of Denmark
Alternative: Fuelwood? (storage, Siberia) Wood provides less than 1% of U. S. energy, but provides up to 95% in poorer countries Potential: Limited
Alternative: Biofuels? • Potential: Limited • OK, if grain is in surplus, can increase farmers income • But seems to increase price on all food crops (maize, grain, vegetables) • Agric. waste is OK! • Not many biofuels save energy or decrease CO 2 emissions! Algae may be the best raw material
Biofuels problem
Alternative: Hydropower? • Total world hydropower potential estimated at about 3 million MW. Eq. to 6000 Nuclear power reactors, or 7 times present nuclear production. • Current use about 10% of potential supply. • Most recent hydropower development has been in very large dams.
The huge Three Gorges Dam, Yangtze River, China DTU Environment Technical University of Denmark
Alternative: Wind energy? • Estimated potential is 20 million MW. • Fifty times current nuclear generation! • Producer electricity prices typically run 0. 03 US $/k. Wh. • Too little to pay the investment • Subsidies are rampant • Largest wind mills now at 3 -4 MW. DTU Environment Technical University of Denmark
Figure 12. 32 Wind turbine wing
Figure 12. 34 Idealised future world energy supply scenario up towards 2100. World Energy Council (2002) Fossil fuels still 54%
Alternative: Energy Conservation? – Most fossil energy is wasted as heat – Household energy losses can be reduced up to 75 % by using better insulation, glass, protective covers, etc. – Orienting homes to gain advantage of passive solar gain in the winter, and avoid sun input in summer. – When oil prices are high, cars become efficient. European/Japanese cars now run up to 30 km/l – Industries waste energy. High energy taxation is effective in reducing consumption – Conservation is probably the best way to reduce the greenhouse gas emission – Potential: very high, 50% is possible overall DTU Environment Technical University of Denmark
Alternative? Proposed technical fix against global warming: Injecting SO 3 into the stratosphere. White particles shielding against irradiation DTU Environment Technical University of Denmark
Conclusions on future energy • Fossil fuels are still abundant, especially coal and natural gas. Oil is in short supply. Most is gone in 100 -150 years • Fossil fuels may be feasible if CO 2 sequestration is in place. If not, we are in for a “hot” future • Renewables (wind, solar, biomass, hydro etc. ) are comparatively much less environmentally troublesome than fossil fuels • Biofuels are questionable at present practise (high food prices) • Nuclear energy is pursued by some countries, but most are reluctant • Energy taxation is effective in reducing greenhouse gas emissions, and promote alternatives DTU Environment Technical University of Denmark
Energy questions • Where is Russia now getting its energy from? • Where will Russia get its energy from in 2050? • Is renewable energy on in Russia? • Is Nuclear Energy favoured in Russia? DTU Environment Technical University of Denmark
DTU Environment Technical University of Denmark
c41b1c02c203f3205fb4e2f842528e57.ppt