A Sustainable Energy Future?

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2 We should start by asking what we mean by sustainable energy? We need energy sources that won t run out. We need energy sources that won t degrade our planetary environment. Slide - 2

3 We need energy sources that won t run out. The prosperous economies of developed countries are built on a foundation of abundant energy from fossil fuels. Developing countries like China and India, with the world s largest populations, are following the same route. Demand for fossil fuels keeps rising, but Earth s supplies of fossil fuels are finite and eventually they will be used up. Slide - 3

4 People talk a lot about Peak Oil, the time when world oil production reaches its highest point and then declines further and further each year.. When will it happen? What will its consequences be? Little consensus among experts on exact timing, but most predict sometime in the next couple of decades. Slide - 4

5 Perhaps more relevant is when demand starts to exceed supply. The developing economies of Asia have rapidly growing demand for oil. World production rates are straining to keep pace. This is reflected in the dramatic increases in the price of a barrel of oil in recent years. The price of a barrel of crude oil has increased by a factor of 5 over the last decade. Slide - 5

6 We can no longer count on cheap & abundant oil in the future. Natural gas supplies are similarly strained. Coal supplies are much more abundant, but cannot be used as simply for transportation. Need for energy alternatives The decline of fossil fuel supplies dovetails with another important area of concern. We need energy sources that won t degrade our planetary environment. Slide - 6

7 The 2007 Nobel Peace Prize was awarded to the IPCC and Al Gore for their work documenting and bringing attention to the issues of global warming and climate change. The International Panel on Climate Change is the U.N. sponsored organization of scientists that has carefully studied evidence establishing that. Earth s atmosphere is warming Rising levels of greenhouse gasses (like CO 2 ) that result from burning fossil fuels play a major role Many aspects of Earth s climate will change in response to warming The impact on human societies and other forms of plant and animal life may be severe How severe these effects will be depends on how much higher GHG levels rise. Slide - 7

8 Burning fossil fuels releases CO 2 and other GHG s into the atmosphere. How much higher GHG levels go depends in large part how fast the world can move away from reliance on fossil fuels. Trillions of kilograms of Carbon emitted from burning fossil fuels each year. Again this strongly points to the need for energy alternatives Slide - 8

9 Unfortunately, all the trends are pointing in the wrong direction The U.S. Energy Information Agency makes predictions for the future based on current data and trends. Total world energy usage by source, with EIA projections through Source: Energy Information Agency, 2007 International Energy Outlook EIA shows fossil fuels increasing more rapidly than renewables. Slide - 9

10 Let s make an inventory of our future energy options and try to understand their future prospects. Fossil Fuels Nuclear Wind Solar Biofuels The Hydrogen economy? Hydroelectric, Geothermal, Waves, Tides, Slide - 10

11 Fossil Fuels.. Even with oil and natural gas running low, we shouldn t think that fossil fuels will soon become irrelevant. What is on the horizon for fossil fuels? Non-conventional crude oil - heavy oil, tar sands & shale oil. Clean coal. Slide - 11

12 Non-conventional crude oil - heavy oil, tar sands & shale oil. As oil prices rise, some more costly to exploit petroleum-like substances will become profitable. Total world oil reserves 1300 Billion bbl Athabasca Oil Sands 1700 Billion bbl Orinoco Heavy Oil 1200 Billion bbl Green River Oil Shale 2000 Billion bbl How much non-conventional oil is economically recoverable is unclear. Slide - 12

13 When you think coal, think electricity 50% of U.S. electricity comes from coal fired power plants. Over 90% of coal mined is used to produce electricity. U.S. coal reserves are estimated at 250 years at current production rates. Extremely attractive to the electric power industry and to politicians interested in energy security. Slide - 13

14 Why Clean Coal? Coal is the dirtiest way to generate electricity. Burning coal produces the pollutants SO 2, NO and NO 2 that cause acid rain. Burning coal produces more CO 2 than other fossil fuels relative to the amount of energy released. Slide - 14

15 The U.S. Department of Energy, the coal industry and power companies are working together on implementing clean coal technologies through the prototype FutureGen power plant. The FutureGen plan includes The coal is first gasified allowing pollutants to be removed and the CO 2 to be separated, leaving H 2 as a fuel for clean electricity generation. The CO 2 will be sequestered in an underground geological formation. In the meantime, non-clean coal power plants are being built at a rapid pace both in the U.S. and worldwide Slide - 15

16 Nuclear Power The U.S. has 104 nuclear power plants generating 20% of our electricity. No new nuclear power plants have been approved since 1978, the year before the 3 Mile Island accident. However, with concerns over GHG emissions and economic encouragement from the Energy Policy Act of 2005, new applications are beginning to roll into the Nuclear Regulatory Commission. The NRC received 4 applications for new nuclear plants last year and is expecting 15 more in the coming year. The industry talks about a nuclear renaissance. Slide - 16

17 Renewable energy.. Earth gets a very nice allowance of energy from the sun every day, but can we learn how to make better use of it? Solar Power Wind Power Biofuels There is reason to be optimistic, but technologies have a long way to go to be economically competitive with fossil fuels. Of course, government policies can have great effect in leveling or tilting the playing field! Slide - 17

18 Solar Power. There are many ways to make use of the Sun s energy. Let s focus on how we can use solar energy to generate electricity. Two main ways. Photovoltaics (PV) A solar cell is basically an LED light working in reverse. An LED is a silicon device that procudes light from electricity. A solar cell is a silicon device that makes electricity from light.. Rooftop solar panels supply houses and other buildings with electricity. In grid-tied systems, the electricity flows into the power grid when excess electricity is generated & your meter turns backwards. One vision of the future for electricity is many small scale producers Slide - 18

19 The big issue with solar panels is cost. The price for a new coal fired power plant is about $1000 per kilowatt of capacity. To put solar panels on your roof costs about $7500 per kilowatt. The operating costs are zero, but the payback time is still long. Big efforts are going into lowering the costs of solar panels. Silicon is abundant, but the pure silicon crystals used in solar cells are expensive Technologies (a very recent MIT based startup) is one of many companies aiming at using innovative technologies to match the $1000 per kilowatt cost benchmark for solar cells, 1366 Watts per square meter is known as the Solar Constant - the amount of solar power hitting the Earth. Slide - 19

20 For large scale power plants, the choice is solar thermal power. Mirrors are used to concentrate the Sun s rays on a heat transfer material used to make steam which drives a turbine generator. One dramatic scheme is the solar power tower. Another is a system of parabolic troughs with oil piped through tubes at the center. Feb. 2008, Arizona Public Service contracted with the Spanish company Abengoa Solar to build the world s largest solar power plant (280 MW), covering 3 square miles. Slide - 20

21 Wind power.. Winds come from the differential heating of the atmosphere by the Sun, so wind power is another form of solar energy. Wind power is much closer to being cost competitive with coal and is growing in the U.S. at over 25% annually. Texas has become the U.S. leader in wind power. Cape Wind in Nantucket Sound is the the first offshore wind farm proposed in the U.S. Slide - 21

22 Intermittency One major problem with solar and wind power is that they fluctuate with the sun and winds. Electricity is difficult to store. For solar & wind to become major components of our energy infrastructure, this problem needs to be solved. Hydrogen is one possible energy storage solution. Hydrogen can be made from water using electricity. It can then be burned as needed to produce electricity. Companies are hard at work linking solar, wind and hydrogen technologies. Slide - 22

23 Biofuels. The major player is ethanol, which is the basic alcohol that we drink. It is produced from sugars by fermentation. There are many ways of going from plant matter to ethanol. C 2 H 6 Ethane C 2 H 5 OH Ethanol The easiest way is to start with sugar cane, as they do in Brazil, where ethanol accounts for about 40% of automobile fuel. In the U.S., most ethanol is currently made from corn. Before fermentation, the carbohydrates in the corn kernels must be converted to simple sugars. This is itself an energy intensive process. Slide - 23

24 Corn based ethanol has a number of serious drawbacks The energy gain relative to the energy input is at most a modest 30%. Savings in GHG emissions are even smaller. Using corn for ethanol displaces land from food production. If 100% of the U.S. corn crop went to ethanol, it would replace only 12% of gasoline. Slide - 24

25 An alternative route that holds great promise is cellulosic ethanol Cellulose is the primary structural component of green plants. One advantage is the ability to use agricultural waste products, such as corn stalks, industrial waste, such as paper making sludge, or crops such as switchgrass that can grow in poor soils with little fossil fuel input. Another advantage is that biomass is typically used as a fuel in the conversion of cellulose into sugars, greatly reducing CO 2 emissions. The challenge is in converting the cellulose into sugars for fermentation into ethanol. Many biotech firms are working on developing biological agents tailored to this task. is a local start-up company founded in the summer of 2007 by UMass Microbiology Professor Susan Leschine Slide - 25

26 Should we be optimistic about a sustainable energy future? A couple of random examples Although the federal government has not shown much leadership on climate change, individual states are stepping forward. Massachusetts vs. EPA (2007) - The Supreme Court ruled that the EPA must either regulate CO 2 emissions, or give a scientific justification for not doing so. Kansas recently turned down an application for two new non-clean coal fired power plants based solely on their GHG impact. Governor Sibelius recently vetoed an attempt by the Kansas Legislature to reverse this decision. Slide - 26

27 And if government won t listen, we can always turn to Slide - 27