The great energy transition
“These words: transition, sustainable, they’re too polite. This is a very serious problem that we’re facing, and fortunately we’re starting to realize that.” - John B. Heywood on transitioning to a more sustainable energy economy
At the 2003 MIT forum, 100 top scientists had to decide on and order the top 10 problems for the next 50 years. In order of priority the 10 problems selected were: Energy, Water, Food, Environment, Poverty, Terrorism & War, Disease, Education, Democracy and Population. - Source
Transforming the way we use energy is the most vital step in moving towards sustainability. Climate change, fossil fuel depletion, and human health are three issues that are causing us to rethink our energy use. The great energy transition is an open-minded look at the tools we can use to overhaul the entire energy system.
The goals of sustainability lend themselves to a straightforward definition of the energy transition.
Economics: It is no longer acceptable to treat energy security as an exercise in crisis management. A proactive energy policy with longer time horizons is needed to ensure short-term price stability and long-term security.
Ecology: Emissions from fossil fuel burning must be reduced dramatically, and health hazards from pollution must be addressed.
Equity: Clean and reliable energy technologies are not available in many parts of the world. Safer energy sources and lower energy prices are extremely important for developing countries.
Treating energy as a group of services rather than a commodity makes a host of engineering solutions apparent. Performing life cycle assessments on our energy use makes the sources of emissions and other pollution plainly visible. These two tools are sufficient to evaluate the tradeoffs we face, and they are essential for creating the policies that will see us through the energy transition.
Steven Koonin - Mobilizing Research and Ingenuity for the World’s Needs
State of the Planet 2006 - Earth Institute
Description, Play video (Real, 21:00)
Chief Scientist for BP Steven Koonin sets the stage for all the following talks by reviewing the current energy situation.
He expands on this talk in “Energy for the Coming Decades: Trends and Technologies” MITWorld, Video and description (Real, 1:20:00)
“The headline is the world is not going to run out of energy any time soon,” says Koonin, but he notes that the environmental, political and economic costs of energy supply are likely to increase.
Energy as a service
All of our activities related to energy fit somewhere along the energy conversion chain. As consumers of energy we make decisions towards the right end of the chain, yet we derive value from and care about elements of the entire chain. By reversing our view and taking the services perspective it becomes apparent that energy services are what we really value, and that there are multiple options available to provide them.
Some energy services are readily available and cost nothing. Radiative heat and light come from the sun, and geothermal heat comes from below ground. These direct services are environmentally benign and easy to capture. They are experiencing a renewal in modern buildings via new technologies: solar heating, daylighting, and geothermal heating.
When direct energy is unavailable we use stores of sunlight in the form of plant life (wood and coal), sea life (oil and gas), wind, and wave motion. These sources of energy open up the rest of the conversion chain, introducing large engineering challenges. Behind each stage in the conversion chain is a host of technologies designed to preserve as much energy as possible.
The first thing we notice when using energy indirectly is that not all Joules are equal. What we normally call energy is actually exergy, the potential for doing work. Exergy can be accessed by transforming energy from one type to another. It comes in the same flavors as energy, but unlike energy it can be expended.
Exergy helps us to quantify energy stores, but it does not explain how we might access them. To measure the value we derive from the coversion chain we need to know the economic returns of energy services relative to the total cost of extracting the energy. The ratio of these two quantities is called Energy Return on Investment (EROI). EROI is notoriously difficult to measure, in part because it is obscured from standard economic measures. Charles Hall indicates where more information is needed to help us make better EROI calculations in the talk below. The section Sustainable economics expands on his ideas further.
Charles Hall - Energy Accounting
Sustainable Energy Forum 2006
Audio, slides (mp3, 18:00)
Charles Hall reviews the assumptions needed to calculate EROI. He points out the areas where data is scarce, emphasizing the need for better accounting methods for energy related industries.
For a new energy source to make a dent in global use it must have the potential to scale to a terawatt, which is the output of 1000 large power plants. A Framework for Understanding Energy Resources shows that several sources are available, but that no single source is a shoe-in for providing energy in the future. The tradeoffs each energy source faces are covered extensively by articles and books in the resources section.
The most challenging energy service to provide sustainably will be transportation. Vehicles benefit from energy carriers that have a high energy density both by volume and by mass. Oil and its chemical neighbors offer the most convenient combination of the two. Oil’s energy density and its easy access has made it the dominant fuel for transportation.
The graph below shows how the transition to lower-carbon fuels has proceeded over centuries. The downward trend is entirely due to economic gains from increasing energy density. Unfortunately there are no more gains to be had in volume density of energy for fuels beyond oil. Ethanol, methane, and hydrogen each have less energy per unit volume (in their liquid state). The last step in de-carbonization the transition to hydrogen. It is more of a leap from an economic and an engineering standpoint because there are no chemical compounds between methane and hydrogen.
Data source: Jesse Ausubel 2007
Hydrogen can be used as a zero-emission energy carrier, but it requires clean energy for its generation. If a clean energy source is secured, the hydrogen economy still needs technologies to be invented across the entire conversion chain. Current research is focussed on finding nano-scale catalysts to make each step more efficient. The development of hydrogen as a truly sustainable fuel will take time, but the potential benefits are huge.
Thomas Klassen - Hydrogen Storage in Future Zero-Emission Vehicles
A technical background on storage options for hydrogen.
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Joseph Romm - Climate, Coal and the Car of the Future
The list of technologies that can harness renewable energy is growing at an incredible rate: Photovoltaics, solar ovens, biomass, wind power, tidal power, wave power, hydro power, geothermal power, and even algae bioreactors. The previously mentioned exergy slides show the geographical variablility of each renewable energy source, as well as the upper limit on their scale. The trio of solar, biomass, and wind are making the largest gains in actual capacity. Investment in renewable energy jumped to a record $100 billion in 2006, and is set to increase further.
Above: Figure 13 from the energy [r]evolution report shows that renewables will be economically competitive
in the not-too-distant future. The costs will be even more competitive once a carbon tax is enacted.
Jefferson Tester - Geothermal - An Undervalued Primary U.S. Energy Source
Tester considers what it would take to generate a terawatt of geothermal power in the US.
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Lee Lynd - The Role of Biomass in America's Energy Future and Cellulosic Biofuels: A High-Beams Perspective
Lynd gives a very pragmatic overview of the potential for biomass to offset other energy sources.
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Angela Belcher and Daniel Nocera - The Role of New Technologies in a Sustainable Energy Economy
On the outlook for renewable energy research to meet increasing energy demand.
Renewed interest in nuclear energy comes at an interesting time. Researchers have addressed past problems with nuclear power, and nuclear engineers have derived huge gains from existing plants. Today, new reactor designs, safer fuels, and better waste storage options are catching the interest of countries around the world. Nuclear fuel reserves are not unlimited, but they are at least as large as fossil fuel reserves. The MIT panel on “The Future of Nuclear Energy” concluded that nuclear energy could be scaled up over the next 20 years, continuing to supply energy until replacements become available around 2060.
Andrew C. Kadak - The Politically Correct Atomic Reactor
Pebble bed reactors: A clean, safe, and reliable source of electricity.
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Panel - The Future of Nuclear Energy
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Panel - Can Nuclear Energy and Non-Proliferation Co-Exist?
Nuclear fission is the reaction that nuclear power reactors take advantage of. Also called nuclear decay, it occurs throughout earth’s mantle, ‘shelling out’ for a substantial part of earth’s heating bill. The balance is provided by fusion reactions in stars, including 162 000 TW from our sun and an incredible 63 000 TW from beyond.
Steven Koonin, physicist and head scientist at BP, says that the major energy sources for the long term future will be advanced solar and fusion. Specialized high energy lasers are able to create fusion, but magnetic confinement reactors called tokomaks are currently much more efficient. The ITER project is a 500MW confinement reactor, and once constructed it will be 800 times more powerful than its predecessor. ITER is the next step towards harnessing fusion energy on earth, setting the stage for an actual fusion power plant to be built as soon as 2030.
ITER Fusion energy primer (part 2) and component testing
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Robert Bussard speaks about his work with compact fusion reactors
Distributed micropower
Physical laws dictate that mechanical systems gain efficiency as they increase in size. Since power plants are designed for high efficiency, it makes sense that they should be large. Distributed power generation is an entirely different take on scalable energy. Technologies like solar panels and batteries work well at any scale. They take advantage of a different scaling law: mass production. As the number of units produced increases, the cost of each unit approaches the cost of the materials it is made of.
Klaus Lackner - Scalable Energy Options
Earth Institute - Cross Cutting Initiative Seminar Series `06
Play video, description (Real, 1:17:00)
Klaus Lackner shows how the economy of mass production can compete with the economy scale.
to be continued...
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References
1. Global energy use was 13 terrawatts in 2006. That amounts to 410 exajoules in one year, which is more than four times the amount of sunlight used by the entire ecosystem. 86% of that energy came from fossil fuels, the equivalent of 9.1 billion tonnes of oil. 7 billion tonnes of carbon were ‘liberated’ as a result, released as 26 billion tonnes of CO2.
2. Earth is heated partly by nuclear fission of radioactive elements. The amount and distribution of radioactive material is still being studied. Geologists have found evidence of natural nuclear reactors in parts of earth’s crust where there are dense uranium deposits. These pockets once reached critical mass, but have long since burnt out.
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From Kyoto to Bali
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