Energy Transitions Past and Future: BP's Gulf of Mexico Oil Spill in Context (by Cutler Cleveland)

Below the fold is rerun of an essay from Cutler Cleveland on energy transitions. The unfolding drama in the Gulf of Mexico serves as a reminder of how dependent our modern civilization has become on fossil fuels. Dr. Cleveland's essay provides an excellent big picture overview, especially for readers here new to the topic, of what supply side variables we need to consider as we transition away from our extreme fossil fuel subsidy. Replacing stock based (fossil) energy with flow based (renewable) is not as simple as one for one BTU substitution. Professor Cleveland previously wrote "Energy From Wind - A Discussion of the EROI Research", and "Ten Fundamental Principles of Net Energy" posted on Cutler Cleveland is a Professor at Boston University and has been researching and writing on energy issues for over 25 years.

Image: Prometheus chained to Mount Caucasus. Source: Pieter Paul Rubens: ''Prometheus Bound,'' 1611-1612, Oil on canvas, 95 7/8" x 82 1/2". (Philadelphia Museum of Art: The W.P. Wilstach Collection)


In Greek mythology, Prometheus defied the will of Zeus by stealing fire and giving it to the mortal race of men in their dark caves. Zeus was enraged by Prometheus' deceit, so he had Prometheus carried to Mount Caucasus, where an eagle would pick at his liver; it would grow back each day and the eagle would eat it again. Fire transformed mortal life by providing light, warmth, cooking, healing and ultimately the ability to smelt and forge metals, and to bake bricks, ceramics, and lime. Fire became the basis for the Greek culture and ultimately all Western culture. It is no wonder, therefore, that the Greeks attributed fire not to a mortal origin, but to a Titan, one of the godlike giants who were considered to be the personifications of the forces of nature.

If fire was the first Promethean energy technology, then Promethean II was the heat engine, powered first by wood and coal, and then by oil and natural gas. Like fire, heat engines achieve a qualitative conversion of energy (heat into mechanical work), and they sustain a chain reaction process by supplying surplus energy. Surplus energy or (net energy) is the gross energy extracted less the energy used in the extraction process itself. The Promethean nature of fossil fuels is due to the much larger surplus they deliver compared to animate energy converters such as draft animals and human labor.

The changes wrought by fossil fuels exceeded even those produced by the introduction of fire. The rapid expansion of the human population and its material living standard over the past 200 years could not have been produced by direct solar energy and wood being converted by plants, humans and draft animals. Advances in every human sphere — commerce, agriculture, transportation, the military, science and technology, household life, health care, public utilities—were driven directly or indirectly by the changes in society's underlying energy systems.

In the coming decades, world oil production will peak and then begin to decline, followed by natural gas and eventually coal production. There is considerable debate about when these peaks will occur because such information would greatly aid energy companies, policy makers, and the general public. But at another level, the timing of peak fossil fuel production doesn't really matter. A more fundamental issue is the magnitude and nature of the energy transition that will eventually occur. The next energy transition undoubtedly will have far reaching impacts just as fire and fossil fuels did. However, the next energy transition will occur under a very different set of conditions, which are the subject of the rest of this discussion.

The Magnitude of the Shift

Figure 2. Composition of U.S. energy use. (Source: Cutler Cleveland) Click to Enlarge

The last major transition occurred in the late 19th century when coal replaced wood as the dominant fuel. Figure 2 illustrates this transition for the United States, a period often referred to as the second Industrial Revolution (the first being the widespread replacement of manual labor by machines that began in Britain in the 18th century, and the resultant shift from a largely rural and agrarian population to a town-centered society engaged increasingly in factory manufacture). Wood and animal feed suppled more than 95% of the energy used in the United States in 1800. The population of the nation stood at just 5.3 million people, per capita GDP was about $1,200 (in real US$2000), dominant energy converters were human labor and draft animals (horses), and the population was overwhelmingly rural and concentrated near the eastern seaboard.

Figure 3. The global flux of fossil and renewable fuels. (Source: Smil, V. 2006. "21st century energy: Some sobering thoughts.'' OECD Observer 258/59: 22-23.) Click to Enlarge

The nation was completely transformed by World War I. Coal had replaced wood as the dominant fuel, meeting 70% of the nation's energy needs, with hydropower and newcomers oil and natural gas combining for an additional 15%. Steam engines and turbines had replaced people and draft animals as the dominant energy converters. The population had soared to more than 100 million, per capita GDP had increased by a factor of five to $6,000, more than half of the nation's population lived in cities, and manufacturing and services accounted for most of the nation's economic output. Thus, the transition from wood to fossil fuels, and its associated shift in the energy-using capital stock, produced as fundamental a transition in human existence as did the transition from hunting and gathering to agriculture.

How much renewable energy is needed if it were to replace fossil fuels in the same pattern as coal replaced wood? The United States first consumed as much coal as wood in about 1885. Total energy use then was about 5.6 quadrillion BTU (1 quadrillion = 1015), equal to about 0.19 TW (Terawatts or 10^12 watts). Consider what it would take today to replace even just one-half of U.S. fossil fuel use with renewable energy: we would need to displace coal and petroleum energy flows of 2.9 TW, or 32 times the amount of coal used in 1885. Current global fossil fuel use is about 13 TW, so we need more than 6 TW of renewable energies to replace 50% of all fossil fuels. This is a staggering shift.

Is renewable energy up to this challenge? There are physical, economic, technical, environmental, and social components to this question. Figure 3 depicts one slice of the picture: pure physical availability as measured by the global annual flow of various energies. The only renewable energy that exceeds annual global fossil fuel use is direct solar radiation, which is several orders of magnitudes larger than fossil fuel use. To date however, the delivery of electricity (photovoltaics) or heat (solar thermal) directly from solar energy represents a tiny fraction of our energy portfolio due to economic and technical constraints. Most other renewable energy flows could not meet current energy needs even if they were fully utilized. More importantly, there are important qualitative aspects to solar, wind, and biomass energy that pose unique challenges to their widespread utilization.


Most discussions of energy require the aggregation of different forms and types of energy. The notion of "total energy use" in Figures 2 and 3 indicates that various physical amounts of energy—coal, oil, gas, uranium, kilowatt-hours (kWh), radiation—are added together. The simplest and most common form form of aggregation is to add up the individual variables according to their thermal equivalents (BTUs, joules, etc.). For example, 1 kWh is equal to 3.6x106 joules, 1 barrel of oil is equal to 6.1x109 joules, and so on.

Despite its widespread use, aggregation by heat content ignores the fact that not all joules are equal. For example, a joule of electricity can perform tasks such as illumination and spinning a CD-ROM that other forms of energy cannot do, or could do in a much more cumbersome and expensive fashion (Imagine trying to power your laptop directly with coal).

These differences among types of energy are described by the concept of energy quality, which is the difference in the ability of a unit of energy to produce goods and services for people. Energy quality is determined by a complex combination of physical, chemical, technical, economic, environmental and social attributes that are unique to each form of energy. These attributes include gravimetric and volumetric energy density, power density, emissions, cost and efficiency of conversion, financial risk, amenability to storage, risk to human health, spatial distribution, intermittency, and ease of transport.

Energy Density

Figure 4. Energy densities for various fuels and forms of energy. (Source: Cutler Cleveland) Click to Enlarge

Energy density refers to the quantity of energy contained in a form of energy per unit mass or volume. The units of energy density are megajoules per kilogram (MJ/kg) or megajoules per liter (MJ/l). Figure 4 illustrates a fundamental driver behind earlier energy transitions: the substitution of coal for biomass and then petroleum for coal were shifts to more concentrated forms of energy. Solid and liquid fossil fuels have much larger mass densities than biomass fuels, and an even greater advantage in terms of volumetric densities. The preeminent position of liquid fuels derived from crude oil in terms of its combined densities is one reason why it transformed the availability, nature and impact of personal and commercial transport in society. The lower energy density of biomass (12-15 MJ/kg) compared to crude oil (42 MJ/kg) means that replacing the latter with the former will require a significantly larger infrastructure (labor, capital, materials, energy) to produce an equivalent quantity of energy.

The concept of energy density underlies many of the challenges facing the large scale utilization of hydrogen as a fuel. Hydrogen has the highest energy to weight ratio of all fuels. One kg of hydrogen contains the same amount of energy as 2.1 kg of natural gas or 2.8 kg of gasoline. The high gravimetric density of hydrogen is one reason why it is used for a fuel in the space program to power the engines that lift objects against gravity. However, hydrogen has an extremely low amount of energy per unit volume (methane has nearly 4 times more energy per liter than hydrogen). Hydrogen's low volumetric energy density poses significant technical and economic challenges to the large-scale production, transport and storage for commercial amounts of the fuel.

Power Density

Figure 5. Power densities for fossil and renewable fuels. (Source: Smil, V. 2006. ''21st century energy: Some sobering thoughts.'' OECD Observer 258/59: 22-23.) Click to Enlarge

Power density is the rate of energy production per unit of the earth’s area, and is usually expressed in watts per square meter (W/m2). The environmental scientist Vaclav Smil has documented the important differences between fossil and renewable energies, and their implications for the next energy transition. Due to the enormous amount of geologic energy invested in their formation, fossil fuel deposits are an extraordinarily concentrated source of high-quality energy, commonly extracted with power densities of 10^2 or 10^3 W/m2 of coal or hydrocarbon fields. This means that very small land areas are needed to supply enormous energy flows. In contrast, biomass energy production has densities well below 1 W/m2, while densities of electricity produced by water and wind are commonly below 10 W/m2. Only photovoltaic generation, a technique not yet ready for mass utilization, can deliver more than 20 W/m2 of peak power.

The high power densities of energy systems has enabled the increasing concentration of human activity. About 50% of the world's population occupies less than 3% of the inhabited land area; economic activity is similarly concentrated. Buildings, factories and cities currently use energy at power densities of one to three orders of magnitude lower than the power densities of the fuels and thermal electricity that support them. Smil observes that in order to energize the existing residential, industrial and transportation infrastructures inherited from the fossil-fueled era, a solar-based society would have to concentrate diffuse flows to bridge these large power density gaps.

Mismatch between the inherently low power densities of renewable energy flows and relatively high power densities of modern final energy uses means that a solar-based system will require a profound spatial restructuring with major environmental and socioeconomic consequences. Most notably according to Smil, there would be vastly increased fixed land requirements for primary conversions, especially with all conversions relying on inherently inefficient photosynthesis whose power densities of are minuscule: the mean is about 450 mW/m2 of ice-free land, and even the most productive fuel crops or tree plantations have gross yields of less than 1 W/m2 and subsequent conversions to electricity and liquid fuels prorate to less than 0.5 W/m2.

Energy Surplus

Figure 6. The energy return on investment (EROI) for various fuel sources in the U.S. (Source: Cutler Cleveland) Click to Enlarge

Energy return on investment (EROI) is the ratio of the energy extracted or delivered by a process to the energy used directly and indirectly in that process. A common related term is energy surplus, which is the gross amount of energy extracted or delivered, minus the energy used directly and indirectly in that process. The unprecedented expansion of the human population, the global economy, and per capita living standards of the last 200 years was powered by high EROI, high energy surplus fossil fuels. The penultimate position of fossil fuels in the energy hierarchy stems from the fact that they have a high EROI and a very large energy surplus. The largest oil and gas fields, which are found early in the exploration process due to their sheer physical size, delivered energy surpluses that dwarfed any previous source (and any source developed since then). That surplus, in combination with other attributes, is what makes conventional fossil fuels unique. The long-run challenge society faces is to replace the current system with a combination of alternatives with similar attributes and a much lower carbon intensity.

Most alternatives to conventional liquid fuels have very low or unknown EROIs (Figure 6). The EROI for ethanol derived from corn grown in the U.S. is about 1.5:1, well below that for conventional motor gasoline. Ethanol from sugarcane grown in Brazil apparently has a higher EROI, perhaps as high as 8:1, due to higher yields of sugarcane compared to corn, the use of bagasse as an energy input, and significant cost reductions in ethanol production technology. Shale oil and coal liquefaction have low EROIs and high carbon intensities, although little work has been done in this area in more than 20 years. The Alberta oil sands remain an enigma from a net energy perspective. Anecdotal evidence suggests an EROI of 3:1, but these reports lack veracity. Certainly oil sands will have a lower EROI than conventional crude oil due to the more diffuse nature of the resource base and associated increase in direct and indirect processing energy costs.


Figure 7. A typical 24 hour load profile for a residence in San Jose, CA. (Source: NREL) Click to Enlarge

Intermittency refers to the fraction of time that an energy source is available to society. It is an essential feature of electricity generation systems that must combine power generated from multiple sources and locations to supply electricity "24/7." The wind does not blow all the time and the sun does not shine all the time, so a wind turbine and PV array sometimes stand idle. One aspect of intermittency is the load factor or capacity factor, which is the ratio of the output of a power plant compared to the maximum output it could produce. Due to the more or less continuous nature of fossil fuel extraction, thermal power plants have capacity factors of 75 to 90 percent. Typical annual average load factors for wind power are in the range of 20 to 35 percent, depending primarily on wind climate, but also wind turbine design.

Figure 8. The variability of wind energy over a 1y day period. The figure compares the hourly output of 500 MW wind power capacity in two situations, calculated from observed data in Denmark. The red line shows the output of a single site; the blue line shows the multiple site output. Source: European Wind Energy Association, ''Large scale integration of wind energy in the European power supply: analysis, issues and recommendations'' (December 2005) Click to Enlarge

Load profiles show characteristic daily and seasonal patterns (Figure 7). For example, most hourly profiles for commercial and institutional facilities rise in the middle of the day and then taper off during early morning and late evening hours. Wind and solar energy availability frequently do not match typical load profiles (Figure 8).

Such intermittency means that wind and solar power are really not “dispatchable”—you can’t necessarily start them up when you most need them. Thus, when wind or solar power is first added to a region’s grid, they do not replace an equivalent amount of existing generating capacity—i.e. the thermal generators that already existed will not immediately be shut down. This is measured by capacity credit, which is the reduction of installed power capacity at thermal power stations enabled by the addition of wind or solar power in such a way that the probability of loss of load a peak times is not increased.

So, for example, 1000 MW of installed wind power with a capacity credit of 30% can avoid a 300 MW investment in conventional dispatchable power. A recent survey of U.S. utilities reveals capacity credits given to wind power in the range of 3 to 40 percent of rated wind capacity, with many falling in the 20 to 30 percent range. A large geographical spread of wind or solar power is needed to reduce variability, increase predictability and decrease the occurrences of near zero or peak output.

These and other "ancillary costs" associated with wind and solar power are small at low levels of utilization, but rise as those sources further penetrate the market. In the longer run, the impacts of these additional costs on the the deployment of wind and solar power must be compared with the effective costs of other low-carbon power sources such as nuclear power, or the costs of fossil thermal generation under strong carbon constraints (i.e., carbon capture and storage).

Spatial distribution

Figure 9. The distribution of wind speeds at 80 meters, the hub height of a modern turbine. (Source: Cristina L. Archer and Mark Z. Jacobson, Evaluation of global wind power) Click to Enlarge

All natural resources show distinct geographical gradients. In the case of oil and natural gas for example, the ten largest geologic provinces contain more than 60 percent of known volumes, and half of those are in the Persian Gulf. Coal and uranium deposits also are distributed in distinct, concentrated distributions. The pattern of occurrence imposes transportation and transaction costs, and in the case of oil and strategic minerals, also imposes risk associated with economic and national security.

Figure 10. The distribution of solar energy exhibits a strong geographical gradient. (Source: NREL) Click to Enlarge

Of course, renewable energy flows exhibit their own characteristic distributions (Figures 9 and 10), producing mismatches between areas of high-quality supply and demand centers. Many large urban areas are far from a high-quality source of geothermal energy, do not have high wind power potential, or have low annual rates of solar insolation. Indeed, many of the windiest and sunny regions in the world are virtually uninhabited. The spatial distribution of renewable energy flows means that significant new infrastructures will be needed to collect, concentrate and deliver useful amounts of power and energy to demand centers.


The transition from wood to coal occurred when the human population was small, its affluence was modest, and its technologies were much less powerful than today. As a result, environmental impacts associated with energy had negligible global impact, although local impacts were at times quite significant. Any future energy transition will operate under a new set of environmental constraints. Environmental change has significantly impaired the health of people, economics and ecosystems at local, regional and global scales. Future energy systems must be designed and deployed with environmental constraints that were absent from the minds of the inventors of the steam engine and internal combustion engines.

Air Pollution and Climate Change

Figure 11. The Mauna Loa curve showing the rise in atmospheric carbon dioxide concentrations (Source: Keeling, C.D. and T.P. Whorf. 2005. Atmospheric CO2 records from sites in the SIO air sampling network. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.) Click to Enlarge

Atmospheric releases from fossil fuel energy systems comprise 64 percent of global anthropogenic carbon dioxide emissions from 1850-1990 (Figure 11), 89 percent of global anthropogenic sulfur emissions from 1850 to 1990, and 17 percent of global anthropogenic methane emissions from 1860-1994. Fossil energy combustion also releases significant quantities of nitrogen oxide; in the United States, 23 percent of such emissions are from energy use. Power generation using fossil fuels, especially coal, is a principal source of trace heavy metals such as mercury, selenium, and arsenic.

These emissions drive a range of global and regional environmental changes, including global climate change, acid deposition, and urban smog, and they pose a major health risk. According to the Health Effects Institute, the global annual burden of outdoor air pollution amounts to about 0.8 million premature deaths and 6.4 million years of life lost. This burden occurs predominantly in developing countries; 65% in Asia alone. According to the World Health Organization, in the year 2000, indoor air pollution from solid fuel use was responsible for more than 1.6 million annual deaths and 2.7% of the global burden of disease. This makes this risk factor the second biggest environmental contributor to ill health, behind unsafe water and sanitation.

Climate change may be the most far-reaching impact associated with fossil fuel use. According to the Intergovernmental Panel on Climate Change (IPCC), the global atmospheric concentration of carbon dioxide has increased from a pre-industrial value of about 280 parts per million (ppm) to 379 ppm in 2005 (Figure 6). The atmospheric concentration of carbon dioxide in 2005 exceeds by far the natural range over the last 650,000 years (180 to 300 ppm) as determined from ice cores. The primary source of the increased atmospheric concentration of carbon dioxide since the pre-industrial period results from fossil fuel use, with land use change providing another significant but smaller contribution. The increase in carbon dioxide concentrations are a principal driving force behind the observed increase in globally averaged temperatures since the mid-20th century.

Carbon intensity is an increasingly important attribute of fuel and power systems. Social and political forces to address climate change may produce another distinguishing feature of the next energy transition: environmental considerations may be a key important driver, rather then the inherent advantages of energy systems as measured by energy density, power density, net energy, and so on.

Appropriation of the products of the biosphere

Figure 12. Human appropriation of net primary production (NPP) as a percentage of the local NPP. (Source: Imhoff, Marc L., Lahouari Bounoua, Taylor Ricketts, Colby Loucks, Robert Harriss, and William T. Lawrence. 2004. Global patterns in human consumption of net primary production. ''Nature'', 429, 24 June 2004: 870-873. Image retrieved from NASA) Click to Enlarge

The low energy and power density of most renewable alternatives collides with a second global environmental imperative: human use of the Earth's plant life for food, fiber, wood and fuelwood. Satellite measurements have been used to calculate the annual net primary production (NPP)—the net amount of solar energy converted to plant organic matter through photosynthesis—on land, and then combined with models to estimate the annual percentage of NPP humans consume (Figure 12).

Humans in sparsely populated areas, like the Amazon, consume a very small percentage of locally generated NPP. Large urban areas consume 300 times more than the local area produced. North Americans use almost 24 percent of the region's NPP. On a global scale, humans annually require 20 percent of global NPP.

Human appropriation of NPP, apart from leaving less for other species to use, alters the composition of the atmosphere, levels of biodiversity, energy flows within food webs, and the provision of important ecosystem services. There is strong evidence from the Millennium Ecosystem Assessment and other research that our use of NPP has seriously compromised many of the planet's basic ecosystem services. Replacing energy-dense liquid fuels from crude oil with less energy dense biomass fuels will require 1,000- to 10,000-fold increase in land area relative to the existing energy infrastructure, and thus place additional significant pressure on the planet's life support systems.

The rise of energy markets

When coal replaced wood, most energy markets were local or regional in scale, and many were informal. Energy prices were based on local economic and political forces. Most energy today is traded in formal markets, and prices often are influenced by global events. Crude oil prices drive the trends in price for most other forms of energy, and they are formed by a complex, dynamic, and often unpredictable array of economic, geologic, technological, weather, political, and strategic forces.

The rise of commodity and futures markets for energy not only added volatility to energy markets, and hence energy prices, but also helped elevate energy as to a key strategic financial commodity. The sheer volume of energy bought and sold today combined with high energy prices has transformed energy corporations into powerful multinational forces. In 2006, five of the world's largest corporations were energy suppliers (Exxon Mobil, Royal Dutch Shell, BP, Chevron, and ConocoPhillips). The privatization of state-owned energy industries is also a development of historic dimensions that is transforming the global markets for oil, gas, coal and electric power.

Global market forces will thus be an important driving force behind the next energy transition. There is considerable debate about the extent to which markets can and should be relied upon to guide the choice of our future energy mix. Externalities and subsidies are pervasive across all energy systems in every nation. The external cost of greenhouse gas emissions from energy use looms as a critical aspect of energy markets and environmental policy. The distortion of market signals by subsidies and externalities suggests that government policy intervention is needed to produce the socially desirable mix of energy. The effort to regulate greenhouse gas emissions at the international level is the penultimate example of government intervention in energy markets. The political and social debate about the nature and degree of government energy policy will intensify when global crude oil supply visibly declines and as pressure mounts to act on climate change.

Energy and poverty

Figure 14. Energy and basic human needs. The international relationship between energy use (kilograms of oil equivalent per capita) and the Human Development Index (2000). (Source: UNDP, 2002, WRI, 2002) Click to Enlarge

The energy transition that powered the Industrial Revolution helped create a new economic and social class by raising the incomes and changing the occupations of a large fraction of society who were then employed in rural, agrarian economies. The next energy transition will occur under fundamentally different socioeconomic conditions. Future energy systems must supply adequate energy to support the high and still growing living standards in wealthy nations, and they must supply energy sufficient to relieve the abject poverty of the world's poorest.

The scale of the world's underclass is unprecedented in human history. According to the World Bank, about 1.2 billion people still live on less than $1 per day, and almost 3 billion on less than $2 per day. Nearly 110 million primary school age children are out of school, 60 percent of them girls. 31 million people are infected with HIV/AIDS. And many more live without adequate food, shelter, safe water, and sanitation.

Energy use and economic development go hand-in-hand (Figure 14), so poverty has an important energy dimension: the lack of access to high quality forms of energy. Energy poverty has been defined as the absence of sufficient choice in accessing adequate, affordable, reliable, high quality, safe and environmentally benign energy services to support economic and human development. Nearly 1.6 billion people have no access to electricity and some 2.4 billion people rely on traditional biomass—wood, agricultural residues and dung—for cooking and heating. The combustion of those traditional fuels has profound human health impacts, especially for woman and children. Access to liquid and gaseous fuels and electricity is a necessary condition for poverty reduction and improvements in human health.


The debate about "peak oil" aside, there are relatively abundant remaining supplies of fossil fuels. Their quality is declining, but not yet to the extent that increasing scarcity will help trigger a major energy transition like wood scarcity did in the 19th century. The costs of wind, solar and biomass have declined due to steady technical advances, but in key areas of energy quality—density, net energy, intermittancy, flexibility, and so on—they remain inferior to conventional fuels. Thus, alternative energy sources are not likely to supplant fossil fuels in the short term without substantial and concerted policy intervention.

The need to restrain carbon emissions may provide the political and social pressure to accelerate the transition to wind, biomass and solar, as this is one area where they clearly trump fossil fuels. Electricity from wind and solar sources may face competition from nuclear power, the sole established low-carbon power source with significant potential for expansion. If concerns about climate change drive a transition to renewable sources, it will be the first time in human history that energetic imperatives, especially the the economic advantages of higher-quality fuels, were not the principal impetus.


* Dimitri, Carolyn, Anne Effland, and Neilson Conklin, The 20th Century Transformation of U.S. Agriculture and Farm Policy. Electronic Information Bulletin Number 3, June 2005, Economic Research Service, U.S. Department of Agriculture.

* European Wind Energy Association, Large scale integration of wind energy in the European power supply: analysis, issues and recommendations (December 2005).

* Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science Basis. Summary for Policymakers, February 2007.

* Johnston, Louis D. and Samuel H. Williamson, The Annual Real and Nominal GDP for the United States, 1790 - Present. Economic History Services, retrieved April 1, 2006.

* Milligan, M. and K. Porter, Determining the Capacity Value of Wind: A Survey of Methods and Implementation, Conference Paper NREL/CP-500-38062 May 2005.

* Reddy, A.K.N., Energy and social issues, in World Energy Assessment: the challenge of sustainability, UNDP/UNDESA/WEC, New York, 2000.

* Smil, V. 2006. "21st century energy: Some sobering thoughts". OECD Observer 258/59: 22-23.

* World Bank PovertyNet.


Cleveland, Cutler (Lead Author); Peter Saundry (Topic Editor). 2007. "Energy transitions past and future." In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published April 11, 2007; Last revised May 3, 2007; Retrieved August 7, 2007]. Source here

**Prometheus chained to Mount Caucasus. Source: Pieter Paul Rubens: ''Prometheus Bound,'' 1611-1612, Oil on canvas, 95 7/8" x 82 1/2". (Philadelphia Museum of Art: The W.P. Wilstach Collection)

Interesting graphics. I'd like to a log - log plot of my own to this discussion. The following describes how energy is used for transportation:

That's an intersting plot. It just needs better categorization according to travel objectives, i.e. freight vs people vs scientific objectives (Voyager). And the big distinction is in where the transportation fuel comes from. .

The following link looks like a much more comprehensive view of what you are trying to get at:


Thanks for your reply. Regarding objectives, I tried to compare personal transportation to everything else, by making the other labels self-explanatory. Note that the personal machines all carry 70 kg, so that the horizontal lines in the shaded corner indicate constant speed.

I will return at some later time to digest that analysis.

Two quick comments; one: I like the concept of "Knol, a unit of knowledge."
two: This caught my eye in the intro:

In evaluating transportation choices, energetic economy is an important and well-characterized consideration commonly expressed in miles per gallon of gasoline. Average speed is also important, since people are paid by the hour and “time is money.” Others have considered this interplay between vehicle speed and energetic economy.

In the seminal technical article entitled, "What Price Speed?" Giuseppe Gabrielli and Theodore von Karman [1] defined the specific resistance of a vehicle, e, as maximum motor output power P, divided by total vehicle weight W multiplied by maximum speed VM.

emphasis mine.

I was sent an email yesterday that contain a quote from a Tuareg woman, who was getting a university education in a first world country.

She said this about the country where she was studying compared to here nomadic life style, "Here you have clocks, there I have time."

To those who say to me that time is money, I now say to them, if you can pay me in time I prefer that to money... though I might even accept a couple of "Knols."

Best hopes for an understanding that time is worth infinitely more than money!

Sure enough, time is money. A road bike is obviously the energy winner at the expense of time spent on the road.

Cutler never really explains the reasons for wind intermittency and other apparently random efficiencies. This has more to do with the concept of entropy than anything else, which unfortunately never appears in his discussion. I expect that we will have to learn how to deal with entropic sources of energy. Yet unless we understand the sources of uncertainty and variability, the BAU crowd will use that as a hammer to criticize our new "crappy" energy sources.

I have a new blog post on variability of thermal conductivity in the context of heat exchangers here:

Wind characterization:

Photovoltaic characterization:

Old forms of energy require new ways of thinking.

The vast amount of current energy use is waste and extravagance; the major change in the future will be conservation--not replacing current energy use on a one-to-one basis.

You can see that on the energy/HDI plot where increasing energy consumption per capita past about 1000 kgoe has minimal effect on further development. Some of that is probably due to geographical factors (eg., Australia will probably always have a higher per-capita energy consumption than Luxembourg due to the huge size of the former and the spread-out population centers), but a lot of it is probably just waste.

Actually, a major driver of the shape of this graph is the role of a logarithmic scale in the HDI.

The Human Development Index is an unweighted average of a health index, a literacy index, and an economic index. The economic index is based on a logarithmic transformation of GDP per capita.

A plot of GDP per capita against energy use is much closer to a line than a flattening curve.

However the flattening curve more or less remains if you take the economic component out of the HDI and just average the health and literacy components. That suggests that greater wealth is a real help to greater quality of life when you're poor, but becomes less and less important once you pass around $10,000 GDP/capita. (This is a result that shows up in otherways, such as the Easterling paradox.) So greater energy use has a strong effect on making you richer, but past a fairly modest point has only a modest effect on making your life better.

So greater energy use has a strong effect on making you richer, but past a fairly modest point has only a modest effect on making your life better.

It's probably more accurate to say that greater energy has only a modest effect on increasing the index, once the economic component is removed. I would personally be very cautious about making claims about how changes in the index are related to how well off individuals are. I have at least a passing knowledge of the happiness literature, and there is still considerable reluctance about making quantitative comparisons between responses at different points on the scale. The usual treatment is to use methods for ordered outcomes that don't assign magnitudes to different responses. In other words, if individuals are asked to rank life satisfaction from 1 to 10 (or in four categories, ranking from very unhappy to very happy) there is no sense in which an individual answering 8 is twice as well off as someone answering 4. And while income may place a reduced role in moving from an 8 to a 9 than it does in moving from a 4 to 5, I'm not sure that this is equivalent to saying that past a point, income plays a modest role in making one better off, in so far as its not clear that these increments are comparable in the way that is implied by the claim.

Can ice-storage cooling systems balance renewable electricity sources?

Electricity is hard to store, so fluctuating renewable systems typically require other generators on the grid to be deliberately fluctuated. Rapidly adjustable generation tends to be expensive.

Wouldn't it be nice if there were a kind of load that required lots of electricity, but didn't much care when it was used? Something that could store lots of work and then use it efficiently? As a bonus, it should be relatively concentrated in commercial locations, to minimize the extra infrastructure (technical, financial, and regulatory) needed to control it.

These systems already exist. They make ice using relatively cheap off-peak power, and use the ice to cool the building the next day. Modern chillers can cycle on and off in minutes. It should take very little infrastructure to make them remotely switchable, so that they can be used to balance the grid.

This would require a hefty amount of R&D - but a lot less than wiring up millions of plug-in hybrids or domestic water heaters to perform the same function (ideas that I've seen seriously proposed).

Chillers seem to use tens of percent of the total electricity load (haven't yet found a figure for the US, but it's 30% in Taiwan). So this one load category could, all by itself, balance a substantial fraction of renewables.

The control problems of remote-controlled chillers might seem difficult, but the addition of an ice tank might actually reduce the overall complexity of controlling an installation; cold water delivery could be adjusted minute-to-minute, utilities could adjust on a 10-minute cycle (staggered between different installations to give sub-minute control of load), and balancing decisions could be made locally hour-to-hour.

If this idea is technically sound, it will probably require regulatory assistance to support industry-wide implementation. Whatever power utilities and chiller companies do the research first will be able to advise on the legislation, and will become the go-to sources for consulting and installation.

Even a relatively slow roll-out should be able to keep pace with the current rate of renewable installation.

Wouldn't it be nice if there were a kind of load that required lots of electricity, but didn't much care when it was used? Something that could store lots of work and then use it efficiently? As a bonus, it should be relatively concentrated in commercial locations, to minimize the extra infrastructure (technical, financial, and regulatory) needed to control it.

Perhaps because of the fact that if your only tool happens to be a hammer then everything ends up looking like a nail I have thought for a long time that I would like to see more done with CAES.

Disclaimer: I at one time I was a hyperbaric tech and worked extensively with high pressure compressors and pneumatic tools underwater. Currently I'm a partner in a small solar energy business.

Ae there cheap materials that would work really well as heat sinks that could be used to store heat during cold months?

I know water has a very high heat storage capacity but real storage with water depends on a phase change, as in freezing,and steam storage is not going to be economical.

But other materials such as gravel might work out ok simply because the temperature could be raised up to several hundred degrees F if the costs work out favorably.

Somebody here has undoubtedly run some numbers along these lines but I haven't seen the results.

Check out the first link in my comments up above. I did a transient analysis of earth heat exchange and reference an interesting experiment that a Dutch company did. Its really a matter thermal conductivity and harnessing the inertia of a thermal mass.

But other materials such as gravel might work out ok simply because the temperature could be raised up to several hundred degrees F if the costs work out favorably.

You don't want the storage temperature to be too different from the end use temp. The thermodynamic efficiency of your heat engine is limited by Tmax/delta(T) (where we use absolute temperature). So we would like delta T to be as small as practical. Gravel storage has been recommened in combination with solar thermal power. But for that application the gravel is at the working temperature of the heat engine, so it doesn't sacrifice efficiency.

Thermal mass can also be pretty cheap when it is incorporated into new construction;an extra inch or two of concrete in a floor or wall could add up to a huge collective heat sink if the building code were changed to require this feature.

The human component is the tough part here. In order for the thermal mass to accomplish anything you have to tolerate temperature swings. No more building temperature on demand, but rather a few degrees below average in the morning and a few above in the afternoon (for typical passive solar apps, using low cost off peak power may change the timing). But you gotta get the building occupants in on it, otherwise it won't do a thing for you.

"Ae there cheap materials that would work really well as heat sinks that could be used to store heat during cold months?"

check this out

No need to re-invent the wheel.
Please consider Phase Change Materials.
An Example:

A sodium acetate heating pad. When the sodium acetate solution crystallises, it becomes very warm. Wikipaedia quote.

30,000 compounds were inspected for suitability by DOW.
Candle wax was found to be a winner. It is cheap, its melting point could preselected from a range of carbon molecule lengths.

Isn't candle wax or paraffin made from petroleum? Sometimes the arguments go circular and we don't even realize it.

I guess the wax does get reused ...

Chillers seem to use tens of percent of the total electricity load (haven't yet found a figure for the US, but it's 30% in Taiwan). So this one load category could, all by itself, balance a substantial fraction of renewables.

That strikes me as a rather large figure, but then Taiwan has a pretty tropical climate.
And if I think about my home electric usage averaged over a year, chillers: AC and refrigerator might well be in the ballpark.

I've seen similar arguments made for commercioal scale coolers, run the temp[erature down during low demand periods, and let it rise a bit during the day. Without ice or hightech I try to bank "coolth" by using cold nighttime air to cool the house down far below the normal summer temp (78F). In this case the night-time cool is cheap because it is simply cools air advected via fans (or wind). How does the energy efficiency of using your ice chiller comapare to on demand cooling? I could see the net efficiency (ignoring time of use issues for the moment) going either way. More expensive per BTU to have a colder exhaust temperature (below freezing), versus the ambient temperature being less at night.

In any case, I think demand management is something we will grow into a little bit at a time. We should start with the lowest hanging fruit, then as the need increases go a little further each year. Asking people to go cold turkey from on demand to as available power is pretty frightening to most. But, I think by taking it one baby step at a time we will barely notice it.

Making ice is said to cost, IIRC, 5 to 10% efficiency vs. direct chilling. So it's noticeable but not too bad.

If we can find a few large applications that can usefully absorb energy on-demand, then the rest of the applications may never have to go into demand mode. The less re-engineering we have to do, the easier the transitions will be.

One thing I noticed about the energy-source graph: The highest percentage trends downward over time. As new sources come online, we gain more flexibility and redundancy. If any one major source disappeared completely today - even oil - we'd lose only 10-40% of our energy supply. Of course, that's not the whole picture, because some applications are geared toward single types of energy.


The majority of United States of Americans would rather pay hydrocarbon taxes to Washington than any multi-national organization. Unless standards and enforcement within our borders is an entirely domestic run operation, it would be a tough sell. I see no reason why Washington could not get its standards at least in part from beyond its borders provided the American people were convinced that such standards did not represent some sort of punishment from the global community for being 'successful'. Foreign ideas do not scare the average American, unless those ideas represent the 'loss of the Empire' to us. After all, is not democracy itself an import for us? I do not necessarily agree with this logic, but that is my opinion and observation. Maybe this incident in the Gulf will open up some minds.

I think the low US fuel taxes refute your first sentence.

We have paid Saudi Aramco billions and yet, when gas prices rose, Americans asked congress to lower the gasoline tax, not raise it.

Some points that stand out;

1. Intermittent energy sources CAN replace fossil fuel plants (such as coal), if there is sufficient dispatchable energy sources available, ie., hydro, gas peaker, geothermal, etc) and/or smart grid HVAC/appliances that varied consumption according to commercial, industrial, and residential building load control profiles (i.e., if the wind goes to lull and electricity prices go above $0.13/kWhr, then set thermostat to 78F). It could be that some coal plants could be mothballed most months of the year, except for summer in warmer locals where A/C creates extreme load peaks.

2. Energy density is of modest importance, primarily for medium and long haul transportation (though electrified trains could be substituted even then). EVs would considerably change the need for high densitiy liquid fuels for local transportation - the focus would then be on the energy density of the battery technology.

Is renewable energy up to this challenge? There are physical, economic, technical, environmental, and social components to this question. Figure 3 depicts one slice of the picture: pure physical availability as measured by the global annual flow of various energies. The only renewable energy that exceeds annual global fossil fuel use is direct solar radiation, which is several orders of magnitudes larger than fossil fuel use.

Figure 3 seems to show that wind is an order of magnitude greater than total fossil fuel use, but then the x-axis is in watts (power), not watt-hours (energy). Is the claim that total wind energy is less than the available FF energy due to intermittency?

Interesting article so far, but just need to flag this error: "Terawatts or 1012 watts" should read "Terawatts or 10^12 watts"

sorry that was my mistake. fixed now.

I seem to recall having seen a similar chart. I thought tidal and ocean currents were about ten times higher than you have. It doesn't change the overall picture, they are both modest increments to available world totals, but have have local or regional importance. Also wave energy is significant, and less time variable than wind. Salt gradient, fresh water mixing with seawater potentially has about as much potential as gravity stream flow.

The areal density can be a bit of an apples to oranges conumdrum. For instance for hydro I think you use the area of the watershed. The area of the dam, or run of river turbine would be much smaller. So one estimate is useful for comparing impact, the other for comparing the size of the resource. Of course a fair assessment os area demand of fossil fuels would assign greater than the active mine plus power plant areas. What is the land impact over hundreds or thousands of years of the mine area after closure? What about lost land to sealevel rise etc.

How about something that addresses both issues at once?

From the website:
"We recently received a patent (7484561) for a novel method of regulating the power grid, PyroStorage. When wind, solar and other intermittent energy sources are used, the grid can endure unacceptable fluctuations. As renewables garner a bigger slice of the generation pie, storing that excess power may be impossible. Our method acts as a storage battery, but unlike other battery technologies, we return 6+ times more energy than was consumed in the first place. All this while allowing large scale renewable power generation to become viable. reducing America's dependence on foreign oil, and reducing CO2 production in unconventional resources by over 30%."

Hmmm, use excess and intermittent power to heat unconventional oil underground, killing two birds with one stone.

I wouldn't label this as green energy, but rather as some form of renewable or stranded renewable energy for enhanced oil recovery. Still a valuable thing to do, but unless the fuel creation process absorbs the CO2 from the air it isn't a "green" technology. Nevertheless using excess renewable energy for say oil lifting, or underground retorting in the oilshale case theoretically allows us to tap low EROEI sources.

From your link: "No CO2 is produced in making this clean wind oil." That is straight up nonsense. Hard to credit anything they say after reading that. In any case, we eventually run out of the bitumen as well.

Nuclear power gets a passing and dismissive mention at the end of the article.TOD appears to have a culture of either rabid antinuclear ideology or just ignoring the issue.There have been only occasional articles on nuclear.

I am not dismissive of renewable technologies.I own a domestic solar PV system,grid connected, with battery backup.This system can stand alone if required.There are many ideal applications for solar PV and solar thermal.However,renewables do not have the potential to supply base load power in the foreseeable future.Some people seem to be believe that we can do without reliable baseload electricity by lifestyle changes and conservation.
I challenge those people to take a long hard look at their own lifestyle and how they would fare without on tap,24/7 electricity.If they think they can manage then they should try and put themselves in the place of other people who may not have the ability to change.They should then examine the structure of our society and economic system and imagine how lack of reliable base load power would affect that.

Nuclear,in places without the water resources for hydro, is the only proven technology which can generate clean base load electricity without the proven toxic effects of burning coal,or gas to a slightly lesser extent.

It sure is hard,isn't it,to give up those long cherished prejudices? And a technocopian outlook will not last very long in the harsh light of reality.

I challenge those people to take a long hard look at their own lifestyle and how they would fare without on tap,24/7 electricity.If they think they can manage then they should try and put themselves in the place of other people who may not have the ability to change.They should then examine the structure of our society and economic system and imagine how lack of reliable base load power would affect that.

I had the "pleasure" of living without electricity in early March this year for four days. Despite the fact that my portable gasoline generator provided enough power for the natural gas furnace, it was not fun. We've managed and even hooked up my Internet access as well and fired up the computers. Sitting at my desk and browsing the Internet by candlelight at night was something that I won't forget soon.
Nuclear power plans sound good to me...

Given the challenges ahead, I think it is time to give up the goal of 24/7/365 on-demand electricity and plan accordingly. We have no birthright to on-demand electricity. While there are some good ideas out there for load balancing of solar and wind, they will not be enough. Heck, we know already that we can't ramp up solar and wind fast enough to replace fossil fuels even if there was not a problem with the variable output.

So let's look at this problem from an end user perspective. How can we redesign home, business, and commercial use of electricity to allow for times when absolutely none is available and times when a restricted amount is available?

Using smart electric meters and smart circuit breaker panels, we should be able to control how much electricity for specific uses, if any, is available and for how long. Anyone who has used a potable generator knows the difficult tradeoffs. Those who have wired in a Gentrans unit ahead of time have fewer tradeoffs as they simply switch on circuit breakers instead of running extension cords when using a portable generator. We need to go a few steps further.

At 6:00 pm you will have to choose between running your range, hot water heater, and dryer. Can't have all three, just one. During peak load periods in the summer, residential electric may need to be shut down on a rotating grid pattern for a hour or two at a time. Time of day, day of week, day of year, unique personal circumstances, all these will play a role in how much electricity you have available.

As long as we know in advance, we can cope effectively. We act as our own load balancing solution.

Business and commercial users of electricity can do the same thing.

This is nothing new. We are already using these methods to modify when people can use their hot water heaters. We are using day and night rate structures to smooth out demand. This is just the next logical step. Of course try telling the American public that 24/7/365 unlimited electricity is soon to be history. They would prefer to have rolling blackouts and blame everyone but themselves for the problem. But the sooner we get started, the easier the transition will be.

I think it is time to give up the goal of 24/7/365 on-demand electricity and plan accordingly. We have no birthright to on-demand electricity. While there are some good ideas out there for load balancing of solar and wind, they will not be enough. Heck, we know already that we can't ramp up solar and wind fast enough to replace fossil fuels even if there was not a problem with the variable output

I think this vision is uncessarily stark. There is a huge difference between having zero available at some time, and having even 5 or 10 percent of normal supply. Power can be stored. But storage is expensive, so power that has been stored should be priced accordingly. We also have some baseload sources, including nuclear, hydro, geothermal, tidal etc. Plus with some long distance transmission capability we can tap far away sources to some extent. Again if demand for 24/7 power, versus interruptable power is too large, the price differential will be greater. Most likely the user will have to select which appliance are interruptable (and hence get lower rates), and which ones he wants 24/7 despite the higher rates.

But an any case, we have decades before the strong form variable power comes along. No need to grighten people too soon. This issue is frequently used as a straw man argument against renewables.

I like your points about price being a substantial motivator.

Still, I can't help but wonder what is going to happen as our nuclear plants start to reach their end of life and more natural gas in the coming years has to be diverted to transportation fuel to replace oil, leaving less for electrical generation. Ramping up coal to maintain the loss of nuclear and natural gas seems unlikely.

I'm not sure if we are seeing year over year increase in electric power use in the US. That would also be a factor if use is growing.

I guess what I'm saying is you got me thinking that even if solar and wind are a decade or more away from being substantial enough to cause a variability issue, we may find that price alone can't influence consumers to conserve enough electricity before then.

That leaves us with forced conservation, an interesting social experiment to say the least. Should large users of electricity who can afford to pay say .50¢ or .60¢ per kWH be allowed to continue that use if much smaller users on fixed incomes can't afford to? Or would it be better to develop a system of sharing the available electricity based on time of day and the total amount available in the grid service area, while keeping the average price per kWH much lower?

In other words, use price as part of the equation and pre-planned restrictions on availability as the other. Otherwise we have tens of millions of households living at or below the poverty level who can't keep up with the ever increasing electric rates.

Cutler Cleveland suggests that we will decide to embark on an energy transition, not due to lack of oil or other fossil fuels, but to mitigate climate change. The changes will be gradual and top down.

This is rather different from my perspective as a young person living 3 years after this article was published. Things seem to be moving quite quickly regarding people's attitudes towards energy, and these trends are accelerating. For example in Sheffield the cycling rate has been increasing by 7% annually over the past 5 years and there seems to be a paradigm shift underway regarding how young people see transport.

Cutler also focusses excessively on the macro-scale, but with the exponential growth in communication power (what proportion of global population now has access to the internet compared with 3 years ago?), small-scale solutions and educational tools become increasingly viable.

My favourite examples of this are the inspirational book 'The Human Powered Home' published 2009, after Cleveland's article was written - please check it out - haven't seen it mentioned on TOD before, and my own project to build a pedal-powered generator. Small, somewhat pathetic projects maybe, but do not underestimate the potential of small scale technologies to influence the 21st energy transition.

A subcultural antidote to Cutler's lucid but now mainstream (not that the mainstream is lucid) thinking can be found on page 16 of this magazine.

Given the fact that our government is bought, I agree that the changes will come from the ground up, rather from the top down. Individuals producing power or decreasing their use of power is how we'll adapt. Problem is that path may not be fast enough either. Then the human nature to take what is needed or desired comes out and things could get nasty.

Current global fossil fuel use is about 13 TW, so we need more than 6 TW of renewable energies to replace 50% of all fossil fuels. This is a staggering shift.

This is ignoring the losses of using FF energy(50-85% losses). 4TW of renewable energy(as electrical energy) should be able to replace all 13TW of fossil fuel.

The estimate for wind energy( 0.5W/m sq) is probably too low, more like 2-3W/m sq.The diffuse nature of wind is not an issue because electric transmission lines can move very high power densities >1,000km.
Denmark is a very small country(42,000km sq), N America is X200 larger area, larger than the size of most weather systems.

The EROEI for wind of 20 is based on old small turbines(50-300KW). Turbines above 1MW capacity seem to give EROEI of 30-60( similar to present oil).

It's time to stir the oily Drum,
to see what scum might come
along with the oily sheen
that kills the lovely preen
of the fowl now so foul
oh they surely do howl

the pain the pain in glorious vein
of a coming hurricane
it's time to spread the stain

and don't forget the gas
that bubbles and burps on past
the jagged rents of the BOP tents
defying anything BP invents.

decay is surely here to stay
by the smell of the air and the deadened care
something nasty this way comes
beating upon the empty oil drums.

Total energy use then was about 5.6 quadrillion BTU (1 quadrillion = 1015), equal to about 0.19 TW (Terawatts or 10^12 watts)
BTU is an energy unit, Terawatt is a power unit. Which do you mean?

The conversion I get is:

5.6 Quadrillion BTU = 1641 Terawatt-hours

Judging by the context I think this might be what he meant but I don't know about the 1.9 or the Terawatt unit.

The essay was written a while ago by Cutler Cleveland and posted by Nate.

Power is energy per unit time. Normally when someone uses just energy, such as BTUs, it is understood to be per year. There are rougly 31.6 million seconds in a year. So a gigawatt equals 31.6e15 Joules/year.

The energy is per year. 5.6 quads per year averages out to about 0.19 TW.

Talking about the here and now:
By Dwight Baker
June 8, 2010
Energy Transitions Past and Future: BP's Gulf of Mexico Oil Spill in Context (by Cutler Cleveland)

I am third generation oil and gas from Oklahoma. My sons are forth. Our family has never had a scar to wear as the one being put on BP now and BP will add this one too with the other scars that they wear.

So this article as good as it was, should not draw our attention away from the crooked and perverse way some of the oil giants go about screwing who ever they will and taking away peoples rights to live on or around the land where they drill.

Coming out and about the BLOW OUT today June 8, 2010 is news so horrid that only devils alone could read without a tear being shed.

Now the Viet Nam war was waged and got pass the Congress to get funding and all went well for the warmongers until some in the news media went there to un-cover the REAL TRUTH about war and that war in particular, when that news hit the air in the USA a revolt against the war was waged and soon it ended.

Therefore let that be our example: let us that have a will to defend our industry not get sucked into anything other than putting the guilt where it is. BP committed the crimes against those men and against us allowing the oil and gas to continue to BLOW OUT.

For a FREE COPY of the TAME NATURE overshot plan E-mail Dwight Baker for What Went Wrong and the Cure for the BP Blow Out.
All rights reserved Dwight Baker PO BOX 7065 Eagle Pass Tx 78853 Tel 830-773-1077

This is an excellent article that summarizes the trends in historical energy transition. One area not addressed is the change needed to address energy storage. The catch with large scale renewable systems is that massive energy may be generated when there is little demand. As an example, an off-shore Wind Farm may run at full capacity at 3am, when the local communities are sleeping and not consuming the power.

Instead of talking about energy storage, a different approach would the energy transition where the energy is used to drive a chemical reaction that creates a "fuel." The Sebatier Process uses a metal catalyst to create methane from Hydrogen and Carbon Dioxide. (We all know how to handle methane, right?)

Matt Simmons (the same one on a video in a separate thread) is a founder of who is planning a huge wind farm in the Gulf of Maine. They are planning to use the surplus energy to create Ammonia.

When you build these massive (Megawatts or Gigawatts) renewable energy systems within a region, the opportunity to capture unused energy is leveraging the investment in capacity that would otherwise be unused at that time, but energy consumption needs to be as massive to be effective!

My transforming unused energy into fuel, the fuel has near-infinite shelf-life, unlike a battery, and can be sold on the open market. Generating new fuel can also reduce greenhouse gasses (i.e., Sabatier consumes C02) which can generate carbon credits to reduce the total market price.

The need to restrain carbon emissions may provide the political and social pressure to accelerate the transition to wind, biomass and solar, as this is one area where they clearly trump fossil fuels.

My emphasis.

I think that the negative feedback loop will be collapse not consensus.