The Hydrogen Humvee and Other Fairy Tales

I suppose that the Hummer is an extreme example of inefficiency, but the present governor of California drives one, and fills it with hydrogen to power its fuel cell. It is put forward as an example of how high technology will allow us to retain our energy bloated lifestyle.

The hydrogen in question is merely a storage medium. Hydrogen doesn't exist (for very long) in its pure state in our biosphere, what with all that attractive oxygen everywhere wanting to make water (H2O). Most hydrogen is obtained by extracting it from natural gas (CH4) these days, but in the "hydrogen economy" plan, we will make it by splitting water with renewably produced electricity. Lets look at the numbers on this hydrogen Humvee.

A Hummer gets a miserable 13 miles per gallon. At 132,000 BTUs per gallon of gasoline, this works out to roughly 10,000 BTUs per mile, or 3 kilowatt hours. That is in absolute terms, but converting a conventional gasoline vehicle to electric propulsion generally doubles the energy efficiency. Of course, the fuel cell is not perfectly efficient, and neither is the electrolyzer that splits the hydrogen. At present, the top end efficiencies for these devices are 48% and 65%, respectively. This means that our electrical input into the electrolyzer to produce enough hydrogen to get this Hummer one mile is 4.5 kilowatt hours. How big a solar array would this require? Assuming we want to travel this mile on a daily basis, and using solar data for Bakersfield California, out in the brutally sunny Mojave Desert, we would need 810 Watts of solar electric modules. With the modules tilted at the optimal angle, this would take up about 50 square feet of flat desert. If the governor wanted to drive even fifty miles a day, it would take more than 2500 square feet, because there would have to be spacing between rows of modules to avoid shading. A fifty mile a day solar array in the Mojave would take up almost 7,500 square feet (a sixth of an acre) and at present prices would cost over a quarter of a million dollars. Maybe the governor could afford it, but not your average commuter. Even with a quarter of a million dollars in your pocket, you can't make the sun shine on command. If you are a city dweller, you probably don't have the space for a large personal solar array. In the absence of a suitable space for solar power, consider a 1 megawatt wind turbine in a decent wind location as the source for your hydrogen Humvee. This million dollar, three-hundred foot tall technical marvel, requiring heavy equipment for installation, a transformer and industrial switchgear, utility scale transmission lines and regular skilled maintenance and supervision, will supply you and 35 of your Humvee driving friends with a daily commute. You must also face the fact of the energy embodied in the massive vehicle and its high tech components, plus the huge industrial infrastructure required to produce its myriad parts.

Our society in general cannot drive around in renewably powered Humvees, or renewably powered anything that weighs in at a couple of tons. Personal vehicles of any significant size are dependent upon fossil fuels.

Some may point to biodiesel or ethanol as renewable fuels, but these fuels rely on a highly fossil fuel dependent agricultural infrastructure. More on that next time.

Ecological Design - The 5M Rules, Part 4

(Part 4 of a 4-part series)

First Principles

One important behavior for a conscientious designer is to take any design problem back to first principles. The first principles of a car are to transport people and their cargo from point to point within boundaries of speed, comfort, cost, privacy, and convenience. They must do this using an existing network of roads that have particular characteristics of width, curvature, slope, and roughness. Many of the design parameters of a modern automobile have little to do with these principles, but much to do with the manufacturer’s stock price.

Two important parameters for the auto manufacturer are apparent value and sales effort. Put simply, consumers will pay proportionally more for a big, loaded vehicle than a small, basic one, with the same cost of marketing and sales per unit. The manufacturer is also interested in maximizing the return on investment in factory equipment. This means that designs requiring radical changes in manufacturing technology will be delayed. American auto manufacturers bank on most consumers buying a new car about every seven years. If cars were to become more durable, or American buying habits should change due to financial constraints or social pressures, this might extend to eight, nine, or ten years. The drop in income would be disastrous for the industry as it is now structured.

This might explain why we use 4,000 pound wheeled boxes of steel and glass with operating ranges of 300 miles or more to move 100-300 pounds of us and a few pounds of groceries back and forth to the supermarket. The motive force for these vehicles is a device with hundreds of moving parts operating at high temperatures, plus sophisticated electronic controls and a set of (usually) automated gears in the drivetrain. Most are designed to run exclusively on highly processed liquid fossil fuel at less than 20% efficiency. This should prompt some questions. Why 4,000 pounds? Why use steel? Why build asphalt roads at millions of dollars (and gallons of oil and cubic feet of gravel) per mile? Why use the gasoline engine? Most importantly, why isn’t the grocery store within walking distance?

The last question brings up an important point. Every technology must be analyzed within a context. The answer to a technological problem may lie in that context rather than in the technology itself. The 5M standard for transportation may be best served by looking at urban planning rather than vehicle design. Going back to the basic question, “What are we actually trying to accomplish here?” allows us to simplify our approach. We can solve the problem with a minimum of energy and materials, rather than trying to make complex modifications to the dead-end system we have inherited.

A good example

If you want an example of truly sustainable housing in America, look for a mid 19th century farmhouse. It was constructed using human and animal labor, using virtually all local materials, which themselves were harvested using human and animal labor. The only semi-high-technology materials in the structure are the window glass, some iron door hardware, the nails, and perhaps some tar paper in the roof. The building was originally heated with wood, also harvested and processed with human and animal labor. Often the owners would use simple design techniques to make the house more comfortable. They would put a deep porch to the south to block the high summer sun, but allow in the low winter sun. Likewise, they would plant (or leave in place) deciduous trees on the southeast and southwest corners of the house. In the summer, the leaves would shade them, and in the winter the bare branches would allow the sunlight through.

Although this house would not meet modern building codes and standards for comfort, especially during the winter, it shows that people can build a habitable structure with virtually no use of non-sustainable inputs. It is worth investigating how close we can come to this paradigm while maintaining acceptable boundaries of comfort, cost, and safety.

One of my personal mottoes for designing sustainable housing is “Never use a pump if a brick will do.” The solar houses of the 1970’s tended to have complex active systems. They pumped fluids or blew air through gravel beds, slabs of concrete, or containers of water. Timers and electronic sensors controlled all of this activity. Much of the collected heat leaked out through thin walls and leaky window seals. Most of these systems failed and were torn out. From this experience, designers have come to rely on energy conservation strategies first, such as thick walls, good air seals, and good site work. The input is from simple systems of south facing glass heating exposed dense building materials such as concrete, brick, stone, or even gypsum board. There are no moving parts and minimal use of heavily processed material.

Briefly: Clarify your purpose. Simplify your methods. Minimize your consumption. Localize your range.

Ecological Design - The 5M Rules, Part 3

(Part 3 of a 4-part series)

In the last post I discussed minimizing mass flow and movement. Here are the 3rd and 4th factors, Modification and Mechanization, and some thoughts on the interrelations between the four M factors.

Modification

The more we modify the materials the world provides us, the more profound and lasting our impact on our environment. There is a general hierarchy to modification:

Guided natural processes – fermentation, bacterial growth (beer and cheese)
Phase – freezing, melting, boiling
Shape – cutting, splitting, abrading (think basic wood shop)
Mixture – traditional paints
Extraction and distillation – lye from wood ashes, alcohol
Oxidation/Reduction reactions – burning, acid etching, smelting metal ores
Reagent Chemical reactions
Polymerization - plastics
Nuclear reactions

At the top of the list are processes that leave naturally occurring materials in a state that is either reversible or biodegradable, including byproducts and waste material. These processes do not markedly increase the persistence of materials in the environment. The processes at the bottom of the list are difficult or impossible to reverse, and produce materials alien to the natural environment. The toxicity of the products is generally increased over the raw materials. In the case of nuclear reactions, the reversibility is zero, the toxicity is extreme, and the persistence is measured in tens of thousands of years.

This is not an exhaustive list. Not being a trained chemist or environmental engineer, I don't stand by it as the final word on the hierarchy of chemical reactions in terms of persistence and environmental compatibility. Still, it gives an idea of how to look at the way we use the materials around us.

Mechanization

Mechanization is an amplifier of the three other concepts. Once we adopt technology that uses moving parts, we increase mass flow, both in terms of the energy source and the products being manufactured. This is true whether we are transforming raw materials into usable energy, or processing raw materials into manufactured objects. The increased concentration of energy and resource use tends to demand resources from farther away and demand more distant markets. Our ability to process materials into useful work also increases our ability to move at greater speed and with greater persistence. Machine parts moving against each other and containing the heat and corrosive nature of reactions introduce the problem of wear and accelerated deterioration. This problem requires replacement parts, lubricants, coatings, coolants, seals, insulation, and the energy to install or remove them. The concept of mechanization is not confined to the cranks and pushrods of the iron-bound industrial age. The electronic devices that permeate our lives may not have the bulk of a diesel engine, but their transport distance can be long, their service lives can be short and the persistent toxicity of their parts, in both manufacture and disposal, is high.

Interrelations

The analysis of any technology requires that we balance all these considerations. A technology might have high mass flow relative to another, but the material used might be unprocessed, with low embodied energy. We might be making a decision between two machines, one more complex, yet lighter and more energy efficient.

The further development of this theory will require the quantification of these factors. That quantification will rest upon an estimate of an ecosystem’s capacity to tolerate particular kinds of stress. It is important that we must make these estimates for the earth as a whole, and for individual ecosystems. The earth has one atmosphere, and a pollutant with enough persistence will eventually become part of a global problem. However, a rate of environmental insult that would be tolerable spread over the planet may be intolerable when concentrated, let’s say, in the air over Los Angeles County.

We have data on the concentrations of many toxins that pose a threat to human, animal, and plant life, and the persistence of those toxins. There is also data available on the use of extracted resources for various technologies. We know the locations of extraction, production, and consumption centers. It is possible to create a database and a set of algorithms that would relate these factors. This would allow a designer to analyze a beginning design and then modify it in a way that balances function against environmental impact. This would be true environmental value engineering.

The sticky point would be a quantification of the quality of mechanization. For mechanical devices we might look at parts count, the working temperature and Ph extremes to which it would be exposed, and the number of mechanical cycles it is expected to endure in a time period.

The balance between modernism and Luddism

Note that the first M in the theory stands for “minimize.” It is not an E for “eliminate.” Perhaps the human species may someday regress to a technological state similar to chimpanzees, but that is not possible at present human population densities, nor desirable from the standpoint of a member of our species. The goal is for us to make thoughtful choices about our development and use of technology.

Modernism is the belief that increased use of technology is the solution to the problems of humanity, and that the solution to the problems of technology is the further development of technology. Luddism, in its popular sense, is the absolute rejection of technology. A student of labor history will tell you that even the original Luddites were not averse to the use of technology. They opposed the use of particular technologies that threatened their way of life. Both Modernism and the popular meaning of Luddism are the extremes of a spectrum of thought, and not useful in the pragmatic business of finding a sustainable way to live.

The transition we have to make is both technological and cultural. We have to acknowledge and accept the present context in both areas. We can’t immediately abandon our interstate highway system, nor can we immediately abandon people’s expectation of self-governed interstate travel at 65 mph. It is actually the psychological transition that poses the greatest problem. People dislike change, dislike the unfamiliar, and bridle under rules that enforce changes. People will reject new designs that don’t feel comfortable. Back when I was involved in converting gasoline vehicles to electric propulsion, my partners and I had a saying: “Converting cars is easy, converting people is difficult.”

Next time, some thoughts on basic principles, and a conclusion.

Ecological Design - The 5M Rules, Part 2

(Part 2 of a 4-part series)

The 5M Rules

By what rules do we judge individual technologies and compare parallel technologies? I have formulated a few qualitative rules. Let me state again, this is not the grand unified field theory of environmentalism. It is but a first step. It is a set of cautionary statements about excess that I call the “Five M Theory.” Stated simply: Minimize Mass flow, Movement, Modification, and Mechanization.

Mass Flow

Weigh your garbage. I mean it. Start on the first of a month, and whenever you put the twist tie around a plastic bag destined for the landfill, step on your bathroom scale, pick up the bag, put it down, and record the difference between the two weights. At the end of the month, add it up and multiply by twelve. You may be appalled. According to archeologists, an average Colonial American family of four produced four pounds of garbage a year. That is, four pounds of material that couldn’t be reused, reprocessed, or composted. A recent study estimated that an average modern American family of four produced four thousand pounds of garbage a year.

One of the major insults to our environment is the sheer mass of material that our species extracts from the environment and deposits back into it each year. No matter how benign the content or method of extraction, the billions of tons of natural resources we dig, cut and pump each year have a toxic effect. Likewise the products, both intended and wasted, that result.

The subject is mass flow, not absolute mass. Making a shelter from polyethylene sheeting rather than stone would dramatically reduce the mass, but compare the two-year lifespan of 6 mil polyethylene in sunlight to the two-thousand year potential lifespan for a stone structure. A square foot of poly weighs 0.232 pounds, disregarding any support framework. A square foot of 6” thick limestone weighs 81.5 pounds, roughly 350 times as much. So, once the stone building has survived 350 years, its yearly mass flow has become lower than that of polyethylene. A standard framed wooden wall, weighing 6 to 10 pounds per square foot, would reach mass flow equivalence as soon as 25 years. (I am laying aside energy efficiency, aesthetics, comfort, safety, and privacy concerns for his comparison.) Construction methods are an important part of minimizing mass flow. Take that same 6 mil poly and encase it in a wall as a vapor barrier and it could easily last a hundred years, saving large quantities of energy during its service life. Those energy savings will reduce mass flow, in terms of heating fuel, by far more than the mass of the plastic vapor barrier.

Movement

Let’s say you live on the East Coast of the United States. It is mid-winter. You go down to the store and buy a pound of potatoes that has been trucked in from California. You will get about 320 food calories from eating those potatoes. The energy cost of trucking that pound of potatoes was somewhere between one and one and a half times the calories actually in them. In effect, you are eating as much diesel fuel as potato. (This doesn’t count the energy used in growing the potato.)

Moving things from place to place in our biosphere has several effects.
First, it takes energy, and the use of energy involves the extraction of resources, the modification of portions of the biosphere, and the production of waste material. In the best case scenario, the resource is biomass, the transportation technology is an animal used for transport, and the waste material is manure. Still, the effect of feeding and maintaining the animal is there.
Second, it takes a path, or makes a path. Roads, rails, pipelines, ports, and canals modify the landscape, and their construction and maintenance involve all the factors in this theory. Aircraft need only ports, but are far more energy and pollution intensive per pound of cargo than any other mode of transport.
Third, there are always unintended consequences of moving something away from where it was doing no harm. The world’s ecosystems have evolved interlocking networks of species. The history of human migration and commercial transportation is replete with examples of destructive introduced species. We are also now seeing the effects of transporting stored carbon out of the ground in the form of coal, oil, and natural gas, and spewing it into our atmosphere.

A corollary to this rule is that moving certain things vertically seems to do much more harm, per mile or kilometer, than moving things horizontally. This is mostly manifested in mining and fossil fuel use. Compare the movement of carbon 15 miles vertically, oil well to atmosphere, versus 15 miles horizontally from a decaying tree to a living tree. Vertical movement of the carbon into the atmosphere increases the greenhouse effect. The pumping of the oil uses energy, especially because it is moving against gravity. The oil, if spilled, is toxic to life on the surface. Air transport moves cargo vertically as well as horizontally. Overcoming gravity is a major factor in its energy intensive nature. When we compare movement, we must compare it to the dimension of the biosphere in its direction.

Just as mass flow, not mass, is the first standard, the speed of transportation affects its environmental impact. The natural world evolved over hundreds of millions of years with nothing moving faster than a bird, and most things generally moving at a human walking pace. If we categorize methods of transportation by their average speed in actual use, we find that the faster, the worse for the environment. Faster vehicles require more energy to accelerate and overcome air (or water) resistance. Faster vehicles also require greater mass to withstand the stresses of high-speed travel and to protect their occupants, and are generally more complex, using highly processed materials. This encompasses energy use and pollution in particular, plus noise and the other M rules.

Invasive species require their own standard for movement. Transporting an invasive animal species 2400 miles, yet 100 miles short of an isolated island, is proportionally much less damaging than transporting it 2500 miles to the beach.

The damage inflicted by the movement of an animal, plant, or substance is relative to a number of factors:

-Compatibility with the destination environment - Compare dropping a pound of European marble into an American lake versus dropping in a pound of European zebra mussels. The former would be unnoticed. The latter has already happened, with disastrous results for the Great Lakes and Lake Champlain.
-Persistence in the destination environment – Compare the transport of a few dozen Norwegian rats to a Pacific island with the transport of a few dozen koala bears. The koalas will immediately starve without eucalyptus trees, whereas the rats, as history shows, will take over the place. With substances, the persistence of the stuff itself, wherever it might be, is the consideration.
-Whether a substance is chemically inert or reactive
-Thresholds of effect

In order to quantify the effects of moving something, we will have to develop a taxonomy of substances and living things according to the factors listed above.

Next time, the two other M rules and thoughts on their interrelations.

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The 5M theory: Guidelines for Ecological Design

(Part 1 of a 4-part series)

What follows is the first of four posts on my nascent theory of ecological design. It is really one long essay, but I have split it for readability. The other sections will follow, separated by a few days.

Introduction

What is ecological technology, and how do we know it when we see it? How does a designer, an architect, or an engineer set out to create ecological technology? How do we compare two or more technological options for their effect on the environment? Designers can perform embodied energy analyses, study toxic waste products, and calculate energy efficiency, but each of these approaches lacks a global view of ecology. They also require specialized analytical skills and perhaps more time than a residential architect or line engineer might have. What we need is a simple set of rules that can be applied successfully a various levels of detail – from the casual and qualitative to detailed numerical analysis. Ideally, a non-professional could make sense of them and use them to make decisions as a citizen and a consumer.

This is an infant theory of ecological technology. It is not a grand unified theory in the manner of the quantum physicists, but a broad outline, a general direction for to be developed in more detail. It is not perfect – the way to tell if you are dealing with a theory is to look for the holes. It is a set of rules that will assist environmentally conscious people in their technological pursuits. Please read, ponder, test, discuss, add, discard, and develop as your experience leads you.

Ecological Technology

The adjectives “ecological,” “sustainable,” and “environmental,” are used somewhat interchangeably and vaguely. At worst, they are used in advertising copy as buzzwords. The problem with defining them is that they are absolute adjectives used as relative terms. Once a society gets beyond a very basic level of technology it uses non-renewable natural resources and creates artifacts that do not work their way back into the ecosystem. The Swahili herdsmen, the Yanomamo, and the Australian Bushmen use sustainable technology. Once European and Asian societies started smelting copper, they entered the fringes of non-sustainable territory. Today, we speak of sustainable architecture when we are actually referring to buildings constructed using fossil fuels, with materials that include petrochemicals. The buildings in question may use less of these materials and consume little or no fossil fuels, but less and little aren’t none.

Barring a sudden return to stone knives and bearskins, which would be impractical for most of the world’s population, how do we define ecological (sustainable, environmental) technology? How do we know when we have gone far enough towards Yanomamo-tech? The answer lies in carrying capacity. The earth can survive a certain amount of abuse and recover, just as we personally can sustain periodic illnesses and injuries without dying prematurely. Others have attempted to put numbers on this concept, so I won’t try drawing that line at this moment. The point is to understand that there is a line, a level of damage and resource extraction below which we must stay if we are to leave a livable world for our grandchildren. The other things to understand are that we are operating well beyond the earth’s carrying capacity, and that getting there will involve significant lifestyle changes for those of us at the top of the technological ladder.

Any realistic person will admit that no social movement or government, no matter how effective at persuasion, will get an average American out of a car and directly onto a bamboo-framed bicycle with an organic hemp drive belt. Nor will it be able to get an aerospace engineer to give it all up for Amish-style subsistence farming. What is necessary for any movement towards sustainability is to chart a realistic path. This path must be informed by trends in population, technology, customs, and politics. Planners must set the pace by the level and speed of environmental degradation in various parts of the world and the projected speed of environmental remediation. We need to define a turning point well on this side of the point of no return and aim for it. Planners must acknowledge that people learn with one foot planted firmly in what they already know, and one toe dipped into the unfamiliar. Each step of such a plan must be fecund – it must not be designed as an end in itself, but as something that will naturally give birth to the next step. Improving the pollution controls on a gasoline engine is a good short-term step, but ultimately a dead end.

Ultimately, our grandchildren, or their grandchildren, will live a sustainable lifestyle. This is inevitable, with that inevitability contained in the word “sustainable.” The only questions are when, how much of the change is voluntary, and how much chaos and deprivation we and our descendants must endure. We can’t predict exactly what it will resemble. Perhaps something like late 19th century America with a leavening of high tech where absolutely necessary. I doubt it will involve fossil fuels, petrochemicals, high speed transportation, or any intensive use of energy. (The laptop computer I am using right now involves all four.) Our job is to manage the transition so as to reduce the chaos and upheaval inherent in such a dramatic change. Note that I used the word reduce, not minimize or eliminate.

Next time, the first two of the 5M rules.