Energy for the 21st century; an engineer’s view

Many solutions have been proposed to get us beyond the final days of cheap fossil fuels. I would like to try to add some clarity to this high stakes, highly politicized topic. Please note that this is only a bottom line appraisal of topics that deserve volumes. This is a study of current technical feasibility, and, importantly, will consider the affect that each alternative will have on our environment. Remember, the environment is not an issue; it’s where we live.

Fossil fuels, e.g. oil, natural gas and coal, are limited. We can’t make any more of them. Since the beginning of industrialization,150 years ago, we have developed an insatiable thirst for cheap energy to run the machines that produce goods and save us time and labor. The best estimates are that we have used nearly half of all the petroleum on earth. The second half will be much harder to produce, so we must look for, and develop, alternative sources of energy before we need them. At the same time we must learn that a quality life doesn’t require burning huge amounts of fuel. To endure, as a species and an ecosystem, we must make some wise decisions.

Hydrogen engines and hydrogen powered fuel cells

Hydrogen has been touted as an environmental solution, since these engines and fuel cells emit only water vapor. Hydrogen doesn’t occur in any practical form that can be made into a fuel. Two principal methods of producing hydrogen are proposed: electrolysis of water (using surplus electricity to separate water into oxygen and hydrogen), and breaking down natural gas or oil to release the hydro part of the hydrocarbons. This process leaves the carbons, which are a good fuel, but by them selves are pollutants. Other organic materials can be broken down but not on a realistic scale and not without similar byproducts. Hydrogen is not a solution; it is only a means to make excess electricity portable.

Ethanol

Hydrocarbons can be made from crops, such as corn but not on a large scale and they take more energy, traction horsepower and fertilizer (which is made from natural gas), to grow than the fuel they produce.

Electric cars

Electric cars don’t pollute and don’t use fossil fuel, directly. They rely on power plants or fuel cells for their power. There is no free lunch. Generally power plants are more efficient than small engines but they have distribution, power factor and peak power losses. Also, batteries are not particularly efficient (discharging a battery doesn’t produce as much energy as it took to charge it). Batteries also have a finite life and contain poisonous chemicals.

Wind power

Wind generators work well in certain areas, where the wind is frequent and steady. Nobody wants one in their backyard and birds don’t much like them. Some studies indicate that it takes more power to build a wind generator than it will produce. With today’s high gas prices, wind energy is becoming competitive.

Solar power

Solar power is getting more efficient but is still far from being a solution in either efficiency or cost, even in areas of optimal insolation, such as the desert southwest. Solar electric energy is about 5 times as costly as wind energy.

Ocean power

Tides and ocean currents are a potential energy source in certain areas but have not been proven.

Hydroelectric power

Hydroelectric power is renewable, but most worthy sites have been developed. They always have a disastrous impact on the local environment, aquatic biota and the immediate area, usually rich bottom land.

Nuclear fission is essentially renewable and doesn’t release emissions either in power generation or in mining or drilling for fuel. Most reactors make their own fuel, using excess radiation. They do dump waste heat into the atmosphere or local waterways. One problem with nuclear power plants comes from the radioactive waste they generate. Many components in the reactor must be replaced every 30 years or less. Radiation embrittles even the best stainless steels and makes it radioactive. The resulting material will poison everything it touches, especially ground water, for the next thousand years. What do we do with this mountain of old pipes, valves, spent fuel and handling equipment? How do you safely transport it to the dumpsite? Do you put up a sign for future generations saying, “Don’t Dig Here”? Or will that attract the wrong people. Using fission power, we gain 30 years of electricity but have to safely store the resulting waste for at least one thousand years. If the entire lifecycle is considered, nuclear power is not a good solution.

Providing security for the plutonium that reactors generate is another concern. In the worst case a small quantity of this could be used to make a nuclear device. Nearly as bad and requiring no equipment or technology, is the possibility that the materials would go into a dirty bomb, which could poison a huge area making it uninhabitable forever. There is no known safe level of plutonium.

Spent fuel reprocessing has been proposed recently as a way to reduce the amount of waste that must be stored. Twenty years ago, when this idea first came up, it was discounted because burning spent fuel was considered too dangerous. It still is.

Nuclear fusion holds promise for unlimited power with little radioactive waste, but it won’t be commercially available for a couple of decades.

Neglecting nuclear, none of the alternative energy sources can replace fossil fuels, though all of them together could satisfy a good portion of our demand. It would take an enormous initial investment, probably from government leadership, and a change in the energy company paradigm. Making that investment, though, would help reduce the costs of these technologies, as they become less like prototypes and more like production equipment.

Making the most of what we have

Finding our energy future can’t just be a supply side search. That’s the mentality of an energy giant. We have to look at the consumption side as well. There is an almost limitless potential to trim our energy usage and no one has taken a serious look at it. Power generation is only about 35% efficient; so reducing our power use by one kilowatt-hour actually saves almost 3 kilowatt-hours, plus the emissions and mining, drilling required to procure the fuel. Think about how much we could save, how much longer our fossil fuels could last.

Conservation can take many forms. Use less fuel by adding insulation, employing high efficiency appliances and lighting and fuel-efficient cars. Avoid waste by building smaller, more space efficient houses, closer to jobs and shopping, designing walkable neighborhoods, and developing a practical public transportation system and encouraging its use, and by requiring the recycling of all manufactured goods.

You will see that these “solutions” are long-term projects of ten, twenty or fifty years, and so won’t yield immediate answers. This is why it is important to begin them now, before their time has come.

Three options

First option - we can continue our “standard of living” and consume the rest of the world’s fossil fuels, no matter what the cost. The US can continue to get oil from all parts of the world, until the cost of production or the cost to our country’s image, makes the price rise and demand fall.

Second option - we can reduce our energy consumption to sustainable levels using renewable alternative technologies while saving the last of the fossil fuels for things they are good for, such as plastics, fertilizer and medicines. This would require lowering the standard of living measurably for most Americans.

Third option - Conservation can reduce energy use, pollution, drilling and mining. Nuclear power can potentially support our population without drastic changes in standard of living and even bring other parts of the world up to a similar level.

I believe the third option is the most likely. Will we poison the earth with radioactive waste, or the spread of nuclear weapons? I don’t know, but I suspect we will bear that risk, to extend our technologically-fired standard of living, and to avoid the inevitable population crash when the energy runs out.

Ultimately, are we stewards?

Given the limitless potential of nuclear energy, there is nothing to keep us from satisfying our needs well into the future (setting aside for a moment that agriculture and fresh water supplies are in imminent danger). We have the power to make machines that will manufacture goods and produce the resources and food we need. The human population will grow and the standard of living, on average, will increase. A terrible burden comes with this bright future. We are crowding the rest of the life on this earth out of a place to live. Already humans use a third of the earth’s productivity, plus, every acre we plow and plant in a monoculture is half as productive as the complex, healthy ecosystem it replaces. Its no wonder we are in the midst of one of the greatest mass extinctions ever. This may ultimately be the greatest danger of nuclear power.

So the question is, are we smart enough to protect the life systems that we depend upon, even if it means limiting our standard of living and our population, or will we take all we can get, increasing our numbers, using up the earth’s resources and driving her ecosystem to collapse, leaving this as just one more lifeless sphere? We, together, have that power.