If a nation’s
power is measured by the amount of
energy it consumes, then the
United States is clearly the
world-leader. This title is meaningless, however, if the energy use of the present is at a level on in such a manner that it
impoverishes the future of the
nation. Ensuring the stability and longevity of the United States means developing
technology and lifestyles that promote lasting and renewable energy for future generations.
Americans receive their energy through two general methods:
centralized production of
electricity and direct use of
fuels through
primary consumption. Electricity is generated at
plants largely through the combustion of
coal and
natural gas, and
nuclear and
hydroelectric generation. Primary consumption, or
fossil fuels directly burned by
end-users, are commonly associated with
transportation,
industrial operations and
heating. In the future, America will continue to take advantage of all the
resources it currently commands. There will come a
time for each
non-renewable resource when it is no longer
economically viable to be used on a large scale. By this point,
economics alone will have forced the development of
alternative energy sources. In the meantime, America needs to stringently allocate these resources so those more scarce or polluting go only towards those tasks that require them. For there to be any
hope of advancing America’s energy practices, it is necessary to recognize how different kinds of energy are required for different tasks. Resource conservation and appropriate delegation, and possibilities for eliminating
wasted energy, must therefore take into account the different demands of the transportation, residential and commercial, and industrial
sectors of America.
In 2002, electricity accounted for 39% of all primary energy resource consumption and is the most used single form of energy by end-users. The thermodynamics of electricity generation are somewhat dismal. Only a fraction, 31% in 2002, of the energy potential of combined nuclear, coal, natural gas and hydroelectric generation was actually sold as electricity. Most of the loss occurs through the processes’ heat lost to the environment and transmission over power lines. Despite this fact, because of its flexibility in method of generation and ease of conversion to numerous forms of work, electricity is likely to replace primary resource use in many applications as fossil fuels are depleted. For this reason it America needs to focus major attention on the future of electric generation, which, as important as it is now, will be much more so in coming years. To put America’s electricity generation in perspective, in 2002 coal accounted for 50% of the electricity received by end users, nuclear generated 20%, gas 18% and hydroelectric 7%. America, whether it does now or later, is going to have to transition non-renewable fuels out of electricity production.
Within the next 40 years, dams across America will start to be removed from rivers and the energy business. The first reason is that dams have a huge negative impact on local ecology and hydrology, of which the American public is becoming less sympathetic to. The other is that once they become backfilled with sediment, they are just as expensive to maintain, but are no longer productive sources of energy and serve no purpose. Coal will continue to be a major electricity producer in America for at least the next 50 years. Coal is the most damaging to the environment in both its extraction and combustion. Some of this, however, is can be alleviated by modernizing the older, more polluting coal plants. Cogeneration technology can increase the first-law energy efficiency of a coal plant from 33% to as much as 75%. America’s coal resources, which are estimated to last well into the next century, should always be at least considered for electricity production, especially in times on international instability. Natural gas, however, shows the most promise out of the fossil fuels as a transitional resource. Gas is clean to burn and, relative to coal and oil, environmentally safe to extract. Its reserves are not as impressive as coal’s, but some estimate that world production will not peak for another 70 years.
Transitional fuels are only helpful if there is something to transition to. What is most likely to occur in the electricity sector is a revisiting of the possibilities of nuclear energy. Nuclear power has become subject to strongly negative public opinion that questions its safety. As environmental costs associated with other fuels become better understood, expansion of the nuclear program could once again be a viable. The greatest potential rests with breeder technology that can extend the life of nuclear fuel much beyond current estimates for nuclear fission. For this process to be put to broad use, however, some technological advances are still necessary to minimize the dangers associated with it. Solar and wind power, while becoming crucial to American electricity as coal and gas is transitioned out, will probably never be produced in the centralized way electricity is today. Because wind and solar intensity vary in every location with no relation to actual human inhabitance, it will more likely serve to supplement centralized plant generated electricity. Broad distribution of smaller facilities, along with reduction in demand for electricity through efficiency advances, will work to locally take strain off of power grids in areas that can benefit from these renewable resources. Within 120 years, ideally increase in the technology and human practices will have reached the point where even nuclear can be phased out and the task left entirely to solar and wind power.
Americans spend most of the time the inside their homes and offices, and consequently, in these places they are most familiar with how energy is consumed. In 2002, 40% of the Americas total energy consumption was in the combined commercial and residential sector. Not including energy lost through electric generation, 43% of the energy used in this sector was in the form of electricity and 57% came from primary consumption of mostly non-coal fossil fuels. Primary consumption is almost exclusively used for heating of buildings, along with electricity in some systems. Because high quality, high temperature, fossil fuels and electricity are used for a task that requires relatively low quality energy, the second-law efficiencies for water and space heating are respectively 2% and 6%. Clearly the fossil fuels used here could be better employed in other ways while they still exist, and the potential for conservation through low-tech solutions is high. Metallic-laminated and inert gas-filled “superwindows”, reflecting summer sun and insulating against winter cold, can dramatically reduce the energy demands of climate control in both seasons. The Rocky Mountain Institute, built in western Colorado with these windows and high insulation, maintains comfortable temperatures in the winter despite its lack of a furnace and water-heater.
The future of this sector, however, is still uncertain because success at conservation is most dependant on participation by individuals. Ideally building codes will be revised to take advantage of the ultra-efficient techniques currently economically available. Electricity, because its centralized production can be more easily regulated, will be the only high-quality energy consumed by this sector, and not excessively wasted on temperature regulation. The technology to make almost every electricity-using appliance in offices and homes energy efficient exists today; and implementation will require industry compliance and simple education of Americans about their benefits. Hydrogen fuel-cells are getting a lot of attention for their ability to safely and cleanly produce electricity on any scale. Likely hydrogen will replace fossil fuels as a high quality, portable energy source. The current problem is, however, that conventional energy sources are still required to collect the hydrogen, making the process non-economic.
The transportation sector is a somewhat bad news/good news situation. In 2002, transportation uses accounted for 27% of America’s end-use energy, and virtually all of it came in the form of primary fossil fuel. While for some applications, grid electricity is less useful than primary fuel, only with transportation is it completely unusable. The batteries necessary to hold enough electricity to compete with gasoline engines would be so heavy as to actually decrease the efficiency of the car. Cars are therefore totally dependant on extremely high quality, portable energy. The good news is that current technologies are already beginning to exploit the many opportunities to increase efficiency of automobiles. Hybrid gasoline-electric forego a massive engine for much smaller one running at optimally efficient rpms, continually charging a battery-operated motor that runs the drive train. Efficiency is compounded by the decreased weight of the engine and related components. Replacement of metals with strong carbon compounds could reduce weight to two to three times less than a conventional car. The actual fuel used to power the vehicles becomes less important when increases in efficiency can be so dramatic; the first hybrids already achieve 20 to 30 mpg over other cars. If fossil fuels are successfully conserved in areas that do not require their quality, there should be plenty of petroleum or natural gas to satisfy demand until technology makes alternatives economical. When hydrogen fuel-cells, or whatever future processes are devised, become economical, transportation is an ideal application for them.
Industrial manufacturing energy in 2002 expenditures totaled 33% of the nation’s consumption, and could conceivable have the most difficulty making the transition from fossil fuels. 75% of this was in the form of directly consumed fossil fuels, with 55% of all energy consumption going towards process heating. The other uses include machine operation, refrigeration and chemical processes that can all use electricity. 12% of the energy consumed by industrial is in the form of lighting and climate control expenditures that can be dealt with in similar ways as the residential and commercial sector. The machinery of manufacturing can function on electricity, whether not it is produced with fossil fuels. There are, however, numerous ways to increase the efficiency of their operation that currently exist; it is only an issue of implementation. The real problem lies in the 55% of industrial energy used in heating the processes of, among others, primary metals, food and chemical production. The reality is that there may be no economic alternatives for their energy needs. Electrical resistance is a highly wasteful method of heating something. For these fossil fuel-dependant industries, the future will see an escalating necessity to combine massive increases in heating efficiency, possibly through cogeneration, with a total reduction of the use of those products in all sectors. If unregulated by the government, what will regretfully happen is a total outsourcing of fossil fuel-dependant processes to other nations with governments eager to increase capital through industrialization, and where environmental regulations may be far inferior to those in America.
The energy situation in America is unsurprisingly neither apocalyptic nor utopian. What is surprising is that it is likely that focusing the country’s attention on the consumption rather than production side of energy use may prove far more rewarding. The largest consumer of energy in America is simple waste. It is not found just in the inescapable laws of thermodynamic, but in the easy to correct design and behavioral patterns we construct our lives with. As everyone knows, fossil fuels are going to become depleted if their use continues as in the present. What this writer is hoping to express is that this, while crucial for some applications, Americans are not as dependant on fossil fuels as they think they are. Just as ancient Rome made the transition from wood burning to passive solar energy, efficiency in all sectors of American energy use will have to be scrutinized. Large, centralized power generators will continue to be important energy producers, as long as there are resources available to supply them. As individuals, Americans will need to evaluate their lifestyles and decide what role they are going to play in America’s energy story.