Consumption of renewable energy rose to supply approximately 6% of total energy consumption for the Unites states in 2003. Biomass and Hydroelectric power made up more than 90% of the total renewable contribution while solar and wind made up less than 2½% of this contribution. It is also important to note that the end product of many alternative energy sources such as nuclear, hydroelectric power, wind, solar, geothermal, and tides is electricity, which is not a satisfactory replacement for oil and natural gas in their important roles as liquid fuels for transportation or the raw material for a host of products ranging from paints and plastics, to medicines, and inks. But probably the most vital of all uses is to make the chemicals which are the basis for modern agriculture. Certainly, the costs and infrastructure required to retrofit the 900 million+ internal combustion vehicles currently in use on the planet to an electricity-based propulsion will pose significant challenges.

Coal:

At current usage rates, there is enough coal left in the ground to supply us for 200 years. But if the United States starts increasing coal consumption at 2% per year it reduces the 200 years supply to 100 years, and if we also start liquifying coal for motor fuels it reduces the supply to less than 50 years. Coal mining operations, machinery and transportation all run on fossil fuels. Coal currently has an EROEI (energy return on energy invested) ratio of 8 to 1, meaning 8 units of coal can be produced using the energy produced by one unit of coal. Compare that to oil’s current EROEI of 10 to 1 (10 barrels of production at the energy cost of one barrel of oil) and, with oil supplies depleting and coal resources becoming more difficult to mine, coal’s EROEI estimate for 25 years from now is 1 to 2, meaning it will take the energy equivalent of two units of coal to produce a single unit of coal. When it takes more energy to extract a substance than that substance can produce, it is no longer an energy resource, rather it is an energy drain. And let's not forget that coal is one of the dirtiest fossil fuel energy sources. Unless carbon sequestration can be made effective, use of this energy source will pose an extreme danger to the Earth's biosphere through additional global warming.

Hydrogen:

Hydrogen is not an energy source, rather it is a carrier of energy. Hydrogen currently supplies approximately 0.01% of the energy used in the United States. Hydrogen must be made from oil, gas, coal, wood, biomass, or water. Yet in every case, it currently consumes more energy to make hydrogen than the energy it can provide (an EROEI of less than 1.) The infrastructure to deliver and use hydrogen (converting the internal combustion engines in use today and gas stations) is not currently in place, will cost untold billions to develop and deploy, takes four to eleven times the physical space to transport and store (as compared to oil), is not suited to aircraft or sea-going vessel propulsion, and cannot be used to manufacture plastics or fertilizers. Experts estimate a "hydrogen economy" is at least 30-40 years away.

Nuclear Power:

This energy source currently provides about 8% of US energy resources through approximately 103 nuclear power plants. This number would need to be increased by 800 to 1,000 plants to replace the energy provided by oil today in the United States alone, and from 7,000 to 8,000 additional plants globally. Further, it would require the retrofit of fossil-fuel-powered machinery and vehicles to an electricity-based propulsion system in order to use its energy to replace oil-based propulsion systems. It cannot be used to produce plastics or fertilizers and has its own waste and security implications to consider. The infrastructure required to power the five to ten year manufacturing process to build each nuclear power plant is currently based on fossil-fuel-powered machinery and manufacturing processes. To build 1,000 nuclear power plants at current costs would require from 3 to 5 trillion dollars. And, uranium is also a finite natural resource. The entire world's current known reserves of uranium would not last even half of a single human lifetime if all our energy requirmetns were supplied by nuclear power. Nuclear power would provide only a bridge to other energy sources in the future.

Natural Gas:

This energy source currently provides approximately 25% of energy production in the United States and more than half of the grid energy in Washington County (coal currently provides a significant amount of the balance.) The US natural gas supply already peaked in 1970 and is currently only producing at 1/3 its peak level. Global natural gas deposits will start running out from 2020 on. Demand for natural gas in North America is already outstripping supply, especially as power utilities take the remaining gas to generate demands for electricity. North Americans will continue to face high prices to power, heat and cool their homes and may even endure some natural-gas shortages during cold winters. The rising demand for gas, coupled with flat production, has dramatically increased prices in the last four years. The infrastructure to import and transport natural gas is not in place (although 59 LNG terminals have been approved for development in the USA), and will take years to develop. Finally, natural gas is not well suited for existing aircraft, ships, vehicles, and equipment for agriculture and other products. The International energy Agency has publicly stated that they are deeply concerned about "very tight" natural gas supplies by the end of this decade (2010.)

Shale, tar sands and coal beds

Tar sand mining in Canada. Photograph: Jeff McIntosh/AP
The major problem with these sources is that they cannot be exploited sufficiently before the oil shocks cripple attempts to bring them on line, the rate of extraction is far too slow to meet the huge global energy demand, and the process to extract the oil causes catastrophic environmental destruction. The process is to extract sand which has bitumen deposits within it; essentially wash the sand with very hot water to extract the bitumen, and then add hydrogen to the bitumen to make fuel. The enormous environmental implications tied to the extraction of oil from shale, tar sands, and coal beds are very worrying – the process requires the use of enormous quantities of natural gas and fresh water. In Alberta, at Fort McMurray's open mines, it takes 2 tons of tar sand, 250 gallons of water and 1,400 cubic feet of natural gas to produce one barrel of synthetic crude. The EROEI is approximately 3:1. Some reports indicate that extraction of these fuels is some of the most environmentally damaging activity that exists on the planet. Further, even the shale experts in Alberta, Canada, suggest that the maximum daily extraction would yield about 3 million barrel equivalents of oil -- just under 4% of the world's current daily oil consumption. Doing the math, this proposed daily yield of 3 million barrel equivalents would require 6 million tons of sand, 750 million gallons of fresh water, and 4.2 billion cubic feet of natural gas, per day.

Hydroelectric power:

Currently accounting for 2.8% of U.S energy production, it can be safely stated that virtually all locations suitable for large hydroelectric power plants have been exploited, and many of the rivers and lakes behind these dams are silting up rapidly, threatening their long-term viability. Some dams are being removed to protect wildlife and habitat. In the northeastern United States there are a still a number of locations where small hydroelectric operations could be reactivated – providing supplemental power to small towns and communities.

Solar Energy:

Power from photovoltaic arrays account for 0.07% of current energy production in the United States. To increase this amount to any meaningful degree of energy production would require more than a 1000% increase in the deployment of solar power generating platforms. Estimates are that more than 20% of our land area would be required to replace one half of our current energy needs. Energy production is also largely impacted by cloud cover and density, the daily pattern of light and darkness, seasons, and dust in the air. This energy is not easily storable or portable energy like oil or natural gas, so it is unsuited for present vehicles and industry. The platforms additionally require the use of extensive fossil fuels to manufacture the solar cells, and to install the energy platforms. The batteries are bulky, expensive, wear out in 5-10 years, and have their own disposal issues due to the toxic materials contained in them. There is good news in the manufacturing sector with dramatic increases in efficiency, and numerous rebates and tax benefits are available to offset the cost of solar installations. Solar water heating, is, in fact, a very valuable commodity provided by solar energy, with more than 10,000 megawatts of generating capacity installed worldwide as of 1998. (the typical American home uses approximately 15-20Kwh of energy per day.

Wind:

Wind power is now the world’s fastest growing energy source, accounting for about 0.1% of the US energy supply, and is a worthy alternative energy source. It is four times as efficient as solar PV. But, again, to increase power production from this resource to any meaningful level of contribution to our energy needs will require increases in wind farm deployments of astronomical proportions. It is also worthy to consider the enormous energy requirements, in the form of oil-dependant machinery and manufacturing processes, to construct the generators, towers, new transmission grids, and to deploy wind farms. Further, wind energy is dependent upon variable wind speed and, although there is wind blowing all night, energy demands are at their lowest point at that time and wind energy is not easily storable. Massive energy storage applications must be developed. (Consider, for example, that if United States consumers owned millions of electric vehicles, which were all plugged in overnight to recharge, those millions of storage batteries would provide a massive ability to store such energy.)

Methane Hydrates

This is methane gas trapped in solid water ice located under the sediments on the bottom of the ocean in various locations around the world. It is estimated that within these deposits exists enough energy to completely supply the world's energy needs for 300+ years. The problem is that they are located in very deep waters unaccessible to human workers, or they are too dispersed to make harvesting economically viable. They are also apparently an important component of sea-floor stability. Methane hydrates were created by millions of years of the normal lifecycle of plankton and bacteria dying in the oceans and falling to the ocean floor, then being processed through thermal decomposition over time, and ultimately releasing methane gas which became trapped in water ice under great pressure at these depths . To harvest these methane hydrates is an extremely risky business: First due to the perceived stability of the ocean floor -- it is suggested that large mining of these ice crystals could potentially cause under-sea landslides on the ocean floor which could generate tsunamis. As important are the fears that if mining equipment created a spark that ignited any of the methane, the entire methane hydrate field could potentially explode causing untold damage to the field, the ocean and the sea floor, not to mention the obliterated miners sucking the stuff up on ships on the ocean's surface. Further, methane is a powerful greenhouse gas, worse than even carbon dioxide, and an unexpected release of large quantities of this gas during a mining operation could have catastrophic effects on the world's ecosystem (it is hypothesized that large releases of methane gas may have caused the Permian-Triassic (P-Tr) extinction event on the planet 250 million years ago.) These potential hazards have not stopped scientists from studying how to harvest this immense source of energy. This year (2007), China successfully harvested some methane hydrates in the South China Sea after nine years of research in this field, and a research and development project in Japan is aiming for commercial-scale extraction by 2016.

Ethanol:

Ethanol takes more energy to produce than is derived from its use and is only viable in America today because of massive government subsidies. The massive increases in ethanol production have dramatically affected the price of corn and other food products due to the enormous quantities required. "Our current ethanol production represents only 3.5 percent of our gasoline consumption -- yet it consumes twenty percent of the entire U.S. corn crop, causing the price of corn to double in the last two years and raising the threat of hunger in the Third World." [See this article in Rolling Stone] Do we trade food for fuel? There is apparently some promise with cellulosic ethanol, although it will take years to scale any commercial operations to a meaningful level.

Methane gas

... is generally derived from decaying biological matter (such as from land fills and animal manure.) When produced from animal manure, each pound of manure generates roughly only 50 cubic feet of gas, less than ¼ of typical family gas usage per day in a typical home. It is also worth mentioning that the methane gas generation process requires considerable time to produce because it is a biological process depending upon decay. Biogas digester's are quite common on farms throughout China's rural areas for providing the daily gas needs for cooking, lighting and heating.

Biomass:

Most biomass energy is produced from wood, wood waste, and agricultural or landfill byproducts and waste. Essentially this process captures methane gas from the process of decaying organic materials, or requires burning. Biomass energy is produced from non-fossilized materials derived from plants. Wood and wood waste are the largest sources of biomass energy followed by energy from municipal solid waste (MSW) and alcohol fuels. In 2004, biomass accounted for 47% of renewable energy consumption, with about 50% of this used for heating, 40% for electrical power production, and the rest as transportation fuel.

Wood – Wood biomass includes wood chips from forestry operations, residues from lumber, pulp/paper, and furniture mills, and fuel wood for space heating. The largest single source of wood energy is “black liquor,” a residue of pulp, paper, and paperboard production. It supplies over 50% of these industries’ energy requirements. Lumber mills and furniture manufacturers use chips, sawdust and bark for nearly 60% of their energy requirements. A small but growing amount of wood is co-fired with coal in utility power plants. Cordwood, wood chips, and pellets made from sawdust are used for space and water heating in buildings, including in over two million households as primary or supplemental heating fuels.

Municipal Solid Waste and Biogas – Waste-to-energy facilities burned 29 million tons of MSW in 2004 to produce heat and electricity. There are also about 380 landfills that recover methane, which forms as waste decomposes in low-oxygen (anaerobic) conditions. The methane is burned to produce electricity and heat. Methane is also produced in anaerobic “digesters” for heat and electricity generation at municipal sewage treatment facilities, concentrated livestock operations, and dairy farms.

Summary:

While none of these alternative energy sources is currently a viable replacement for the enormous energy demands currently supplied by oil and fossil fuels, especially liquid motor fuels, the rapid development and deployment of all of these resources, combined, is absolutely vital to meeting the future energy needs of the nation and our world, and will certainly ease the impact of the depletion of energy derived from fossil fuels in the years ahead.

However, even with the best technology and funding, the sum of all of these alternatives will not be able to replace the enormous amount of energy we currently derive from petroleum. The difference will have to be made up through extraordinary gains in both conservation and efficiency.

You can expect a transition in the coming years in the way we will live our lives in this country and in our community. In fact this will most probably be the greatest transition in lifestyle in the vast history of humankind...the powering down of humanity. What we as individuals and as a community do now, today, will have a direct and significant impact on the comfort levels, duration, and challenges of that transition.

We urge you to take this issue very seriously, to become educated on the issue, and to take action now in your personal life, that of your family, your neighborhood, and your community at large.

Submitted by Peter Lunsford © 2007, Petraworld