Conventional Energy

History of Energy Use in United States- in order of supremacy.

Wood, slaves, coal, steam engine, and oil. Undeveloped countries still use biomass as 90% of their energy source. Amercians and Canadians (at 5% of the world population) use over one quarter of the WORLD's available energy. Hummer=Dummer. If we stopped driving gas hogs and living in sieves we could drastically reduce the amount of oil we use. Each person in the US uses an average of 60 barrels of oil/year- most of which is imported.

The 20 richest countries (1/5 the world's population) use 80% of the world's gas, 65% of the world's oil and 50% of the coal produced each year.

Calorically:

Hunter-gatherers required 2500 cal/day

World consumption is 31,000 cal/day

US consumption is 108,000 ca/day (including oil)

Fossil Fuels- provide 64% of the worlds electricity. Made from fossilized remains of once living organisms buried for years under intense heat and pressure.

 

 

Oil (liquid form of petroleum)- our primary source of energy.

Oil is formed when microorganisms accumulate at the bottom of the sea where oxygen is limited. There it is chemically transformed anaerobically into oil and gas by a process called maturation. The longer the hydrocarbon molecule, the more solid it is. Less than 5 carbon atoms is gas. Huge numbers of carbon atoms turn into crude oil. Geologists drill exploratory wells to find a "proven" reserve, a known large quantity of oil. Measured in barrels which are equal to 42 gallons of oil. We have a very vague idea of how much oil is left, but most estimates place our world reserves at 50 more years and US reserves at 25 years. The Hubbert peak theory predicts that the oil production will soon reach a peak and then decline rapidly. We reached peak world oil production in the mid-90's most likely. Iran and Saudia Arabia are a little touchy about informing us of EXACTLY how much oil they have. The US peaked in the 70's.

Petrochemicals are chemicals refined from oil. They include plastic, synthetic fibers, medicine, wax, synthetic rubber, insecticides, fertilizers, detergents, shampoos!!!

Extraction from a reserve is done by pumping (first 25%), then another 50-60% is done by pressure extraction- whereby steam, salt water is pumped into the oil field and pushes out the oil. As oil prices rise it will be more cost effective to remove more of the oil from the field. Right now removing oil from tar sands and oil shale is cost prohibitive.

Oil prices in the US are heavily subsidized by the government. Europeans pay at least twice as much for oil. The US imports more than half of its oil.

Coal

Most coal orginally formed from a dense swampy mat of decaying plants during the Carboniferous period- 300 million years ago. As plant material becomes buried it turns to peat (5% carbon). Further compaction and burial create lignite coal which is 60% carbon. Coal has various grades depending on purity and degree of metamorphism. The least favorable is lignite, then bituminous (sedimentary, 75% carbon) then anthracite (metamorphic, over 90% carbon).

We have roughly 200 years left of coal supplies. It is the most abundant fossil fuel and creates over one half of our electricity in US. Most of the coal supplies are in US, Russia and China.

Coal mining occurs through strip mining and underground mining. Underground mining requires shafts to be sunk to reach deposits. Networks of tunnels are created to reach the deposits and can be very unstable and dangerous. Stip mining is horrible for the environment. The earth is removed all the way to the coal seam. Hazardous slag heaps are created containing sulfur which can leach out and damage the water table.

Coal fired electric plants are only 30% efficient AND they emit tons of sulfur and mercury into the air.. floating on the wind currents.... straight to NPZ! Scrubbers should be mandatory to remove S from coal's combustion gases.

Natural Gas

Its convenient, cheap and cleaner burning the the previous two fossil fuels. It emits considerably less CO2 when combusted. Only 10% of energy lost during conversion. (As opposed to 95% energy lost in a light bulb!) Difficult to transport as it has a tendancy to blow up if hit. If transporting must keep under pressure to keep in liquid form or put into pipelines.

2/3 of natural gas is burned off when activating a oil well. Maybe they should rethink that.

Nuclear Fusion

2 isotopes of light elements are forced together at high temperatures till they fuse to form a heavier nucleus. 15 million degrees C to fuse H into He. Forgetaboutit. Too unstable. Cars running on nuclear fusion keep on blowing up. Very annoying trait. Takes

 

Nuclear Power

India and China create the most nuclear power

-Designs and Disasters

Nuclear reactors have fuel rods of uranium and some kind of control rod (cadmium, boron, graphite) to absorb neutrons and slow the chain reaction in the core inside a containment building, a heat exchanging material, steam generator, cooling system and a turbine. The greatest danger is a cooling system failure.

Types of reactors include- Boiling reactors, pressurized water reactors, heavy water reactors and graphite reactors.

After the Three Mile Island partial meltdown in Penn in 1979 and Chernobyl disaster in Russia in 1986 all new nuclear power plant construction projects in the US have been on hold.

-Radioactive Waste Management

-"Too cheap to meter?"
"Technology and engineering would tame the evil genie of atomic energy and use its enormous power to do useful work."
-nuclear power was supposed to be a cheap and safe solution for the projected natural oil and gas deposits being depleted.
-a lot of the future projections for the use of nuclear power were made under the assumption that future advancements in technology would figure out a way to get rid of the waste.
-1970-1974, 140 new reactors for power plants were ordered. Only forty of which were actually built.
-Nuclear energy supplies 20% of power in the US, 8% world wide.
-Nuclear power first developed in the 1950's after WWII, and the invention of the atomic bomb.
-Scientists thought this would be a safe and renewable energy source, but it was proven dangerous to work around, and even minor accidents could have long lasting, and long ranging affects.
-Technology did not catch up with the expectations of the scientists for disposing of the hazardous wastes.
-Another major problem is that because the reactor can not be allowed to melt down, all the systems had to be redundant, making an extremely complex and delicate system that causes more accidents than it prevents.
-Nuclear power plants need to be located next to an abundant source of water to provide the power plant with water. This harms the natural environment of the waterway, and poses great risk if the power plant were to leak nuclear waste. The Hudson river has thermal pollution from Indian Point.

"How does our misunderstood friend work"
-the thing that makes something radioactive is the fact that it is an unstable isotope. All isotopes long to be stable. That is their goal in life. Most plants use 97% U-238 and 3% U-235.
The way they attain this goal is by releasing charged particles. These particles can alter animal DNA
by mutating it in undesirable ways. Exposure to high levels of radiation creates bizarre types of cancer.
This very same process is what gives us power.
-when radioactive isotopes like U238 come in contact with neutrons, they break up into more stable
isotopes releasing massive amounts of energy such as heat and light. This is called nuclear fission. It also releases other neutrons, 2 or 3,making a chain reaction. The way this reaction is controlled is by the use of neutron absorbing materials like graphite. When the operators want to slow down the reaction, they put neutron absorbing material between the fuel rods. This material is removed if the reaction is to speed up. The way the energy is harnessed is
through the use of steam. The nuclear rods sit in a pool of water causing the water to become super heated. This heat is then transferred to another water pool that boils which then spins a turbine that spins a generator that creates electricity.
... And there is no harmful air pollution- no NOx or SOx. Environmentalists are pessimists. Air pollution will kill us slowly, nuclear power will kill us within a few short days! The half-life of uranium (the amount of time it takes for one half of uranium to decay is 4.5 billion years! It would take 10 half lives for uranium to decay to a safe level.

Waste disposal aka just put it where no one will find it.
- There are many ways to dispose of the waste that is generated by nuclear power.
-Waste is generated when the isotopes are first mined, and again when the isotopes are refined, and later when the isotopes are used. All the equipment that comes in contact with the isotopes also becomes waste.
-Countries that use nuclear power have devised many interesting ways to get rid of the waste.
Some countries, ahh, like America, have chosen to store the waste on the nuclear reactor site for many years,
and then beginning in 2010 move it to Yucca Mountain, Nevada. This long term storage facility is between two active fault lines, above a major aquifer! Other countries, like Russia took the NIMBY approach, and decided to transport the waste to unprotected cites that are easily accessible by hostile peoples. They even dumped a bunch of nuclear waste on the bottom of the Arctic Ocean!