An important step that could help reduce the dependency of the United States on fossil fuels would be to increase the efficiency of the electric grid that sends electricity from place to place. It is moved by invisible air waves and waves in wire and electric field energy. The U.S. Energy Information Administration estimates a loss of 6 percent of electrical energy as heat radiating into space based on years 2004 through 2013.
With the emergence of smart phones, tablets and laptops, most homes now contain at least a couple charging units and power packs.These convert the grid’s volts into lower volts and the appliances take only the energy they need. The desired voltage and current is achieved through wrapping the power pack’s insulated wire from the wall receptacle several times to create a magnetic field. With 20 wrappings, the mobile phone will get 1/20th of the voltage. For example, 120 volts delivers 6 volts to the phone.
A power pack gets warm because the magnetism converts some of the magnetic energy to heat. In transformers, energy is dissipated because of windings resistance, called load loss, and magnetic effects mostly from the core, called iron loss. Large power transformers are up to 99.75 percent efficient, but plug-in power packs can be less than 85 percent efficient. Researchers have added silicon to steel and rolled it into thin sheets to make it more efficient and faster at building and maintaining magnetic fields, and to decrease energy loss to heat.
Leaving devices plugged in all the time wastes more energy which is called no-load power loss or vampire loss. Old televisions use 10 watts while turned off. A new standard is to make every device use less than half a watt in standby mode, from little clocks on appliances like coffeemakers to television tuners. This could be further reduced to free up more electricity.
Large hydroelectric dams like Grand Coolee Dam generate as much as 500,000 volts. This is sent down to community electric lines and reduced to 800 volts. It gets reduced again in transformers on power line poles before reaching homes. Historically, Thomas Edison wanted to use a Direct Current (DC) electric system and Nikola Tesla wanted Alternating Current (AC). A DC system would be more efficient, but the voltage would have to be the same at both ends. Tesla won, but died a poor man. The dominating company was named after the better business man who became rich, Thomas Edison. Today over long distances the more efficient DC is used.
The electromagnetic fields are prevented from losing their energy to the Earth’s surface by using heavily insulated wires. However, with those wires high above the ground, some energy is lost to heat and power lines sag. Most are made of aluminum with steel or fiberglass in the middle for strength. Old lines are copper, which is a better conductor but is also heavier and requires bigger towers. There is also the skin effect where the energy travels in the outside of the wire. The more current being used, the warmer the wires get and the more they sag. That makes them thinner so the skin gets thinner too.
There are some ways to change the loss of 246 billion kilowatt-hours in the United States each year to heat. Superconductivity is becoming one in Essen, Germany. A one kilometer (0.6214 mile) 10,000 volt superconducting cable replaced a conventional 100,000 volt line between two power stations under the AmpaCity project The cable chilled to -200°C conducts five times more electricity than copper cable of the same size. It has virtually no resistance so electric losses are very low. This can reduce use of high-voltage cables and transformer stations, and simplify grid structures. Watch the video of how superconductivity works.
Another possibility is using nanotubes of carbon atoms which was the late Rice University professor Richard Smalley’s dream. Electrons have almost no resistance in carbon nanotubes, but it is not yet possible to grow the nanotubes more than 50 nanometers long without a mix of conducting and semiconducting versions. They must be sorted into only conducting nanotubes, which is cost prohibitive, or else their electrical resistance is about eight times greater than copper wire resistance. If all power lines including in homes could be replaced with no resistive loss nanotubes and if commuter trains did not need to have power boosted between track ends, an amazing amount of energy would be saved and less would need to be produced.
One problem with the grid is the various parts of it do not communicate, so the whole grid is not monitored. Using biomimicry and copying how bees with limited brainpower sense what needs to be done for their colony and do it without being told, Regen Energy developed Swarm Energy Management®, a network for demand response and demand management of a building’s machines and appliances. Through controllers communicating wirelessly, loads are balanced during the more expensive and less reliable peak-power times and all the “bees” in the hive are synched. Work is being done to improve grid communications.
While the U.S. is looking at ways to improve its electric grid, in electricity-poor countries like rural India and Sub-Sahara Africa over a billion people have no electricity or frequent blackouts. In South Sudan’s population of 11 million people, the World Bank noted in 2012 that only 5 percent have electricity. There it costs three times as much as in the rest of the developing world and manufacturers suffer two months of power outages yearly.