New power solutions
Since the dawn of the electric age, 130+ years ago, one of the main issues has been to generate and distribute the power required by the growing number of devices.We have gone from a simple selection of lights and motors to a bewildering (and sometimes bizarre) array of power-using devices.Lights are no longer just a heated wire in a glass bulb (incandescent) — there are competing technologies including fluorescent and solid-state lighting (LEDs). Motors have gone from the earliest DC and AC motors to motors that spin or run along lines; from inefficient motors of a few horsepower to hyperefficient motors operating at 16,000 hp and more. And the other devices… computers, phones, GPS systems, TVs, radios and who knows what else!
The most difficult part of all has been the supply of power to these devices. Options to generate power include hydroelectric dams, nuclear, gas or coal, solar, wind, tidal and geothermal. Then, getting power from the generator to the device is not trivial. The development of AC power allowed the use of long transmission lines to deliver power to distant locations. However, the last few feet or inches of connection can be the most difficult. Power cords are okay for stationary equipment, but look into any modern home or office to see the tangle of power cords — just look under my desk or behind my TV! And portable equipment uses bulky batteries that do not seem to have improved in decades.
Help may be on the way. A group at the Massachusetts Institute of Technology is developing a concept first proposed by Nicola Tesla.He had originally proposed power radiation towers set in each neighbourhood to power all nearby devices.The MIT researchers have experimented on a smaller scale system that would power devices on a room-by-room basis.The system works in a fashion similar to a conventional transformer using non-radiative electromagnetic induction — essentially, a moving magnetic field inducing a current in a matching receiver. This sounds simple, but requires careful tuning of the transmitter and receiver to ensure efficient energy transfer. However, it could allow the elimination of power cables, the way Wi-Fi has untethered Internet access — you could surf the Internet on your portable device while it charges, as you sit in the Starbucks at the airport.This system could even power items requiring more oomph, such as any appliances that you might normally plug in with a power cord — wireless vacuuming!
One of the options for generating power mentioned above was nuclear.When you think of nuclear power plants, you envision a very large installation generating 1,000 megawatts or more. However, there is another option for nuclear power. Toshiba has been working on a design called the 4S “Super Safe, Small and Simple”, which uses a sodium-cooled, breeder-reactor design to produce up to 30 megawatts, called a nuclear battery.The power source for this reactor is only about the size of a large refrigerator, a steel cylinder containing uranium, plutonium and zirconium. The design allows for up to 30 years before refueling, and the use of liquid sodium coolant allows the production of a much higher quality steam than with a conventional reactor — the steam generated is at about 500C, much higher than the typical 260C in a conventional water-cooled reactor, which improves the thermodynamic efficiency. Security is insured by the simple expedient of burying the power source about 30 m deep, and generating steam from water circulated to the reactor.Operating costs are expected to be about 5 to 13 cents per kilowatt hour.
There are more options for generating and distributing power than are ever considered by the mainstream media and the general public. Improvements in efficiency will definitely help our power consumption, but there is no question that ours is an energy-intensive society. Not all the efficiency in the world will decrease our need for energy; it will just help us to better use the sources of energy that we have and can create.
Freelance writer Dan Davies can be reached at [email protected].