Electricity has made our lives easier, more convenient, and (by reducing our dependence on an explosive gas for lighting) safer. But despite the fact that electricity has been a part of our everyday lives ever since Thomas Edison developed the first really viable electric light, the electric utility has always had its share of problems. Many of these problems have been solved already, such as achieving economically viable long-distance transmission, maintaining a constant 50Hz or 60Hz current, and keeping the wall voltage within about 10% of what it is expected to be. However, numerous electrical problems of great magnitude remain.
Air conditioners are by a wide margin the single most energy-hungry appliances found in the home. They use four times as much energy as an electric clothes dryer and run all day instead of for just an hour or so. Between long periods of operation and low efficiency, nothing else even comes close to the power consumption of an air conditioner (not even a refrigerator, which benefits from being small, well-sealed, and heavily insulated). During hot summer months, when millions of homes across the United States turn on the A/C, the demand for electricity skyrockets and power generation plants are pushed to their limit.
Aside from somehow increasing their efficiency (which manufacturers would doubtless do if they could), there is no good answer. Finding alternate ways to keep cool during the summer months will help, but our convenience based society doesn't like hearing that. Getting out of the house, going swimming, dressing lightly, using fans to keep the air moving, and even drinking iced tea are ways to reduce our dependence on air conditioning but all suffer from the disadvantage of requiring more effort than turning a dial on the wall to "cool". This is more a problem of social engineering than technology.
Generation of electricity is either expensive, polluting, or unreliable:
And sometimes all three. Every couple of months, my power company sends, with my bill, a pamphlet of some kind. The last one I got explained the difference between the various sources of power generation, such as reliable but polluting coal or gas power plants and environmentally friendly but unreliable hydroelectric and wind generation. There was also a nearly inverse relationship between the cost of producing electricity and the reliability of the method.
Unfortunately, there is no magic bullet for power generation yet. We simply cannot rely completely on tapping the wild and untamed forces of nature to keep the electricity flowing — there would be unacceptable power outages, brownouts, and other problems that would interrupt not only our daily lives but also our economy. This is not to say it's impossible. Iceland generates a huge amount of its electricity with geothermal power and New Zealand provides over half of its electrical needs with hydroelectric. Unfortunately, these solutions rely on specific natural conditions that occur in these countries and aren't available everywhere.
Fusion power looks like it could solve most of our problems without producing radioactive waste like fission plants do, but we haven't been able to sustain a reaction that provides more power than it consumes to start.
In addition, what most people don't realize is that even if a workable method of fusion is achieved, it can't provide for 100% of our needs. A fusion reactor, like modern fission reactors, cannot quickly change the amount of power that it produces. Nuclear power is best used when generating a constant output of electricity at some pre-specified level, and fluctuations in demand caused by factories starting up, people turning on their air conditioners, and millions of lights coming on when the sun goes down would have to be absorbed by some other method of power generation (however, this could in fact be provided for by environmentally friendly means such as wind, solar, or hydroelectric). No one knows when fusion power might be available, the running joke is that it is always 50 years away.
More futuristic solutions involve building orbital solar panels that wouldn't be subject to day/night cycles or cloud cover found on the surface of the Earth and fission plants on the moon which would irradiate a dead rock in space rather than our backyards. This power would be transmitted to Earth as microwave beams.
The reason high-tension power transmission lines operate at hundreds of thousands of volts is to reduce efficiency losses in the wires. The power lost in the lines during transmission is proportional to the square of the current through the lines times the resistance of the lines (P=I2R), so the voltage is increased as high as possible to reduce the current that travels through them. This is why AC power has dominated DC power, despite the additional problems that must be overcome -- transformers can be used to increase the voltage of AC power, but it is much more difficult to do this with DC.
The other option is to reduce or eliminate the resistance of the transmission lines. So far this hasn't been possible, superconductivity is only possible at very low temperatures. So low, in fact, that "high-temperature" superconductivity is defined as the temperature of liquid nitrogen! Research continues into room-temperature superconductivity, but the results so far aren't encouraging.
Batteries do not store much power:
The low power reserves of batteries is what limits the power of portable electronic devices today. This is easily seen in the price and performance differences between a desktop and a laptop computer. Although batteries are getting more powerful all the time, both pound-for-pound and volume-for-volume they are still a long way behind fuels in terms of the amount of power they store. Even small, hand-held weed whackers run on heavily polluting (but very efficient) two-cycle engines rather than batteries because of weight restrictions. The average human being can't haul around enough weight in batteries while doing yard work.
Battery powered electric cars are likewise unacceptable alternatives to gasoline fuel due to their notoriously short range; hybrid cars such as the Honda Insight and the Toyota Prius (which store in Nickel-Metal Hydride batteries spare energy from the gasoline engine that would otherwise be wasted) being the best compromise found so far.
Battery technology is improving all the time. I don't understand how archaic dry cell alkaline batteries are even still around in an age with reliable rechargeable batteries (I personally run everything off rechargeables and haven't bought a battery in years). The old, problematic Nickel-Cadmium cells gave way to less troublesome Nickel-Metal Hydride cells, which are in turn in danger of being rendered obsolete by the more powerful Lithium-Ion (higher price being the biggest reason they haven't). Even so, I'm not holding my breath for the day when a two-pound battery will hold as much power as two pounds of gasoline. Hydrogen fuel cells, which blur the distinction between chemical batteries and fuel, may prove to be the answer.
AC power must be generated as it is consumed:
Batteries store DC power, not AC. Although DC can be converted to AC using an inverter, the efficiency losses are substantial. In practice, there is no good way to store AC power and it must be generated in real time as demanded, with the ever changing demand being handled by complex systems. This results in a difficult juggle by the power companies to keep up exactly with demand at all times. The briefest interruptions or blips in electrical service cause all kinds of problems, from nuisances like VCR clocks flashing 12:00 to major problems like computer shutdowns and even damage to delicate electronics.
Because the demand for power is greatest during the day, some power companies use their spare nighttime capacity to pump water uphill for later generation of hydroelectric power when the demand increases. This requires expensive, high maintenance equipment and nearby hills with huge natural or artificial reservoirs at the top. Some power companies can afford to do this, others can't.
For critical systems, expensive uninterruptible power supplies provide back-up emergency power, but only for a few minutes at best. As battery technology improves, perhaps one day our homes will run off batteries that only rely on the power company for recharging purposes, which can be done during off-peak usage times when the power company has spare capacity. There are already high-efficiency homes in California that do this.
Rolling blackouts are sometimes necessary:
Since AC power must be generated as it is consumed, batteries do not store much power, and many countries are becoming increasingly dependant on electricity, power companies can find it difficult to keep up with demand during times of highest power usage. If the power company cannot keep up with demand in real time, such as in summer afternoons when millions of residential air conditioners are turned on, it must find ways to reduce its load.
Some large consumers such as steel mills have interruptible power agreements, meaning the power company can tell them to shut down their operations until the demand goes back down. Lately similar agreements have been made with blocks of residential neighborhoods, so that their air conditioners can be shut off for, for example, 15 minutes out of every hour on a rotating cycle. These plans cost the power company money of course, as customers demand discounts for interruptible service.
Sometimes even these methods aren't enough and rolling blackouts are issued, cutting off power completely to huge areas to avoid overloading the power grid. Building new power plants is expensive, and becoming more difficult all the time due to increasingly restrictive environmental laws. Upgrading the transmission and distribution systems is likewise expensive but necessary to get the higher levels of power out to the ever hungrier customers.
Solve all of the problems listed above.
Considering the enormous scale of the power grid, the demands placed on it, and the complexity of maintaining the system, it's nothing short of amazing that the electric system is as reliable as it is. Large scale interruptions of service, such as the August 14, 2003 blackout, are remarkably rare events. That is not to say the system is sufficient for our needs, only that the average customer generally doesn't notice the problems that do arise.
But the problems are getting worse. California has the most severe power crisis in the United States so far, due to its large population and number of high-tech industries combined with some of the most strict environmental policies in the world. Unless good solutions to the above problems are found soon, the rest of the country, and indeed all developed countries in the world, could be facing a similar crisis.