Wind turbines and solar may be clean safe ways to make electricity, but besides being expensive, they are also undependable. The power company can’t count on the wind to blow at just the right time; the sun for sure doesn’t shine at night, and in some places, it can’t even be counted-on to shine in the daytime. And electricity users are also undependable. Air conditioning, electric home heating, electric water heaters, refrigerators, and freezers all use huge amounts of electricity, and it is hard to predict when they will turn themselves on or off. Because of this, it is very hard for the power company to predict when large amounts of electricity will be needed.
This is a serious problem because big coal-fired electric plants, and nuclear reactors cannot just be switched on at a moment’s notice. All this unpredictability requires the power company to keep big coal-fired and nuclear power plants operating even though they may not actually be needed.
Fortunately, none of these big electric appliances (air conditioning, home heating, water heaters, refrigerators, and freezers) have to run all the time. They only have to run long enough and often enough to properly do their heating or cooling. If the power company could somehow turn off your home heating or your refrigerator for a few minutes, while it starts up a coal-fired plant, or while it waits for the wind to start blowing again, it would help a lot! If the power company could do this, they wouldn’t have to keep so many big coal-fired or nuclear power plants operating on the off-chance that they might be needed.
It turns out that the power company can do this. The system is called a smart grid and it has already been used in Sequim, Washington and several other towns around the United States. The smart grid reduces the highest user demand for electricity by about one-tenth. This might not sound like much unless you happen to know that there are more than 610 coal-fired power plants in the United States alone. One-tenth of 610 is 61. If the United States changed-over to a smart grid, 61 coal-fired power plants could be shut down, without any need to replace them.
Electric cars can make the smart grid even better. With a smart grid system, the power company can decide when it is easiest for them to charge the batteries in your car. But here is the amazing part: the smart grid can actually use the batteries in your car for short periods of time when they need a little extra power! The system only takes a small part of your electric car’s charge, so you will still have enough of a charge to get to work in the morning. Even more amazingly, it turns out that Denmark is already doing this, and Israel is in the process of planning such a system.
In another ten years, when most families will have an electric car as their second car, many countries such as Israel, Denmark, and the United States will -in effect- have massive backup battery storage in their tens of thousands of electric cars. These countries will use their electric car's batteries to store the electricity randomly produced by wind, tidal and solar at the times when it was NOT needed - making the wind, tidal and solar power FAR more efficient.
Eventually, the smart grid will be able to smooth out random user demand AND smooth out random production of electricity by wind and tidal. When combined with the energy gained from tidal, smart grid efficiency may well be able to "replace" as much as one-seventh of the energy we now use, making the smart grid a significant contributor to the "production" of energy.
The Electric Power Research Institute (EPRI) estimates that US implementation of the Smart Grid will cost $165 billion over the next 20 years, which would suggest that the world-wide cost might be about $1 trillion.