One of the key environmental commitments of the UK’s new coalition government is to implement a smart electricity grid. But what exactly is a smart grid?
A small power station
Our present electricity grid is pretty stupid in at least two significant ways. Firstly it regulates supply, but not demand. Since demand fluctuates wildly day by day and week by week, we need quite a few power stations idle for much of the time, but ready to come on line at very short notice. Secondly, the electricity flows only one way – from big, inefficient power stations to end users.
A smart grid addresses these problems. A smart grid regulates demand as well as supply: here’s how. Instead of the price of electricity being fixed for long periods of time, the price varies second by second in line with demand. This information would be sent down the cables with the electricity itself. When electricity happens to be very expensive, some devices, like fridges or battery rechargers would turn themselves off for a bit until the price fell or they really needed to be on. Other devices such washing machines would wait for cheap electricity before turning themselves on at all.
Secondly, electricity would flow both ways. When you plug in your electric car to recharge, it would generally be drawing power from the grid. But if there were a sudden demand for power, you might want to sell the power in your car’s batteries back to the grid. You’d be happy because your car would be buying electricity when it was cheap, and selling it when it was expensive. The power generation companies would be happy because you’d be providing them with the infrastructure to deal with peak demand, instead of their having to build extra power stations to cope with such surges.
When will we have a smart grid in the UK? This is where the government is a bit vague. But if we don’t do something soon to reduce demand or increase supply we’re going to run short of electricity in the UK by the end of this decade.
