Imagine a future where everybody drives electric cars. Or a future where people both buy electricity from national suppliers and produce their own for domestic use, perhaps using solar panels. One of the biggest problems for energy conservation will be loading, trying to balance the use of electricity with its production, in an effort to minimise the difference between the peak load and the average load. This is crucial for energy conservation because of two reasons. First, power stations are most efficient if their output is continuously being delivered at the designed optimal level of output. This is better than increasing and decreasing output to reflect changes in demand. Second, transmission over distance involves wastage. The better the match between local demand and local supply, the less energy is used just to move electricity around the grid. Of course, the problem of loading is already with us, but increased demand through using electricity for cars, or increasing the variability of demand through erratic home micropower generation, might accentuate that problem further.
One partial solution would involve a change in mindset. Solutions historically have focused on supply-side management techniques, like building lots of small local Combined Heat and Power stations to service local communities, building international connections to transmit between different national grids, or by storing energy through techniques like pumped storage of hydro electricity. In contrast, there is less effort placed on demand-side management, and techniques used to manage demand are relatively crude. These focus on the promotion of energy conservation and applying different charges for consumption depending on the time of day. This in turn promotes relatively crude mechanisms for storing energy locally. For example, heat energy can be stored in order to utilize off-peak electricity supply. Put simply, electricity is used to heat up a large pile of bricks during the middle of night, and the bricks radiate this heat during the day. A timer in each house will click on the supply of electricity at the start of the off-peak time, and click off at the end. This may help balance the load overall, but it is pretty unsophisticated, and arguably not very efficient. Imagine if, instead, a remote computer could chose when each house’s pile of bricks is heated up, with the goal of trying to keep a constant demand by switching on and off the use in each house in order to match demand with supply. Think then of the battery in the electric car, or of a battery connected to the micropower generator in the person’s home. These would simply be more sophisticated stores of energy than the piles of bricks. They could also be used to help balance the load, storing electrical energy during off-peak times, but also contributing electricity during peak times. The car’s battery would be fully charged during the night, ready for the commute to work in the morning. Any excess left in the car battery after the return home at the end of the working day could be run down during the evening to help meet household needs, especially if there is a sudden surge of demand in the house. Balancing the load in such situations would require a lot more co-ordination, meaning a lot more communication between the electricity company’s computers and the ones in the car and in the home.
There is already an elegant solution for communications for demand-side energy management: transmit data between the relevant devices using power line communications. Despite having lots of promise, power line communications have so far failed to evolve into an effective competitor for delivering broadband, and even less so for voice. Problems with power line communications include poor quality because of the inherent noise in using power lines, and interference with radio. But for electricity demand management, power line communications provide a straightforward solution once the infrastructure is installed. All the relevant devices will already be connected by electric power lines – the battery in the car, the home meter, and a computer to manage the regional electricity load – so this mechanism avoids the need to connect a separate communications line to each device. Also, the bandwidth needed for such communication will be small, decreasing the issues with quality and interference. In future, power line communications could enable far more intelligent load management, balancing demand and supply by controlling exactly which household devices receive electricity and when. Better still, it can be used to deliver cost savings in the here and now. Power line communications could be used to eliminate the need for a person to visit the home in order to read the electricity meter. It would also improve billing accuracy by doing away with the need for estimated bills.
Like everything else in life, there is some bad news and some good news for demand-side management. The bad news is that the many politicians who have jumped on the green bandwagon mostly think in terms of old-fashioned solutions to problems. Prefering solutions that focus on the state and central control, most politicians talk in terms of punitive taxes for the perceived “undeserving” use of energy, such as personal travel, especially when this supposedly has to do with carbon emissions. Note that according to the International Energy Agency’s 2006 report, more energy is used globally for electricity than for transport, and that coal, a fuel with only a negligible level of use in modern transport, is a greater source of carbon dioxide emissions than oil. Other favourite solutions for our unimaginative leaders include the building of more nuclear energy power plants and increasing storage capacity to manage load. At the same time, we also see some tinkering with daylight savings time and increasing promotion of the benefits of pumping up tyres on cars, but these initiatives are better at getting cheap publicity for politicians than they are at reducing emissions. So what is the good news? You may have thought what I wrote about demand-side management of electricity using integrated communication is science fiction. Thankfully, it is not. Not only is it science fact, but it is becoming commercial fact too. Forward-looking businesses are already planning for demand-side management of electricity. Take this press release from Manitoba Hydro, explaining their plans for a pilot installation of new automated meters. They will be using Cannon Technologies solutions that incorporate power line communications. Though Manitoba Hydro is starting small, they identify that the benefits will be long-term. At first, the power line communication will enable Manitoba Hydro to remotely read meters and identify outages, but it is also an enabler for management of demand. Intelligent real-time balancing of electricity supply and demand will likely be a key technology for increasing energy efficiency and reducing carbon emissions. The sooner it is implemented in practice, the better.