What is Electricity Demand?
Electricity demand is the amount of electricity being consumed at any given time. It rises and falls throughout the day in response to a number of things, including the time and environmental factors. Managing demand is key for utilities, and this became an increasing issue at the end of the 20th century, as utilities struggled to balance electricity needs with aging electrical grids. The infrastructure behind the electrical grid is woefully outdated in many regions of the world, presenting a potential serious threat to economic well being.
One problem with electricity is that it does not lend itself well to storage. As a result, utilities typically generate power in an on-demand style, ramping up electricity generation when energy demand rises, and slacking off when the demand falls. Storing electricity is extremely inefficient with existing technology, making it difficult for utilities to bank energy against a time of sudden demand.
Electricity demand can fluctuate wildly. At 5:00 AM during temperate weather, for example, demand is usually very low. People don't have climate control systems on, heavy machinery is often not running, and people aren't engaging in activities like cooking, washing dishes, running hot water heaters, and so forth in large numbers. In contrast, at 3:00 PM on a hot day, demand can spike, with businesses requiring a lot of electricity to run their equipment while people run air conditioners to keep cool.
The difference between extremes is important, because utilities must be able to match demand with supply. This means that generators may be taken on and offline, and slowed or sped up to provide what's needed. Utilities also need to balance needs like taking generators fully offline for maintenance and shutting down part of the grid for repairs. When a utility has to shut down a power plant, it needs to know that the electricity demand can be met by other facilities.
One approach to managing electricity demand is building more generation facilities that can be brought online to manage peaks. Another solution is to encourage consumers to moderate their electrical consumption. For example, people may be encouraged to purchase energy efficient appliances, to use equipment that automatically shuts off when idle, and so forth. These tactics reduce energy demand and help to curb the steady rise in demand that has been documented in many regions of the world.
For those who are curious, some governments maintain charts online which track the demand for electricity throughout the day. People can use these charts to look at national as well as regional electricity consumption.
@alchemy- The use of renewable energy, especially solar, has promise to help meet demand at peak times. The biggest downside is that solar can have a negative effect on electricity prices because of the high capital costs. What solar brings to the table however, is promising for utilities because the electric grid in this country is reaching maximum capacity. In some cases, there is simply no room to add mega power plants to the grid infrastructure. Solar and other renewable technologies will help create a more decentralized grid. Solar is also most efficient at producing electricity during what is normally seen as the on-peak hours. This can allow for a utility to generate electricity without bringing another generator online.
@Alchemy- it is true that the peak electricity demand response is to have a generator online to ensure that the grid can handle demand, but there are new ideas and technologies that are helping utilities level demand loads.
Some utilities use the potential energy of water to help level loads on the grid. The utility will pump water up to a reservoir when demand is low, effectively storing energy in the reservoir. When demand peaks, the utility lets the water fall down from the reservoir to spin a turbine to help meet demand. There are also different ways to convert electricity to chemical energy to store it for later use. Some of these techniques are also being used to make renewable energy like wind and solar more reliable.
What are some specific ways to manage the peaks of demand without adding new coal and gas fired reactors to the grid just for peak generation? I think it is ridiculous that the utilities have not figured out a way to store potential energy that can be released to level demand. I wonder how many power plants have turbines spinning on standby just for peak demand moments. Global electricity demand is increasing rapidly so the industry should be working just as hard to level demand and reduce consumption as they are spending to bring on new fossil fuel power plants.
Post your comments