Smart Grids, Grid Emulators, and a Nice Cup of Tea
For a very long time the National Grid has seemed to most folk a fairly basic utility, a necessity even, providing a steady flow of electrical power to customers, be they industry, business or household consumers.
However, behind the scenes, an unseen, tireless and diligent army of power professionals have constantly monitored the supply of energy and demand from users, matching the two to secure a consistent flow of electricity.
Demand for electric power ebbs and flows, following patterns that can be daily, monthly, and of course seasonal. As an example, particularly hot days can see a surge in demand for energy as air conditioning units are powered up to cool offices.
But what about at half time during a national team’s televised football match, or when the drums roll after an episode of EastEnders? That’s a spike in peak demand called TV pickup. Just as the show finishes, hundreds of thousands, sometimes millions of Britons go to the kitchen to put on the kettle.
It’s a phenomenon unique to the United Kingdom as us Brits are particularly fond of a nice cup of tea between shows on TV. Typical demands imposed on the electricity grid are around 200-400 megawatts (MW) but this can push towards 3 gigawatts (GW) at times, that’s 3,000 megawatts or the equivalent of around 1.5 million kettles switching on.
The National Grid’s Energy Balancing Team is responsible for maintaining mains frequency across the nation of between 49.5 and 50.5Hz. TV Pickup’s demand for power means the grid has to generate extra energy and quickly too. Gas and coal-fired power stations are slow to “spin up” so hydroelectric power stations in Scotland and Wales are on standby to match demand in seconds. If this is not enough, the energy can be supplemented with power supplied from France and the Netherlands.
Fun fact: Did you know that the record for TV pickup demand is 31 years old? That demand was 2,800 MW (2.8 GW) back on the 4th July 1990 when England played West Germany in the World Cup semi-finals.
The Rise of the Smart Grid
Times have changed and just like electricity, TV is on-demand now too. With digital and catch-up options, we can stagger our viewing of nail-biting episodes of EastEnders. However, peak demand still remains as does a level of TV pickup.
Solar and wind power are also an issue, because the sun doesn’t always shine, and wind does not always blow and turn the turbines. At the time of writing, wind power has been contributing approximately 12% of the country’s power, around 4.69 GW. In September, with a UK-France power link damaged by fire, wind power generation dropped to a low of 2.5% of our energy mix.
It’s times like these when the reliance on solar and wind falls back to “traditional” methods of electricity generation, chiefly coal and gas-fired power plants, hydroelectric and nuclear.
The grid itself has evolved too with not just the consumption but also the feeding back of surplus generated energy into the electricity grid as well. Consumers with solar panels have been able to sell back to the grid for years now. With digital technology allowing advanced, two-way communication between consumers and the grid itself, the network is becoming more intelligent and increasingly complex.
As an example, electric vehicle sales are picking up and their own onboard batteries can help the grid. The smart grid that trickles power into an EV’s lithium ion battery system, can also use any excess power to help the nation. Say you’ve returned home at 18:00 with just 50% of your charge left and wish to top-up for a long journey the next morning, you don’t need that additional 50% top-up charge immediately. As long as you have 100% “in your tank” the next morning, you’re happy.
What the smart grid can do is use some of your remaining 50% charge in the National Grid when demand is high at dinner time and provide your full charge later, when energy demand is lower. This is vehicle to grid or V2G technology.
Grid Emulators/Grid Simulators
How do you build systems for electric vehicles that can adapt to the smart grid and provide V2G?
Easy. Caltest Instruments supply a number of grid simulators that can help researchers, developers and manufacturers to emulate grid scenarios.
We supply programmable grid simulators that create AC grids and emulate its disturbances. You can load and execute test profiles from a simple CSV file.
Being bidirectional, the test energy can be regenerated to the grid, essential for testing Distributed Energy Resources (DER) or generators where the equipment under test and generate, consume or store energy.
Take a look at the GE-AC Grid Emulators and call us on 01483 302 700 to discuss any specific requirements you may have. Our expert team are always on call to provide you with the best, bespoke solution to you power requirements.