Dynamic Demand Technology
– Dynamic Demand adjusts the load demand on an electrical power grid to support demand response.
– It is a semi-passive technology that switches domestic and industrial loads on/off at optimal moments.
– The technology aims to balance the overall grid load with generation and reduce power mismatches.
– Switching appliances on/off only advances or delays the operating cycle by a few seconds.
– Dynamic Demand Control was patented in the United States in 1982 by Fred Schweppe.
Spinning Reserve and Frequency Control
– Power utilities predict demand patterns and schedule base load in advance.
– Imbalances in supply and demand are removed by requesting generators to operate in frequency response mode.
– Grid frequency indicates overall power imbalance, dropping with excessive demand.
– Generators in frequency-response mode run at reduced output to maintain spare capacity.
– Spinning reserve is costly and often relies on fossil fuel-powered generation, leading to increased greenhouse gas emissions.
Local Load Control
– Appliances with duty cycles can provide grid balancing by timing their cycles in response to system load.
– Dynamic-demand enabled appliances react to frequency imbalances by switching off or on.
– Controllers measure grid frequency in real time and ensure appliances stay within their operating range.
– Millions of dynamic demand devices acting together can act like a fast-reacting peaking power plant.
– This technology can facilitate the integration of variable sources like wind power onto the grid.
Ancillary Services
– Dynamic controllers can aid blackstart recovery by managing reactive loads during power grid restoration.
– Fast reserve, using standby plant to replace lost generation, can be achieved by shedding load quickly.
– Dynamic controllers can spare the high cost of fast reserve generators.
– This technology can help facilitate the use of generation from variable sources.
– Demand-side techniques can work with virtual power reserves to provide dispatchable capacity.
Implementation Issues
– Regulation or market mechanisms are needed to mandate or incentivize installation of dynamic demand control.
– Electricity meters could measure grid frequency and switch to a higher tariff during frequency drops.
– Consumers without smart demand management would pay extra costs, while those with smart technologies save money.
– RLtec (now Open Energi) launched Dynamic Demand frequency response service in the UK.
– The national grid in the UK already uses dynamic demand technology at an industrial scale. Source: https://en.wikipedia.org/wiki/Dynamic_demand_(electric_power)
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Dynamic Demand is the name of a semi-passive technology to support demand response by adjusting the load demand on an electrical power grid. It is also the name of an independent not-for-profit organization in the UK supported by a charitable grant from the Esmée Fairbairn Foundation, dedicated to promoting this technology. The concept is that by monitoring the frequency of the power grid, as well as their own controls, intermittent domestic and industrial loads switch themselves on/off at optimal moments to balance the overall grid load with generation, reducing critical power mismatches. As this switching would only advance or delay the appliance operating cycle by a few seconds, it would be unnoticeable to the end user. This is the foundation of dynamic demand control. In the United States, in 1982, a (now-lapsed) patent for this idea was issued to power systems engineer Fred Schweppe. Other patents have been issued based on this idea.
Dynamic demand is similar to demand response mechanisms to manage domestic and industrial consumption of electricity in response to supply conditions, for example, having electricity customers reduce their consumption at critical times or in response to prices. The difference is that dynamic demand devices passively shut off when stress in the grid is sensed, whereas demand response mechanisms respond to transmitted requests to shut off,
