Low Carbon London: Smart ways to make electricity demand flexible

Imagine a future where electricity demand is flexible to flatten short peaks on the network, lowering electricity distribution costs and making better use of green energy.

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Varying electricity-intensive household chores to coincide with times when wind power is plentiful may sound like something from science fiction, for example, but this relatively new technique has just been tested for the first time in Britain.

It was part of the cutting-edge Low Carbon London smart grid trials led by London’s electricity distributor, UK Power Networks, to plan for the future energy demands of a sustainable city and accommodate low-carbon technologies such as electric vehicles and heat pumps.

The trial involved 1,100 EDF Energy customers in London, where three rates were paid for electricity – 4p, 12p or 67p per unit. Households received day-ahead prices via their smart metering in-home display units or text messages so they could plan their electricity use.

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A large majority modified their electricity consumption in response to the price signals. Participants found appliances like washing machines and dishwashers the easiest to adapt and lighting, cooking and showering the hardest.

The average household saved £21 over the year, while the super-flexible family saved £148. A small minority would have been worse off but were financially protected during the trial. Some 91 per cent of participants supported the tariff and 81 per cent felt it should be standard for everyone.

Participants reported experiencing an element of a game or challenge in fitting their behaviour around the high or low rates. A survey showed 60 per cent would be more likely to sign up to such tariffs if there was a link to using variable renewable energy output.

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Martin Wilcox, head of future networks at UK Power Networks, said: “There are clear reasons why we did this trial, which are about supporting the country as we try to reduce carbon emissions. We were trying to find out how flexible people could be in the way they use electricity, to see if this can make better use of intermittent renewable energy and reduce short peaks on the electricity network, keeping down the costs of delivering electricity for consumers.”

While this trial was with domestic customers, researchers tested the same “demand side response” principle with large business customers. Hotels and shops were among those financially incentivised to either lower or defer their electricity use at peak times, or generate electricity locally when required.

Key findings from the trials…

Demand side response contracts

In this trial, business consumers were rewarded for reducing their electricity consumption or generating electricity locally, when required. Big hotels, for example, turned down their air conditioning. Some 37 participants voluntarily reduced enough electricity to supply 18,000 homes at peak. This approach is expected to save customers in London, the South East and East Anglia £43million on the cost of delivering their electricity over the next eight years.

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Smart meter trial

Electricity consumption data was collected from 5,500 homes across London and a home appliance survey identified the number and type of electrical devices in 2,830 households, helping electricity distributors plan for future power demand. It found there could be a 10TWh saving in electricity consumption by 2020, equivalent to approximately 9 per cent of the projected domestic demand in 2020, by switching to more efficient appliances.

Electric vehicle study

A trial of 72 domestic, 54 fleet and 1,408 public charging points provided new information on how much networks must be strengthened to cope with extra electricity consumption.

One concern was that drivers would simultaneously charge their vehicles after the daily commute, potentially overloading the electricity system. Researchers found the EV charging system could be more manageable than feared, with a later EV charging peak than anticipated at 9pm. The impact of mass-scale charging remains substantial for electricity network operators, at around a third of household electricity consumption.

Active network management

Trials monitored the impact of green electricity being exported to the London network, such as from combined heat and power plants. The team calculated spare grid capacity and controlled output where the customer allowed it. Researchers found this approach could allow up to a third more distributed energy plants to
export power to urban networks.

Smart grid findings revealed

Results are out from one of Britain’s largest smart grid trials. After four years’ work, 27 reports have been published revealing results from the Low Carbon London trials.

London was the test bed for a range of cutting-edge trials, the results of which could help millions of people across the UK. Carbon emissions from today’s electricity system are around 450g/kWh and the Government is seeking ways in which to reduce this by between 100-200g/kWh by 2030. If only one of the initiatives demonstrated was fully adopted across the country, an additional contribution of 5g/kWh towards this reduction would be achieved, with the potential for far more. This could only be otherwise achieved by replacing a further 700MW of conventional generation with low carbon generation.

The £28.3million project explored ways to meet extra demand on the capital’s electricity system anticipated from local green electricity, heat pumps, electric vehicles (EVs) and solar panels – without overloading the network or adding significantly to electricity bills.

The trials included rewarding customers to reduce or increase their consumption as required, flexible energy tariffs based on renewable energy output, EV-charging schemes, a home appliance survey and monitoring the impact of green electricity systems.

Low Carbon London was funded through Ofgem’s Low Carbon Networks Fund and by UK Power Networks. The partners were Imperial College London, Siemens, CGI, EDF Energy, Greater London Authority, Transport for London, National Grid, the Institute for Sustainability, Flexitricity, Smarter Grid Solutions and EnerNOC.

The Low Carbon London findings are accessible online at www.lowcarbonlondon.info


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