Utility Week

UTILITY WEEK | 2ND - 8TH NOVEMBER 2018 | 23 Operations & Assets Scottish and Southern Electricity Networks: the Nines Project SSEN set out to develop a smart grid on the island of Shetland, having already created one on Orkney. The 67MW Lerwick Power Station is nearing the end of its life, and the DNO wants to replace it with a smaller one, if enough flexibil- ity can be found elsewhere. The Northern Isles New Energy Solutions (Nines) project piloted the concept that simple domestic loads such as hot water tanks and storage heaters could balance an electrical system. Smart electric storage heaters were installed in around 750 homes to pro- vide more comfortable and affordable heating to residents, while helping to balance the electricity network. An electric boiler was added to the existing district heating system to link to a proposed windfarm on the island. The project also saw new technology deployed to allow more small- scale renewable generators to connect to the network, and new commercial arrangements to encourage businesses to change the times when they used the most energy. A 1MW battery was installed at Lerwick Power Station. Stewart Reid, head of DSO and innovation at SSEN, says the project deliv- ered more than 1MW of frequency response from fewer than 240 homes, with the system responding to demand in under a second, contributing to system stability on the island. However, the trial also found that the business case for third party organi- sations, whose core purpose was not flexibility, along with the uncertainty of the value of flexibility, resulted in challenges in securing sufficient flexibility in a small geographical area within normal investment timelines. This meant the market would need to be designed with the bankability of flexibility provi- sion in mind, Reid says. Ensuring that residents knew and understood the motive for the trials, and the potential benefits was a resource-intensive exercise even on a small Scot- tish Island, he says. The DNO partnered with Hjaltland Housing Association to keep tenants informed. "In future we would not anticipate a DNO being the organisation directly engaging with the customer with regard to the detail of their heating system, but this does emphasis the need for the organisations taking on this role to have a customer-centric philosophy, and for DNOs to work closely with them providing the data and information necessary for the flexibility operator to provide customers with the information, guidance and certainty they need," he says. project out to its 2.4 million customers, and expects to complete this by May 2019. Another project, Smart Street, has also used voltage control to increase capacity on the network. However, rather than kicking into action when there is a significant power outage, voltage is controlled continuously in response to changes in demand to keep the network as efficient as possible. Trials identified that the average con- sumer would save £70 a year out of a £100 network charge by deferring expensive net- work reinforcement while operating their appliances more efficiently. If rolled out across Great Britain, the total annual saving could reach £519 million. ENW maintains that its projects are much simpler and quicker to implement than engaging customers in providing demand response themselves through an app, as some DNOs have trialled. "A lot of companies have for an almost consensual approach to asking customers to sign up to a particular tariff and change demand when they ask for it. That has its space, but it's hard to persuade customers to do that – an individual customer will only save a small amount, £5-10 a year if you're lucky. "What we're doing is getting a tiny bit of response, but from millions of customers, which gives us useable demand response, and customers absolutely don't notice," Cox says. "A lot of what we've been doing is what makes a material difference now. Although our innovation strategy looks ahead to 2025, 2030 and 2035, we also want to save money for customers in 2018, 2019 and 2020," he adds. OVERVIEW OF SYSTEM ARCHITECTURE 4MW Boiler 150MWh thermal store Storage in hand (measured) Smart heating and hot water – 234 homes Small generation and storage schemes 6MW windfarm Comms Network constraint monitoring 1MW battery System stability constraint monitoring Active network management system Storage in hand (inferred) Historic networks have no active voltage regulation Low-carbon technologies create network issues Customer demand could cause voltage to dip below statutory limits Customer generation could cause voltage to exceed statutory limits Smart Street stabilises voltage across the load range and epitomises power flows Conservation voltage reduction Stabilised voltage can be lowered making our network and customers'' appliances more efficient SMART STREET RAN FROM JANUARY 2014 UNTIL APRIL 2018

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