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16 | 28TH OCTOBER - 3RD NOVEMBER 2016 | UTILITY WEEK Operations & Assets Market view T he core business of distribution net- work operators (DNOs), such as Scot- tish and Southern Electricity Networks, is to provide a safe, top level of service to customers through delivering electricity to homes, maximising cost-effectiveness, reli- ability and sustainability. In doing this, each DNO must balance the needs of a wide range of stakeholders. DNOs have a responsibility to meet a minimum standard for all customers, par- ticularly those most vulnerable to the effects of energy disruption. However, the rela- tionship between DNOs and customers has traditionally been limited to two specific circumstances: 1) When a customer suffers a service disruption. 2) When a new customer is connected. The New Thames Valley Vision (NTVV) project has given Scottish and Southern Elec- tricity Networks the opportunity to further develop this relationship. Shiing patterns in electricity consump- tion and generation are presenting new and significant challenges for the DNOs in managing their networks. However, these challenges also present real opportunities for DNOs to change the way they operate. One such way is to embrace emerging tech- nologies that tap into the flexibility custom- ers could provide and establish this firmly within the DNOs' network operation toolbox. Scottish and Southern Electricity Net- works has been investigating exciting and innovative methods of harnessing customer support through projects conducted under NTVV, a project funded through the Low Car- bon Networks Fund (LCNF). Thermal storage can shi peak demand Customers with flexible demand can reduce or shi consumption, alleviating stress on the network at critical times. In doing so, that flexibility can provide the DNO with more options to manage thermal and volt- age constraints and, in the longer term, defer capital investments on the network. One rapidly emerging technology that can provide demand flexibility is energy storage. As part of its NTVV project, Scottish and Southern Electricity Networks undertook tri- als in the UK exploring exciting new storage technologies that have the scope to broaden the types of customer that are able to provide demand flexibility. The NTVV trials focused on investigating the benefits that (hot and cold) thermal storage solutions can provide to the DNO in managing its network. Academics at London South Bank Univer- sity estimate that in the UK about 16 per cent of electricity may be consumed by refrigera- tion and air conditioning, and that world- wide this may contribute to 10 per cent of carbon dioxide emissions. NTVV trialled the Ice Bear, a cold thermal storage technology that can integrate with an industry characterised by a mixture of inflex- ible off-peak generation and daytime peak consumption. In the US, the Ice Bear device has proven its ability to alleviate a build- ing's peak-time air conditioning demand and is now being trialled for the first-time in the UK. The Ice Bear freezes water during periods of lower electricity demand (off-peak), which is then stored as ice until periods of high demand, when it is used as an alternative to an air conditioning system's compressor, thereby reducing demand on the system dur- ing peak periods. The NTVV project also undertook tri- als of energy and micro-generator manager (EMMA) heat storage devices. These are linked to domestic solar PV systems to store energy generated during times of low sys- tem demand or high generation. Small-scale PV (≤4kW), which is typically mounted on domestic properties, has skyrocketed from about 10MW at the start of 2010 to 2,391MW in mid-2016. The EMMA device transfers the surplus electricity produced by the solar PV system to a customer's hot water tank, which is then used in a building's hot water heat- ing, providing the double benefit of diverting solar PV electricity from the distribution net- work and reducing the customer's electricity demand for heat at periods of higher system demand. The Ice Bear and EMMA systems provide just two examples of how smart technology can be used to manage different network challenges. An Ice Bear is ideal for consum- ers with a large cooling load, whereas an EMMA is most appropriate for domestic consumers with water tanks and solar PV installed on the roof. The NTVV thermal storage trials delivered tangible benefits to both Scottish and South- ern Electricity Networks and its customers. The Ice Bear trial delivered a number of real successes: one trial unit works so effec- tively that the user has been able to turn off their existing 4.8kW air conditioning units and rely solely on their Ice Bear to provide cooling to their building. At peak usage the EMMA system will result in approximately 0.5kW of energy diverted to a customer's hot water tank. By harnessing customer flex- ibility in this way, Scottish and Southern Electricity Networks has been able to signifi- cantly reduce reverse power flows at times of high solar PV generation, reduce system strain on the electricity distribution net- work and deliver savings to those customers adopting the technologies. Automated demand response can help to manage peaks NTVV also conducted initial testing of auto- mated demand response (ADR), in which the network operator is able to control customer appliances and devices to optimise their operation with network demand and supply. While this technology is mature in the US, until now there has been little experience in its application to British DNOs. In this trial, Scottish and Southern Elec- tricity Networks used ADR to tap into the flexible elements of customers' electricity demand to turn off, turn down or cycle elec- tricity-consuming devices in more than 1,000 instances across 30 trial locations. Sched- uled load-shedding events were tested up to four hours in duration with no-notice load- shedding events up to an hour in duration. The road to effective DSR Scottish and Southern Electricity Networks' NTVV trial sought to evaluate different on-site storage technologies to increase the viability of small-scale demand response.