Utility Week

UTILITY WEEK | 2ND - 8TH NOVEMBER 2018 | 21 Operations & Assets UK Power Networks: Kent Active Systems Management UK Power Networks (UKPN) has seen significant changes on its network recently. Its network is in the south east and east of Eng- land, an area attractive for both wind and solar PV generation. It has 7.9GW of decentralised energy connected to its network, from 220,000 individual generators. It also has 1.2GW of battery storage. In Kent in particular, electricity generation far outstrips demand because of the high number of solar farms and offshore windfarms. Until now, energy from some renewable sources could be supplied to the network at certain times. Its Kent Active System Management (KASM) project is trialling sophisticated modelling and forecasting tools to plan and operate the network more accurately and understand the impact of extra generation. Ultimately, as many generators will be connected for as long as possible. The project is designed to enable the DNO to make better decisions when modelling planned outages, explains Ian Cameron, head of innovation at UKPN. KASM is trialling con- tingency analysis, an advanced form of power flow modelling that can evaluate in near real-time the potential for adverse conditions to affect the distribution network. It is also using advanced forecasting tools to provide bet- ter information on the performance of generators. For example, weather data from equipment on the site of a renewable energy plant is more detailed than Met Office data, and could include how cloudy it will be above a solar PV plant. The forecasting tool also takes power flow direction data from a far greater number of points, to take account of the increased complexity of power flow on a network where the grid is taking in energy and transmitting it. Part of the project has been to link UKPN's distribution net- work control centre with National Grid's transmission system control centre so real-time data can be shared to allow both organ- isations to build an accurate long-term picture of exactly what is happening on the network, and plan future capacity accordingly. The combination of the data sharing and the new soware is expected to give control operators the confidence to allow more energy on to the system by analysing complex scenarios in sec- onds and predicting the possible impacts of control decisions as they are made. Ultimately, it aims to increase the export of renew- able energy to the network by releasing more capacity than would otherwise be available. "Generators need to be available more than they would have been historically," Cameron says. "There are more than 350 grid supply points in the UK. Just on the four in our East Kent trial area, we've been able to achieve 4,000MWh more renewable energy generation than we would have a year ago. The aim is to achieve 8,000MWh of additional renewable energy generation in one year, enough to power about 2.6 million homes for an hour." One issue that was not expected was the reliability of data flowing into the soware, Cameron says. "We selected the loca- tion for the trials mainly because of the volume of renewable energy connected there, but also because we thought the data there would be good, but actually we found that the input data was not as good as a system like this would require." Another tool was developed, which used algorithms pro- grammed to understand power flows to deduce missing data, he says. Understanding the importance of getting consistent and accurate data from the network and third parties was a key lesson learnt during the project, Cameron says. system automatically calculates whether it is cheaper to provide that warmth through the air source heat pump or the gas boiler, and switches between them accordingly. Air source heat pumps from three dif- ferent manufacturers were selected and installed in a range of housing types, which were chosen to broadly represent UK hous- ing stock. During the trial, which took place over last winter, the operation of the hybrid heating systems was varied to explore dif- ferent scenarios, for example changing the fuel cost ratios that determined when the system would switch from one energy source to another. Hybrid heating systems would benefit the energy system in several ways, explains Ollie Lancaster, project manager of Freedom at Wales & West Utilities. If the UK chooses to meet decarbonisation targets by electrifying heat, the electricity network will have to be rebuilt to take the extra heat. But if homes were instead heated using air source heat pumps that can switch to the gas boiler at peak times to reduce demand on the system, network operators can avoid the costs of infrastructure upgrades. It avoids the cost of building more peak generation capacity, such as low carbon and peaking gas plants, he says. Hybrid heating also avoids the huge cost and disruption to householders of replacing pipework and radiators, since the system can be bolted on to existing heating equipment, Lancaster says. Research carried out by Imperial College London as part of the pro- ject found that smart hybrid systems could provide £15 billion a year savings to the UK compared with full electrification. Hybrid systems were also found to reduce customer bills. Lancaster explains: "One of the case study houses was a stone miner's cottage on a hillside, that had no insulation – the hardest type of home to decarbonise. The heat pump provided 78 per cent of the heat demand in that home, meaning that they saved £736 over the winter, compared to using their LPG boiler. "This presents the opportunity to install low-carbon ready smart hybrid gas systems now to help with fuel poverty, which is more prolific in areas off the gas grid," he adds. The main challenge experienced by the project was gaining consumer trust in the heating equipment, which is very different to the typical "on/off " boilers most people are used to, Lancaster says. "There was a lot of confusion about why the heat pump needed to be on a few hours before you wanted heat. People thought that would waste energy, whereas it was actually continued overleaf

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