Area of work:
Electricity distribution networks have traditionally been passive, designed to handle all eventualities without much monitoring or management, but this approach increases the cost of connecting new renewable energy generation, as infrastructure has to be upgraded to handle the extra power.
However, the situations when the existing network would not cope with the new renewable generation are infrequent, and if the network is ‘smart’, it can restrict generation when it might cause a problem, allowing existing spare capacity to be utilised the rest of the time.
Smarter Grid Solutions has developed Active Network Management to solve this problem, and by making the UK grid smarter, it has enabled 259 MW of new renewable energy generation to be connected.
The traditional way of designing electricity distribution networks was to calculate the maximum power flows that could occur, build the network to cope with that, and then carry out minimal monitoring of it. This approach has delivered reliability, but is now limiting the ability to connect renewable energy generation, because transmission lines, transformers and substations would need upgrading to provide the extra capacity required to deal with the new generation. The result is significant costs and delays, often making new renewable energy generation uneconomic.
Smarter Grid Solutions (SGS) works with Distribution Network Operators (DNOs) and renewable energy developers to install hardware and software to make the network smart. The technology is economically viable down to sites as small as a 50 kW wind turbine, and 62 renewable energy generation sites have been connected so far, totalling 259 MW and saving about 177,000 tonnes of CO2 annually. Approximately £100 million of capital expenditure has been avoided or deferred by the use of SGS technology – expenditure that would otherwise have been borne largely by renewable energy developers, and would have rendered many of their sites uneconomic. In addition to the direct benefit to renewable energy developers, the DNOs also benefit, gaining better information about their networks and control over generation embedded in them, and all electricity consumers benefit as the cost of maintaining the network is reduced.
The technology SGS has developed to implement ANM is split into two parts: ANM Strata, which is installed in the DNO control room, and ANM Element, which is installed at the renewable energy generation site. One ANM Strata installation can control hundreds of ANM Element sites, but ANM Element sites can also operate in standalone mode if required.
The system works by measuring current and voltage at points on the distribution network where constraints could be breached, and making decisions about when to act. When required, renewable energy generators are automatically instructed to reduce power output or shut down entirely. This is done in a gradual process, one generation site after another, to avoid sudden fluctuations in the network, although sites can be shut down all at once if the circumstances require it. Once conditions on the network have improved, generation sites are brought back up to full power in sequence, with the network constantly being monitored for any adverse effects.
The result is that areas of the network that would have been regarded as congested and unable to accept new renewable energy generation without being upgraded can now have new connections made to them at an affordable cost. Renewable energy developers can now build sites without delays and excessive cost, in return for accepting that their output will occasionally be curtailed – SGS can provide them with estimates of expected curtailment to use in their business plans. The DNOs find the SGS technology useful, as it gives them more insight into their networks, and also puts them firmly in control of the power entering their networks, which enables them to ensure stability at all times.
Impax Ashden Award for Energy Innovation
SGS is one of the world’s leading companies in the smart grid sector, working with DNOs and utility companies in the UK, Ireland and the USA, and will soon be offering its products in India, South Africa, Australia and the Middle East. Although the company has already enabled a significant amount of renewable generation to be connected to the grid, there is huge potential for ANM to be applied more widely as awareness of what it can do increases. It is also possible that the technology could be applied to management of grid-connected energy storage and demand response, as both have already been trialled by SGS and been found to be effective.
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