Keeping up with chargeable devices, electric vehicles and renewable energy

By 2020 it's estimated between 500,000 and 2million electric vehicles will be used daily in the UK. This, in itself, presents a number of challenges for the electricity network. For more than 50 years these have been designed on the assumption that no household uses all appliances at once and also not at the same time as neighbours. However, questions about whether this is still valid are being raised with the advent of electric vehicles and shift to more renewable power. If, for example, everyone charges their cars at the same time, for those few hours the networks would go in to overload. Brian Shewan, development manager for low carbon networks at Scottish and Southern Energy Power Distribution, says: "As a power engineer, I like peak power. We design everything with peak in mind, but going forward we're not going to be able to do that. We now need to design for profiles of behaviour and usage. "While we are sure demand for electricity will increase, we also think that this will only be at certain times of the day and night. So we need to use the network in a more intelligent way." My Electric Avenue Understanding how to mitigate and manage the problems caused by streets of electric vehicles being put on charge at the same time is the focus of My Electric Avenue, a Low Carbon Networks (LCN) Funded project between EA Technology and Scottish and Southern Energy. It sees 10 households in the same street using the all-electric Nissan Leaf as its daily driver. Typical usage is being monitored including the times of day they typically wish to charge. An essential part of the project is to evaluate a charging point technology. This communicates to a local feeder station to reduce peak loads on the grid to stop it becoming overloaded. "We've got a product that is able to shift around demand," says Dave Roberts, future networks director at EA Technology. "We monitor capacity at the substation and when it reaches a limit it sends a signal down to different charging points to say switch off, switch back on in half an hour, for example. This is called Esprit." The hope is that Esprit could actually work over quite short periods of time, perhaps seconds, to gradually feed electricity to all the charging points. It might mean a car may take an hour or two longer to fully charge as the electricity is continuously spread around different charging points, but the peak load on the grid will be dramatically reduced. A solution in the problem Electric cars while posing one set of problems, may well offer a solution to another. As networks ramp up the amount of renewable electricity flowing in and out of them, there intermittent nature means demand is often out of sync with supply. Electricity needs to be used almost as soon as it's produced, so it needs to be produced only when needed. And this points to a need for energy storage. The potential of having an electric vehicle in every house in a street enables the possibility of something known as vehicle to grid (V2G). The average vehicle is parked for 95% of its life, so utilising electric vehicles batteries for temporary electricity storage is an obvious solution. The concept allows V2G to provide power during peak times to help balance loads by 'valley filling'. Vehicles would charge at night when demand is low, and send power back to the grid when demand is high. V2G could also help buffer renewable power flowing in to the grid by storing excess energy produced during windy periods, and sending it back when needed, stabilising the intermittency problem. Some see this application as a possible method of penetrating the baseline electricity requirement that largely relies on large centralised fossil fuel and nuclear power stations. The National Grid and Big Data The premise behind Big Data is the idea of capturing minute details about very large and complex systems. Big Data is touted as a future trend to look out for and it's hoped it will provide fresh insight into many big societal challenges, from providing better healthcare to tackling climate change. Delivering the UK's future energy demand is one such challenge. It's an enormous and daunting task, and it's hoped it can be made more manageable by having a clear view of the equipment behaviour and user trends at national, regional and local levels. Continuously monitoring the electricity distribution network is something a team from the National Grid has been busy developing, at the moment to quantify the quality of electricity. It has to balance the demand for electricity with the supply of electricity on a second by second bases. However, direct current connections with Europe as well as increasing electricity from renewable energy sources produce a number of quality issues and as a result have to be closely monitored. The current methods of monitoring are not fit for purpose and would have problems scaling any further. So with the help of National Instruments, National Grid has developed a monitoring system to measure voltage and current to get a complete picture of power quality. The monitors use NI's CompactRIO platform and are programmed using LabView. It has given the National Grid the platform it needs to evolve and scale as requirements change. "We know we need better data in this new era of electricity transmission," says Dr Danson Joseph from National Grid, "because we can't manage what we can't measure. "The biggest problem is the equipment that we did have just couldn't scale for our requirements. And the data was inaccessible, and uncoordinated, and actually the hardware just couldn't detect what we needed it to. For instance, some wind farms produce high frequency harmonics, and that equipment just could not detect it." Despite having quite a narrow remit at the outset, it has become apparent that it's opened Pandora's Box, still only scratching the surface of what might be possible. But one of the biggest problems is the sheer volume of data that it logs. Peter Haigh, power systems engineer at National Grid says: "I see 'Big Data' as critical advantage, as a thing that needs to be controlled and managed. It's harvesting information that is useful to form knowledge to make decisions, be it controlled decisions on a system, investment decisions or whatever. The way we correlate it and distil it down in to something useful can guide the way we plan the network. That is the value to the business." Although the remit of the project has clear short term deliverables, the scope and potential of the work being undertaken is huge. And continuous monitoring systems are in the process of being placed in 110 sites around the UK. And engineers at National Grid are getting more curious about what 'knowledge' can be leveraged from all this data. "If it is something that can be calculated from a voltage or current measurement then we can do it," says Dr Joseph. "And once we have a monitoring fleet deployed completely, or even partially but with good coverage, we will start seeing things we haven't been able to measure before and that is when we can start getting more creative." At the moment the system is essentially logging the voltage and current to gain a view of network performance and manage connections. As offshore wind farms and interconnections to Holland and France cause major problems in power quality, this is one of the biggest challenges and areas that is intensely scrutinised. "The system gives us a way of managing on an individual project level the impact of each connection, and it also gives us trended system wide data," says Dr Joseph. "And it is system wide trending that gives us some really valuable information that we didn't have before. This is an opportunity to start looking at a bigger picture, on the national scale." The data from the permanent monitors will correlate through to a central server and be available through a web application allowing different users to access, for example, geographical trends or changes over seasons. And as more wind power comes online, it will be able to assess, in real-time, how much electricity is fed in to the grid, and how it's distributed and used. And this is also set to help speed up development work for new connections, so fast charging points for electric vehicles or to the planned roll out of more electric rail connections. "We don't want to find there is a problem with power quality at a certain connection after two years of operating it," says Haigh. "So we can provide a power quality map to planning officials so they can see the areas with the most reliable power, best quality or least intermittency. The power industry has not changed greatly since the 1930s, it's still essentially copper wire in the ground. However, with more renewable sources of electricity flowing in and out of the grid on both the macro and micro scale, coupled with more electric vehicles, the effect this will have on existing infrastructure needs to be monitored so it can be effectively managed. "We recognise as the sector evolves we need to be agile and stay flexible," says Haigh. "And as we add more of these, the resolution will get greater and we'll be able to start using this data as we design and install new systems and infrastructure. "At the moment, designs are based on rules of thumb, but that's got to change. If we start to quantify things, we can design closer to the point of failure, not so we hit the point of failure, but so we are able to run our assets at a higher capacity. This way we'll be able to get the biggest bang for our buck in the future, and handle all the challenges facing the industry."