The energy revolution

For years we’ve all taken energy for granted, expecting it to be there whenever we need it in limitless amounts at a price that’s right. But with worries over the security of energy supplies and mounting evidence of climate change we need new technologies to help us adapt.

If we were to continue generating, distributing and using energy as we do now then energy’s future will be far from bright. The UK’s own gas and oil reserves are dwindling, so without alternative, secure energy sources we could be at the mercy of volatile global energy markets.

At the same time the burning of these fossil fuels has led to a build up of greenhouse gases in the atmosphere (especially CO2) which is causing the lobal warming that is driving recent rapid climate change. Left unchecked climate change will lead to droughts, temperature changes and flooding that will devastate economies and ecosystems around the globe. If we want to avoid both these catastrophic scenarios then we will need an updated energy infrastructure that can integrate ‘renewable’ energy sources – such as bioenergy, wind, wave or tidal, and solar power – that do not add to global warming.

“The existing infrastructure is designed around a small number of large power plants,” Professor Tim Green of Imperial College London tells us, “but however renewable technologies develop they will require many more and more geographically dispersed plants.”

Professor Green, a member of the Supergen – Future Network Technologies Consortium, explains that this presents a major challenge in how to control and co-ordinate many more, smaller devices that are likely to be distributed throughout the UK and often located in remote areas. Another challenge is the variation in the power supplied by renewable energy sources: wind varies with the weather while tides may be predictable but will only coincide with peak demand for power some of the time. Consumers used to getting power whenever they want it are unlikely to be impressed if they can’t use their hairdryers because the wind has dropped or watch TV until the tidal conditions are favourable.

The aim of Professor Green and colleagues at the other consortium universities is to be able to ‘iron out’ any variations and deliver a reliable supply to our homes and workplaces. Advances in energy storage technology, such as those being addressed by the Supergen – Energy Storage Consortium, may help but while a close eye is being kept on these developments such mass storage of power is not yet economically viable.

“What’s certain is that the current network is not as actively managed as we will need it to be,” comments Professor Green.

The energy networks of tomorrow are likely to incorporate a mix of different technologies and approaches to ensure that they are flexible and reliable. Managing such highly complex networks, where small changes in one part of the system could have system-wide consequences, is going to be a considerable challenge.

Researchers from the Future Network Technologies Consortium are developing mathematical models to show how a range of devices and resources can be controlled and co-ordinated.

“The model quickly becomes very large,” says Professor Green, “what we need to do is find a way of modelling with the right degree of detail so that we capture all the most important information.”

With so many different things to control the current set-up of an all-encompassing central control system may not be viable, it is likely that more control will have to be devolved to local systems. There are different ideas about what these systems would actually look like. One option might be a de-centralised control system.

“There would still be a UK-wide network,” Professor Green explains, “but the different regions would ‘import’ and ‘export’ energy to and from each other to ensure they could satisfy demand. It might be that these regions would, for instance, manage voltage fluctuations across a particular area without the need for the national control room to step in.”

Another approach that has stimulated a lot of interest are so-called ‘microgrids’.

“Unlike the regional systems these are completely self-sufficient and independent, like a national grid in miniature, generating and distributing power to their customers. However, a lot more research has to be done before we can tell if this is a viable solution.”

The Supergen – Highly Distributed Power Systems Consortium is working in this area.

Balance of power

Another approach involves looking at things from the demand-side or consumer point of view. During an advertising break in a popular TV soap millions of consumers switch on their kettles at the same time demanding power. Should we discourage people from behaving in this way by, for instance, charging them more for drawing power at a peak time? Or maybe any future network should have a say in how many power-hungry devices we run at once, perhaps switching off your fridge for the short period when the kettle is on? “It all depends what people are willing to accept, would it bother you if an external system was controlling your fridge?” says Professor Green.

Elsewhere researchers are examining trends and take up rates for key energy technologies, as well as how fast technologies can be rolled out. Sustainability, energy security and affordability have to be considered at every turn – it’s no good contemplating a raft of clever devices if they are too expensive to use.

Underpinning all this research is work into developing six different scenarios showing what might happen to our energy networks.

“We’ve looked at what kind of power plants we might have in the future and what tomorrow’s national grid might be like, this has helped to inform the debate on the engineering, economic and social side,” Professor Green says. It is important to remember that the design of the energy market affects what technical developments are favoured: for instance we could end up with a market that discourages small scale power generation.

Dr Green comments: “While we’re working to meet Government targets such as the 60% reduction in CO2 by 2050 we also have to look at how we can accommodate new forms of generation now, in a more traditional system.”

Britain has plenty of wave and tidal resources that could provide secure, carbon emission free power. As a source of renewable energy marine power has many advantages, for instance tidal currents can be predicted with complete accuracy and by tracking waves crossing the Atlantic today we can say what the wave climate will be tomorrow.

“One of the biggest challenges we face is quantifying and characterising the natural resources available so that we can predict the true potential of different sites for investors and developers,” explains Dr Robin Wallace, a member of the Supergen – Marine Consortium.

While there are a number of pioneering prototype devices making their way to sea in the UK, the Consortium is engaged in generic research that looks up to a decade ahead, supporting the wider progression of concepts and technologies into deployment.

“We look at things in a way that isn’t device specific, to increase our understanding of the extraction of energy from the sea,” Dr Wallace explains.

“Our goal is to reduce uncertainty and risk in deployment and contribute to increased ‘installability’, operability, reliability and survivability of the technology.”

Breaking the waves

What combination of devices you might need depends heavily on the site: is it near shore or far shore? Deep water or shallow water? Further research needs to be done into the combined effect of tidal currents and waves on arrays of wave/tidal energy converters: you don’t want wave converters to be influenced by strong currents or tidal devices to be unduly affected by waves on the surface.

Then there is the further consideration of whether electricity generated in a remote location will be commercially uncompetitive once the cost of transporting it is factored in.

“Initially we want to find areas with good marine mresources that are close to where the power is needed so that delivery costs are low,” comments Dr Wallace.

In the next few years there is much to do and learn as this generation of marine energy devices are made ready for the marketplace and wider deployment.

However our energy infrastructure is transformed over the next few decades it will have an impact far beyond the world of engineers and scientists. This is why addressing public attitudes to each technological option, and its social and economic consequences, is so important.

“You could find a reason to object to every form of energy but we can’t let this result in an insecure or unreliable energy system,” Professor Tim Green tells us, “in a changing world we can’t afford not to change.”

This article, written by Pete Wilton, was reproduced from the November issue of Newsline by kind permission of the EPSRC.The complete November issue can be downloaded here:http://www.epsrc.ac.uk/CMSWeb/Downloads/Publications/Newsline/Newsline34SR.pdf