Putting a new spin on energy

Beacon Power flywheel cut away

Never before has energy generated so much excitement and activity. Energy's creation is no longer the sole domain of the utility company. Consumers can now transform themselves into energy providers. Everyone has the opportunity to feed back into the network: from the individual homeowner with solar panels to the company with a spare bit of land on which an array of wind turbines can be erected.

It makes for a much more complex picture, and one in which the edges are blurred. The traditional relationship between service provider (the giant utility company) and consumer or customer is changing.

This well-established model has not, in the past, been one characterised by speed of change. It takes years to plan and put into operation a power station or a hydroelectric facility that will supply power to a city or industry. It is hard for players in this environment to be reactive; modelling and predictive analysis have been more the name of the game.

New business models

A report from IBM's Institute for Business Value, part of its Global Business Services unit, talks of the need for energy and utility companies to create new business models. The report identifies three main drivers: shifts in governmental policy, new technologies and changing consumer demand. These, it says, are 'changing the traditional model and creating relentless pressure on energy providers'.

The report says that the traditional approach to growing and building energy infrastructure 'needs to be replaced by fresh business models that can facilitate both traditional and emerging technologies of energy generation, delivery, storage and use'. It is also thought possible that PHEVs (plug-in hybrid vehicles) may change the way in which customers demand power on a local basis, causing localised load (demand) fluctuations – for instance, when everyone arrives home from work and plugs in their cars to recharge.

Wheels of change

The different ways in which energy will increasingly be produced and fed into the grid require utilities to think of different ways of handling their energy. Traditionally power stations are started up and produce energy which is then available for use. All highly regular. It just takes a lot of time to stop and start them, so timetabling is of the essence.

Energy produced using renewable technologies – wind, solar, waves, and so on – is not that predictable. The wind blows when and how it will; the sun does not shine at night and may not shine during the day. This means that the amount of power available for use will be more highly variable: sometimes there will be too much; sometimes not enough.

The emerging intelligent grid needs to find ways of dealing with this inconstancy. One of the ways of doing this is to store excess power until such time as it is needed. New technologies are just starting to come on stream to deal with this. One of them is the flywheel.

While this is by no means a new technology, it is proving exciting for its ability to store and release power extremely quickly. The flywheel (rotor) is used primarily for evening out the delivery of power. It stores energy as its speed increases and emits energy as it slows down. Driven by a motor, the rotor spins at high speed in a vacuum, which reduces friction. The energy it produces is stored as kinetic energy.

When that energy is required, the motor is driven in reverse. This causes it to act as a generator and release the stored energy, which can be fed back into the grid rapidly and exactly when required – one of the major benefits of the technology. Because of their ability to respond so rapidly, flywheels can be used to improve, or condition, the quality of the power, or voltage, generated by renewable systems.

A 20 MW flywheel plant can replace a coal-fired regulation plant, says Gene Hunt, corporate communications director of Tyngsboro, USA-based manufacturer of flywheels Beacon Power. This would save the emission of more than 300000 metric tons of carbon dioxide over 20 years. It would take the planting of 660000 trees to achieve the same savings, says Hunt.

The company views its flywheel product offering as a viable 'green' alternative to the power plants currently used for power regulation. Flywheel-based energy storage systems can be 90 per cent efficient, consume no fossil fuel and produce no emissions in operation. In addition, maintenance requirements are negligible and they do not have the disadvantages of other storage technologies such as batteries: low capacity, heavy weight, long charge time and short lifetimes.

Output optimisation

While flywheels are proving useful for grid load balancing, evening up between supply and demand, they can also be used to maintain network performance. When the local transmission line experiences problems, intelligent control agents in the network can direct the flywheel to over-ride the 'normal' setting of regulation to maintain optimum network performance, preventing power 'outages'.

A study made by Joe Eto at the Lawrence Berkley Laboratory says that power outages in the USA currently cost USD79 billion a year in the US. Interruptions that last 5 minutes or under account for 67% of that figure, or USD52 billion.

Flywheels are just one of a number of different storage technologies being looked into as a different approach to handling power. Others are flow, dry cell, lithium-ion and sodium-sulphur batteries and compressed air storage.

Standards – necessary evil or strategic advantage?

The arrival on the scene of these new storage technologies and the huge increase in interest in the concept of the Smart Grid have their effect on standards-setting bodies too. National grids are also being viewed in a different light by them.

EDF's Richard Schomberg, who is also Chairman of TC (Technical Committee) 8, 'Systems aspects for electrical energy supply', says that because storage of electricity has not really been practical until recently, utility regulation has not had to make specific provision for it.

Regulation is evolving slowly, taking into account opportunities as they emerge. 'Storage is being mandated by an increasing number of regions which is causing new strategies for deploying storage to emerge', says Schomberg. 'It is possible that the physical landscape may yet be changed considerably by the emergence of new and different storage technologies'.

Schomberg's view is that the new conundrum for energy storage is to work out who will pay for the technology and who will benefit from it. There is a complex relationship between technology vendor, utility, and regulator in this area and Schomberg believes that Standards can make a difference to that picture.

He believes that 'a new kind of standards, sharing generic ways of using technologies, independently of the technologies themselves, will help in unlocking the full potential of storage.'

For this reason IEC will be making available a comprehensive series of 'Generic use case standards' as quickly as possible. Storage applications will be incorporated in those generic standards.

Typically, any Smart Grid deployment project will reuse 80% of those generic use cases. This enables all of the stakeholders to share a common understanding of what a project is about. This helps streamline the application and decision-making processes as well as design and implementation. IEC has already published a PAS (Publicly Available Specification) of a methodology to craft Use Cases, IEC/PAS 62559, IntelliGrid Methodology for Developing Requirements for Energy Systems.

Summarised from an article by Julia King in IEC e-tech, May 2010.

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Published in energy.