An engineering solution

As the leaders of the world’s industrial nations meet Edinburgh, the case for action to tackle carbon emissions is becoming ever more pressing. The summit follows grim news in May from the Office for National Statistics that the UK’s carbon emissions are rising, and the European Environment Agency’s announcement in June that European greenhouse gas emissions are also on the increase.

Two new bills were put to parliament at the end of June that seek to reduce carbon emissions by practical and cost-effective means, and which have implications for the building industry.

The first, called the Climate Change and Sustainable Energy Bill, aims to stimulate government action to support small-scale domestic energy generation, known as micro-generation. The second is called the Management of Energy in Buildings Bill. If enacted in law, these bills would require the government to introduce a number of policies to help achieve targets that would reduce greenhouse gas emissions. Measures include the granting of permitted development status, the use of Building Regulations to ensure that building will include a minimum standard for energy generation, and would also facilitate the development of small community-based sustainable energy schemes.

Familiar energy-efficiency measures such as insulation and double glazing will be encouraged, but the Management of Energy in Buildings Bill also includes a clause introducing an innovative approach to energy management called “dynamic demand”. This has the exciting possibility of making the National Grid more efficient and enabling a greater proportion of variable renewable energy sources, such as wind and solar, to be connected.

Currently, National Grid operators pay power generators about £200m a year for a host of “ancillary services”, which are designed to keep the power system in balance every second of the day. Supply must always match demand, even as we all switch our electrical appliances on and off – even if large failures occur, such as a generator being suddenly lost. The problem is that, although these methods are effective, they are inefficient because they involve using partly loaded generation plant, which is less efficient than plant that is fully loaded.

There is an interesting possibility of using the demand side – that is, you and me – to smooth out fluctuations. It is possible because we can monitor the subtle imbalances between supply and demand from any plug socket in the country, simply by measuring the alternating current frequency of the electricity supply.

Dynamic demand involves fitting low-cost microcontrollers to suitable electrical appliances. These measure the AC frequency of the grid; nominally this is 50 cycles per second, but it fluctuates as generators speed up and slow down.

We can monitor the subtle imbalances between supply and demand from any socket in the country

Simulations showing the effect of many such appliances in operation suggest that they could provide a service similar in scale and behaviour to the current system provided by power generators, only without the associated carbon emissions.

To give a sense of the scale of the potential savings, early estimates indicate that replacing power-generator grid-balancing services with “dynamic demand” appliances could save millions of tonnes CO2 emissions a year – comparable to the savings that would be gained by the government meeting its energy-efficiency target for public sector buildings.

Suitable appliances include domestic and industrial refrigerators and air-conditioners, which already turn on and off throughout the day, and could time their energy use to match the needs of the national grid. With the right changes to regulations and policy, it should be possible for such devices to earn a portion of the payment currently made by the National Grid Company for ancillary services, making such an approach commercially viable.

However, the electricity market does not favour small-scale providers and does not create enough incentive for upfront investment in innovative carbon-saving approaches such as dynamic demand. This is why the technology is being promoted by a new not-for-profit organisation called Dynamic Demand, funded by a charitable grant, and set up by engineers, academics and environmentalists keen to promote technological solutions to climate change.

As the G8 summit draws to a close and the world’s leaders return to their countries to address the looming threat of climate change, the coming months will see a flurry of parliamentary and campaign activity to support the two energy bills currently before the UK parliament. A crucial debate will be held on 11 November, where MPs will debate the Energy Management in Buildings Bill, which would commit the government to investigating the potential for dynamic demand technologies and reporting on what changes would be needed for it to be introduced.