Monday 16 December 2013

Asphalt plants get energy kit for demand response

Aggregate Industries’ asphalt-making plants are getting technology to adjust their energy demand to help balance the National Grid.

Asphalt made at the 40-odd sites across the UK has gone into the M8 motorway extension to Scotland, London’s Olympic Park and Silverstone Race Track.

Bitumen tanks used to make the asphalt will be fitted with a new sort of ‘demand response’ technology.

Called Dynamic Demand, it alters energy use automatically when it detects an “imbalance” in the grid frequency, rather than waiting for a signal from the National Grid to change. 

The technology can also increase energy use when there is excess electricity available on the grid.

The grid hits a certain frequency when it is fully supplied and this changes when it's under or over supplied. This is how the technology senses whether to switch Aggregate's equipment off or on.

These changes can happen several times a day but usually only for a few minutes at a time. Aggregate is looking at the same technology for moving water at its sites.

Chris Hudson, Director of Asphalt at Aggregate Industries said: “At the start of this project none of our bitumen tanks were individually metered and we had very little understanding of the efficiency of each tank. Open Energi’s technology has given us complete visibility of how every tank is performing.”

Although energy intensive, the bitumen tanks are suited to this practice as their electricity use is not “time critical”, according to smart grid technology firm Open Energi. It has been working with the manufacturer on the project for two years.

It says the ‘demand response’ kit could cut CO2 emissions by almost 50,000 tonnes over the next five years.

The retailer Sainsbury's also uses the technology for its heating, ventilation and air con.