road energy system

In June 2006, IHS installed a unique system in the carpark of their new offices in the Scottish Highlands.  The Road Energy system is hugely exciting.  Capable of heating and cooling buildings, roads and airport runways it takes advantage of the superior absorption capacity of asphalt.

The longer and more intensively solar energy is used, the more important it becomes as an environmentally friendly way of supplying our energy needs.

Storing energy in the ground is an energy-saving, environmentally friendly heating and cooling technique.  The environmental benefits are enormous; CO2 emissions are lessened by 50-90% when compared with conventional heating.

The system comprises an asphalt layer with a reinforced structure and a water-bearing medium.  Asphalt's dark colour has an excellent heat absorption capacity.  This represents a novel way of harnessing solar energy.  The aim of the Road Energy system is to achieve energy savings by using thermal energy stored in aquifers for cooling and/or heating in commercial, residential and industrial buildings.

Click here to download a copy of our Road Energy Brochure.
 

how it works

In summer, the Road Energy System generates considerable heat.  In the appropriate geological conditions, this heat can be stored in the ground in aquifers and pumped up for heating purposes in winter.  Conversely, the stored winter cold can be used for cooling in summer.  The warm and cold water are separately stored in an underground water-bearing sandy layer (aquifer).  The hot and cold groundwater can be pumped up from the aquifer or it can be injected back.  If used with a geothermal heat pump, for every 1kW of energy put into the system, 7kW is achieved out.  Typical temperature of extracted water is 20ºC (ideal for storage areas, warehouses); therefore less energy is required to bring temperatures up to comfortable levels. 

The Road Energy System system saves considerable primary energy as less cooling and heating is required by the central heating and cooling system.
 

output

Approximately 33m sq of tarmac is required to heat each 100m sq of a house.  A small area of tarmac (10 x 40m) can generate 108mW of energy per annum.

Typically, an airport runway can heat 2500 homes.

It's been calculated in Holland that if 15% of Dutch roadways had the Road Energy System, more energy than all the combined utilities in Holland would be produced. 

The lifespan of roads is prolonged about two-fold as they can be kept cool during the summer and frost-free during the winter.  Resurfacing costs are typically halved as maintenanced is reduced accordingly.  Traffic jams are decreased as there's reduced road maintenance and bad weather doesn't impede drivers as badly.  

Icy surfaces don't have to be sprayed with salt - an obvious cost saving for local authorities and an ideal solution for airports (it's not possible to spray airport runways with salt; the Road Energy System resolves the problem of ice on runways).
 

benefits

• Major savings on energy consumption when used to heat buildings
• Reduced CO2 emissions by 50%-90%
• Lengthened lifespan for roads, carparks, runways
• Improved traffic safety (roads frost and ice-free, less road works, free-moving traffic in poor weather)
• Reduced maintenance costs for roads and engineering structures (eg bridges); resurfacing costs are halved
• Airport runways and roadways - reduced costs of anti-ice measures
• Excess heat and cold collected from asphalt surface can be used to warm and cool surrounding homes and buildings