CPD Specifier May 2015 issue September 2014 | Page 38

Outdoor Engineering

Coal-fired
power stations
here to stay

Fly-ash, a by product of the combustion process at coal-fired power stations, is an established and much-valued construction material due to its
environmental and technical benefits over primary raw materials. However, with the closure of some coal-fired power stations and the current fluctuations in the energy market, specifically cheaper wholesale gas, many in
the industry are wondering what this means for the future of fly ash.
This summer has seen very low gas prices coupled with reduced demand
for energy during the summer months. This has raised a few questions
about the role of coal-fired power stations in both the immediate and longterm and the impact this will have on the supply of fly ash to the construction market.
True, the energy landscape in the UK is changing and low gas prices, new
nuclear projects and the burgeoning renewables industry will all have an
impact on more traditional sources of energy like coal. However, the shift
is slow and while many of the new energy generation projects are still in
their infancy, coal-fired power generation continues to account for almost
a third of our energy needs - a figure that remains largely unchanged over
the past decade.
Recent European emissions regulations mean that some of these coalfired stations have and will need to close or convert. After half a century
of operation however, the UK already has stockpiles of up to 50m tonnes
of coal ash, in addition to daily production. What’s more, the construction
industry only uses half to two thirds of what is readily available, meaning
that stockpiles are and will remain plentiful well into the future.
Closed power stations such as Tilbury in Essex (pictured), continue to be
a source of usable fly ash. Tilbury ceased to operate in August 2013 but
after 44 years of operation, producing a minimum of 200kt a year, stockpiled ash is plentiful. Carefully excavated and screened, the reclaimed fly
ash is compliant with the BS EN 13055 standard and is suitable for use in
a variety of different applications from block manufacture to engineering
fill, grout and hydraulically bound mixtures as used in road construction,
such as the widening of the M25 for example.
So the message to specifiers, architects and contractors is clear - despite
flux in the UK energy market, coal-fired power stations are set to continue
to have an important role in meeting our energy needs. As a result fly ash
will continue to be easily accessible and a readily available construction
material, whether sourced from silos, stockpiles or reclaimed from the ash
fields across the UK.

UK QUALITY ASH ASSOCIATION

TEL: [phone]

WWW.UKQAA.ORG.UK
38

READER ENQUIRY NO: 51