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Attempts to make buildings more energy-efficient by installing
expensive 'green technologies' have resulted in the
rise of 'eco-bling', a symposium in Trinity College
heard.
Academics and practitioners of sustainable energies said
that much money was being spent on micro-renewable energy
systems when extra insulation and draught-proofing would be
more effective.
The symposium - part of TCD's 'Energy & Sustainability'
Trinity
Week 2009 (11 - 15 May) - heard that some expensive
technologies - such as photo-voltaic cells, which take energy
from sunshine - can take up to 50 years to pay for themselves
in saved energy costs. However, photo-voltaic cells often
have a useful life of just 20 years, making them effectively
'eco-bling'.
Howard Liddell of Gaia Architects, which has been working
on eco-design in Scotland and Norway since 1984, said heat
pumps, photo-voltaic cells, solar panels and even in some
instances, wind turbines, were types of renewable energies
which frequently did not stand up to "crunching the numbers”.
In his lecture - 'Nega Watts - the antidote to Eco-bling'
- Mr Liddell said preventing heat loss was, by definition,
among the best ways to achieve energy efficiency. He said
he had never seen a heat pump in operation which offered a
return as good as three units of energy output for each unit
which went in, yet these were regularly advertised as 'four
units of output for one unit in'.
Photo-voltaic cells which make energy from sunshine offered
a 50-year payback, but all too often have a 20-year useful
life. He was critical of new housing schemes which advertised
'10 percent of energy from renewables' - when research
showed clearly that the best way to achieve energy efficiency
was simply to reduce waste.
The optimum measure was “super insulation” - making a house
air-tight, “instead of heating the sky”. However, he asked,
“How do you make insulation and air-tightness sound as sexy
as 10 per cent from renewables?”
He said 'green' buildings with micro-renewable energies
tended to be lived in by environmentalists and cost more to
build. Super-insulated buildings with only air tightness and
passive solar gain tended to be lived in by “ordinary people”
and did not cost more to build.
In his address - 'Sustainable Energy - Without the Hot
Air' - Prof David MacKay of the Department of Physics
at Cambridge University, England, asked whether renewable
energy has the capacity to meet society’s demands. He concluded
that Britain, as an example, could survive on renewable energies
alone - but only with massive societal changes and most of
its landmass utilised by biofuel crops, alongside tidal, wind
and wave energy farms.
Source - The Irish Times
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