SUSTAINABLE ENERGY TECHNIQUES AND INCREASED ENERGY EFFICIENCY

Sustainable energy techniques and increased energy efficiency

Sustainable energy techniques and increased energy efficiency

Introduction

The profligate material and power utilisation of the constructed environment dictate that the construction part has a key function to play in forming a sustainable energy economy. This paper presents an overview of the current rank and potentials within the sector and recognises the mechanical schemes and principle means by which these potentials may be realised.

Background

The built environment accounts for an estimated 40% of total US energy consumption (European Commission, 2005), while arguably more than 50% of all US carbon emissions can be attributed to energy use in structures (including residential and enterprise emissions, and power station emissions ascribed to constructed natural environment electricity utilisation) (Department for natural environment, nourishment and country Affairs, 2008). The constructed environment thus has a crucial function to play in deliveringa sustainable energy economy as recognised by the US Government in recent Energy White Papers ([Department of Trade and commerce, 2003a] and [Department of Trade and commerce, 2007]) and Energy Efficiency Action designs (Department for natural environment Food and country activities, 2007a).

Such ambitious policy aims are in contrast to a worrying 15% rise in overall energy consumption (heat and power) between 1990 and 2005, producing in no substantial carbon emission decreases since the mid-1990s (Department for natural environment, nourishment and Rural activities, 2007b). In the household part, increasing energy consumption has been propelled by a multitude of components: a 30% increase in the number of households since 1970 (Self and Zealey, 2007); the deployment of central heating in over 90% of US households; and the doubling of power consumption by appliances since 1970 (Shorrock and Utley, 2003). At the same time, the US has a legacy of poorly performing buildings, with 85% of the housing stock being more than 20 years old (Self and Zealey, 2007).

A consequence of this is that, while central heating has increased average indoor air temperatures by 6 °C since 1970 (Shorrock and Utley, 2003), it has been at the expense of energy efficiency because of inadequate thermal insulation levels. The poor value of the construction stock has furthermore contributed to the position where an approximated 2.5 million families are classified as fuel poor (Department for enterprise Enterprise and Regulatory restructure, 2007). In the non-domestic sector, a similar picture emerges, with energy consumption increasing by 17% between 1990 and 2003 (Department of Trade and Industry, 2003b), driven by trends such as the explosion in information technology, poorly regulated and designed speculative developments, and the often unnecessary installation of air conditioning; the energy consumption associated with air conditioning is projected to rise 25% by 2020 (AEA Technologies, 2007b). Further, it has been estimated that 40% of the energy used in non-domestic buildings over 10 years old is wasted due to poorly maintained plant and fabric (Johnson, 1993).

The present reduced grades of power efficiency in the built natural environment offer huge scope for enhancement in energy performance, which may be accomplished through the ...