Engineering for greater energy efficiency

Energy researchers have long seen improvements in energy efficiency as a potentially important means of improving energy security and, more recently, for climate change mitigation. Researchers have seen enormous potential for energy savings from efficiency improvements in all energy sectors. They have pointed out, for example, that only 3 % of the primary energy in the coal feedstock to a power station finishes up as useful lighting if an incandescent bulb is used, and that only 15-20 % of the energy in the petrol tank actually drives the wheels. Energy efficiency is regarded as having the potential to ameliorate both energy availability and climate change problems, and even local air pollution. This chapter looks in detail at the considerable energy savings potential in the transport, buildings (including office and domestic equipment) and energy conversion sectors. But actual experience in recent decades has shown that while in the growth-oriented global economy, energy efficiency is steadily increasing, so is global energy use. Energy efficiency is valued in our economy, but so are time efficiency (speed), land-use efficiency in agriculture, labour efficiency etc, and these can all conflict with energy efficiency. For this and other reasons, there are formidable barriers to achieving the energy reduction potentials that research has identified as possible.