Posts filed under 'Energy end-use sectors'
Electric domestic kettles represent an increasingly high proportion of total energy consumption in the EU. They benefit from the efficiency of electricity at the point of use, and also from a reduction of losses associated with convection, the thermal mass of larger heating elements etc. They have been estimated to consume half the energy needed to boil water on a stove.
However their size and energy ratings are increasing rapidly, particularly in households provided with high capacity electrical wiring circuits. In the UK they are now estimated to account for almost a third of the electricity used by cooking appliances. New features, such as incorporating a “keep-warm� capability, could increase carbon dioxide emissions by 220,000 tonnes a year.
January 10th, 2006
One of the complexities of energy efficiency, and a barrier to creating an energy efficiency culture, is a lack of understanding of the non-temperature related aspects of consuming energy. These are particularly important in Northern Europe, and include:
- humidity control, prevention of rising damp, moulds, damage to fabrics, furniture and clothing
- keeping heating systems on while away from home, as a precaution against water supply and wet heating systems freezing
- the true value of the heat output from incandescent lamps.
December 2nd, 2005
Does the rapidly increasingly geographical dispersion of energy end-use points require a new approach to addressing energy efficiency in the EU? The high growth rates of the commercial and domestic sectors, and improving social equality and living standards, are probably the main driving forces.
Some key areas including house construction, insulation, are already being tackled by legislation. Others such as lighting, standby mode, mobile charging, have been identified and addressed with varying degrees of effort, mainly by labelling and promotion.
The creation of distributed electricity generation and transmission systems provides a similar and related new challenge to minimise energy losses. Possibly more sophisticated instrumentation and control is one of the most underated contributors?
November 29th, 2005
The Green Paper recognizes that energy efficiency in buildings is an area where important savings can be made.
A number of factors may have contributed to neglecting the commercial sector as a point of focus. Many properties are in Europe are rented, with the energy bill paid by the client, creating a lack of incentive to make investments in energy saving. A trend to set high standards of appearance, with frequent refurbishments, can make this worse. Here legislation to require air conditioning to be installed in new commercial buildings may not have helped.
Commercial buildings have not received the benefits of the detailed attention given in the past to the domestic and industrial sectors, in terms of auditing and consultancy advice, development of energy saving strategies, and financial incentives. So that the effectiveness of methodologies and specific actions such as product standards, labeling, training has not been tested.
But, together with the closely related area of public sector buildings, this area is now growing very rapidly. It is also evolving fastest in terms of the use of new technology, and is probably the best candidate for intelligent energy management systems.
November 23rd, 2005
Diesel trains consume 460 kJ/tonne.km and emit 35 g/tonne.km. For electric trains, these figures become 230 and 9.3 respectively. The use of electric trains improves CO2 emissions by a factor 4, and energy consumption by a factor 2. Another illustration of the booster effect on carbon saving through the use of electricity.
November 15th, 2005
CO2 emissions per passenger.km for air travel are 186 g to travel from Hamburg to Munich (source - p41). Making the journey by rail reduces this to 43 g CO2 per passenger.km. Replacing air travel by high speed rail over medium distances reduces CO2 emissions by a factor 4. Energy consumption reduces by a factor 3, from 7.8 to 2.5 l/passenger.km.
November 11th, 2005
In Factor Four - Doubling Wealth, Halving Resource Use, one of the solutions mentioned are super-refrigerators. In the 70’s, the average refrigerator consumed 3.36 kWh/yr per liter volume, but refrigerators nowadays achieve much better performance (for example, see Certified Environmental Product Declaration ER 8117B achieving 1.15). Despite this improvement of a factor 3, there is potential to achieve 0.26, almost 5 times better.
November 10th, 2005
The most wide-spread lamp type (incandescent) is also the most inefficient one. It is more like a heating convector that just happens to produce some light. Per watt input power, incandescent lamps produce typically about 10 lumens. Cf below graph, fluorescent lamps do a factor 8 better, while technologies exist today to achieve more than factor 10.
Going the other extreme, a candle just produces 1 lm/watt, and is even 10 times less efficient than an incandescent lamp.
Figure: light efficiency for various technologies (source: European Ballast Group)
November 6th, 2005
Passive Houses consume less than 15 kWh/m2.year final energy for their heating requirements, compared to a typical use of 100-150 kWh/m2.year for standard homes, i.e. a reduction of minimum 85%. In Europe, about 6-7000 Passive Houses have been constructed so far, primarily in Austria, Belgium, Germany and Scandinavia. The concept is spreading to other countries such as e.g. Denmark, France and The Netherlands. Passive Houses strive as well for economy in their other energy uses, such as electricity and hot water production, targeting a 50% reduction, and setting a criteria for maximum 50 kWh/m2.year total final energy use.
More information
October 22nd, 2005
Today, the Brussels energy agency ABEA organised a noon meeting for general public demonstrating how users can save up to 30% of their domestic energy use by simply paying attention and changing habits. A family of 2 adults and 2 children spends annually 1100 euro on energy, and could save 330 euro on its energy bill. Simple measures include:
- Avoid standby power of TV (10 euro per year)
- Regularly de-ice refrigerators (2 mm ice means 10% more energy consumption)
- Control heating per room
- Reduce temperature (1 degree means 7% less energy - from 22 to 19 degrees means 20% reduction)
- Cold wash (30-40 degrees) saves 70% energy compared to 90%
- …
Considering these figures, the Green Paper targets seem particularly modest.
October 20th, 2005