Archive for March, 2012

March 14, 2012

Would You Live in a Passivhaus?

Passivhaus is an energy efficiency standard, developed in 1988, which sets out various criteria for homes and commercial buildings for maximising energy savings – thanks to its orientation, materials used and insulation, amongst other features.

This standard sets maximum values for energy consumption of space heating, cooling, primary energy usage, as well as the highest temperature inside and the level of air tightness – not allowing virtually any air to leak from the house. These requirements can however vary in different countries due to different circumstances, for instance the age of existing buildings.

Passive houses have to be designed and built precisely to the specifications – for maximum gain. The most important features include the specific positioning of walls in order to capture the most sunlight, or the super air tightness. Despite some myths windows on these houses can be opened but due to excellent indoor air quality, the air ventilation system and other factors it’s usually not needed.

Various materials are used for the construction and even the colour of the outside wall is suggested to improve efficiency through either absorption or reflection. Insulation has to be of highest standard and very thick, both at the walls and the roof.

Meanwhile, heating is hardly required as a Passivhaus also utilises the heat energy generated inside the building, for instance by various appliances. Thanks to the careful design interior temperature does not go below 15C  and due to the air tightness there are no cold spots or mould growth inside these buildings.

Lighting solutions are also energy-efficient, thanks to the use of solar-powered lights outside or LED lamps inside – amongst others.

Another great advantage is that such houses can be built in any climate, and there are now over 30,000 such homes all over the world.

Also, the main criticism of being very expensive is addressed by the continuously decreasing construction costs, while savings could be enormous. In the case of a UK office building, the company Interserve in Leicester managed to save GBP 26,000 at their annual energy costs after moving into a Passivhaus.

Thus, passive houses may mean homes of the future for us or our companies, offering significant energy savings, which is also important for our wallets.

For more info, check out: Energy World, March 2012, “Passivhaus in the UK – an alternative to zero carbon”

Written for the Energy Saving Warehouse

March 7, 2012

Lost a Shoe? Print it Yourself at Home!

The 21st century is the ‘age of stuff’. All of us are piling up ‘things’ at home and every minute we are encouraged to buy even more. If we can’t resist the urge to collect more and more, a new technology can now help at least in reducing our ecological footprint: 3D printing.

3D printing is essentially layers of specific materials – mainly plastic -, printed on top of each other with a special device, enabling the creation of virtually any kind of object. For years it has been used for developing prototypes, for example by architects, but now it’s becoming more mainstream. One of the world’s largest consumer printer manufacturers, HP has already launched 3D printers, and MIT’s researchers have been conducting trials by printing food and working clocks with every little detail included.

A key market player today is MakerBot Industries, offering 3D printers for personal use, including the latest Replicator, and the Thing-O-Magic models. These can print shoes, jewellery, toys, everyday items for the kitchen or the bathroom or anything you can think of. It’s also very handy if small parts or components break or go missing, which would be very expensive or even impossible to replace.

Schematics and blueprints are already freely available for everyone to download, thanks to a whole community that has been developed around MakerBot, sharing the designs of toys or art pieces. [6]

3D printing also offers several environmental benefits. It could reduce or virtually eliminate local and inter-continental shipping and packaging costs. Also, MakerBot’s community is already working on further developments, for instance how to re-cycle or use leftover plastic in order to reduce waste. It has even been claimed that 3D printing can stop over-production as only items that are actually needed are ‘manufactured’ avoiding stock remaining in warehouses.

3D printing thus could really change our shopping habits and our life in the very near future.


Written for the Energy Saving Warehouse

Image: MakerBot


March 4, 2012

Enhanced Geothermal Systems

Heat from the earth has been tapped for a long time. However while conventional geothermal systems utilise the energy from underground only at locations with ideal geological features – where hot water and thus steam already exists -, now also less favourable places can enjoy the benefits of geothermal energy – thanks to Enhanced or Engineered Geothermal Systems (EGS).

These systems use the potential of the “hot dry rocks” under our feet for generating heat and electricity. In the case of the conventional geothermal energy, known as hydrothermal, hot water is in situ, while the new technology artificially fractures hot dry rocks, and then circulates cold water, which eventually turns into steam and so drives turbines on the surface. Later the water is re-injected and the loop is started again.

According to a study by the MIT Enhanced Geothermal Systems have the potential to provide 100 GWe generating capacity just for the US in the next fifty years. This technology is scalable and can provide a continuous base load, but further investigations, including field tests, are needed to determine the real benefits.

Potential challenges include that it may cause minor tremors, and it requires a rather large initial investment, which may hinder companies and countries who are willing to finance such projects.

Australia is already leading the way in testing this technology, while there are further trials in Germany, as well as France and the US. In the UK the Eden Project is one of the latest examples.

According to the forecasts of the European Commission EGS systems can offer cost-effective electricity virtually anywhere, with an estimated potential of 1 GW and a maximum potential of 6 GW for the EU countries by 2020 – about one per cent of gross electricity consumption. For heating purposes the potential is even higher. The EU has supported about ten projects since 2002, including the key pilot project in Soultz, France.

Enhanced or Engineered Geothermal Systems thus offer great potential both for heat and electricity generation and hopefully with more investment it can be developed into a promising new energy source.

Written for the Energy Saving Warehouse 

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