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…it is possible to reduce the energy demand to near zero without relinquishing comfort.
Energy efficiency does not mean that one has to feel cold all the time. Improved efficiency means that it is possible to provide more comfort while consuming less energy at the same time. It is all about intelligent technology and not about having to forgo comfort.
The potentials for better energy efficiency are much, much bigger than the potentials for energy savings by reduced comfort. With contemporary available solutions, energy efficiency can save some 90% of the consumption - while it will be hard to save 25% by lowering temperature, and so, comfort. This insight is often a surprise but has been demonstrated in practice, it's not a theoretical potential. Again: This is not a typo, the potential savings are in the range of 90%, the remaining energy requirement will be reduced to one tenth of the value it originally has been.
Measured results have shown that the actual heating consumption values of such houses are about 90% less than the consumption values of ordinary existing buildings in Germany.
|Example of a modernised old building with over 90% savings
in heating energy through improved thermal protection
(“Passive House Building Stock” Project by GAG Ludwigshafen).
Today's available possibilities for improving energy efficiency are often underestimated:
Applying these measures will help to achieve extremely high levels of energy efficiency and extremely low levels of energy consumption, substituting the greatest part of the energy originally used in a building.
There are numerous possibilities for covering the remaining energy demand - even if this energy is provided by conventional energy carriers, the situation is much better as less energy is required in the first place making energy resources last longer and reducing the environmental impact. Sample projects show that it is even possible to meet the energy demand by using renewable energy sources.
Energy efficiency means substituting energy consumption by intelligent, innovative products and clever process management; in short: “brains instead of brawn”.
Achieving high levels of energy efficiency mainly requires a certain additional investment which will pay off in the long term. The required products can be manufactured locally, creating employment and encouraging innovation.
Improving energy efficiency is a universal task. Wherever energy is used to provide a service, efficiency can be improved, often quite considerably. The required measures for this can be carried out together with new acquisitions (such as an energy-saving refrigerator) or with maintenance or modernisation measures (e.g. thermal insulation during the application of new plaster). This is usually very attractive economically. Sometimes it even makes sense to replace old systems immediately: for example, old heat circulation pumps, boilers pre-dating 1982, old lighting systems, insulation of basement ceilings and attic ceilings as well as replacement of old single-paned windows.
|The “service” that needs to be provided in
this example is keeping coffee warm.
→ This task can be achieved either by
applying energy (hotplate on the right)
→ or by avoiding the loss of heat in the
first place (thermos flask on the left).
While there is still minor heat loss,
it is so small that there is no need for
|The illustration shows the basic principle of improved energy efficiency using an example.
It becomes clear why energy efficiency not only “saves some energy”, but can also replace
the provision of energy to a great extent.
|Another example: an old CRT screen (left) and energy-efficient|
flat screen monitor (TFT); the savings in electricity are over
70 % - while comfort is improved at the same time.
|State-of-the-art technology: an electronic ink display
with near-zero energy consumption.
Yet, there’s more to come with new methods currently being developed for utilising incident light (so-called electronic paper). The physical limit for the energy consumption of a display is extremely low (…reading a book doesn’t require any energy at all).
The computer sector could do more to improve the energy efficiency of products. The possibility of maintaining the full performance of a PC including the monitor and peripherals while using a continuous output of a mere 5 to 10 watts, has been demonstrated by the “One Laptop Per Child” project.
And that's only one-tenth of the normal electric power of personal computers today. Maximising energy efficiency helps minimise the energy otherwise needed.
We supported this project - it is a contribution to the most important task of the future: the improvement of education worldwide.
There are several reasons:
In recent years, this has been the question most often raised in the discussions after lectures by Passive House experts. Indeed, almost all systems for assessing sustainability focus on completely different aspects – in such assessments, energy often only plays a very small role in comparison with water, building materials, socially sustainable concepts, costs and aesthetics.
This is not about provoking reactions, but it must be said that energy is the most important and decisive factor regarding our civilisation’s progress towards sustainability. When the best scores in building sustainability assessments go to buildings with mediocre energy performance – it only misleads the public.
This can be easily demonstrated:
Does this mean that all other issues are less important or even unimportant? Not at all. In reality, our society values other topics greatly: accessibility for the disabled, the separation of waste, the living environment, a socially acceptable distribution of costs, the preservation of our historical monuments. The fact is that we have already fixed very extensive requirements for most of these issues, sometimes even through laws, and these are not in conflict at all with the measures for much more efficient uses of energy. The latter has been almost reprehensibly neglected in the decades since the 1950s; energy consumption has increased five-fold since then. The per capita consumption of non-renewable energy in developed countries today is too high for sustainable global development, by a factor of almost four. Thus, something really has to happen, and that on a large scale.
The good news is that this is possible. The possibilities for increasing energy efficiency by a factor of more than 5 are available to us, and the remaining energy demand can be covered sustainably through regionally available energy sources all over the world. Exemplary demonstration projects in especially committed regions have already proven both this and also that this is possible without neglecting other important objectives.
This is one of the outstanding features of energy efficient solutions: that they represent a comparatively small intrusion, both objectively and economically. Passive House refurbishments taking into account requirements for the preservation of historical monuments and also for construction with regard to accessibility for the disabled have already been carried out.
Architects, designers and craftsmen need to pay attention to this issue, which is why educational opportunities with this focus are increasingly being offered. After all, it is these professions that will benefit from this development – their expertise is required.
[Feist 2002] Feist, Wolfgang: Mit dem Passivhaus in eine nachhaltige Zukunft. In: 6. Internationale Passivhaustagung, Tagungsband. Basel, Darmstadt 2002, New edition with footnotes from 2010 available here in German: Passivhaus - nachhaltige Zukunft
[Feist 2001] Feist, Wolfgang: Energieeffizienz (Energy Efficiency). Heidelberg, 2001 PDF (in German)