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High-tech Ecohouse in Brussels
Sarah Rich, 27 Mar 06

house.jpg Some time ago, we talked about an "ecohouse" in Brazil - a renovation project that took an existing traditional building and turned it into an experiment in integrated green design. Now we've come across another such project in Brussels, located on Rue D'Arlon, neighboring the European Council and the European Parliament. In this hub of European leadership, where the EU Spring Summit took place last week, the townhouse serves as a demonstration site for European officials to witness alternative energy in action.

The house uses pellet fuel heating - a process of burning small, compact cylinders (think rabbit food) of compressed biomass such as sawdust or agricultural waste in a boiler. Pellet fuel is considered "carbon neutral," and because it's made from waste materials, pellet fuel has a sustainable future. In addition to the pellet system, the building obtains heat and cooling by transferring geothermal energy from underground pumps in the courtyard.

Of course a number of solar technologies have been integrated into the renovation, including panels along the hallways with embedded solar cells. On-site converters channel energy collected in these cells as well as in rooftop photovoltaics into the building's lighting system.

Natural ventilation, double-glazed windows and energy recovery complete the array of energy-efficient technologies, although the building remains partially reliant on the grid until wind power becomes more readily available and widely adopted in Belgium. While the initial cost of these efficient and high-tech systems exceeds traditional techniques, the long-term operations costs are 70% reduced from pre-renovation rates.

With luck, the building will be a convincing testament to strategies for an energy-efficient future for the EU. Now if they could just add some rainwater catchment systems, gray water treatment, and a green roof...

Thanks, Tim!
via:BBC News

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I visited it when it had an open door day. The nice thing about this house is that it shows how 'discreet' and well designed all the eco-features can be. The entire house is an example of neat integration of different functions without disturbing the look of the house.
Some people still think that "eco" and "house" means all kinds of ugly pipes and windmills and boilers and solar panels juxtaposed in a disorderly, shack fashion. This house proves the contrary.

Posted by: Lorenzo on 27 Mar 06

Oh my goodness, I used to walk past it all the time and I never would have known.

Posted by: Alexa on 27 Mar 06

we have a few of these in the UK already, the best (and most famous) of which is BedZed (Beddington Zero Energy Development). 100 carbon neutral apartments were built in 2001 with passive solar, microgeneration, rain water collection, locally sourced materials and a car pool. and they look good - they sold like the proverbial hot cakes. now we just need another 50,000 of them...

Posted by: joy on 28 Mar 06

We have a few of these in a new Eco-Village in Cincinnati too. I hope it spreads!

Posted by: Navy nerd on 28 Mar 06

A little more careful, logical thought and a little less band-wagon jumping is in order here.
Pellet as well as regular wood-burning, high-efficiency stoves have been around a long time and are very prevelant in my neck of the woods. Pellets have to be created, using energy, from solid wood, so why not just use the solid wood. This is as "carbon-neutral" as any pellet process, even more so.
Regarding solar voltaic energy, the relatively higher cost per KWh compared to hyrdro or coal generated electricty should give us a clue about the relative inefficiency of solar over the other sources...inefficiency means more energy consumption, not less.
Regarding preserving the energy inside a house once it is generated, this has done been for many years - using double-glazed windows, natural ventilation, insulation and sealing (up to a certain point, that point being the avoidance of condensation of moisture). This is nothing new, and is standard practice for every new house built according to current building codes.
In other words, these so-called "experiment(s) in integrated green design" are nothing new. Most builders I know produce the most efficient construction possible, with currently-available materials and methods. These highly efficient houses are everywhere.
We won't save 70% of our energy costs by installing pellet stoves, solar-voltaic systems, or wind generators. All three of these methods are less efficient (therefore less "green") when the installation costs are amortized over their life spans, expressed as cost per KWh.
Do we really think that by using some eco-speak, politically correct buzz words, that somehow we have created something new and better?

Posted by: Ron Olfert on 28 Mar 06

Ron - Thank you for your comments. I appreciate and share your circumspection around the use of "eco-speak" and buzz words to doctor or reframe existing and old practices that have no benefit or sustainable aspects over the traditional stuff.
I suppose my use of "experiment" may be a poor choice, as you are correct about all (or most) of these technologies' age. The BBC article from which I learned about this house referred to it as a "laboratory," which I believe was meant to express the building's service to the European officials and visitors who would use it as a tool for understanding how these technologies work, both on their own and in concert, to create a more energy-efficient building. This was also where the statistic of 70% energy savings came from, but perhaps they were misinformed.
My reseach through several gov't agency websites suggested that pellet fuel heating does offer advantages in efficiency and air quality compared to other fuels. I'm not as familiar as I could be with building codes in the EU, so the use of photovoltaics, double-glazed windows, etc, seemed to be outside of the norm.
I will pursue some further information on these issues and I appreciate you taking the time to comment.

Posted by: Sarah on 28 Mar 06

"Regarding solar voltaic energy, the relatively higher cost per KWh compared to hyrdro or coal generated electricty should give us a clue about the relative inefficiency of solar over the other sources...inefficiency means more energy consumption, not less."

You just confounded economic efficiency with energy efficiency. Nice try.

Posted by: Joseph Willemssen on 28 Mar 06

I'm interested that no-one has picked up on who is occupying this building and the function it will perform for them. The tenants are all the European renewable energy trade associations (European Wind Energy Association, European Photovoltaic Industry Association, etc), who are celebrating moving in to their new offices after a lengthy refurbishment. My colleagues at EWEA have been really excited by having a home where they are walking the talk, and which acts as a showcase for their technologies to the officials and MEPs they work with. I am looking forward to getting the Eurostar to the next Euro-wind networking meeting. And I don't say that very often. :-)

To address a couple of Ron Olfert's points: Wood pellets are made from sawmill waste which otherwise would have no, or only low-value, use. It is also important that the input material to the pelletiser be finely ground. The manufacturing process involves using standard extrustion technology to apply high pressure to the sawdust; the pressure causes the dust to heat up, so the resins in the wood melt and bind the pellet when it cools. No heat is applied - pressure only - so it is quite low-energy. Pellets also enable the use of automated boilers in peoples' homes; the increase in convenience that pellets' ease of handling provides allows the technology to spread more easily. Sawdust is a limited resource, admittedly, but it is supporting widespread use of pellets in Finland and Austria, and there is enough to support considerable growth in other European countries. I would hope that use of wood as a building and design material increases in a bright green future, and thus that the supply of sawdust will increase also. Other wood materials such as chipped waste or solid blocks can be used in different burners - chip is suitable for larger boilers of a few MW thermal output or more, for instance. There's certainly no shortage of these wood streams, in the UK at least - millions of tonnes of wood waste goes to landfill here every year. No joke, really.

Re the cost of solar: its high cost is not to do with inefficiency of the technology but rather of its manufacture. With the current high growth of the sector, economies of scale production are kicking in. One study I remember, admittedly a few years old, estimated that a factory with annual production of 500MW-worth of cells (the global PV market is about 1000MW/year) would bring the cost of the power from those panels down to competitive levels. That was with crystalline silicon technologies which currently dominate the market - next generation technologies, some of which employ nanotechnology, may improve the situation further but are currently still in the development phase and have yet to face the challenge of moving to mass production.

Posted by: Doctor Edge on 28 Mar 06

There was no confounding of economic efficiency with energy efficiency. Since there was no qualification of the word "efficiency" I should think you would have asssumed the meaning to be "overall efficiency" (conveniently measured by cost). With commodities such as photovoltaic cells, coal, and water, cost is the great leveler. Energy efficieny has nothing to do with the "green" issue. (By "energy efficiency" I am assuming you mean energy ouput divided by energy input in a device or system)
Why does solar energy cost more? Consider that the cells require more energy and therefore cost more to produce, whether you measure cost in terms of man-hours per KWh or dollars per KWh.
At some point in time possibly the cost of producing photovoltaic cells and associated equipment will come down to where solar energy will become competitive with other means, but I doubt it. Since the cost of cells, i.e. mining, manufacturing, and installing, are constantly increasing, how are we going to bring down the cost per KWh of solar energy? The relative cost of solar energy will always be high. I don't think further economies of scale (mass production) will ever overcome the countervailing costs of labor and raw materials. It would be wonderful if I am wrong and that solar energy of this type could become economically feasible. I'm not holding my breath.

Posted by: Ron Olfert on 28 Mar 06

It's a lot cheaper to get your electricity from the pellet stove. Look at web site and see how.

Pellet stoves can be controlled to maximize efficiency and minimize effluents much more easily than log wood stoves.

Posted by: wimbi on 29 Mar 06

ron, with respect your thinking is a little out of date. building integrated solar pv can be relatively cheap to install and saves on transmission losses (5-10% on the national grid). with a bit of smarts, a highly effective decentralised system can be set up that saves both emissions and money.

a good example of this is the london borough of woking. they began with a traditional energy efficiency drive on all council buildings, but made sure to recycle and ringfence all resultant financial savings for energy purposes only. after a couple of years they used this money to install several solar pv systems and a CHP system. as you know, after the capital cost, solar energy is free, so after that lump went out, more savings came in over the following years, which were used for more microgeneration (wind & solar) and to offer householders condensing central heating and water boilers for the same or lower price than a conventional boiler as part of an energy conservation package.
off-grid solar pv was also used for applications such as parking meters and bus stop lighting - this saves the (v expensive) cost of digging up the road.
and the effects? Between 1991/92 and 2003/04, the town enjoyed a 48.6% saving in energy consumption. Carbon dioxide emissions were down 77.4%, while nitrogen oxide emissions fell by 76.6% and sulphur dioxide levels were reduced by 90.9%.
all this without having to increase the original energy efficiency budget.
(they also ran a parallel project on water conservation, for anyone who's interested).

Posted by: joy on 29 Mar 06

also the cost of solar cells is gradually decreasing, not increasing, due to thinner crystalline cells and increased use of amorphous silicon. sanyo mass-produce a hybrid cell now that is one of the most efficient on the market in terms of cost per kWh (and the conversion efficiency isn't bad either at close to 20%)

Posted by: joy on 29 Mar 06

The house is a prototype. The first light bulb cost much more than €1 or $1.

Cheers to Ron for asking questions about economics. But comparing average costs isn't the right approach - we have to compare costs at the margin. In other words, should we add more insulation or drill more oil wells? Should we double glaze or build a nuclear plant? Should we integrate PV into buildings or build gas pipelines across Kazakhstan? Should we pelletize biomass or refine crude oil? And so on.

Right now, at the margin, efficiency improvements trump every other approach, including nifty renewable technologies. This project could have gone further - in the similar climates of Freiburg and Darmstadt, you can see hundreds of Passivhaus units, developed by Dr. Wolfgang Feist and colleagues. Nothing glamorous, nothing to excite avid readers of, say, Wired magazine, but - wow - those houses really get the job done. They use less energy for space heating, water heating and appliances than a typical German house uses just for appliances. And a Passivhaus is economic - it's designed as a low-cost "social housing" model for Germany.

When you get the job done that well, then the energy loads are so small that PV, biomass and other approaches are relatively easy. But not until then.

Posted by: David Foley on 29 Mar 06

good point david. it always pays to get the energy efficiency stuff down before moving onto microgeneration.

Posted by: joy on 29 Mar 06



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