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House that runs on solar power takes part in international competition

Brazil Consortium Architectural illustration showing a side view of the Flex Solar House, designed for Brazil’s range of different climatesBrazil Consortium

A hammock on the veranda is to be the most visible Brazilian differential in the Casa Solar Flex [Flex Solar House], a home designed and built by a consortium of six universities that is self-sufficient in terms of electric energy, entirely drawn from sunrays. The house has been entered into the Solar Decathlon Europe to be held next June, in Madrid, Spain, a competition among universities from nine countries that is being held in Europe for the first time. The four preceding competitions, the American Solar Decathlons, were held in the US and organized by the US Department of Energy (DOE), which is also involved with organizing the event in Europe. The Decathlons’ aims are to show society that one can live sustainably, to expand knowledge in the field of solar energy, and to train professionals in this type of technology. The competitive show is open to the public and includes visits to the interior of the houses, which helps to disseminate the use of solar power to produce electric energy.

This will be the first time that a team from South America has taken part in the Decathlon. The challenges are huge. As in a sports decathlon, the competitors are put through 10 tests. What guarantees that points are not lost is energy sustainability, which must cover all the lighting and power required for all electronic devices in the house. It is also necessary to maintain thermal comfort inside the house, i.e., a suitable temperature. The Brazilian project has been under development for more than one year and takes into account the competition’s rules and requirements.

We were invited to take part in the competition by Professor José Manuel Páez Borrallo, vice-president of the Madrid Polytechnic University, who visited the Federal University of Rio de Janeiro (UFRJ) in August of 2008. “The group of researchers that was present representing the universities at that time decided to form a consortium to combine their skills and share costs,”  explains the general coordinator of the project, Professor Adnei Melges de Andrade, deputy director of IEE, the Electrotechnics and Energy Institute of the University of São Paulo (USP). “Afterwards, while still in 2008, we held a competition among architecture students from Brazilian universities to get an autonomous, attractive, functional and sustainable house, suitable for construction in different types of Brazilian climates, ranging from cold to hot, from dry to humid, from Rio Grande do Sul to Ceará,” Andrade tells us. The group is hoping that it can be reproduced in the future, possibly by a company, with the aim of having it set up in isolated places, such as the Amazon Region. It would be set aside for sustainable tourism to ensure that the presence of humans in a given locale did not have an impact on the environment.

Seventeen projects were presented in this competition, and a jury comprising three Brazilian architects and two Spanish ones chose four winners. The first and third places went to the Federal University of Santa Catarina (UFSC) , while the second place went to the State University of Campinas (Unicamp). The third place, however, involved a draw and was shared with a project from the Federal University of Rio Grande do Sul (UFRGS). The winners formed a team that took the best features of each project and prepared a final design. A large multidisciplinary team was then formed, with more than 100 members, including mainly undergraduate architecture students, but also engineering, design, marketing and journalism students, besides two PhD candidates, one in architecture and the other in civil engineering. The students were from the six universities that formed the Brazil Consortium (USP, UFSC, Unicamp, UFRGS, UFRJ and the Federal University of Minas Gerais/UFMG), and were coordinated by one or more professors from these institutions. The construction of the house is to start in January 2010 at USP’s Cidade Universitária campus in São Paulo City, within the IEE area, where the house will be assembled and tested. In April, it will be dismantled and shipped by sea to Spain. There, in early June, it is to be put together again over a ten-day span, in preparation for the competition?s opening on the 18th.

Stefano Paltera/U.S. Department of Energy Solar DecathlonSolar panels distributed in two different ways: vertically, in such a way that they can be moved, and fixed, on the roofStefano Paltera/U.S. Department of Energy Solar Decathlon

Inside space
The Brazilian house has a floor area of 43 sq. m and is to be installed in a 74 sq. m area. It has no foundations and will be anchored at 50 cm from the ground. It is entirely flexible, in the sense that one can easily change the internal area, which has partitions made from reforested timber, this being one of the requirements of the competition regulations, based on sustainable production concepts. It also has interchangeable metal window and door frames. There is only one area reserved for the kitchen and the bathroom. On the outside, the house will have multiple slats that will regulate sunrays and ventilation. One of the house’s innovations concerns part of its solar panels. Installed vertically, they can be automatically moved to the three sides of the house where the sun is strongest during the course of the day. On the roof, the panels are horizontal and fixed. One of the competition’s rules requires that these devices be acquired in the market, to show the project’s feasibility. The Brazilian house is to hold 64 panels, of which 48 will be on its roof. Jointly, they will generate 15 kilowatts (kW) of total installed power when the Sun is at its midday peak. “We’re negotiating with the companies that resell these panels in Brazil,” says Andrade. To date, there are no manufacturers of this type of equipment in the country.

The European competition is to present an innovation that is a world trend when it comes to solar energy. The electricity of the solar panels will be injected into the power grid of Madrid. Thus, the local power distribution company gets the electricity generated during the course of the day and supplies the house during those hours when it cannot produce any power. “There are two meters, one for the house’s energy output and the other for the intake which will keep the house supplied. This energy equilibrium or balance is part of one of the tests, the one that concerns energy sustainability, specifically,” explains Lucas Sabino Dias, an architecture student at UFSC.  In the US competition, held in 2002, 2005, 2007 and 2009, the house was entirely self-sufficient, the solar power that it captured being stored in large batteries, reminiscent of car batteries (which are expensive and take up room) for nighttime use.

Among the tasks related to power consumption, some are odd, such as a dinner party that the team must throw for six guests from the other countries’ teams. The menu is yet to be defined. Trivial functions are also covered by the regulations, such as warming 60 liters of water twice a day. This simulates the hygiene needs of the house’s theoretical inhabitants. “However, what really counts is innovation and sustainability, which stand for points on almost all the tests,” Andrade explains. Another of the Brazilian team’s innovations for the house is using a layer of paraffin in the wooden walls to keep the temperature between 22 and 24 degrees Celsius, one of the competition’s rules. The paraffin, which is to be encapsulated within microspheres and incorporated into the house’s plaster, changes state depending on the temperature. During the day, the sun liquefies it, as a result of which it absorbs heat and keeps the temperature inside the house agreeable. At night, when the temperature is lower, it solidifies, releasing head and warming up the rooms. “We will also use water in the walls, floor and ceiling. Water also absorbs and releases heat, thanks to a process called thermal inertia,” explains Professor Roberto Lamberts, from UFSC, the project’s technical coordinator. Still, despite all this, the house will also boast an air-conditioning system to regulate the temperature, as determined by the competition’s rules.

General control
The house will also have a residential automation system to enable several operations, such as opening and closing the outside slats, controlling via an electronic panel the amount of electricity being drawn in and how much energy has to be used or saved, among other functions. The software for this control system is ready and the group is currently engaged in negotiations with a São Paulo automation firm. The structure of the house also involves an innovation, the use of extended timber, meaning that the beams have a steel cable running through them. This makes it feasible to use less wood, which counts for points when it comes to sustainability.

Readymade solutions are also included in the design of the house, such as dry bathrooms, in which excrement is heated and transformed into powder. This equipment is Swedish and accepted by the European Union. Home appliances such as a TV set, air conditioner, refrigerator, cooker, washing machine and dishwasher will also be purchased in the market. “The lighting will rely on LEDs, which use less power,” says Lamberts. The hammock to relax in is to be purchased from an NGO or a community that produces such materials manually.

Jim Tetro/U.S. Department of EnergyFrom the University of Wisconsin, USAJim Tetro/U.S. Department of Energy

Fundamental support
19 teams from 9 countries in Europe, the Americas and Asia have already registered for the Madrid competition. The country with the largest number of representatives is Spain, with 6 teams, followed by Germany, with 4, France and the US, with 2 each, and Brazil, Mexico, China, Finland and England with one each. In the last two competitions in the US, in 2007 and 2009, the winner was the University of Darmstadt in Germany, which is not competing this year. For the European competition, each team gets a grant of –  100 thousand (roughly equal to R$255 thousand), from the Spanish Ministry of Housing to cover part of their expenses. The total cost of the undertaking is substantial: R$3.5 million to R$4 million.

By December, in addition to the Spanish grant, the Brazilian project found funding in the amount of R$1.5 million from Eletrobras and R$500 from Petrobras. Therefore, half of the funds required for the house to make it all the way to Madrid. “The shortage of cash limits a lot of things and we need to get further aid in a very soon. I compare the Decathlon with a Formula 1 Grand Prix car, rather than with a regular car,”  comments Professor Roberto Lamberts. “We’re still running the risk of not making it to Madrid,”  he says. Just transporting the house by sea and the delivery truck to the Spanish capital, which is in the interior of the country, costs some US$200 thousand, or almost 20% of the entire budget.

One cannot rely on the support of the research foundations or science and technology promotion agencies because this type of event cannot be made to fit any of their programs. Therefore, the group will have to resort to support from companies and from other levels of the federal and state administration. “We have already got help for the trips from Capes, the Coordinating Office for the Training of Personnel with Higher Education, as well as from the Foreign Ministry, which is providing logistical support and putting people up at Casa do Brasil [Brazil House] in Madrid for the preparatory meetings,”  Andrade tells us. In May 2009, nine students and three professors went to Spain to settle the details of the project and to become acquainted with the site of the event. “This support will also be fundamental to export the house and to bring it back later.”  Capes is considering a support project to pay the expenses of the 36 Brazilians (students and professors) that are to attend the competition in Spain.

Vila Solar, the site of the exhibition and competition, will be in a park near the headquarters of the Spanish government. “During the days of the competition, from June 18 to 27 of 2010, a meeting of the prime ministers of the EU is scheduled to take place in Madrid, and they are expected to visit the solar houses,” says Professor Adnei Andrade. “The Spanish government is hoping to exceed the 100 thousand visitor mark achieved at the last Decathlon in Washington, USA.”

Another aspect of the large team that has formed around the Flex Solar House project is the academic mobility of the 11 undergraduate students (7 from UFSC, 2 from UFRGS and 2 from Unicamp). As they have to focus on the project, which is based in São Paulo, these architecture students are taking their courses at USP, attending classes, preparing papers and taking exams, all of which are equivalent to their regular university courses back home. “There are agreements concerning this among the São Paulo universities and we had cooperation from the heads of the federal and state universities,” says Adnei Andrade. “We must train professionals that can design and assemble solar power equipment that is integrated into the architecture.”

The Flex Solar House is not merely a didactic product; it should also help to expand the solar energy culture in Brazil. “It reflects the maturing of a new style of living. But this isn’t just technology, it changes people’s habits,”  says Professor Lamberts. “We imagine that after the Madrid competition this house might travel around the country. It would be great if it could be set up next to the Unicamp Science Museum,”  says Professor Lucila Labaki from the School of Civil Engineering and Architecture and coordinator of the Flex Solar House at Unicamp.

Stefano Paltera/U.S. Department of Energy Solar DecathlonGeneral view of the houses in the competition in downtown Washington last yearStefano Paltera/U.S. Department of Energy Solar Decathlon

Confusion and outlook

The layman normally gets the most common solar energy systems confused. There are solar collectors to warm up water for the shower, which typically consist of a large black panel that the liquid travels through to warm up. And there are the photovoltaic panels, also black or dark blue, which are made of purified silica. This is the technology that is more widely used and on which the hopes of a universal energy source currently lie, when it comes to generating power cleanly, with no waste being left behind. Their chief limitation is the cost of the equipment itself and of installing it. “However, the cost is dropping from 5 to 7 percent a year, as panel production grows,”  says Professor Ricardo Rüther, from the Federal University of Santa Catarina (UFSC). The technology has evolved and the panels now last for more than 20 years. “The worldwide production of photovoltaic panels and cells grew by 82% from 2007 to 2008,”  says Professor Roberto Zilles, from USP’s Electrotechnics and Energy Institute (IEE). In Brazil, these systems are still limited to sectors that are not served by the conventional power grid, such as rural areas, remote telecom stations and water pumping systems. It is estimated that a total of 20 megawatts (MW) is installed in the country, of which only some 170 kilowatts (kW) have interchange with the power distribution grid and run without a battery. Most of this is at universities and power distribution enterprises. One example is the IEE administration building, where half the power consumption is supplied by photovoltaic panels. Germany, the country that is the solar power leader, has 6.5 thousand installed MW, equivalent to almost half of the power produced by the Itaipu Hydroelectric Power Station.

“The connection with the grid is not regulated in Brazil when it comes to small generation units. This should change, thanks to a federal government bill (PL630) currently being evaluated by Congress. If passed, it will benefit microgeneration among small producers of photovoltaic power,”  Zilles informs us. “It should also make it cheaper to provide incentive mechanisms and to oblige the power concessionaires to pay a higher rate than the conventional one for those who inject solar energy into the grid,” says Rüther. This will help to offset the cost of buying and installing the panels and the solar power equipment, which currently cost more than R$10 thousand per installed kW in Brazil (a house needs 3 to 5 kW). In order to disseminate solar generation further, taxes must also drop or be eliminated. These actions should encourage the establishment of equipment production companies, especially of photovoltaic panels, a type of industry that is non existent here. “I believe that in 5 to 10 years tariff parity between solar power and power supplied by the grid will be achieved, because the former is dropping while that latter is rising. So it will become attractive for people to draw money from their savings, buy the equipment and put it on their roof,”   Professor Rüther forecasts.