Green Solar Cafe – renewable energy and green construction

It was a great Columbus day weekend in Washington DC and solar decathlon was making waves of news… We, actually it did not. Not even bigger green sites and blogs cover this truly green event. Probably there are much more important things happening in our capital – like Obama’s newly “adopted” dogs .

So I’ll let the big guys do their things, while I tell you about the event which so many people waited 2+ years for, and worked so hard to make it happen – ladies and gentlemen – Solar Decathlon 2009!

This was our first Solar Decathlon, but certainly not the last. Since we were sponsors of Team Boston Solar Home, most of my coverage will be focused on it. However, there are many great solar homes this year and judging from the results so far, our creation is not looking to win this year – Team California and Team Germany are now battling for the first place (you can see Team Germany solar home in the picture above – a black house, second from the right).

As I wondered through the Mall, looking at these homes and being hesitant to stand in line to see very similar interior set-ups, my main focus was on the outside. Solar technologies, energy efficiency and exterior design were my main concern, as these are what make a true solar home, while the inside can always be remodeled.

Team Boston Solar Home:

As a future architecture student, and a “construction worker” now, I look at these houses with a lightly different perspective than most people. For me, the ease of construction, most energy efficiency and reasonable cost are the most important things, followed by a nice design. Unfortunately, many of the innovative approach used for this competition, are not usable in a mass market and are left to the most extravagant home buyers with deep pockets. While I have no problem with it in general, the purpose of a Solar Decathlon in my opinion is to move innovative green building technologies into mass housing market, so that such technologies would actually make a major difference in improving the environment and reducing CO2 emissions.

It is expected of all these homes to be super insulated and have solar PV panels on their roof. I was interested in innovative new approaches at achieving maximum effect (energy efficiency or energy generation) using the least expensive methods. In this regard, the Boston Solar home has (had) great potential, if not for the massive glass array on the norther side of the house. All these windows and doors will let all the heat escape in the winter, which makes it that much less efficient. This is a fixable situation however – just remove most windows and put a wall there

Despite potential heat loss, the liquid-filled glass units on the southern side of the house will collect tremendous amounts of solar heat and store it, making it much easier to heat this house. Find out more about these liquid-filled solar thermal windows and wall panels.

In addition to solar thermal wall panels, Boston solar home has about 6.4 KW solar pv system on the roof and a solar thermal hot water, for heating and domestic use. There are many other new and innovative design features used by BAC (Boston Architecture College) and Tufts University students in construction of this home – to many to list here. You may check out the project’s website – www.livecurio.us.

Team Spain solar home:

Other solar homes that attracted my interest where the one build by Team Spain (which for some reason is doing VERY poorly in this competition).

Apparently, these bi-pv cells are very good at capturing indirect sunlight and help the house generate the most electricity it possibly can.

Team Spain used a very interesting )in my opinion) approach at capturing ALL available solar energy with their powerful solar PV array. This roof mounted array ca rotate at the center, following the sun going across the sky, thus always keeping the most efficient angle of the PV panel to the sun. It is basically a gigantic solar tracking systems, which is however complicated and expensive systems to implement, which make this house not as competitive int terms f costs and ease of building.

Additionally, the glass walls of this home have integrated solar PV cells, which captures even more solar energy. It is a good idea, but and overkill in my opinion, and the roof mounted solar system should be more than sufficient and, unless they used “dummy” cells on east, west and north sides of the house,  it is a wase of solar capacity as sun will barely or never hit those solar cells.

Cornell University Solar Home:

Another interesting design, which for some reason reminds me of the Water World movie – a solar home built by Cornell University students. It features three round “rooms” connected to each other and a large solar PV system, which for some reason is mounted flat to the ground.

It may not be the best designed house (in terms of competition rankings), and round rooms make it ever more difficult to build, but the steel frame and a VERY cool vintage design make it very attractive. As I’m writing this, Cornell’s solar home is in 6th overall place, with few more contests to go. You can view current team rankings here: http://www.solardecathlon.org/scoring/

As a side note, as of Oct. 13th, Team Boston solar home is in 12th position and Team Spain is in 18th place, while 1st place belongs to Team California.

Let the best solar house win!

The Solar Decathlon will continue for another week or so, and there is a lot of contests left in which either team can pull forward dramatically. Therefore I will not even try to predict the winner. All houses presented in the Solar Village this year and very well designed and built, and the green building technologies used in them will in (hopefully) near future migrate into traditional construction markets and help home and building owners reduce the over all energy use and make our environment better. These competition is also an inspiration for the new wave of architects who will be literally building our future homes and infrastructure, and as you can see, they all have great ideas. I will continue the coverage of solar decathlon 2009 in future posts, and soon you will be able to review the IB flat roof installation which we did on the Curio Home – look forward to see it soon on our cool roofing blog.