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.

Although winter is finally over, it is still somewhat cold outside and we have to turn on the heat. Recently I’ve found a very interesting product which can be used by anyone to heat their home or apartment for free. Even if you rent, you can do it without getting the land lord involved. The only things you’ll need are the south-facing windows and a thermal mass solar window.

As you can see from the image above this windows measure 72 degrees F, while outside temperature that day was 22 degrees, with a 27 F high. (Historic weather data).

The 50 degree difference in temperature is the free heat that enter your home and stays. Here is how the Solar Thermal Mass windows work: In a nut shell, it as a 2 inches thick air and water-tight container filled with special liquid that collects and stores solar thermal energy. Special chemicals added tho the liquid prevent stain deposits on the inner walls if the unit. In the picture above, these units are used a building blocks, and cover almost a half of the south-facing wall.

In the winter, when the sun is low, these solar thermal mass windows collect solar heat since the sun hits them directly. In the summer, sun is much higher and with appropriate shading, these thermal mass windows keep home well insulated without collecting any heat. Additionally, a special low emittence and high solar gain, argon filled window unit is installed just outside the thermal windows, so they are not directly exposed to the outside temperature.

How to heat your existing how for free

The picture above was taken in a new construction house, but for most people the interesting question is how to use these thermal mass windows in the existing home or apartment?

My plan was simple: I have 6 large windows that face south and an unheated balcony which cannot be used in the winter because it is too cold there. In the heated living space, we have new double pane Low-E windows installed which are much more efficient than the original single-pane wood windows from the 50’s. I am going to build an enclosure in which I can stack 4-6 thermal mass solar window units, and have them up in the window during the winter months, and take them out in the summer.

This won’t be as efficient as the one in  the new construction home above but it will certainly help reduce my heating bill and carbon footprint.

As for the balcony, I first need to replace all the single-pane glazing and then I can stack the thermal mass windows all along the bottom if the windows. I’ll build special shelves to make the process of putting them up for the winter and removing them in the summer, easy.

Resources:

Find more green construction ideas at Green Home Ideas blog.

More green blogs at Home Blog Directory

Why we believe that Metal Roof with Solar is the most practical, and sustainable option for residential Solar PV installations?

In the next two weeks we will have a complete guide to designing a beautiful, long-lasting Metal Roofs with integrated Solar PV technology. Watch this video and read on:

The main problem associated with general Solar PV systems that you can now see on many homes around the country, is the fact that an asphalt shingles roof will fail much sooner than the Solar panels, and when that happens, those home owners will be faced not only with re-roofing expense, but also with complete removal of solar array and re-installation. This MUST be performed by both the roofer and the solar integrator, as the roofer alone will 99% of the time screw things up. And bear in mind that roofing warranty will usually not cover demages to the solar equipment, let alone all the possible short-circuit type situations.

The additional cost associated with these procedures should be at-least the same as the cost of the new roof itself. Think about it: Electricians unlike roofers have to be licensed. Apprentice electrician needs at-least 4 years of schooling/work experience. This is like an undergraduate degree. Master electrician needs another 4 years. Therefore, electricians usually charge $75-100 per man-hour. You’ll need at least two electricians for this job, which will take a whole day to remove the panels and another day to put them back, if not more.

The math is simple: 2 guys * $75/h * 8 hrs. * 2 days = $2400 plus any possible parts and supplies that may be required. So let’s say it costs you $2500 extra. In some parts of the country that is how much an average 1200 sq. ft. cape house roof will cost today with the material.

Metal Roofs vs. Asphalt shingles

Unlike very “popular” asphalt shingles, metal roofs are pretty much permanent. They are for the most part, produced from recycled metals, and when installed by a trained professional, should not leak for decades. Read more about residential and commercial metal roofing .

Metal roofs combined with Renewable Energy technologies can create a perfect combination of light, long-lasting and affordable solution for Solar Electric and Solar Hot Water, as demonstrated in the image to the below:

There are other numerous benefits to having metal roof combined with Solar PV and other renewable energy technologies. When looking at metal roof vs. asphalt shingles, also consider that metal roof will save our land fills from getting more shingles dumped there in 10 years or so. Combined with beautiful looks, you get a permanent roofing solution, various solar technologies, and when paired up with geo-thermal system, you can easily design a 100% energy-free home, with a great curb-appeal.

Check back in a couple of weeks for a complete Solar Metal Roofing Guide.

I know it’s May 1st, and you are thinking about beach, sun-tan and barbecues, but now is the prefect time to start thinking about the next winter season, which is not that far away, and by the time it come, it is in your best interest to be ready. Especially if your home is not yet fuel efficient.

Why $5 heating oil? Well, look at the diesel price today. Here in Massachusetts (which has some of the lowest fuels prices across the United States, and is second only to NJ, which has no gas-tax and thus has nation’s lowest gas price) the price of diesel in most places is above $4.45 per gallon and given that gas jumped 35 cents in last two weeks it is safe to assume the $4-plus gas and above $5 diesel/heating oil by the fall / winter time.
Thank you Mr. Bush. Oh, and it is such a pity that Exxon-Mobil missed their earning expectation and made only $10.89 BILLION in net profits, instead of $11.65 billion projected by analysts.

Any way, enough sarcasm, we need to make our home use less energy. First thing you can and should do, is replace those old, drafty windows.

Despite the fact that this is Green & Solar site, I’m going to recommend Vinyl windows. That is right, not the wood-green-built but vinyl. Why? It is simple. Remember the Practical Approach thing? The the carbon-footprint of vinyl windows is less than that of wooden windows if you include the heat loss accumulating over time, and the vinyl window are cheaper and more fuel efficient – therefore they are Practical!

Here I’ll discuss a specific type of vinyl windows – Alside UltraMaxx line, that comes with triple glazing, double low-e and two argon packets. Combined together, UltraMaxx gives you 6.67-r value. Bear in mind that standard and well-built double-glaze, low-e argon window has an R-value of less than 4.

Why Alside UltraMaxx? Well, this is not a commercial paid for by Alside. I just love those windows, and had personally installed many of them. They are very-well built, and have the most durable and sturdy frame of all othee Alside lines.

You may ask why not Anderson or Harvey or Pella windows? Well, non of those actually make a tripple glaze windows, so my choice is Alside.