Biosphere near Tucson, AZ Sept. 9

Today we had the pleasure of visiting a building called the biosphere 2. It was designed to mimic the place we all live in-"biosphere 1" or Earth. It is the largest closed system ever created, like a greenhouse but it has the capacity to completely seal itself from the outside environment, a somewhat incredible feat considering the enclosed area is 3.14 acres and has 6,500 windows. It has changed ownership several times and hence the tour was a little confusing but I'll try to present it here as clearly as I can. The picture below shows just a part of the outside.

Here is the entrance to the facility. The reason it looks like a spaceship door is because it is supposed to. Space Biospheres Ventures originally built the structure to research the viability of a self sustaining space colony (hence the futuristic look). They ran two missions in which scientists were sealed inside for a period of 6 months to 2 years.

The biosphere is divided into several ecosystems, the first one you see as you walk in is the ocean/mangrove forest. All the windows and joints you see had to be engineered to minimize air leakage.

Here you can see the same room but looking down. The ocean is made complete with a wave machine, a coral reef and a beach. It can sustain itself almost entirely, with only the need to add chemicals to balance the pH.

Here is another view of the ocean from below.

The next ecosystem they have is the rain forest. There was not too much to see here as the forest was very dense and you were not allowed to walk off the short path. In my opinion the national botanical garden has a better one, at least for tourists anyway.

They also have a dessert.

Another view of the dessert. The plant in the upper left corner is greener than the rest because there is a small leak in the roof that gives it extra water.

The scientists who lived in Biosphere 2 actually had a pretty nice place to live. Here is a picture of their kitchen. They lived completely off what was grown inside the biosphere, although this has been disputed. They each took turns preparing meals completely from scratch.

To account for the expansion of the air due to heat, the facility has two large diaphrams that equalize the pressure with the outside but prevent any air from leaving. They call them lungs. Here you can see we are going down in the the lung on the south side. They can only be accessed through a long corridor that goes down into the ground.

Below are several pictures of the massive diaphram.

Here is what the outside of the lung looks like.

The Biosphere 2 is now owned by the nearby The University of Arizona and houses some research projects. Here is one in the dessert ecosystem that is researching the effect of plant-microbial associations on weathering of basalt, granite, schist and rhyolite. The picture just shows some of the rocks that it is testing. The actual experiment can barely be seen at the top of the photo. Unfortunately I did not get a photo of it.

Their flagship project however is a series of experiments that will take place at the newly built Landscape Evolution Observatory (LEO). Its goal is to determine where water goes after a rainfall period in different terrains. We know some goes into plants, some runs off and some evaporates but we don't know exactly how much or how long it takes outside of small laboratory experiments. They have 3 large slopes with soil on them (one shown below) with all kinds of sensors to read things such as such soil moisture, water content, ect. They have set up so many tranducers that the engineer I talked with said he doesn't even know how many sensors they have set up. Also, JMU engineers will love this-all the sensors are all hooked to Labview!

Here is another view of one of the massive slopes. They have load cells on all the supports so that they can measure the weight on each beam before and after "rainfall". It will help them see major changes in water movement. I also got to speak with a hydrologist on the project, the first experiment that they did is pretty neat: they let heavy water (identical to normal water in every way accept with an extra neutron in the nucleus so it is heaver) flow into the top of the slope and are timing how long it takes for it to flow through the system with no plants. This gives them a baseline. Then they allow regular "non-heavy" water through the system and they can tell the difference. Since heavy water is chemically the same as regular water, it does not effect the experimental results while still enabling them to trace it.

For all the engineers out there, here is a blurry picture of all the sensors they are using. I couldn't get a better one without using a flash and having it reflect on the glass.

They also had a lot of solar panels out everywhere for their sustainable model city. It houses undergraduate and graduate students while they do research at the biosphere. It is also available for rent by the average joe.

Below is a picture of a cool sign I saw that explains the differences between different types of solar technology. I thought it would be fun to do a little calculating to see the difference between the most efficient and least efficient panels listed on the sign (because who wouldn't call that "fun"?? haha). I highlighted the important conclusion so you don't have to read it if you don't want to.

Given that an average house uses 11,280 kWh in a year, the average home uses 1.29 kW on average (11,280/8760). 

This means at $3/watt you would pay $3,863 for a system consisting of the Copper Indium Gallium Selenide.

Since the sun puts down 1.366 kW/m² on average and the cells are 5.8% efficient, the cells are only receiving 0.079228 kW/m² and thus you would need an area of 16.25 m² or an area 53 ft X 53 ft to deploy these solar panels. This about the size of half a football field.

Following the same math, you would need to pay $6,438 and have 6.04 m² or 19.8 ft X 19.8 ft for the monocrystalline silicon.
So, you could save about $2,575 if you happen to have half a football field worth of space you are willing to put your solar panels to power the average house.
Another question you may have is how long must you keep the panels before the cost of them becomes worth not paying an electric bill. This will vary by location (electricity cost) of course but I'll pick Harrisonburg, VA as my datum. Since the average home uses 11,280 kWh in a year and the average price for electricity in Harrisonburg is $0.078175/kWh (ignoring a few complexities), you will pay $882 in a year for electricity without solar. So the Copper Indium Gallium Selenide will pay itself off in about 4 yrs 4 months and the more expensive monocrystalline silicon will pay itself off in about 7 years 3 months.