Natural Fusion at Work in the Solar Decathalon

Part 1 was an intro to the Solar Decathalon, a contest for innovative, high-tech, high-efficiency, solar-powered homes, which is open to the public in DC from October 9–13 and 15–18. In this reposting, guest blogger A. Siegel focuses on one finalist. For in-depth discussion of all the others, go to his website Get Energy Smart! NOW!!!

No, we’re not speaking about Cold Fusion, but Penn State’s entry into the DOE Solar Decathlon, which opens Friday on the Mall in Washington, DC. Let’s take a look at some of Natural Fusion’s features from its website, which is dynamic, enabling rapid connection of concepts and approaches with the home’s physical layout.

Landscaping This a good spot to pick up the dynamic nature of the website and the value of that ‘mapping’ of features. Penn State has a rather vibrant-looking landscaping, well-described and considered. They describe it as follows:

The Natural Fusion landscape integrates the natural environment into the inhabitants’ built environment. The site provides structure but also a natural setting that manages rain-water run-off, supplies food to the residents, and contributes an aesthetically pleasing setting. The landscape allows extension of interior living space to the exterior while maintaining a level of privacy for the inhabitants.

The landscaping has these separate components:

  • Sense garden
  • Green roof
  • Xeriscape meadow (although, let’s be honest, a bit small of a space for a “meadow”)
  • Wildlife Attractant Gardens
  • Bio-Intensive Vegetable Garden

It is an impressive line-up in what might be thought of as very limited space, not even counting the herb garden on the wall in the kitchen, but let’s call attention to two:

  • The Green Roof has an Energy COOL item as it actually is linked to its solar power system, with Green Roof Integrated Photovoltaics (GRIPVs), which I’d never heard of before. (Okay, didn’t feel guilty since a web search of GRIPV green roof integrated showed seven hits, including the Natural Fusion site and two links to the Inhabitat story on the house.) “Roof trays of plants sit below an array of photovoltaic panels consisting of a series of cylindrial tubes. The shape and spacing of the tubes in the panels allow plants to receive the sunlight they need, while functioning cohesively as the solar-power system for the home.” They used a solar panel that allows for 360 degrees of solar collection, allowing the necessary light to support plant life below. The plants aid the PV system in providing evaporative cooling and reflection of light up towards the underside of the panels.
  • Sense Garden: Read the description and decide whether they are transporting you to another place.

Located on the southeastern corner of the home, the sense garden enables the inhabitants to be transported to a different place through enhanced senses. Tall grasses gently rustle in the breeze, while beautiful flowering plants, and fragrant herbs create a tranquil setting just beyond the private bedroom space.

Andropogon gerardii — “Big Bluestem”Asarum canadense — “Wild Ginger”Sorghastrum nutans — “Indian Grass”Asclepias tuberosa — “Butterfly Weed”Aster ericoides — “Heath Aster”Symphyotrichum Oblongifolium — “American Aster”Adiantum pedatum — “Maidenhair Fern”Origanum vulgare — “Oregano”Mentha spicata — “Spearmint”Ocimum basilicum crispum — “Basil”

Sadly, it will be difficult to get the full feeling of calm provided by the planting amid thousands visiting the house, but Natural Fusion’s landscaping seems to be a top notch contender based on web descriptions. (By the way, re web, this is a good example of the difficulties of the site’s design: moving the mouse just a little leads to lost / changed descriptions and, while it might exist, a combined (full) listing of all the landscapting wasn’t apparent to this reader.)

Some Energy COOL Technologies / Approaches

Every one of the Solar Decathlon entrants incorporates some mix Energy COOL technologies and approaches. Let’s take a look at a few of Penn State’s.

  • They having chosen to use water for thermal storage which, among other things, has an interesting life-cycle benefit of not having to be transported to the Mall, but possible to acquire there. Another interesting thermal storage path, phase change materials will also be present in the walls of the home for further thermal energy storage and will aid in reducing energy demands associated with temperature control. The organic PCM responds to a temperature gradient, transforming from a solid to a liquid as it absorbs heat from the surrounding air. This provides a cooling system which, in essences, reverses for heating. Within the context of October DC weather, this will enable cooling in the day and heating in the night passively.
  • The Solar Thermal system is one that I’m familiar with, as the Sunnovation system is on my roof in a beta test (second installation). The great direct advantage of the Sunnovation system is that it is heat pressure based, so there is no requirement for electrical pumps. It is also a drainback system, so there is no freeze (or overheating) risk. And, it doesn’t require copper piping, which can lead to lower installation costs (both in material and labor). Now, to a certain extent, the Natural Fusion team description sells the system short as it has a rather unusual (unique) element that could, if played with, make a bit of a ‘splash’. The “pump” action actually creates an enclosed fountain, which provides a very visible external signal that the system is at work generating hot water. My family jokes that we wished we could have colored fluid, to make more of an artistic statement with our roof-top fountain. It will be interesting to see if Penn State has taken advantage of this ‘decorative’ element.

Now, what will this one-of-a-kind (first of a kind?) Natural Fusion home going to cost you? Well, the budget without a penny for labor (or inspections or …) was $190,460 for a small living space … But, hold it, that isn’t the estimated price for production models. This provides a “build your own” option. Going top-of-the-line, across the board, turned the base-line $41,000, 675 square foot house, into a $166,750 leading edge renewable energy home. Hmmm …


If interested, Natural Fusion is running a live monitoring system. At the time that I looked, 4:09 pm, Tuesday, 6 Oct, it was generating .1 kw …Some other discussions of the 2009 Solar Decathlon: