TCU grads turn to native grasses for business
Green roofs have worked well in Europe for decades and in the northeast United States since the 1990s, but the complex systems of balancing nature, architecture and smart energy usage have been absent in Texas due to the stateÂ’s dreadful amount of heat and dearth of water. So when it came to designing a green roof system that could withstand the stateÂ’s worst, two Texas Christian University graduates went west and looked down.
A green roof is really a catch-all term to describe using soil and plants as an insulation device, of sorts, for buildings. By planting on a buildingÂ’s top, the amount of heat that strikes the building is absorbed and its impact lessened, thereby reducing the overall indoor temperature and the necessary air conditioning to cool the building.
“If you imagine doing that over large swaths of roofscape within Fort Worth or Phoenix, Ariz., you start to make real impacts on building energy usage,” said David Williams, one-half of Prairie Designs LLC.
The catch is, however, that the plants used in green roof systems in other parts of the U.S. benefit from cooler temperatures and a fair amount of moisture. Applying those plants to Texas doesnÂ’t work, so Williams and Jon Kinder decided to figure out what plants would, and how.
The answer out west
Williams never expected to be part of worldwide push
toward an increasingly renewable-centric way of life, in which companies, cities and individuals aim to reduce their environmental impact and maybe reduce their energy bill in the process. After graduating from Carleton College in Minnesota with a degree in physics, he could have pursued a job in business consulting but he knew heÂ’d rather be outside.
He settled on a master’s program in TCU’s Department of Environmental Science, where the concept of green roofs – learned during a class taught by Tony Burgess – sparked an interest. It was here that he met Kinder, who had a similar interest in the concept.
“It sort of struck me as a way to turn waste into a resource,” Williams said. “Now that I’ve been around it for a while, it’s a pretty solid business mentality: Look for waste within your organization and turn it into a resource. Well, we waste all this space on rooftops in our cities when that space can actually be serving a function.”
Williams and Kinder got together to compose a team thesis, with Williams focusing on soil while Kinder studied plants. Together they went to the prairies west of Fort Worth at BurgessÂ’ recommendation and looked at nature to find a system that could work on top of a Texas building.
They found an area known as the barrens – “areas of very thin soils over limestone where you have short-grass prairie communities that live there, and they have their own set of plants that only live in the barrens,” Williams said. They studied the barrens and applied the data gathered to a year-long study. They came out with a much better understanding of how to move forward with native plants and which work best.
There is another system located next to the barrens, where a thick layer of limestone exists with plants on top whose roots find their ways through cracks to locate water below in the marl, or clay. This is known as the glades.
Whereas the barrens plants do well initially, they eventually will succumb to stress and dissipate. The glades, however, do better over the long haul. How could Williams and Kinder achieve the strength of the barrens with the long-term nature of the glades while avoiding using heavy limestone on a roof?
“It became apparent to us almost any species from the barrens do well on the glades if they can find a crack to grow in,” Williams said. “We thought about how we could structure green roofs to work like the glades do, and basically have a thick mulch on top that would help hold water in the soil, because that’s the problem is all the soils get baked really dry.”
They designed a two-inch thick, lightweight tile system that mimics stepping stones. The tiles are hexagonal, fit together and allow plants to grow in the spaces between the tiles, which restricts plant growth and allows them to have water for longer – sort of like drinking in moderation.
“You’re cutting off the peaks and troughs,” Williams said, adding that the design supports the same volume of plants as a traditional green roof model, but in certain locations.
They perfected their tile design with the help of Cam Schoepp and Chris Powell, two sculptors and professors of art at TCU who taught them how to shape the tiles properly, efficiently and in a manner reminiscent of actual limestone.
It works so well that Williams and Kinder are in the process of securing a patent, and the Botanical Research Institute of Texas will use the system on its forthcoming headquarters.
Graduates and business partners
Williams and Kinder finished their masterÂ’s degrees in environmental science in December 2008 and May 2009, respectively, and have been working to launch the business that resulted from their studies: Prairie Designs, a Fort Worth-based operation that soon could set up shop in TECH Fort Worth, a business incubator that has helped launch other local renewable energy solutions companies. They hope to secure funding, and will approach NextEra Energy Resources about becoming an investor. NextEra EnergyÂ’s parent company, FPL Energy LLC, currently is conducting a five-year research initiative with TCU and Oxford University to study wind power.
At the Crowne Plaza Invitational at Colonial in May, the duo debuted a yet-to-be-named prototype structure with potential; it could use a range of energy sources to act as an off-the-grid modular building that can act as housing for the military, people displaced by environmental disasters, or those living in remote areas.
The roof includes the green roof design, while panels on the side could be fitted to house-flexible, sun-tracking solar panels. A wind turbine, if small enough, could be included in addition to a propane tank and rainwater-collection system, making the structure entirely self-sustaining.
Mike Slattery, chair of the TCU Department of Environmental Science, said the Williams-Kinder structure isnÂ’t the future, but rather is an eye-catching, artistic, functional structure that could be the basis for something with which to tackle environmental issues people the world over must face.
“We can’t sit back and wait for some massive genius to fall on our heads and make us environmental sustainable – it ain’t going to happen,” said Slattery, also director of the Institute for Environmental Studies. “We’re going to have to design our way forward, that’s what the structure says.”
The structure might have cost $180,000, but ended up with a price tag of $25,000, thanks to help from Anderson Anderson Architecture in California, Advantage Steel of Fort Worth and plenty of TCU connections.
If funding is secured, Williams and Kinder could turn the prototype into a something more – a touring green energy-education tool.
“If we get funding on it, it’s not a very expensive thing to make this functional and something that I think people at events will get a lot out of,” he said. “For [sponsors] it becomes a great marketing tool, for us it becomes a great project and perhaps even a product that we can sell later: basically, these modular buildings that can be shipped anywhere and can provide power, water and all the basic necessities for somebody who has to live in a remote location or in a location that has been damaged.”
