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Solar Decathlon 2015 Team Nexushaus Part 5: Success at the Competition

Posted 22 October 2015 12:00 AM by Molly K. McNamara, Communications, UT-TUM Solar Decathlon Team

Deconstruction is underway in Irvine. After two intense years of dedication and hard work for the Department of Energy (DOE) Solar Decathlon we can’t believe it’s over. The UT-TUM NexusHaus team came in fourth overall out of the fourteen competitors that made it to California. We also placed first for Energy Balance, second for Affordability, and third for Engineering. Twenty teams were initially selected by the DOE in 2014, but the rigorous requirements and incredible coordination proved to be too much for some schools.

Solar Decathlon 2015 Team NexusHaus Part 5: Success 600

  • Overall: 4th place
  • Energy Balance: 1st place
  • Commuting: 1st place
  • Affordability: 2nd place
  • Engineering: 3rd place
  • Market Appeal: 5th place
  • Home Life: 5th place
  • Communications: 5th place

The competition really began when students from the University of Texas at Austin and the Technische Universität München arrived at the Orange County Great Park at 7 am on Monday, September 28th, 2015. Our first task was to plot the points for the modules, which would inform how the whole site laid out. Having the placement of the corners allowed us to define the grid for our deck, because the design relied on only a few key dimensions. After marking the references, we were ready for the trucks to deliver.

Everything was going smoothly, the modules were set, and we were ready to begin drilling the foundations for the house when we hit our first road bump. Late Monday afternoon, the DOE inspectors requested to see our engineering drawings for the cribbing, or temporary foundations, for the modules. Unfortunately we had not anticipated this requirement. Our neighbor to the south, Sacramento State University, lent us authorized cribbing, which was deemed more stable than the 8X8 blocks we had brought from Austin. We made more units of the approved box crib from 2X4s and eventually were able to lower the modules into place and drill the foundation piers. The generosity and willingness of the other teams to help each other was one of the best parts of the construction process. A sense of camaraderie and community amongst competitors brought out the best in everyone, which was true throughout the Solar Decathlon.

2015 Solar Decathlon NexusHaus Construction

The following days were a whirlwind of activity on-site. The Solar Decathlon village was open for construction from 7am to 2am every day, and most nights were just as productive as the daytime. With the modules in place, we were able to drill the foundations for the deck columns and to erect the steel columns and beams. The entire canopy assembly had not been assembled previously in Austin, so there was a steep learning curve for most of our student assembly crew. Luckily, we had the invaluable expertise of Jerry Fryer, owner of APS Modular, and some students with construction experience. Our neighbor to the north, Clemson University, generously lent us a Genie lift to raise the beams in place. Without this apparatus, Team NexusHaus would have rented comparable equipment adding both cost and time to the whole process. 

Lifting the beams into place was one challenge, but drilling the bolt holes proved equally time-consuming. We ended up going to a local metal fabricator with our steel structure in tow, because the tools we had on-site would have resulted in countless broken drill bits. With the steel structure in place, we raised the 'nexus' canopy in between the day and night modules. Simultaneously, the ramp and deck teams worked furiously to assemble our sizable outdoor space. For the interiors, the cabinet doors and bathroom sink proved the most time-consuming. We had to reconcile the original custom design of the storage system with the appliances and IKEA panels at our disposal. In the final three days, our aquaponics team arrived on-site. Though we did not intend to hookup the system entirely, we set up demonstration beds and the solar water pump to simulate food production. Some of the last tasks to get completed included the installation of our SolarWorld photovoltaic system, putting up the fabric canopy units, and staging the house for exhibition. 

2015 Solar Decathlon NexusHaus borrowed Genie lift

Once we were connected to the grid, our PV array proved to be one of the most effective systems in the whole village. Having individual microinverters allowed us to maximize gains, and considering the relatively small size of our array, we were ecstatic with the energy production. We tied for first place in the Energy Balance competition with our net energy production for the week of 82.86 kWh. The SolarWorld sponsorship helped NexusHaus place in the top five at the competition, and we could not be more grateful. 

Solar Decathlon 2015 Team Nexushaus Part 5: Team Celebration

While we were elated with our energy production and low consumption, Team Texas-Germany suffered from some unforeseen electrical issues, which left us without air-conditioning in one module and various lighting problems. With more testing and foresight, we would have addressed these challenges ahead of the competition. Aside from being unable to properly regulate the temperature and humidity, the exhibition days went extremely well. The architecture and mechanical systems were well-received by the public and jurors. Our team is incredibly proud of the overall accomplishments of NexusHaus and look forward to seeing where the Solar Decathlon experience takes us in the future!