While I’d heard of the US Solar Decathlon, I confess I didn’t know a lot about it other than teams had to design and build small houses that ran on 100% renewable electricity. Then I met Dayna Malich, a team member of Team Ontario, one of two Canadian teams which entered and have been accepted to compete in the 2013 Solar Decathlon. (Team Alberta is the other Canadian team). This event was first held in Washington, DC, in 2002 and has since been held in 2005, 2007, 2009, and 2011. This is the first time is it being held in Irvine, California. Teams from all over the world can put submit a proposal. The top 20 designs selected by the United States’ Department of the Environment are selected to build their homes in Irvine.
The decathlon contest rules require that the homes must be between 600-1000 ft2, affordable and appealing to the consumer, run entirely on solar electricity (have a net zero energy balance or better), and compete in ten different categories, some of which are juried, others are measured. The team with the most points at the end of the competition is the winner. There is a height restriction so that competitors won’t shade their opponents’ solar panels at any time during the day. From the Solar Decathlon website:
Each contest is worth a maximum of 100 points, for a competition total of 1,000 points.
Teams can earn points three ways:
- Task completion
Teams complete household tasks such as cooking, washing dishes, and doing laundry.
- Monitored performance
Team houses perform to specified criteria, such as maintaining a comfortable (71°–76°F) indoor temperature range.
- Jury evaluation
Jurors who are experts in their field (such as architecture, engineering, and communications) award points for features that cannot be measured (such as aesthetics and design inspiration).
Contests based on task completion or monitored performance are called measured contests; contests based on jury evaluation are call juried contests.
Learn more about the 10 Solar Decathlon 2013 contests:
- Architecture Contest (juried)
- Market Appeal Contest (juried)
- Engineering Contest (juried)
- Communications Contest (juried)
- Affordability Contest (juried)
- Comfort Zone Contest (measured)
- Hot Water Contest (measured)
- Appliances Contest (measured)
- Home Entertainment Contest (measured and juried)
- Energy Balance Contest (measured).[source]
I spoke with Karl Kadwell, the project manager of Team Ontario, about their project, the Decathlon itself and what they hope to achieve with their entry.
Students from Queen’s and Carleton universities first got involved with the solar decathlon in 2009 when they entered the competition for 2011. Although they were short-listed for the 25 they were not selected for the final twenty teams so they regrouped. They took the next two years to build the team while improving their modelling and technical skills, and then partnered with Algonquin College for 2013 competition. They went to the 2011 competition to see what had worked for the 2011 contestants and stayed in contact with several of the competing teams during before the 2011 competition. Algonquin was brought in because of their advanced housing program at their Perth campus, and the house will initially be constructed in Perth. They have great technical programs and have been doing the bulk of the drafting and CAD work.
According to contest rules, the houses are supposed to be designed and judged for each respective geographic location. But they also need to perform well in California. A lot has to be taken into account when designing the structure. Not only does the house have to have a low energy load that can be generated entirely by its own solar panels, it has to look good (market appeal) and be affordable (defined as costing US$250,000).
Size and Design: Homes are restricted to being between 600-1000 ft2 — a starter home for a young and small family of a couple and one child. The homes must be places that people want to live in and can afford to buy. That means they must be aesthetically pleasing — which is always a big deal to me, because if it isn’t attractive and functional, and no one wants to live in it, then it’s not a very good design.
Passive house features have also been included in this house. Maximizing southern exposure in winter, and minimizing it in summer is a key design feature of the house. The design team has incorporated a special exo-structure that will help shade the windows in summer, but allow light in in winter. Thermal mass will be incorporated into flooring and counter tops.
The HVAC system will also be an advanced system. So far it is based on a system of heat exchangers and involves two water tanks, one cold and one hot. The hot water tank will provide heating and hot water. The cold water tank will provide a sink for excess heat in the system. It’s a fairly complex system and it will only be with time and testing that the final model will emerge. In all homes with exceptionally tight building envelopes a heat or energy recovery ventilator is used to extract stale air from the home in bring in fresh outside air, preheated or cooled by the exchanger before it is sent into the house. The general debate or rule of thumb is that in warm climates an energy recovery ventilator is best and in cool climates a heat recovery ventilator is best. Karl said that this was in fact an issue that they’d been wrestling with and in the end have found and are testing a unit that can be either an ERV or HRV. If it works to their satisfaction, the unit will be an ERV in California and an HRV in eastern Ontario.
Energy Balance: throughout the contest, the homes will be judged on how energy is used. All homes must operate as they would if they were in use by a normal family. This is the reason behind the hosting of a dinner party — where all food must be prepared and stored in-house — a movie night, to see how the home adjusts to different occupancy and energy loads. Laundry must be done in the house as well, as the home needs to be used as it would in a regular setting. The designers, therefore have to think about energy loads all the way along — how much energy can the solar panels generate? Is there a storage system (battery system) to store excess energy to draw from later, etc. They are striving for a net positive energy balance — where more energy is produced by the home than consumed.
Materials choice: Karl told me that in the past and in current models, all teams do their best to take into consideration the impact of materials used. They look at materials’ embodied energy, where it’s sourced from, its impact on the earth, how recycleable it is at end of life and durability of the material itself. This information has to be incorporated into the overall affordability of the home itself. Many green materials can have an overall price premium on them, so there is a fine balancing act that teams need to play.
One of the interesting materials that they’re looking at using is Panasonic’s vacuum insulated panels (VIPs) for the building envelope. VIPs have an R value of 60/inch. If Team Ontario’s system is successful, imagine what it could mean for urban infills where space is at a premium? The panels themselves are 1/2″ thick with an associated R value of 30. As Karl explained to me, the entire house will not have an R value of 60 because there will be thermal bridging, and of course there are doors and windows. To prevent a certain amount of thermal bridging, they will stagger two layers of panels so that seams are interspersed. The house itself will also have a traditional stick wood frame, a flat roof with more VIPs used and some additional insulation.
Water balance: teams need to account for how much water their homes use during the contest. They will do a water budget at the beginning of the project and incorporate a water storage tank onsite. Each home’s water tank will be filled once during the contest, according to its predicted budget. It’s up to the team to manage the water use throughout the contest. Karl said that low flow fixtures and rainwater harvesting are being incorporated into the design. Waste water will be measured at the end of the contest to see how much water was used during the contest.
One of the key design points that needed to be considered from the beginning of the project is transportation of the home. This house has to travel from Perth, Ontario (where it will be built initially), to Irvine, CA and reconstructed. While the team looked at both train and truck, in the end they decided on a truck shipping system because of the ability to design a slightly larger home. If train transportation was used, all components need to be designed to fit into the train shipping containers.
Budget: While the US DOE gives each team $100,000 over two years upon meeting certain benchmarks, the entire project is projected to cost around $900,000. In addition to engineering, architecture and building departments, students from the commerce faculty are also actively involved in this project helping to raise money and develop and implement marketing plans.
There are several benefits to running this contest:
The students and faculty of the involved schools are pushed to come up with creative new ways to look at housing design. These are designs that can be used by the next generation of architects, engineers and related field technicians.
The students working on the projects get to apply their knowledge and creativity within a real work environment, possible years ahead of where they would be doing similar work in their post-university career.
The public, who are lucky enough to be able to view these homes, learn about building materials and techniques that are feasible with today’s technology but are also affordable.
The event gets wide media coverage from media outlets worldwide and aims to shift general thinking about better and more energy efficient housing.
The US government sees value in the contest because it trains the leaders of tomorrow and helps evolve the housing industry.
It also gets a first hand look at some of the latest thinking and modelling in energy efficient housing.
To see Team Ontario’s progress, visit www.ontariosd.ca.
The house will be open for viewing in Perth, ON sometime in mid 2013, before it gets deconstructed and shipped to Irvine, CA for the contest. After the competition, it will be reconstructed back here, although where (Kingston, Ottawa or Perth, ON), is not yet known.
The Solar Decathlon will take place Oct. 3–13, 2013, at Orange County Great Park in Irvine, California. The competition houses will be open to visitors on eight days over two weekends. Public hours will be from 11 a.m. to 7 p.m. daily:
- Thursday, Oct. 3–Sunday, Oct. 6, 2013
- Thursday, Oct. 10–Sunday, Oct. 13, 2013.
Good luck Team Ontario!