Great news from the recently completed Solar Decathlon in Washington, D.C.: Energy efficiency in homes isn’t just about solar photovoltaic (PV) and solar thermal technologies. In-home energy management and energy efficiency is important to monitor, regulate and control energy use within a home.
The competition, which pitted 19 college teams in a competition to build the most energy-efficient homes, showcased energy-saving technologies that many our homes should boast in the very near future.
In addition to solar technologies that provide electricity and heat for hot water, many of the teams also employed energy management and control systems, sensors and other devices to help shed wasteful electrical loads.
Teams needed to show how efficient their homes could be with regular use, providing all the power needed for cooking, appliances and entertainment.
The overall winner was a home constructed by the University of Maryland, which focused on water conservation—much-needed in many areas. The modular constructed WaterShed home helps filter and recycle graywater from the shower, clothes washer and dishwasher. In addition, a liquid desiccant waterfall serves as both a design feature and provides humidity control in the house.
Other innovations showcased by the teams include:
- Solar thermal systems used for hot water, heating and cooling.
- A Trombe wall that releases stored energy at night for heating.
- Retractable glazing systems on windows to provide relief from heat and humidity.
- Solar canopies and green roofs.
- A solar thermal-powered drying cupboard for clothes.
- LED lighting.
- Heat recovery ventilators for fresh air.
- A self-watering biowall that filters air.
- iPad apps showing real-time energy use.
- Automated window shading.
- A transformable porch with motorized windows.
- Light switches powered by remote transmitters.
A microgrid by Schneider Electric connected the solar homes to the Washington-area utility, Pepco, allowing the village to feed excess solar energy back to the regional electric grid and essentially becoming a power plant. By connecting the homes to the grid, competing teams could power their homes despite changing weather conditions and varying levels of energy demand, such as higher daytime load requirements.
Energy management products provided by Schneider Electric were incorporated into more than half of the homes in the competition. In addition, an Eragy home monitoring system was used in the New Jersey home and Lutron lighting control was used in the New York entry.
Video tours of the homes are also available here.
Maryland WaterShed Home
- Modularly constructed wetland helps filter and recycle graywater from the shower, clothes washer, and dishwasher.
- Green roof slows rainwater runoff to the landscape while improving the house’s energy efficiency.
- A liquid desiccant waterfall serves as a design feature and provides humidity control.
- Excess energy generated by the solar thermal array is harnessed.
- A home automation system monitors and adjusts temperature, humidity, lighting, and other parameters.
- A self-watering biowall helps filter and purify the air.
- An air-to-air heat pump serves as the primary heating and cooling source.
- A heat pump hot water heater uses the ambient air inside the house to produce hot water.
New Zealand First Light
- A triple-glazed skylight illuminates the central section of the house.
- An interactive Tring energy monitoring system shows where energy is being used and displays peak energy use, peak energy production, water use, and weather data.
- A drying cupboard dries clothes quickly by pumping solar-heated hot water through a heat exchanger. Recycled sheep’s wool is used as insulation.
Appalachian State Solar Homestead
- Forty-two bifacial photovoltaic panels supply solar energy while providing filtered daylight and protection from the elements.
- An on-demand solar thermal domestic hot water system uses phase-change materials to provide constant water temperature in compact storage.
- A Trombe filled with phase-change material stores heat throughout the day and releases it at night.
Middlebury College Self-Reliance
- A solar array of 30 panels that can produce 7,930 kWh annually.
- An air-to-air heat exchanger circulates air through a network of aluminum ducts and feeds a green wall with condensed moisture.
- Triple-paned windows with cork-insulated frames have an R-value of 7 and a solar heat gain coefficient of 0.53, which allows them to provide net heat gain over the course of a year.
- Stack effect ventilation pulls in cooler air toward the ground and vents out warmer air from the skylights.
Parsons New School of Design and Stevens Institute of Technology Empowerhouse
- Linear fluorescent and LED lights with wireless switches and occupancy/daylight sensors.
- A highly efficient energy recovery ventilation system that keeps the interior temperature stable.
- A green roof integrated into the electric photovoltaic system modulates the temperature extremes on the roof.
Ohio State enCORE
- A unique solar thermal hot air system and heat pump water heater.
- State-of-the-art triple-glazed windows and natural lighting.
- An 8-kW photovoltaic array of thin-film panels manufactured in Toledo, Ohio.
- A simple control interface operates lighting, mechanical, electrical, and plumbing systems with an intuitive and informative touchscreen display.
SCI Arch & CalTech CHIP house
- Shaped to allow a car port and features an exterior skin made of low-cost billboard material and a vinyl-coated fabric mesh that protects the house and contains the “outsulation.”
- A custom iPad application displays real-time energy use, controls the shades, and provides instant feedback.
- A 3D cameras tracks movement in the house and adjusts the lights accordingly.
- A whole-house fan performs a complete air change in less than 20 minutes.
- Photovoltaic solar panels act as a shading canopy.
- A centrally located air-source heat pump with a forced air distribution system to heat and cool the two zones of the living space.
- Conditioning system fans exchange interior and exterior air while energy is recovered across the heat-pump refrigeration cycle.
Florida International perFORM[D]ance House
- Solar thermal via evacuated tubes.
- Operable louvers that raise and lower as needed for privacy, shading and protection against hurricane-force winds.
- Sensors, timers, and remote controls provide system automation that increases efficiency and reduces costs.
- A weather station with monitoring capabilities allows homeowners to monitor energy production and use, solar panel performance, and water consumption.
Team Massachusetts 4D Home
- 28-panel photovoltaic array of monocrystalline silicon cells that are 19.1 percent efficient
- Hybrid solar thermal panels mounted behind the photovoltaic modules for efficient heat transfer to the domestic hot water system.
- A refrigerator uses less electricity per year than a 60-watt light bulb.
Team New Jersey ENJOY House
- Red acrylic honeycomb panels serve as light emitting decorative and privacy walls.
- Evacuated solar thermal tubes heat domestic hot water and provide preheating for the hydronic radiant floor.
- Energy recovery ventilators and dehumidifiers keep cool air inside the house while providing fresh air from outside
- An Eragy/eGauge energy system allows monitoring of energy use.
Team New York Solar Roofpod
- Rooftop-mounted solar trellis that protects the house from heat gain and is easy to upgrade with new photovoltaic technologies.
- A micro-inverter for each solar panel optimizes system output.
- A thermal storage system uses paraffin as the phase-change material to reduce the size of the tank by half. The solar thermal system even performs cooling.
- A Noveda energy consumption/generation monitor combines with Lutron lighting control system for controlling lights and Schneider Electric for part of the HVAC and home-made systems for linking everything together as well as incorporating windows, blinds, irrigation controls.
Tennessee Living Light Home
- Sensors automatically manage the electric lighting, including color-changing LED strip lights along the facade, and a home automation system that can be programmed with preferred conditions for activities such as watching a movie or entertaining dinner guests.
- A blind system is sandwiched between two panes of glass and programmed to provide year-round lighting and shading.
- And cylindrical modules in the 10.9-kW photovoltaic array capture sunlight across a 360-degree surface.
Tidewater Virginia Unit6
- Window and door sensors provide security system information and prevent the HVAC system from operating when either is open.
- Light switches are powered by remote transmitters that can be placed anywhere in the house and never require replacement batteries.
- And a transformable porch with motorized windows that allow it to be open to the outside or an enclosed sunspace.