September 29 2008 / by Garry Golden
Category: Energy Year: 2010 Rating: 8 Hot
The era of Zero Energy Home (ZEH) construction has taken another step forward with the announcement of a new US Department of Energy project in Tennessee.
The vision of ‘zero energy homes’ is to transform the residential built environment from a major consumer of energy, to a neutral, or net zero energy environment where the annual amount of energy produced and consumed is equal. More forward looking architects and energy system designers envision homes that are (annually) net producers of energy and able to push energy back into the grid, or fuel vehicles. To arrive at both futures, we must first understand the fundamentals of zero energy home design, on site energy storage and power generation, and home power management systems.
Home Energy Use
While energy consumption patterns in homes vary greatly depending on geography the US DOE estimates that nearly half of the average home’s energy consumption is used for heating, 25 percent for lighting and appliances, 17 percent is used for water heating, 6 percent for cooling rooms, and 5 percent for refrigeration.
A Step Forward – Commercial Construction
The key to making zero energy homes a reality is reducing costs around new construction materials and building processes. Last week the U.S. Department of Energy announced a collaborative proejct between the Oak Ridge National Laboratory, Tennessee Valley Authority and Schaad Construction to construct and monitor four commercially affordable ‘smart’ homes.
The homes will be designed to maximize energy cooling/heating, apply home power management systems, and tap on site renewable energy generation using passive and photovoltaic solar energy to power high efficiency appliances.
The Next Steps – Smarter Homes
In addition to new construction materials and building designs, zero energy homes will also require further fundamental advances in on site energy storage to help manage intermittent power generation from on site solar, wind and geothermal systems.
While we are learning to master the fundamentals of physical home construction, researchers and entrepreneurs are simultaneously evolving the home’s digital backbone. Low-cost sensors and network control software standards such as Zigbee are expected play a key role in the future development of zero energy homes.
It is very likely that within a decade energy startups and familiar consumer brands like Intel, IBM, GE, and consumer software brands like Microsoft might release commercial home power management systems.
Once we have mastered the physical and virtual systems of energy systems, the vision of the zero energy home might then become a reality.
From ORNL Press release :
The ZEBRAlliance demonstration homes will consist of about 2,800 square feet of living space. Construction of a home’s shell or envelope (the part that separates the inside from outdoors) can have an enormous impact on energy use. Each home will evaluate the affordability and performance of one of the following strategies
- Structural Insulated Panels (SIPs) consisting of a foam core of insulating material with oriented strand board skins.
- An advanced stick-built wood framing system designed to reduce thermal short circuiting through structural members, provide cavities for ample thicknesses of insulation, incorporate a radiant barrier in the attic, and achieve air tightness through use of a Henry liquid applied weather resistive barrier.
- An insulating system that stores solar energy, shaving peak cooling loads by day and passively heating by night, coupled with other envelope features to achieve air tightness and weather resistance.
-A conventional wood framing system with the insulation wrapped around the outside to eliminate thermal short circuiting through structural members, and use of a trowel applied weather resistive barrier.
ORNL is managed by UT-Battelle for the U.S. Department of Energy.
Other ZEH Resources:
- Zero Energy Home Project to ZEH http://www.toolbase.org/Home-Building-Topics/zero-energy-homes/seven-steps-zeh