No More 'What Ifs'
- By Susan Smith
- April 1st, 2011
What if we could design a school that produced as much energy as it consumed? Experts may tell you a zero-energy building is the future of school design and construction. But “What if?” is no longer the question districts are asking. Now, it’s “How?”
Net zero involves the reduction of building consumption combined with the onsite production of energy through renewable sources. Over the term of one year, the energy use and energy production at this type of facility will “net zero.”
What may have been impossible five to 10 years ago is very possible today due to the advancements in sustainable technologies and the continuing decrease in costs for these systems. With the coupling of energy reduction principles such as geothermal, along with energy production technology of solar, a school district can realize a net-zero building with an estimated 12-year payback on investment. With the solar industry quickly improving production capabilities and lowering costs, this payback estimate will continue to slide, reducing the estimated payback schedule and making this a feasible option for many districts. As districts weigh the value versus the cost of starting a net-zero project, many factors become integral in the discussion.
Net-zero projects are designed to use more than 50 percent less energy than a traditional school of similar size. One option for obtaining a large reduction can be accomplished through the use of geothermal water source heat pump systems for heating and cooling. Other efficiencies can be attributed to the increased building insulated envelope and high-efficiency glazing systems. Particular fixtures within the building can also reduce the power drawn into the building, from installing high-efficiency commercial kitchen equipment to utilizing lighting systems that incorporate daylight sensors to automatically dim or turn off classroom lighting based on natural lighting levels.
A significant reduction in energy can be achieved in reducing the plug load in the building through the use of laptop computers and wireless technology. This approach can eliminate student computers in classrooms, eliminate the need for computer labs and reduce the computer needs in libraries and multi-function spaces within the building.
Net-zero projects primarily focus on energy use, but water conservation is also an important principle. The use of efficient low-water plumbing fixtures and water harvesting systems that collect rain and gray water that condensates into an underground collection tank can be used for ground irrigation.
The production of energy onsite is an integral step in building a net-zero facility. Regardless of a school’s location, solar panels can produce a large percentage of the energy required to power the buildings. Advancements in photovoltaic technology have introduced harvesting methods that maximize the potential power drawn through solar panels. Cylindrical tubing systems installed on a white roof can capture not only direct sunlight, but reflected light from the white roof, maximizing the power produced per square foot of roof area.
Dependent upon the location of the school, wind technology can be used to produce energy onsite. Wind studies will assess the best options for wind and the estimate production for each school site. All systems incorporated into the facility should be monitored to allow facility manager personnel to evaluate system performance and quickly identify areas performing outside the design parameters set for net-zero operation.
Impacting the Learning Environment
Creating learning spaces that allow for studies in sustainable design are the perfect way to educate students on the facility and the environment. A district’s science department curriculum can include the technologies of the net-zero building. For instance, the district might consider installing science learning labs that focus on particular sustainable aspects of the building. Each district determines goals for a net-zero facility, but it’s important to allow the net-zero campus to become a learning opportunity not only for students within the school, but students and parents across the district.
Corgan is currently working on Lady Bird Johnson Middle School in Irving, Texas, which serves as the perfect case study for a project that has incorporated net zero into its educational curriculum for students and the surrounding community. Irving ISD made the classroom and learning space design a high priority. The main corridor in the facility has incorporated “learning nodes” on the main sustainable technologies: solar, geothermal, wind and water conservation. Each of these nodes provide graphic display areas that will display the real time information from the monitoring systems, an educational video, wind maps, earth temperatures and more. Central to each node is a three-dimensional interactive display that will explain how the natural resources work, how the sustainable systems work and how they are used in the new school.
A holistic monitoring system can be included in a net-zero facility that can provide on-site, real-time energy usage information for specific sections or building use as a whole in order to involve building occupants in energy monitoring. At Lady Bird Johnson, students will be able to use computers to access the monitoring system and find out how much energy the solar grid is producing on a cloudy day or how much power is being used in each classroom. The system was designed so a student can electronically monitor the school floor plan to observe changes in each classroom. For instance, if a space heater is plugged in, the student would be able to see a red flash on the plan indicating that room’s increased power use. If a school district commits to using laptop computers and wireless networking as mentioned above, students can use mobile devices to access information anytime, anywhere throughout the facility, eliminating the need for large banks of computers while simultaneously yielding a flexible learning environment.
So why wouldn’t every school district build a net-zero school? Simple – the answer is cost. The design and construction costs for a net-zero facility are approximately 15 percent higher than a traditional school. To recoup initial building costs through energy savings, some districts must commit to being paid back more than a decade later. However, net-zero design can have an impact on the annual maintenance and operations budget for each campus. Depending on the particular sustainable features and finishes included in the school, a net-zero design could require lower maintenance costs over the life of the building, and those net-zero features specifically addressing reduced energy consumption can significantly impact annual utility costs.
Some net-zero projects are projected to save districts more than $200,000 annually. The additional cost and the long-term benefits must be evaluated from the onset of the project by each district’s board, city officials and community. The district and community must build consensus with all partners involved to help advance the idea and increase awareness of the benefits of net-zero design for educational facilities. Irving ISD made a commitment to the environment and to future students and the community by taking a leap and designing the first net-zero school in Texas.
Why are net-zero buildings a good choice for school districts? Districts have long looked at the life-cycle cost and long-term benefits when making capital investment decisions. Net-zero buildings offer districts the opportunity to produce significant savings in building operations over the life of a building while giving taxpayers and local communities the sustainable and environmentally responsible buildings they are demanding.
Susan Smith is vice president at Corgan Associates, Inc. She is currently the project manager for the Lady Bird Johnson Middle School, scheduled to open in August 2011.