MARET stands for Missouri Alternative and Renewable Energy Technology. Crowder College was designated the home of the MARET Center by legislative decree in 1992. Since then, MARET has strived to achieve excellence in alternative and renewable energy. The college competed in the 2002 and 2005 DOE Solar Decathlon’s in Washington, DC. We offer degrees and certificates in solar energy, wind energy and biofuels. We participate in community sustainability programs and help local communities, businesses and individuals with alternative energy projects.
Construction on the new MARET Center building (Phase I) is complete. This building is a jewel in the crown of Crowder College in Neosho, Missouri. It was conceived to be the most energy efficient building possible. It is also designed to be a test-bed of new sustainable technologies. To meet those two goals, the MARET Center building employs a number of state-of-the art building and energy technologies. Some of the technologies are novel, others have never been tried on this scale before and still others were deployed to demonstrate their effectiveness, though they are well known. In addition to sustainable building techniques, we have also employed a number of conservation technologies to reduce our environmental footprint. We are applying for LEED Platinum status.
This is only the 10,000 square foot Phase I. We have plans for two more phases, with a total of 27,000 square feet of classroom, laboratory and conference space.
Ground was broken on the MARET Center in March, 2011. This was nearly six years after the initial funds were made available through the efforts of our (then) US Congressional Representative, now Senator, Roy Blunt. Sen. Blunt is and was a tireless proponent of education and economic development in southwestern Missouri. He provided $3 million from the Federal Government and the rest was raised from private donors.
Design of the building took quite some time, as the two goals of state of the art sustainability and test-bed of new technologies meant that it would be like no other building ever built. The architecture firm of Kromm, Rikimaru and Johansen, out of St. Louis, MO, was engaged to design the building. We also knew that we would need expert engineering skills and so we commissioned TME, Inc. from Little Rock, AR. Both companies are national in scope of work and reputation.
After a rather lengthy environmental impact study, we began. JE Dunn was hired as the construction management company.
The building is oriented to the south to best take advantage of the sun for solar energy.
The walls and roof of the MARET Center employ two different construction techniques, both of which are extremely energy efficient and sturdy. The north wall, which is covered by an earthen berm, as well as the foundation, are both made using ICF or Insulated Concrete Forms. ICF uses polystyrene as the form, connected by plastic ties. The foam can be 1-4 inches thick on both sides. Steel reinforcing bars are applied, then concrete, up to 12 inches thick, is poured between the forms. Once the concrete sets up, the forms are left in place. ICF uses the concrete as a thermal-mass, able to store a lot of heat. The foam then prevents that heat from moving too quickly. And, since it’s monolithic, there are no heat bridges for heat to transmit from outside or inside the building. R values (a measure of heat insulating capability) range from R25 to perhaps R50.
ICF is not only very insulating, but is very strong. It is holding back the earthen berm. Structures built with ICF properly can withstand tornado-force winds.
In the MARET Center, the ICF foundation is 12 inches thick with 2 ½ inches of foam. The wall on the north side is also 12 inches thick with 2 ½ inch thick foam. This results in an R value of near 50. And, since the north side is also covered with an earthen berm, it is much more insulating than a standard construction.
The rest of the walls and roof are made from a construction system called SIPs, for Structural Insulated Panels. SIPs are constructed of (usually) 2 panels of Oriented Strand Board sandwiching polystyrene insulation. The panels can be of nearly any length. The ends and edges are made of wood or metal, the thickness of the polystyrene. In most cases, standard wood sizes are used: 2x4; 2x6 2x8. The R value of a SIPs can range from R 15 for a 4 inches thick panel to R40 for a 12 inches thick panel. This is much higher than a standard ‘stick built’ wall’s R value because of the thermal bridging caused by the structural studs every 16 – 24 inches. A SIPS panel can extend for many feet, without an intervening stud to help transmit heat.
The walls of the MARET Center are 6 inches thick. The roof, which is also the ceiling, is 8 inches thick.
All this insulation, from the foundation to the roof makes for a very energy efficient building.
Since the envelope is so insulating, the heating and cooling system doesn’t need to work so hard. We are employing an unusual, and extremely energy efficient system. We use exposed radiant heating and cooling panels.
Most folks are familiar with radiant floor heating systems. In these systems, warm water is flowed through a flexible pipe under the floor, heating the floor and the air above the floor. It is a very comfortable system. Cooling is usually handled another way, such as standard forced air, using an air conditioner or heat pump.
In the MARET Center, we have panels placed in the ceiling. Warm or cool water is flowed through the panels, heating or cooling the surrounding air. The warmed, or cooled air is then moved about the building using ordinary convection or natural movement of air from warm to cool and vice versa and a small amount of positive air pressure. There are no vents as would be found in a normal forced air system. Make up air is brought in from outside, warmed or cooled as needed and gently flowed into the building.
The water in the radiant panels is heated or cooled using a novel geothermal system developed here at Crowder College. It is a two field systems that will alternate depending on the season and need of the building. Not much more can be said as we are applying for a patent. Once we get the patent application submitted, and we gather sufficient data, we intend to publish our findings. It is our hope that this system will be much more efficient than a normal single field geothermal system.
The heating and cooling system is monitored and managed by a sophisticated computer program that can tell if a person is or is not in a room, and adjusts the flow of water, either warm or cool, into the panels in that room. That way, the room is efficiently managed, without wasting heat or cool when it’s not needed.
In addition to the heating and cooling sensors, there are proximity sensors and light sensors in each room. These are used to turn on or off the lights, depending on whether or not someone is in the room. Since we have skylights and passive solar windows in many of the rooms, the light sensors also make sure that the task lighting is adapted to take this additional light into account.
Since MARET stands for Alternative and Renewable Energy, we have both solar and wind supplying energy to the building. The solar array is 280 Sanyo HIT 220 panels. Approximately 240 are specially modified hybrid panels that have fluid flowing through pipes attached to the back. This allows heat to be removed from the panel, helping the panels be more efficient even during hot summer days. We capture that heat and use it to help heat the building by running it through the radiant panels. Domestic hot water is generated with an evacuated tube thermal system. So, we have three types of panels on the roof: standard, hybrid and thermal.
The PV panels are 90% tied to the grid. The remaining 10% will charge a bank of batteries that will store the power until needed, likely in event of a power outage. The goal is not to run the building at full power off the batteries, but to provide lights and some electric charging and heat for campus security during an outage.
A quick calculation shows that 280 220 watt panels will generate almost 62kw of power. With 10% charging batteries, we will have about 55kw of PV power at peak. Couple that with our 65kw Nord Tank wind turbine, and we will be capable of generating 120kw of power for the building’s use. It is our goal and expectation that the building will be a NET POSITIVE GENERATOR of power. And that we will sell back more than we purchase from our electricity provider.