As Earth Day 2008 Nears, UC Solar House Builds for the Future

The University of Cincinnati’s solar house, located on McMicken Commons, will be open for student-led, public tours from 10 a.m.-4 p.m., on Monday, April 21, and from 9 a.m.-5 p.m., on Tuesday, April 22, 2008 (Earth Day).

On view will be some of the technologies that earned the house attention late last year when it was displayed on the National Mall in Washington D.C. At that time, the UC house received attention from National Public Radio,

BusinessWeek

magazine,

The Chronicle of Higher Education

, Scripps Howard News Service as well as statewide and local media like the

The Columbus Dispatch

,

Ohio

magazine and more.

On view April 21 and 22

The solar house technologies on view April 21 and 22 include innovative evacuated tubes – 120 in all – that form a patio wall. When the sun heats the water in the tubes, energy is created that is used for various household functions: heating, air conditioning and supplying domestic hot water.

Also on view will be one of the houses photovoltaic roof panels. It will be hooked up to a fountain. When the PV panel is turned toward the sun, the collected solar energy powers the fountain, and water shoots up. When the PV panel is turned away from the sun, energy is no longer available, and the fountain ceases operation.

While serving as an alternative-energy display, the current UC solar house is also a laboratory, according to architect Anton Harfmann, associate dean in UC’s

top-ranked

College of Design, Architecture, Art, and Planning.

Experiments that will be running this summer

By summer, a number of experiments will be running in the house. These include

• Determining the presumed energy and cost savings created by air conditioning the house with a hot-water power source vs. conventional grid electricity.

The UC solar house is unusual in its use of evacuated tubes (“tubes within tubes” in which the innermost tube contains water). These 120 tubes are actually used to form a patio fence on the south side of the house. When the sun hits the tubes and heats the water on the inside (even while the tube exteriors remain cool to the touch), it produces enough energy to air condition the house and to produce all the home’s hot-water needs for washing, dishes, laundry, etc. The tubes’ hot water is then moved through an absorption chiller where lithium bromide gas is vaporized then cooled under high pressure. The high pressure, cooled gas is then released to make cold water to cool the house as necessary. The “battery” for storing all of this thermal energy consists of two cisterns (holding a collective 1,200 gallons of water).

• Determining different ways to generate electricity using this hot water.

One experiment, according to Harfmann, will consist of generating electricity via a steam-driven turbine in much the same way that today’s power plants generate electric power via coal- or natural gas-powered turbines.
 
Another experiment will be far more unusual but could be quickly applicable in today’s homes and cars. The UC solar house team of faculty and students will attach thermo-electric modules to the hot-water cisterns that store heated water from the evacuated tubes at a temperature of about 195-degrees Fahrenheit. In what is known as the Peltier Effect, when heat passes through these devices they can create electricity.

According to Harfmann, “The stored heated water is like a giant battery. When that heat is not being used at night when air conditioning might not be needed or on spring and fall days when neither heating nor air conditioning is needed, that’s wasted potential. So, these plates attached to the cisterns will convert heat to electricity for other uses like the need to power appliances and lights.”

If the use of thermo-electric modules to convert heat to electricity is found to work here, such panels could be used just as easily in the chimney of a house to capture heat to reuse as electricity or even in the exhaust manifold of a car to create electricity for the vehicle’s use.

• Using hot water to power current appliances and to create new kinds of appliances.

The UC solar house, with its 120 evacuated tubes, creates a lot of hot water, which translates into heat energy. In addition to heating and cooling the house, this hot water may also be able to help run appliances and/or serve as the basis for new kinds of appliances.
 
For instance, the UC solar house team plans to convert a conventional clothes dryer such that it rests upon what is essentially a radiator. Hot water will move through this radiator, and heat will pass up into a tumbling dryer chamber via vents. Thus, the dryer would require only minimal grid electricity to move the tumbler vs. requiring electricity to provide heat. (The tumbling movement of a conventional dryer requires only one third the electric power needed to provide heat.)
 
In addition, the UC team will create a new kind of clothes dryer: A closet dryer. According to Harfmann, they plan to construct a closet with hangers and shelves where damp laundry will be placed. Hot water running through “radiator” pipes at the bottom of the closet will release heat upward to dry the clothing, with excess heating passing outside the house via a vent placed at the top of the closet.
 
 
 
UC’s solar house was built by students and faculty in 2007 as part of an international competition to build the world’s best solar house. Only 20 global institutions were selected to participate.
 
Students and faculty of UC’s College of Business; College of Engineering; College of Design, Architecture, Art, and Planning; and McMicken College of Arts & Sciences all participated in the project. UC’s 2007 solar house and the ongoing experiments in it will serve as the basis for the university’s next attempt to construct a new solar house planned for 2011.
 
For more information regarding UC’s solar house, visit the following links
 

• View a video of the UC solar house when on the National Mall in Washington, D.C., last October.

• View a construction photo gallery of the house as it was built last year on UC’s campus.

• Read general and technical background regarding the UC house.