From the outside, it appears to be a normal house: no ornate trimming, no visible contraptions on the roof, no strange design. There is even a doorbell and a welcome mat, worn from the thousands of curious visitors who have toured the house.

This house is the Solar House, a project started in 1981 by the civil and mechanical engineering departments to demonstrate how solar energy can be effectively used to power a traditional home. The house is now part of the Solar Center and is located a few feet from the McKimmon Center on Gorman Street.

Though at first sight there seems to be nothing especially remarkable about the Solar House, its design has captured the attention of 250,000 visitors worldwide. The house incorporates both passive and active solar energy attributes.

According to Shawn Fitzpatrick, Solar Center’s solar energy specialist, collecting solar energy passively involves utilizing the design of the house to collect and transfer the sun’s energy. The house’s passive aspects include glass on the south side, a sunspace, the house’s orientation, the general landscaping and overhangs.

The south side of the home, which is constructed mostly of glass, allows sunlight to directly enter the two-story sunspace — an open room designed to harvest the sun’s energy in the winter and remain cool in the summer — and circulate either cool or warm air, depending on the season, throughout the house by way of operable windows.

“[The sunspace supplies] enough heat for the whole house,” Benjamin Rich, the Solar Center’s biomass program coordinator, said.

In the summer, when the sun is high, an overhang and a vine-covered canopy shield direct sunlight from the sunspace so the room remains cool and, in turn, so does the rest of the house.

According to Nic George, the Solar Center’s biofuel crop researcher, the house’s orientation also helps the house remain at a comfortable temperature. Because the front, lower level of the house is built into a hill — which is cool in the summer and warm in the winter — the temperature of the house parallels the temperature of the ground.

Active solar attributes include thermal and electric or photovoltaic solar panels and underground pipes.

There is one thermal solar panel on the roof. According to Fitzpatrick, the panel is made of both an isolated and an absorber plate, which collect and store the energy used to heat the water pump.

The thermal panel provides 60 percent of the house’s hot water.

“[The water] provides enough for a family of four,” Rich said.

According to Rich, the water pipes, or geo-thermal roots, make heating and cooling water more accessible because the pipes containing the water are five feet underground and expand into the yard. “Since the water stays at a constant temperature of about 55 degrees, it’s good for starting [both the] cooling and heating [processes],” Rich said.

The many photovoltaic solar panels located on the roof convert the sun’s energy to electricity that powers the whole house.

According to Fitzpatrick, as light lands on silicone wafers within the panel, the flow of electrons converts sunlight into direct current electricity. An inverter then converts this electricity into alternating current electricity — the form accepted by appliances and then feeds it in to the house’s electrical system.

Upstairs, the main area of the house appears completely inhabitable. The upper level consists of everything expected in a normal house — a living room, dining room, kitchen, conference room and an office which, if the house had inhabitants, would be the master bedroom.

The selection of building materials and the type and function of appliances are other considerations taken into account when building the Solar House.

The living room, which contains a plasma-screen TV, is lit mainly by an overhead light, which deposits natural sunlight from an attachment on the roof. The remaining lights use 60-watt compact fluorescent bulbs, which use only 14 watts of power.

According to Fitzpatrick, refrigerators and other appliances consume 30 percent of the energy allotted to a house. To save energy, the kitchen is composed mainly of Energy-Star appliances, which will help conserve energy better than old appliances, or ones that are not rated efficient.

As part of the solar demonstration, an Alternative Fuel Vehicle Garage, which provides information about various alternatives to gasoline. Fuels such as ethanol, fuel from starches and biodiesels are found and described in the garage.

Though there is an ongoing debate between scientists and the public about whether the output of energy from alternative fuels is greater than the energy required to harvest them, George said scientists are working on ways to increase the output of energy from alternative fuels.

Harvesting the energy from sources such as wood, sawdust and wood chips will produce a great output of energy.

“For every one unit [of energy] put in to making it, we will get 40 units out,” he said.

According to George, it is important to learn about these fuels because as oil reserves diminish, alternative fuels are what most of the population will use in the future.

“We can’t consume energy like we do now,” George said. “[Our oil consumption] is gonna look quite different in the future.”