There are many new alternative energy technologies available today that can impact construction costs, both at time of construction and over the course of the life of the building. Many of these technologies are already available today, and others are still being developed and tested. The two that are currently most widely used are geothermal and solar.
Geothermal Energy Sources
Geothermal energy from natural pools and hot springs has long been used for cooking, bathing, and warmth. Archaeological evidence shows that the first human use of geothermal resources in North America occurred more than 10,000 years ago with the settlement of Paleo-Indians at hot springs. In ancient times, baths heated by hot springs were used by the Greeks and Romans, and examples of geothermal space heating date at least as far back as the Roman city of Pompeii during the first century.
Such uses of geothermal energy were initially limited to sites where hot water and steam were accessible. The world’s first district heating system was installed at Chaudes-Aigues, France, in the fourteenth century; it was not until the late nineteenth century that other cities, as well as industries, began to realize the economic potential of geothermal resources. Geothermal heat was first delivered to residences in the United States in 1892, to Warm Springs Avenue in Boise, Idaho, and most of the city used geothermal heat by 1970. The largest and most famous geothermal district heating system is in Reykjavík, Iceland, where 99 percent of the city received geothermal water for space heating starting in the 1930s.
Today, geothermal systems use water or refrigerant which is moved through loops of pipes buried in the ground or ground wells. When the weather is cold and heat is required, the water or refrigerant heats up as it travels through the part of the loop that is buried underground. Once it gets back above ground, the warmed water or refrigerant transfers heat into the building via geothermal heat pumps. The water or refrigerant cools down after its heat is transferred and then it is pumped back underground where it heats up once more, starting the looping process again. On a hot day when cooling is needed, the system can run in reverse. The water or refrigerant cools the building and then is pumped underground where extra heat is transferred to the ground through the pipes and then loops again. Geothermal energy reduces overall operating costs, along with possible renewable energy tax credits, but these savings may be offset by increased upfront construction costs.
Solar Energy Sources
Solar energy began with Edmond Becquerel, a young physicist working in France, who in 1839 observed and discovered the photovoltaic effect— a process that produces a voltage or electric current when exposed to light or radiant energy. In 1883, New York inventor Charles Fritts created the first solar cell by coating selenium with a thin layer of gold. Fritts reported that the selenium module produced a current “that is continuous, constant, and of considerable force.” This cell achieved an energy conversion rate of 1 to 2 percent. The first U.S. Patent for solar energy occurred on September 4, 1888, by inventor Edward Weston. Most modern solar cells work at an efficiency of 15 to 20 percent.
There are four solar technologies that are projected to have the biggest impact on the energy and construction industry in the coming years. For many, the thought of solar energy goes to solar panels on the roof of a home or business, or one of the many small solar farms that are popping up everywhere. Silicon panels are becoming more efficient and less expensive with time.
A comparison of a standard solar panel installation (L) and solar skins on top (R). Image Credits: Massachusetts Institute of Technology (MIT) News
Solar skins are like ad wraps, allowing an owner to match the rooftop or other features of the area adjacent to the panels. They can also be customized to provide business logos, advertisements, or whatever your imagination allows.
Floating solar farms, sometimes called “floatovoltaics”
Image Credit: Sungrow
The first commercial floating panel system was installed in 2008 in California at the Far Niente winery in Napa Valley (175 kWh). Installation costs of floating panels are less than land-based panels. Research has shown that the power production of a floating system is greater by as much as 10% due to the cooling effect of the water.
Photovoltaic solar noise barriers
With nearly 3,000 miles of traffic noise barriers in 48 states, the goal of the US Department of Energy has now evolved to merge noise abatement with sustainable power generation. It is estimated that the potential of producing solar energy from these is likely to be around 400 gigawatt hours (GWh) annually.
Building-integrated photovoltaics (BIPV) solar technology
Somewhat like skins, BIPV is intended to blend into the building architecture in the form of other building materials. When substituting BIPV panels for standard building materials, an owner could theoretically cut down on the additional costs of mounting solar panel systems. Photovoltaic PV glass installed as a building material would allow natural light inside a home or office and act as an energy-generating device.
The future is bright for energy sources that provide alternatives to traditional fossil fuel. As the new technologies develop, their quality and cost effectiveness continue to improve. These renewable energy alternatives will become more prevalent in upcoming years.
Jim Schuweiler has been a senior project manager with Shingobee Builders for 21 years. He has over 38 years of construction management experience, with involvement in a wide variety of project sizes and types, and has managed hundreds of Shingobee projects for clients such as CenturyLink, Xcel Energy, T-Mobile, Marriott hotels, and many others. His project experience includes several with sustainable / energy efficient construction; in particular, the Dakotah! Ice Center, which features a 32,000 square foot green roof.