Rebuilding with Renewables

It was a warm, humid Sunday in late May and the normally quiet town of Parkersburg, Iowa, was abuzz with activity. On any other typical weekend, the people here would most likely have spent the afternoon relaxing, finishing weekend chores and preparing for another work week. But this was no ordinary Sunday.

Another school year had just concluded the prior week and carefree teens were out in force. A few remaining graduation parties were scheduled that evening, wrapping up a week of gatherings to honor members of the 2008 senior class. For the uncommitted others, preparations were under way for evening barbeques and neighborhood get-togethers.

In the waning hours of the afternoon, the bright blue sky began to darken. Ominous-looking clouds had formed in the west and the day was shaping up to be a storm-chaser’s dream come true. But for the 1,900 residents of this rural community in Northeast Iowa, the clouds were about to become their greatest nightmare.

At 4:59 p.m. it struck. Packing winds estimated by the National Weather Service in excess of 200 mph, the massive twister had reached peak intensity as it began to bear down on the southwestern fringe of town. Most often compared to the sound of a speeding freight train, the roar was deafening. In less than a minute, it was over.

The EF-5 tornado that ravaged Parkersburg was the most devastating twister to strike the Hawkeye state in more than 30 years, unleashing a 43-mile path of destruction spanning three counties and killing eight people. Parkersburg took the biggest hit — 282 homes demolished, another 400 heavily damaged and 23 businesses lost including City Hall, the town’s only grocery store and gas station and Aplington-Parkersburg High School.

Rebuilding a Community

There was never a question that the resilient folks of Parkersburg would rebuild.

By sunrise the next morning, fleets of equipment had arrived and cleanup was under way. School administrators assembled to begin laying the groundwork for rebuilding the high school. Working well into the wee hours of the morning, they came forward with two promises: the school would play its first home football game of the 2008 season on the same field and the new high school building would be complete in time for the 2009-10 school year.

Shortly thereafter, architects were commissioned to submit bids for rebuilding the school. Design specifications were to include two noteworthy features: geothermal heating/cooling and a lower-level storm shelter — just as a precaution.

Superintendent Jon Thompson said the decision to go geothermal made sense on several fronts. He and the five other committee members who led the rebuilding planning process researched as many options as possible given the short timeframe.

“It makes sense to thoroughly investigate ways to make your building cost-efficient,” Thompson says. “We conducted energy audits, plus we’ve had some schools in our area that have had real success with it [geothermal]. We spent a lot of time looking at it and talked with a lot of other schools and it became clear that geothermal was the way to go.”

Although he admits installing a geothermal system costs more initially than a conventional system, the monthly savings in energy bills will help free up money for things more directly related to education — such as new textbooks, computers and teachers.

“Schools have different pots of money to pay for different types of things,” Thompson explains. “Installing a geothermal field costs more up front, but that money comes from a separate pot and not from our operating funds. We also received assistance from various sources after the tornado to fund the construction. Reducing our monthly utility costs allowed us to free up dollars from our operational fund to buy textbooks and hire more teachers.”

The committee determined the most efficient route was to combine geothermal with a conventional system that will be used to heat and cool the gym only.

“One of the things we discovered is that for large, open spaces, geothermal isn’t as efficient as in areas divided by rooms with lower ceilings,” Thompson says. “I’m not an expert, but it has something to do with the amount of air that has to change over. In the case of the gym, an area that isn’t always occupied, a conventional system was the more cost-effective approach.”

A-One Geothermal, based in Earlham, Iowa, was selected to install the geothermal system after participating in an extensive bidding process. Founded in 1975, the family-owned business has a long track record of installing geothermal systems. A-One got its start installing water and sewer lines. In the 1990s, the company expanded services to include fiber-optic installations using horizontal directional drilling (HDD) methods.

Over the years, founder and vice president, Dale McNair, had always been intrigued by the geothermal concept and had taken the initiative to learn more about it. When the fiber-optic market went bust in early 2000, McNair became a geothermal specialist and decided to make it his core business.

“We were installing geothermal systems in the 1970s, long before most people had even heard of it,” McNair says. “When the fiber market began nose-diving, we were well-positioned with geothermal. As geothermal became more popular, so did the demand for installers. It now accounts for over 90 percent of our business.”

Stay in the Loop(s)

Nearly half of the sun’s solar energy is absorbed by the Earth, making it a great source of free renewable energy. A geothermal system taps into this limitless supply of free energy and uses it to keep a structure comfortable.

A typical geothermal system features several loops buried underground either vertically or horizontally. The loops — extending 200 ft or more, depending on the need — are filled with environmentally safe antifreeze and connected to a geothermal heat pump.

During the heating cycle, the system automatically pulls heat from the ground via the antifreeze in the loops and circulates it through the geothermal heat pump, which concentrates the heat and distributes it throughout the structure’s duct work. At the same time, the antifreeze constantly cycles back through the loops, where it reheats, and the process repeats itself.

In hot weather when air conditioning is needed, the system reverses itself. Heat is extracted from the structure and directed to the water heater or back into the ground where it can be stored for reuse during cold-weather months.

Simply put, in the winter months, the geothermal heat pump moves heat from the ground into the building. During the summer months, the geothermal heat pump moves heat from the building to either the water heater or back into the ground. The geothermal system uses renewable energy because earth becomes a natural sink for building and solar heat to be used by the geothermal system. It is up to five times more efficient to move heat than it is to create it with a conventional system such as natural gas or oil.

Often the first step in the installation process is to complete a conductivity test. Since ground composition varies from site to site, conductivity results help to more accurately project the potential energy storage capacity of a specific formation. This is especially important for larger installation projects. HDD is used to install a geothermal pipe that gathers conductivity data over a 40-hour period. The data is sent to a lab to be analyzed and the results determine the ground’s energy storage capacity. If the potential capacity is low, the size of the geothermal field will be increased proportionately and vice versa.

Choosing HDD

McNair prefers the HDD approach for installing the U-shaped loops, citing a number of advantages.

“HDD is a more cost-effective installation method,” McNair says. “It also takes less time and fewer resources than vertical drilling. There is also less ground disturbance and more field installation options. We’ve installed horizontal systems under parking lots, driveways, existing structures and athletic fields.”

McNair’s fleet of HDD equipment includes four Vermeer models of varying size. His crew used the Vermeer D36x50 Navigator model to install the geothermal field at Parkersburg. The field consists of 58 loops and stretches 420 ft from north to south, installed in “piggyback” formation with one line at a depth of approximately 30 ft and a second installed directly above at 15 ft. Bentonite grout, a substance that helps maximize conductivity, is pumped into each of the bores as the loops are pulled back through.

The series of loops connects to several 8-in. supply lines that feed to an underground “vault” where the fluid-filled loops transfer the stored energy to the high school. The entire configuration was installed directly underneath the school’s softball field with minimal disruption. The project took eight weeks to complete. “If you hadn’t driven by and seen all the equipment, you’d never know it was here,” McNair says.

The number of loops necessary to support a specific system is determined by the size and condition of the structure and the capacity of the ground formation to store energy. The amount of energy generated by each loop will vary by design. McNair explains that in order for a geothermal system to operate at peak efficiency, it is critical to accurately calculate the size of the system (i.e. the number of loops needed).

“There is a tendency for most people to think the bigger the system — the more loops — the better,” McNair says. “In reality, nothing could be further from the truth. With geothermal, it’s all about being able to accurately calculate the requirements of the structure and nothing more or less.”

Payback

No one disputes that it costs more up front to install a geothermal system. But there’s also no disputing the energy savings and payback. All systems begin paying for themselves immediately in the form of monthly energy savings, and the additional up-front investment is likely recouped within four to six years, depending on the size of the system. McNair says a conservative estimate for monthly utility cost savings is 50 percent, while many systems can save up to 70 percent over the cost of operating a conventional system.

“We installed a geothermal system for a church building in Bettendorf, Iowa, that paid for itself in two years,” McNair says. “While this is somewhat unusual and I wouldn’t advocate that people should expect to realize payback as quickly, it shows that it can be done.”

Not unlike the example shared by Thompson whose school can now afford to buy more textbooks and computers with funds that previously would have gone to paying monthly heating bills, the same can be said for any homeowner, business or nonprofit organization that chooses the geothermal route.

“It’s money in your pocket,” McNair says. “Take the Bettendorf church for example. The money they save can now go toward fulfilling the mission of the church rather than to their utility company. The same can be said for any business, school, manufacturing plant — you name it, including a homeowner. A 2000-sq-ft home, well-insulated with good windows and so forth, can get by on about $45 a month in heating and cooling bills. Think of the amount of monthly income that savings frees up for other priorities.”

Once installed, maintenance is minimal and repairs are nearly nonexistent. “After the system has been installed and we balance it, we’re done,” McNair explains. “From that point on you don’t have to do anything to it. I know one thing for sure, and that is we don’t include any income from service work when preparing annual projections. We just don’t see any service work coming from these systems. I started installing geothermal systems back in the 1970s so it’s not like we don’t have a track record either.”

A-One guarantees the ground source loop piping they install for 50 years.

Incentives Aplenty

After deciding to go geothermal, Thompson has since learned that a number of residents who are rebuilding after losing homes in the tornado are also installing geothermal systems. “Talking with them made me a bit jealous that I didn’t [have a geothermal system] at my home,” Thompson says.

Numerous incentives are available for individuals and businesses that choose the geothermal route. The federal government and most states have sweetened the geothermal installation pot. Uncle Sam offers direct energy-savings tax credits for homeowners who use energy-saving techniques when building a new home. At the state level, incentives, grants and rebates are available. Even private utility companies are in the game, offering rebates to commercial and residential customers for converting to geothermal systems.

Mortgage companies are also offering rewards. For those who qualify, an Energy Efficient Mortgage (EEM) can increase the purchasing power of buying a geothermal system by allowing the lender to increase the borrower’s income by a dollar amount equal to estimated energy savings.

Road to Recovery

While no individual, or community for that matter, should ever have to endure what the people of Parkersburg did on that dreadful Memorial Day weekend of 2008, their resolve and fortitude should serve as an important lesson.

Confronted with peril and uncertainty, this town never panicked — but instead embraced the recovery process forthright, with responsible discipline. Most viewed the catastrophe as an opportunity to rebuild in the most advantageous of ways — right down to how they would heat and cool their new high school.

“It’s amazing how tragedy can bring people together and actually make them stronger,” Thompson says. “A lot of the pain and suffering will never go away, but people here feel good about how we responded. Who would ever have thought discovering more about geothermal would be part of the process? It validates what those of us involved in education have always believed: We never stop learning.”

Randy Happel is a features writer for Two Rivers Marketing.