Geothermal Energy and Efficiency Upgrades Give New Life to an Old Illinois Church | Article

Courtesy: Euclid Avenue United Methodist Church

When its 50-year-old, gas-powered, inefficient boiler went out in 2011, Euclid Avenue United Methodist Church decided to replace it with something greener. The 114-year-old house of worship, located in Oak Parks, a Chicago suburb just a few steps away from the home and studio of the famous architect Frank Lloyd Wright, had already created a green action team in 2008 to help lead its sustainability journey.

The committee’s research on alternatives to fossil energy for heating buildings led them to look into geothermal energy. The committee found that a geothermal heat pump system for the church would be only $60,000 more expensive than a new high-efficiency fossil-fuel boiler. It would be an opportunity to switch to a renewable energy source and reduce carbon emissions. With the new heat pump system installed in 2011, the church saved 81 percent annually in cooling and heating costs and dramatically reduced its direct-gas usage.

Replacing the old boiler with a geothermal heat pump system started a journey toward net-zero energy for the church. As with many houses of worship and commercial buildings, space and water heating are the pieces that use the most electricity and gas. Switching these critical energy systems to more efficient renewable energy sources helped spur further actions toward sustainability.

“In 2009, we were paying $13,000 for gas and $7,000 for electricity,” Reverend Doctor Marti Scott, lead pastor at the church, said. “We decided to go to geothermal heating and cooling. By 2014, we were budgeting just $1,500 for gas but $10,000 for electricity, including the added electricity needed for the geothermal unit and the installation of air conditioning throughout the building.”

Installing a Geothermal Heat Pump System

Thanks to a local energy audit grant, the church performed an ASHRAE Level 2 energy audit of its facilities in 2011. This type of energy audit includes a walk-through of the facilities and a financial analysis by a professional energy auditor to help organizations understand their energy consumption. The main recommendations from the report were to replace the old lighting fixtures with more efficient lighting, install a geothermal system for heating and cooling, and install a rooftop solar system. Combined, these energy upgrades would help save the church more than 54,000-kilowatt hours (kWh) in electricity usage per year and thousands in annual energy costs. Ultimately, the report helped the church chart its journey to becoming a net-zero church.

Geothermal heat pumps take advantage of the stable temperature in the earth to offer an efficient way to heat or cool a building. Using a heat exchanger, geothermal heat pumps move the heat or cool air from the building to underground pipes. During the summer, the hot air in the building is transferred to the pipes to cool down, and then it is moved back to the building. In the winter, the geothermal heat pump transports natural heat from the earth to the building. During these air transfers, the heat pumps use electricity from the grid, which helps explain why the church's utility bills went up $3,000 annually after installing the units (see below). On the plus side, geothermal heat pumps provide heating and cooling to the building without using natural gas, resulting in fewer carbon emissions and lower overall energy costs, leading to substantial monthly savings.

In fact, geothermal heat pumps are up to 600 percent more efficient than fossil-fuel powered boilers and can adequately heat spaces even on the coldest of winter nights. Though heat pumps are expensive to install, particularly for larger commercial buildings, they pay for themselves over time in reduced energy costs and operating expenses.

Working with a certified geothermal heat pump system designer, the church dug 52 wells in its back parking lot, each 150 feet deep. Underground pipes and loops keep the water temperature in the pipes at about 55 degrees year-round. Then the water is circulated through the 11 heat pumps located throughout the church, either heating or cooling its rooms.

Because heat pumps can also be used as cooling systems, installing geothermal heat pumps saved the church from installing $90,000 in air conditioning units to keep the church cool in the summer. A decentralized system like geothermal helps the church control the temperature independently in each area, using thermostats. This offers the church increased comfort under varying load conditions, better humidity control, and the ability to preserve all the wood furnishings better.

“The geothermal system retrofit installation was a rewarding experience and a long journey,” Richard, a church green action team member and the project's lead, said. “It included a permit from the local government to allow for work and loop construction under the local street. The planning committee also had to analyze the plans and the contractor report and finally approved it.”

Along with the geothermal system, the church retrofitted the building with air handling units inserted in the vents and removed the air conditioning window units. The air handling units help move the heated or cooled air from the geothermal heat pumps to the different church rooms. These units are outfitted with constant-speed motors that run based on a schedule programmed in the building’s control panel.

The total cost for the geothermal system was $350,000, including resurfacing the back parking with permeable pavers, which return rainwater to the ground and reduce runoff.

Financing for the geothermal system came from a $50,000 grant awarded by the Illinois Clean Energy Community Foundation, a $100,000 bequest, and a short-term commercial bank loan to cover the rest of the costs. While the payback period for the geothermal project is somewhat long, about 30 years, it helps the church dramatically reduce its carbon emissions.

The church’s 50-ton geothermal heat pump system has helped the church save about $8,500 annually in operational costs for heating and cooling. With the new system, the church saw its gas costs decrease by $11,500 annually, reducing its greenhouse gas emissions by 81 percent. While the natural gas bill went down, the electricity usage for the church increased by $3,000 due to the need to use grid-sourced electricity to power the geothermal heat pumps.

Continuing the Energy Upgrades with Rooftop Solar

Courtesy: Euclid Avenue United Methodist Church

After installing the geothermal system, the church installed solar panels to decrease its electricity bill. In 2014, the church commissioned a 99-panel rooftop solar system with a 35-kilowatt (kW) capacity. The panels produce up to 43,000 kWh per year, reducing the church’s annual energy consumption by 27 percent. By installing these solar panels, the church offsets the equivalent of 67,651 pounds of carbon emissions annually.

The total cost for the solar panels was $126,000. Using a $76,000 grant, also from the Illinois Clean Energy Community Foundation, the church overhauled its flat roof to prepare for the solar installation and helped pay for part of the solar system. A manufacturer rebate of $15,000 and a donation helped cover the remaining funds needed for the rooftop panels.

Over their 25-year expected lifetime, the solar panels will save the church more than $100,000 and will cut the equivalent of 1.7 million pounds of carbon emissions. The system is interconnected to the power grid to sell unused energy to the utility.

In 2020, the church replaced old light bulbs with LEDs throughout the building, installed LED exit signs, and implemented night setback temperature controls to decrease energy costs and get closer to net zero. With a $20,000 cost, these energy efficiency measures are helping the church save about 47,000 kWh in electricity annually.

Subscribing to Community Solar to Create Economic Development

Courtesy: Euclid Avenue United Methodist Church

When the church could not meet all of its electricity demand through its rooftop solar system due to structural issues, it turned to community solar. Community solar is a subscription-based model allowing homes and businesses that cannot host solar panels on their buildings to receive solar energy from nearby solar arrays. In return for monthly payments, participants receive a bill credit equal to their share of the energy produced by the solar panels. The Illinois community solar program provides incentives to solar installers and income-eligible participants.

“We are adding community solar, which will reduce our energy bill,” Lead Pastor Scott said. “There are no panels, no cost, and you save up to 20 percent of your energy cost. Community solar brings construction and other green energy-related jobs to low-employment regions of the state, and it supports Illinois farmers by paying them for their use of underutilized land.”

In 2021, the church signed a contract with Nexamp Solar, a solar installer, to subscribe to a portion of the Rockford community solar farm, a solar array located in ComEd’s service area, the church's electric utility. To reach its net-zero goals, the church needed to receive renewable energy credits for about 50,000 kWh a year (the electricity consumption not already covered by its rooftop solar panels). The church actually receives about 50,200 kWh annually from the solar farm and is guaranteed a 20 percent discount compared to ComEd's rates. By subscribing to 24 kW of solar power, the church offsets the equivalent of 78,431 pounds in carbon emissions annually.

Now the church receives two monthly bills: one from ComEd and one from Nexamp Solar. The ComEd bill includes a credit for the solar energy received from the community solar project, and the bill from the community solar developer is the electricity covered by the credit on the church’s ComEd bill, with a 20 percent discount. The difference between what the church would have paid for electricity under ComEd and what the church ends up paying under community solar results in energy cost savings.

“At one point in a conversation with folks about the need to move forward on these sustainable projects, I asked them to take out their phones or wallets and show the person next to them pictures of their children and grandchildren,” Lead Pastor Scott said. “They are why we were going green.”

Euclid Ave United Methodist Church Annual Utility Costs
	2009	2013	2015	2020	2022
Electricity	$7,000	$10,000	$5,300	$2,300	0
Direct Gas	$13,000	$1,500	$1,500	$1,500	$1,500
Total	$20,000	$11,500	$6,800	$3,800	$1,500

Euclid Avenue United Methodist Church Energy Projects and Savings
	Project Costs	Annual Savings	Sources of Funding
Geothermal System Installation	$350,000	$8,500	$50,000 grant $100,000 bequest Short term loan
Solar Rooftop Installation	$126,000	$4,700	$76,000 grant $15,000 rebate Donations
Lighting Upgrades	$20,000	$3,000	Internal funds
Community Solar Subscriptions	$1,840 (annual)	$2,300	Internal funds
Total	$497,840	$18,500