Editor’s Note: This text is crossposted from the Interfaith Power & Light Cool Congregations website.

In 2004, the Episcopal Church of St. Martin in Davis, California, took first steps toward becoming a zero-carbon church by installing a small photovoltaic solar array on the roof of our administration building. That process has culminated sixteen years later with recognition by Interfaith Power and Light as a Cool Congregation with 100% carbon reduction.

Achieving this goal involved both baby steps and a few giant leaps! St. Martin’s has always been concerned about environmental sustainability. Davis’ bike-centric environment made it easy to promote bicycling to church by blessing bicycles and providing sturdy bike racks for all who use our facilities. We served as a pilot site for the City of Davis Commercial Composting program, thus diverting waste from our thrice-weekly soup kitchen and Sunday morning coffee hour out of the local landfill. A capital campaign in 2010 enabled us to replace leaky single-pane windows and outdated and inefficient lighting in the church with energy-efficient equivalents.

We took a similar approach to reducing our carbon footprint. Individual and corporate study helped us explore the connections between our faith and planetary stewardship. Parish-wide discussions, energy audits, and careful marshaling of our financial resources provided evidence that our congregation supported this work and that we could undertake it with an eye to reducing both our carbon footprint and utility bill. A parish committee – Caring for God’s Creation – with support from lay and clergy leaders, and congregation members at large supported this effort.

Figure 1. Progress to net zero electricity, Episcopal Church of St. Martin. Data for previous 12 months at mid-year, estimated consistent with available records. Key time points for installations of solar arrays: 2004, small solar array on office roof; 2013, solar car port; 2020, large array on classroom building. We replaced gas appliances with heat pump appliances in 2015, 2018, and 2020. COVID-related drop in usage in 2020 resulted in greater energy production than use.

We took a big step in 2013 by substantially expanding our on-site solar electricity production. We installed a large solar array through an agreement in which St. Martin’s committed to buy the clean electricity produced on its property. The array, sited over part of the parking lot, had the added benefit of providing respite from the sun’s blazing rays to the cars parked beneath it. Two years later, we swapped a lawn for a low-water meditation garden that also provides food and shelter for pollinators and birds.

In 2017, we replaced the gas-powered HVAC system in our sanctuary with a series of energy-efficient electric heat pumps that can be controlled individually, thus reducing both our energy bill and carbon use. What’s more, this experience encouraged the church to consider additional steps to achieve complete carbon reduction.

As a result, when a church member offered in late 2019 to purchase an additional 12kW of solar panels, parish leaders readily agreed. This generous gift provided enough electricity to cover not only existing electric use but also additional electric usage, as the church converted its remaining gas appliances to electric. Thus, our church effectively became solar-powered. The parishioner gained the tax credit and future depreciation, enabling him to fully gift the panels and ensuing clean electricity to the church.

What about the financial implications for St. Martin’s? Our outlays for HVAC electrification and solar retrofits over time, including parishioner donations, total roughly $100,000. In contrast, in 2020 alone, without on-site solar investment and purchase agreements, St. Martin’s annual energy bill would have been roughly $15,000 vs. what we actually paid: a little over $5,000. It typically takes less than a decade to pay for new systems, and savings continue to accumulate after up-front costs are recovered. Further, although electricity rates have escalated moderately over two decades, an 8% increase is expected in 2021 and further increases are likely. In other words, even without the generous financial gift, the cost savings for St Martin’s that come from going solar would have helped pay for the project by 2030.

The people of St. Martin’s believe that climate change constitutes an existential threat to God’s creation and, as a result, have committed to continuing to work toward reducing our environmental footprint to create a more just and sustainable world. Throughout this process, we have encouraged parishioners to look at their own habits around transportation, dietary choices, and other lifestyle decisions that can affect greenhouse gas emissions and global change. We hope our pursuit of becoming a zero carbon church can provide individuals, other congregations, and communities with an example of what can be done, one step at a time.

“The story of St. Martin’s journey to becoming a zero-carbon congregation speaks to what can happen when we align our faith values with practical actions. These changes didn’t happen overnight, but through a steady vision that centered their calling to care for their neighbors and for Creation. Congratulations on this incredible achievement and thank you for your faithful, moral leadership in acting on climate change!” Rev. Susan Hendershot, President, Interfaith Power & Light.

More reading and watching

St. Martin’s Rev. Dr. Pamela Dolan’s presentation

The blessing of the panels (video)

St Martin’s story on the Cool Congregations website

Owen Yancher’s Davis Enterprise article

Gerry Braun’s presentation of the technical aspects below: