Solar success: People, location and renewal in Ōtautahi Christchurch

This article is reproduced with permission from ecochurch.org.nz

In April 2022, 120 solar panels were blessed and commissioned on the roof of Oxford Terrace Baptist Church, Ōtautahi Christchurch, providing around 25% of the church’s energy needs.

Sonia Groes-Petrie from A Rocha’s Eco Church team connected with Bradley Nicolson (General Manager, Kānuka Hopestill Limited - Oxford Terrace Baptist Church) on how the project came about.

Oxford Terrace Baptist Church (OTBC) has had a presence in Christchurch since 1863 and has been on the current site in Oxford Terrace since 1881. Following the devastation of the Christchurch earthquakes in 2010 and 2011, the church went through a period of lament. Out of this a vision for the future was discerned, being summed up as:

PEOPLE. Those here now and those yet to arrive;

LOCATION. We are missionally engaging in our community and beyond;

RENEWAL. Our historic strengths will inform our future.

This clarity of vision allowed OTBC to settle their ‘brief’ with much more certainty as they worked with architect Andrew Barrie to create a modern-day monastery. OTBC wanted to create an oasis in the centre of the city, a multi-use complex where the various uses all ‘banged into one another’. They wanted to create a space where people were working, worshipping and living.

Stage one, completed in 2017, includes church offices, worship space (auditorium and chapel), kitchen, lounge, meeting rooms and a cafe. The upstairs office space is occupied by several social service agencies (World Vision, Workplace Support and VisionWest).

Stage two, due to be opened 10-12 February 2023, has the addition of onsite housing (11 apartments) as well as 400 square metres of office space to accommodate Visionwest Community Housing Trust.

While having solar panels was budgeted for inclusion in stage two of the project, the team at Oxford Terrace Baptist Church (OTBC) found there was no reason to wait as solar could be incorporated into the stage one building for about the same cost. It meant the benefits of generating and consuming their own electricity and thereby reducing the church’s carbon footprint could be realised sooner. The stage one building had a flat roof which gave the ability to pitch the solar panels to the angles required and the building was on the edge of the city’s CBD so there were no major shading effects.

OTBC has nine permanent NGO tenants and over 70 casual groups using their building on a regular basis and the facilities are humming with activities throughout the week. The ability to use electricity from solar as it was being produced was a major reason a solar system would work well for them. There are no batteries as part of their set up as that would have more than doubled the cost of the system. Instead, any excess generation is fed back into the grid via a dual ICP metering system (metering that allows electricity to be fed into the grid as well as receiving electricity from the grid as needed). Since the energy retailer pays less for generated solar fed back into the grid than the church pays for electricity purchased from the grid, it is more economical for the church to use their own solar electricity as it is produced.

Once it was agreed to install a solar system, quotes were obtained from several solar companies. Through Upstream, OTBC found John Wilson from Sunshine Solar, the company the church engaged to install the system. All up 120 panels were installed on the roof along with the inverter (to convert generated DC power into AC power that can be consumed). There were some unexpected challenges and complexities with the project, particularly around metering (connections to/from the grid) and tracking real time generation, usage and flow back into the grid. 

The system has only been operating since April 2022 so has not yet had a full year of generation. The biggest daily generation record so far is 330 kWh (recorded in November) and this will be topped as the summer season gets into full swing. Around 25% of the church’s energy needs are met by the solar system. When there is less activity in the building (usually on Saturdays) the energy from the solar panels is used by heat pumps on automatic timers to heat water for the underfloor heating system in time for use for Sunday services. In utilising as much of the solar energy produced for onsite consumption, the system is on track to be paid off within 5 years.

Once the system is up and running, maintenance will be fairly minimal with an annual pre-summer wash down of the panels to ensure maximised solar production. While the solar panels have a warranty of 25 years, the inverter’s warranty is less (10 years) so it is likely that the inverter will need to be replaced before any solar panels. The inverter is the costliest single piece of equipment within the whole system (~$10k).

A strong motivation for the church in installing the solar panels was recognising the importance of creation care as an act of worship to God. As a church, OTBC members have recognised the need to take environmental sustainability seriously considering the climate crisis. Since the church has been generating their own renewable energy, carbon emissions from church activities have dropped significantly, enabling the church to more sustainably steward the resources God has generously entrusted to them. The solar panels also serve as a demonstrable witness to the wider community that the church is acting in response to the world's climate crisis, something that emerges from a love for God and God’s world.

The decision to go solar was not taken in isolation and what has worked for OTBC may not necessarily work for other churches. Each church’s situation is unique with its own challenges, especially for existing/older buildings. Costs could quickly increase if, for example, the roof needed to be replaced. A clear sense of their vision combined with the design and build of the new facilities have allowed OTBC to move quickly.

Summary of key learnings:

• Being able to bring forward the installation from Stage 2 to Stage 1 meant that the benefits of generating and consuming their own electricity to help reduce the church’s carbon footprint could be realised sooner.
• OTBC’s flat roof gave them the ability to pitch the solar panels to the best angles required to maximise energy generation.
• OTBC’s building was on the edge of the city’s CBD so there were no major shading effects.
• OTBC had daytime tenants and activities and therefore had the ability to use the solar electricity as it was being produced.
• Not having batteries as part of their system significantly reduced the overall costs.
• The use of timers to schedule electricity usage when electricity is being generated is important.

Photo: provided from ecochurch story.