Context and Information for Zero Carbon Church Discussion Gerry Braun May 19, 2019 Personal interest and motivation Solar upgrade at St. Martins Energy inventory RFP Contractor selection PPA negotiation and terms Project construction Residential decarbonization CABS Post carport St. Martins decarbonization Furnace retrofits Water conservation Lighting upgrades Follow up motivation Energy market shifts Community Choice Net energy metering Climate emergency declaration Ground truthing Actual vs. projected economics

Outline Results of St. Martin campus decarbonization steps to date Solar carport experience to date Goal setting experience Full decarbonization Relevant experience Main steps to get there Recommendations 5 minute video Zero carbon church discussion questions Results Some pleasant surprises Some disappointments Some lessons applicable to campus/community energy management Carport experience Production Administration Decarbonization investments Past Future

Decarbonization Results to Date Solar Nearly 1000% increase in on-site solar production 61 percent reduction in grid electricity usage Combined (grid plus solar carport) electricity usage unchanged in spite of major furnace retrofits HVAC retrofits 60 percent reduction in natural gas usage and annual cost Integrated Benefits 60 percent reduction in annual CO2 emissions 18 percent annual energy cost savings 8 percent annual electricity cost savings

2014 – 8394 kWh 2015 – 33663 kWh 2016 – 27254 kWh 2017 – 27948 kWh 2018 – 28569 kWh Episcopal Church of St. Martin Hooked on Solar System Output from August, 2014 to 12/24/18

Changes in Decarbonization Outlook To date: Combination of opportunistic and planned steps Improved understanding of economic factors, e.g. Retrofit cost Retrofit economics, e.g. payback Comments: Unplanned retrofit projects can be more costly and disruptive. Full campus decarbonization would require substitution of additional solar or renewable electricity for grid electricity On-site production will be more cost effective than purchasing 100% renewable electricity.

What Would Full Decarbonization Look Like? Relevant experience Improved summer cooling efficiency off-sets winter heating electricity use. Generally doesn’t pay to wait until NG appliances break even if planning like for like replacements. Main steps to zero carbon Replace NG water heater with heat pump unit Replace remaining NG space heating furnace with heat pump Increase solar production by adding on-site capacity Supplemental steps Washing of solar arrays during dry, dusty peak-production months can increase highest value production by 5-10%. Further lighting efficiency upgrades. Popular sizes of LED fixtures can use up to 30% less electricity than CFLs.

Recommendations Enforce the terms of the current Solar Carport power purchase agreement. Capture what is owed for under-production to date. Renegotiate production guarantee to compensate for future under- production. Implement main and supplemental steps (previous chart) in 2019. Consider options to spread upgrade costs over more than one year. Track progress toward full decarbonization and keep parishioners informed. Pay closer attention to actual vs. expected energy bills and discrepancies lacking a weather or usage pattern related explanation.

Discussion Questions What is meant by the term “Zero Carbon Church”? Should church campus decarbonization deliver inspiration, insight and practical guidance for parishioners? Would a zero carbon church include all of us and even other local churches and the Diocese? Should we celebrate cost savings or carbon savings or both?