1. 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

2. 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

3. 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

4. 2014 – 8394 kWh
2015 – kWh
2016 – kWh
2017 – kWh
2018 – kWh
Episcopal Church of St. Martin Hooked on Solar System Output from August, 2014 to 12/24/18

5. 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.

6. 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.

7. 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 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.

8. 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?