The letter requested that I consider sharing the apparent excess capacity of your solar installation through a community benefit arrangement that would support Sandia Vista's evolving sustainability goals. I had read the letter on the porch with Sigrid. I had written her back politely. I had explained that my off-grid solar array was sized specifically for my own household needs and a future electric vehicle, that I was not interested in any community benefit arrangement, and that any such arrangement would require a formal Public Service Commission interconnection agreement that would be impractical for an off-grid private system. I had sent the letter certified mail.
Sigrid had framed the return receipt. The receipt hangs in the inverter cabinet hallway. She wrote me three more letters in 2021 and 2022 with similar requests. I had declined each one politely. In each declining letter, I had cited New Mexico Public Service Commission rules on private off-grid systems and the general principle that private electricity generation is not a community resource.
The letters had been formal. The letters had been correct. Tamsin had not, by my own observational record across the next 18 months, ever read them with the attention required to understand them. The Tesla Model S Plaid arrived at Lot 12 in late May of 2022. Tamsin announced it in the Sandia Vista community newsletter as her sustainable transportation commitment.
The newsletter article noted that she was committed to charging through renewable sources whenever possible. The article did not mention what the renewable source might be. The renewable source, I would learn in March of 2024, was my 81-kilowatt-hour battery bank accessed through an unauthorized underground cable Kendrick's brother Wallace Bramble, a Houston-based unlicensed electrician, had installed on a Sunday morning in late September of 2023. The custom logging architecture I had built in 2019 deserves a short technical description because the architecture is the structural evidence the case was eventually won on. The architecture is built around a small Raspberry Pi 4 enclosed in the inverter cabinet alongside four custom design sensor boards I had built myself during the system commissioning.
The sensor boards each include a Hall effect current sensor calibrated to a 100 amp range, a voltage sensor calibrated to 240 volts nominal with a 100% overcapacity tolerance, and a phase detection circuit. The boards report their readings to the Raspberry Pi every 15 seconds across an internal CAN bus I had implemented to avoid radio frequency interference from the inverter's own switching activity. The Python logging software I wrote stores all readings in a local SQLite database, generates rolling 15-minute and 1-hour averages, performs anomaly detection against a configurable rolling baseline, and syncs the database every 6 hours to a small AWS cloud account I maintain. The total data volume across the 7 months of operating logs through October of 2023, by which point the unauthorized draw had been ongoing for 2 months, was approximately 14 GB. The Sandoval County prosecutor would later receive the full 14 GB by subpoena and would use the data as the primary technical evidence at trial.