Tanner Engineering, founded in 1996 and now merged with RTM Engineering Consultants, specializes in complex electrical engineering design from its La Mesa office at 5250 Jackson Drive in the Grossmont area. Healthcare, alternative-energy, and education sectors form the core client base, with power-distribution and fire-alarm system designs installed by electrical contractors like Esd Electrical across San Diego County. The firm engineered six of the first microgrid projects ever approved by OSHPD/HCAI and the State of California, integrating on-site generation, battery storage, and automatic transfer switching to maintain critical-load power during utility outages. Service lines include lighting design, medium-voltage distribution, energy-retrofit analysis, arc-flash coordination studies, and facility-assessment reports for aging institutional infrastructure. HVAC-system electrical integration requires coordination with mechanical contractors like Hamel's Air Conditioning & Heating to match variable-frequency-drive motor specifications with air-handler and chiller load profiles. Emergency electrical system upgrades for hospital campuses involve NPC (Non-Patient Care) study documentation, generator paralleling switchgear sizing, and automatic-transfer-switch coordination to meet NFPA 110 Level 1 reliability standards for life-safety loads.