Methodology & Mathematical Assumptions

1. Inverter Efficiency Penalty (85% Standard)

Every AC appliance powered through a DC-to-AC inverter draws additional energy to account for transformer hysteresis and switching FET resistance. We model this as:

Effective AC Watt-Hours = (Appliance Rated Watts × Hours) ÷ Inverter Efficiency

DC circuits (12V/24V native lighting, compressor fridges, USB ports) bypass the inverter completely, saving roughly 15% in daily losses.

2. Battery Depth of Discharge (DoD)

Battery banks are sized by multiplying daily Watt-Hours by autonomy days (typically 2.0 to 3.0 days), then dividing by the chemistry's safe Depth of Discharge:

• LiFePO4 Lithium: 80% DoD (0.80) to maximize 4,000+ cycle lifespan.
• AGM / Sealed Lead-Acid: 50% DoD (0.50) to prevent rapid plate sulfation.

3. Solar PV Array & MPPT Sizing

Solar arrays must replenish not only daily consumption, but also system losses from panel dust, wiring resistance, and thermal derating (modeled at 20% system loss):

Required Array Watts = (Daily Wh ÷ 0.80) ÷ Peak Sun Hours

Charge controllers are sized with a 1.25 continuous duty multiplier in accordance with standard electrical practices to handle high cold-temperature solar irradiance spikes.