A Light Library: Lending Charged Lanterns Like Books — Fleet Size, Fee, and the Loss Rate at Which the Model Dies

Operating design for a lantern-lending library in a 200-household village with episodic demand (160 participating households, 12 loans of 3 nights per household per year). The fleet is 30 lanterns charged by a 30 Wp station panel; annual cost at a 0.5% per-loan loss rate is $640.80, or $4.01 per participating household per year ($0.33 per loan). Households lighting fewer than 45.09 nights per year pay less than owning the cheapest lantern. The model dies at a loss rate of 1.063% of loans against episodic ownership, and fails outright for nightly demand (283 lanterns, $26.92 per household per year). The poorest 32 households are served free for a subsidy of $4.01 each per year ($128.16 total). SIMULATED, NOT MEASURED.