Oxygen for Childhood Pneumonia Where Cylinders Run Out: A Solar Oxygen Concentrator Sized and Priced from Physics

Children with severe pneumonia need continuous oxygen at 0.5-2 L/min, yet delivered cylinders run out in remote facilities. This sizing study computes, from stated clinical demand, the PSA concentrator capacity and photovoltaic plus battery system that sustains a 10-child ward through the night and two cloudy days: 18.0 m3 of oxygen per day, 20.20 kWh of electricity per day, a 4.5 kWp array and a 33 kWh battery, for $22,600 capital. Levelized cost is $0.91 per patient-day and $0.50 per cubic metre, against $18.61 per patient-day for delivered cylinders at $10.00 per cubic metre, or $23.26 per served patient-day at a 20% delivery-failure rate. Break-even and the conditions under which cylinders still win - low utilisation, very small demand, no maintenance capacity, high-pressure applications, and backup - are stated. SIMULATED, NOT MEASURED: a sizing study, not a built or clinically validated system.