Photovoltaic Seawater Reverse Osmosis Module
T-1
Single residences → medium hotels
The documented off-grid 3 hp PV-SWRO module, built around an APP/APM pump and motor for pressure and energy recovery.
PV-SWRO pilot system schematic
Specifications
Pilot performance, measured.
- Operating voltage
- 295–354 VDC
- PV array
- 18 kWp
- Permeate quality
- < 300 TDS
- Seawater salinity
- 33,000 TDS
- Annual production
- 6,500 m³ (avg.)
- Seawater flow
- 21.5 L/min per module
- Operating pressure
- 680 psi (avg.)
- Ultrafiltration
- 0.03 micron
- Recovery
- ≈ 33% (Baja pilot)
Measured water quality
From 33,000 TDS seawater to below 300 TDS permeate
The logarithmic scale keeps both measured concentrations legible. The permeate contained less than 0.91% of the feed-water TDS.
Feed seawater
Permeate
Reported TDS value (logarithmic scale)
Measured T-1 module flow
What happens to 21.5 L/min of feed seawater
The paper identifies 33% as the most cost-effective measured yield for the pilot.
Feed seawater21.5 L/min
- Permeate
- 7.1 L/min
- Brine
- 14.4 L/min
- Pressure
- 680 psi average
Inside a module
Every module is a complete, integrated unit.
- Danfoss APP 2.2 high-pressure pump
- Danfoss APM 1.0 energy-recovery motor
- 3 hp three-phase electric motor
- Adjustable-ratio V-belt transmission
- Variable frequency drive (VFD) + electric controls
- Two 4" pressure vessels — six 4"×40" seawater membrane elements
- Titanium fittings & adapters, HP synthetic hoses, Victaulic couplings
The pilot, in the field
The installation on the Sea of Cortez.
Photographs from the working pilot in Baja California Sur, Mexico.
