PV-driven portable air water generator for remote areas
Scientists in Saudi Arabia have created a PV-powered air water generator that can be used in remote areas or on lengthy vehicle journeys. It can reportedly produce a liter of water at approximately $0.04 for packing and zero for non-packing.
Scientists in Saudi Arabia have created a PV-powered air water generator that can be used in remote areas or on lengthy vehicle journeys. It can reportedly produce a liter of water at approximately $0.04 for packing and zero for non-packing.
Researchers at Jazan University in Saudi Arabia have created a PV-powered adaptive portable air water generator (AWG) that can reportedly produce 2 L of water over a 24-hour period.
AWG systems extract water from humid air through a DC heater that separates the air water content from the humid air using a high-speed brushless DC fan, which condenses it on the surface of the heat sink, producing water that is then transferred to a storage tank.
The novelty of the proposed AWG is its coupling with photovoltaic energy. “In the current market, most AWGs are designed to consume more electrical energy to extract drinking water,” the academics explained, noting that cheap solar power may help adress these costs.
The system comprised a DC heater, a heat sink, a DC brushless fan, a 120 W solar PV module, a 12 Ah battery and maximum power point tracking (MPPT) control algorithms. A DC-to-DC converter, which is also known as zeta converter, is utilized to control DC output, with its switch being pulsed at maximum power using effective control techniques.
“The zeta converter stands out due to its wide range of duty cycle control algorithms and non-inverting output, making it a versatile option in the field,” the research team stated. “A feedforward increment conductance (FFINC) intelligent controller is an excellent choice for increasing the voltage level to 12. 5 V to charge the battery and power the 10 W DC brushless fan and the 50 W AWG.”
Image: Jazan University, Environmental Technology & Innovation, CC BY 4.0
The system also uses a model reference adaptive control (MRAC) to manage the output voltage of a DC-to-DC zeta converter via the FFINC, while the DC heater is controlled by a simple “intelligent” control algorithm. The MRAC is commonly adopted to solve problems related to adaptive control in real world.
The input voltage of the solar panel was 17.5 V at the maximum power point, while the output voltage of the zeta converter was stabilized at 12.5 V to charge the battery.
The scientists investigated the performance of the PV-driven AWG performance under both transient and steady-state conditions and found that total current consumption is was 4.6 A and 3.4 A, respectively. Furthermore, they found that maximum power consumption under steady-state conditions was approximately 48 W.
They also found that a research lab air water generator (AWG) was able to produce 2 L of water in 24 h, with a 40% relative humidity in the AWG itself.
“An AWG set operates for an hour from 9:00 AM to 9:00 AM every 24 h,” the team further explained. “In a span of 9 h, the system produced 65 ml of water at a relative humidity of 35%.” It also noted that the market cost of one liter is about $0.25, while the cost of one liter produced by the AWG is approximately $0.04 for packing and zero for non-packing.
The proposed AWG system was described in “An adaptive control portable air water generator powered by solar photovoltaic,” published in Environmental Technology & Innovation. “It can produce water in a desert area or a lengthy vehicle journey. It is cheap and unanswered to the electrical bills,” the scientists concluded.
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