Two things most – if not all – South Africans can agree on is that Eskom has let the team down with rampant loadshedding and water shortages happen far too often.
With these issues in mind, a research paper published in June caught our attention. The paper (accessible through Joule) titled “Integrated solar-driven PV cooling and seawater desalination with zero liquid discharge” and authored by researchers in China and Saudi Arabia, outlines a system that desalinates water and generates electricity at the same time.
The system is called a PV-membrane distillation-evaporative crystallizer, or PME, and it’s rather clever.
PME consists of a photovoltaic cell which sits on top of a multistage membrane distillation components. This distillation process uses the heat from the PV cell to drive evaporation in each distillation stage. The idea is that you are left with fresh, salt free water. The concentrated brine that is left behind in the desalination process is fully evaporated during this process. This leaves behind salt and the evaporated liquid is used to cool the PV cell.
“In laboratory tests simulating solar illumination at an ambient temperature of 24 °C, the temperature of the solar cell on the PME was around 14 °C cooler than an identical solar cell not mounted on a MSMD component. The led to almost 8% more electricity production, compared to the bare solar cell. In the same test, the PME produced fresh water from seawater at a rate of about 2.4 kg/m2h, which is almost double that previously reported for a combined solar and desalination device,” Physics World reports.
The authors of the paper told Physics World that they are currently scaling up the PME and plan to build a photovoltaic farm that generates electricity and desalinates seawater.
We hope that the PME works at scale because it could help many countries where freshwater is scarce and electricity is just as scarce.
Check it out Eskom, maybe clever solutions like this will help you claw your way out of the hole you’ve place yourselves in.
[Image – CC 0 Pixabay]
