Navitron Renewable Energy and Sustainability Forum

Announcements & News => Media Watch => Topic started by: Nickel2 on July 10, 2019, 09:18:15 AM



Title: PV / Desalination plant
Post by: Nickel2 on July 10, 2019, 09:18:15 AM
The 'scientists' have developed a way of combining PV panels with desalination to get drinking water and electricity. There is a company called MedAd Technologies that has been onto this for a few years now, in Singapore, with research at KAUST in Saudi Arabia.
Think what you could do with your muddy back-yard ditch and a small handful of panels...    :)

https://www.bbc.co.uk/news/science-environment-48910569


Title: Re: PV / Desalination plant
Post by: Westie on July 10, 2019, 12:02:52 PM
I've often thought about adding a heat exchanger to the back of a PV panel, you then have a source of hot water and a more efficient PV panel.



Title: Re: PV / Desalination plant
Post by: azps on July 10, 2019, 06:31:49 PM
I've often thought about adding a heat exchanger to the back of a PV panel, you then have a source of hot water and a more efficient PV panel.

Yeah, people have built hybrid solar OV-thermal panels. They've reached the market. They've never really done well at all.

And now PV is so cheap, and zero-maintenance, that it no longer makes sense to try!


Title: Re: PV / Desalination plant
Post by: Philip R on July 10, 2019, 07:53:01 PM
Most on the energy landing on a PV panel ends up heating the thing. So much so that it reduced the power output of the panel. My 3.5kW system derates to 2.8kW after a good sun soak. cold sunny spring day and power is greater than its rating, even if the sun azimuth is less optimal. Cooling of a PV would have great benefits.I would be summising a copper serpentine water or refridgerant pipe bonded to a flat copper or aluminium plate on the back of the PV. It would increase the cost way more than buying more PV, which is basically what AZPS has said just before.

The methodolgy of cooling is the problem. A typical domestic situation with PV installed would boil the hot water cylinder with energy input availible from the PV panels roof area. So what to do with the heat.  Store it underground and extract it during the winter, even if most of it has leaked away. Forum went there about 7 years ago!!! :fume
cool it with an air blast heat exchanger, then you are using the PV extra captured output as electricity to cool it down again, a bit of a waste.

So yes the solar PV desalination plant sounds great. The Saudis use a significant proportion of their oil production to run steam power plant, ( to run air con) and loads of gas to run the desalination plants. Using this system could conserve the oil or improve their balance of payments situation, which has not been good lately.

It offers a great solution for places in Africa, Australia and the south western United States ( Arizona in particular- even though it is landlocked). The planet surface area is 71% sea water, and a lot of that surrounds sunny climes, so it is a no brainer.

Philip R