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Rainmaker 550 solar water distiller

November 08, 2019 — BarryK

Taking some time out to think about the design, after yesterday's test of prototype #4:

I got to thinking that I should build a simple basin type of solar water distiller, for comparison. It could be run alongside my own design, and could also run the F-Cubed panel alongside, to get a true comparison. I did this awhile back with photovoltaic solar panels, and it was very meaningful to see one particular photovoltaic was shown to definitely have overstated its claimed power output.

While browsing on the Internet last night, I looked up a commercially available simple basin type distiller, the Rainmaker 550, just wanted to see it's specs. The simple basin type is supposed to be the least efficient, I say "least" because that is what I have read, however the published figures for the Rainmaker have taken me by surprise.

Here is a photo:


Here is a webpage with specs:

They are claiming:

In temperate climates, the Rainmaker 550 produces up to 1.5 gallons (six liters) per day in the summer, and approximately half that in the winter months. Thermal efficiency (60%) is equivalent to about 550 Watts when operated in full sunlight. Production is about 0.8 liters per sun hour (kWh/m2).

The surface area is given as 0.93 m2. So, 800 millilitres/hour, and adjust to compare with the F-Cubed panel, 800*(1/0.93) which is 860 ml/hr -- surely not, that is far higher output than I got with the F-Cubed Carocell 1000 panel!

Are the Solaqua people telling porkies?

I only got 564 litres/hour when testing the F-Cubed panel, but that was mid-winter, though a sunny day (ambient was about 17 degC). So, to be fair here, need to compare with the claimed output. See here, for the Carocell 1000 (the model I own):

...they claim 7 litres/day in summer with ambient temperature 30 degC. OK, a tad better than the 6 litres claimed for the Rainmaker 550, but gosh, the Rainmaker is a far simpler design, easier to setup and use in the field also.

Hmmm, I have to find out for myself. I can easily knock one up from bits and pieces lying around in the garage, will hardly cost anything. Already have glass from the earlier prototypes. I could even build it with cardboard, as the inside will be lined with black silicone sealant and should be able to prevent any moisture to reach the cardboard -- good enough for doing the comparison testing anyway. 

Just one extra note: one reason that I went for the sloping wick-type distiller, is want something fairly flat that will slide into the back of a car and take up minimal space. That, and improved efficiency. So if I do decide to go for a simple basin type, it will have to be a collapsible design. 

Tags: nomad