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Cheap solar panels and the SQFlex pump

I found a great deal on some solar panels on Amazon. They are sold by a company called DMSolar. The DM145 panels (145 watts) were sold for $160. If you have Amazon prime, you get killer two day shipping. Such a steal…if the panels are legitimate. Deals like this are often too good to be true. Upon receipt and inspection, the panels look clean and of good build quality. They are marked as being manufactured in Thailand…I wish I knew who really made them.

I hooked three panels up in series to run my SQFlex pump (ideally at 60VDC). The pump runs! At this point I do not have more than anecdotal evidence on the performance. I would guess I’m getting three to four gallons per minute. The watt meter on the pump’s control unit indicated 230 watts (out of a theoretical maximum of 435 watts)

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Solar mounts for the well house

I’m searching for the correct and cost-effective parts for the well-house. S-5 has been great in answering my questions. I settled on using the S-5-U Mini with PV Kit on Champion Snap-Loc raised seam roofing.

I found the clamp and PV Kit combo for $8.64 per piece (both pieces) at ABMartin. I was a little hesitant in using this company, but they had the items in stock, shipped quickly and gave me a reasonable shipping quote.

I also found the GBL-4-DBT grounding clamps at my local Platt. I was able to pick these up and not pay shipping.

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Off grid drip irrigation

There are not many resources on the Internet describing off grid drip irrigation. The major difference is using a dc water pump to pump and pressurize the drip line. Most of the dc water pumps are meant for rv’s. Flowjet and Shurflo are the biggest pump manufacturer’s.

For my rural property, we want to plant some fruit trees. Our well pump and infrastructure are solar powered, so drip irrigation seems a logical choice to conserve resources. This weekend I tested this.

I used a Shurflo Revolution (series 4008 3.0 gpm) pump from Amazon (about $90) and twenty 2gpm pressure compensating emitters. The test setup was 50 feet of 0.5″ trunk tubing directly coupled to the Shurflo pump. Each emitter is on five feet of 0.25″ tubing. I first volume tested ten emitters, then twenty emitters. The volume test was run for two minutes. I found that in both cases the system overwatered by 20%. The amount did not change by more than 5% when going from ten to twenty emitters. I am guessing that the 55psi output from the Revolution pump probably exceeds the spec of the emitter. In the real world, additional friction from longer 0.5″ trunk line will reduce the pressure, at least at the end of thee drip line.