Most reacted posts

I went back today to test the rest of the batch and retest the several with low values. The results confirm what I suspected: in dimming sunshine (day1, 2PM and progressively later) the Amp output declines steeply and very fast. On day2, today, the testing began at 11:30 (bright sunshine) and...

So you have either 240 or 60 or 266 Watts of power? Let's decide which it is. Afterwards, if this were my system, I'd want to do two things: 1) Observe whether and how these values change during the day as a result of MPP tracking by ACTii (and) 2) I would be curious to experiment with...

@Courter: Have you received / installed this controller? I am also considering the purchase. A bit concerned with the seller's lack of replies to several of my messages, both direct and through ebay. The unit looks very good in theory. Why did you go with AC7392 instead of the earlier and...

I am negotiating a purchase of 20 second hand (12yo) poly PV 200W panels. Is $50/panel a decent price? They are a local pickup for me. Originasl Specs: Voc - 33.4v, Isc - 8.12A I was able to test about half of the lot today, in full northeastern November sun, from about 1PM forward. At some...

I am looking at a used AET drainback tank, 10 Gal, with a heat exchanger coil inside. The level sight tube is completely dark - so dark, I thought it was broken and replaced with a dark plastic tube. Seller says it's still glass and is "sediment" discoloration. Anyone seen something like this...

@efficientPV ...I read a lot of your commentary (here and in other places) and learn a lot, although your info is usually above my paygrade. I'll reach out in the future when embarking on my project in earnest. *** @Courter, right now some of the numbers you've posted are not adding up. 4 x...

I am running some tests and trying to estimate the viability of direct PV HW heating. Planning to use a solar HW MPPT controller, but testing a simple direct connection for now. Current setup is a 55Gal dual element HWH with direct DC from the PV array connected only to the 5500/240v lower...

Thanks Rednecktek! My main concern is whether the dark deposit could be residue from melted/degraded PEX or acidified glycol. If these tanks are known for this (dark deposits on the sight glass) in otherwise healthy systems, then cleaning should be relatively easy. I appreciate you sharing...

@Courter, I reread the early thread and found the array specs. you posted. With Vmp 34.1 and Imp 9.37, 4S, your 240v/4000W element, at 14.4 ohms, might be just a bit below where the formulas point, which is an element of 14.56 Also, the "magic formula" says your element could be as high as...

...good idea on the anode. I'll check once I have it in my shop. I am encouraged by that the deposits are not more alarming than a cleaning issue. Thanks for the comment!

What is the resistance of your 400W heating element and is it a correct match to your array? Isn't continuously sending the maximum current to the heating element, regardless of suboptimal current production (due to sun angles and shading) the whole point of MPPT? Why only over 100V? Can you...

>>I use 1 kWh to heat 6 gallons of water. What is your element resistance? PV array specs? MPPT controlled or not?