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Solar panels + cold = A potential problem

linspyre.com

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Re: Solar panels + cold = A potential problem

#11

Post by Animats »

Why doesn't this just produce a shutdown? Inverters have to track voltage and current on the input and outputs sides, and can turn themselves off. They shouldn't be that close to the absolute maximum voltage ratings on the components.

Too much current is a heat dissipation problem, and you've got some time to deal with that, at least tens of milliseconds.

Anyone have a teardown on these things? Are they using under-rated MOSFETs? That's all too common in solid state relays from China.

Re: Solar panels + cold = A potential problem

#12

Post by dhosek »

When I got solar panels for my (former) house 15 years ago, as I recall, the best practice was to have panels in parallel (each with its own microinverter) and not in serial as serial would cause loss of efficiency when there was partial blockage of panels. (I could be misremembering all of this).

Re: Solar panels + cold = A potential problem

#13

Post by syntaxing »

> Plugging in four 400w solar panels in series is similar to filling your gasoline powered car with diesel and wondering why the car manufacturer isn't replacing your new car.

I don’t think this analogy works. The solar input works like Diesel or Gasoline in different temperature. It’s pretty unreasonable to assume the consumer knows when depending on temperature unless the explicitly state in the manual (I’m willing to bet good money majority of the people in US have never read their car manual either)

Re: Solar panels + cold = A potential problem

#14

Post by bobjordan »

BobbyTables2 wrote: post #2

Why would lower temperatures lower the maximum voltage? Sure, diode forward voltages change a little but seems like something else is going on…

Lower temperatures increase PV max voltage output, not lower it. Conversely, when solar panel temperature increases, voltage decreases. So the headline specs/outputs assume to be valid at a particular temperature. As the temperature of the panels change, the realized performance changes.

Re: Solar panels + cold = A potential problem

#15

Post by dgfitz »

therein wrote: post #4

I am sure many are familiar but I found it amusing when someone explained to me why it is called magic smoke. It is because electronics work through magic so when you let the magic smoke out, they stop working.

I’ve never heard it called magic smoke before, but a regular saying at one of my old jobs was “ah yeah we let the smoke out” in relation to 100% electric drive vehicles. Smoked many inverters, shorted 96v bus to a 24v bus, etc.

It was almost a rite of passage to “let the smoke out” in that org. That job was actually great because as a software engineer I happily spent a lot of time with a fluke, a wrench, arm buried in the bowels of a vehicle fishing out sockets, etc. Writing the software was not the hardest part of those programs, but being one of the handful of folks that knew the entire electrical, cooling, mechanical, and software systems made us the most valuable folks on the program. We had to know all those things in order to write the software correctly.

Re: Solar panels + cold = A potential problem

#16

Post by NooneAtAll3 »

dhosek wrote: post #12

When I got solar panels for my (former) house 15 years ago, as I recall, the best practice was to have panels in parallel (each with its own microinverter) and not in serial as serial would cause loss of efficiency when there was partial blockage of panels. (I could be misremembering all of this).

you might be misremembering bypass diodes?

Re: Solar panels + cold = A potential problem

#17

Post by ggm »

dgfitz wrote: post #15
therein wrote: post #4

I am sure many are familiar but I found it amusing when someone explained to me why it is called magic smoke. It is because electronics work through magic so when you let the magic smoke out, they stop working.

I’ve never heard it called magic smoke before, but a regular saying at one of my old jobs was “ah yeah we let the smoke out” in relation to 100% electric drive vehicles. Smoked many inverters, shorted 96v bus to a 24v bus, etc. It was almost a rite of passage to “let the smoke out” in that org. That job was actually great because as a software engineer I happily spent a lot of time with a fluke, a wrench, arm buried…

In the early 80s we used to say electronics ran on magic pixie dust, and when you let the pixie dust out as smoke, the magic went away.

Re: Solar panels + cold = A potential problem

#19

Post by ianlevesque »

NooneAtAll3 wrote: post #16
dhosek wrote: post #12

When I got solar panels for my (former) house 15 years ago, as I recall, the best practice was to have panels in parallel (each with its own microinverter) and not in serial as serial would cause loss of efficiency when there was partial blockage of panels. (I could be misremembering all of this).

you might be misremembering bypass diodes?

No, microinverters are still a thing (Enphase is a popular brand) and they do then get connected in parallel.

Re: Solar panels + cold = A potential problem

#20

Post by nenenejej »

Why isn't there code/regulations for tbis. Why do you need blog advice.

It is like using too thin wiring to your oven or something. Because you based it off how you typically use the oven not is max draw plus decent margin.

Which is why you get a qualified electrician who knows or get qualified yourself.

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