How many Watts do you get from your solar panels? (1 Viewer)

Jul 8, 2019
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Would be interesting to see how much power you all get from your panels and see what we're all doing right or wrong.

I've got an eco worthy 120w folding panel, generally get 40 to 55 watts in England full sun.

I've got 3 x Renogy 100w compact panels
Today I got 47w, 47w and 39w respectively on full slightly hazy sun.

Hoping the sun is the reason for the lower than expected figures
 
Jan 17, 2010
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I have two 80W panels and back in May while charging an ebike battery thru a inverter I pulled 145W out of my panels, I was in Daventry Midlands.
 

Two on Tour

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What you read from your solar charge controller will be dependant on the state of charge of the batteries your panels are connected to.
The lower the state of battery charge the great the reading you will get and if your battery is in a full state of charge then your solar charge controller should be doing its job and passing very little output from your panels to your battery or your battery will be over charged and cooked.

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Mar 30, 2019
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Yes true but once your batteries are full if you put a decent load on your system it will pull the max power from the solar then the rest from the battery, so load it to the max and see what watts you can draw.
 
Dec 2, 2019
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This is my solar harvest few days ago. Location, just north of Watford, midd day with a electric grill on. Panels 2x295w panasonic. Most of the time, if there is enough consumption, the panels consistently produce more than the nameplate.
 

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Oct 29, 2008
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Had my 12v coffee machine on and saw 142w from my 140w panel, it was only a spit second as the sun came out from behind a cloud and settled at 130w and over when the sun was bright

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Bobby-gg

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As everyone has said, it doesn't just really on what sunshine you've got, but how much power your consuming too.



Here's my 30day graph, most days I pull in about 2kWh during summer, but if I pull a load out at the same time I can obviously use more solar

For example, the highlighted bar, 18th July, I generated 3.36kWh and used 1.18kWh
 
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TobyQuest
Jul 8, 2019
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I have two 80W panels and back in May while charging an ebike battery thru a inverter I pulled 145W out of my panels, I was in Daventry Midlands.
Hmm. That's impossible because inverter loses are 15 percent so even if your solar panels produced a full 80w and you had zero losses through your wires or charge controller you would get 136w in perfect sunlight
 

Jim

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Jul 19, 2007
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I get more when it is sunny, less when it is dull and practically nothing when it is dark...


JJ :cool:


I have a couple of Lunar panels for sale, along with your solar it should keep you topped up 24/7 Give me a shout if you want a pair, they come in at a very reasonable £100 a Watt (y)

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TobyQuest
Jul 8, 2019
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I'm really impressed though that some of you so far have exceeded the power rating of your panels, that's great.
 
Jan 26, 2017
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I get more when it is sunny, less when it is dull and practically nothing when it is dark...


JJ :cool:
Yep, same here, I don't have one of those fancy monitoring systems, (they look the biz) , but have plenty of 12v to easily get through the night, with both batteries dropping to about 12.6 or there abouts.

Then they're charged up the next day.
 
Oct 9, 2019
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I have a couple of Lunar panels for sale, along with your solar it should keep you topped up 24/7 Give me a shout if you want a pair, they come in at a very reasonable £100 a Watt (y)
Is that sunlight or nighttime Watts ?

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Sep 12, 2011
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The solar controller plays a big part in efficency always fit mppt they are 90/95 % efficient at converting the solar panels output.

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TobyQuest
Jul 8, 2019
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Why would inverter inefficiencies affect the output of his solar?
Because the more inefficient your system is, the less watts you will get out of it. He's mentioned the power he got through his inverter to charge the ebike, unless the 147w was already factoring in the inverter inefficiencies in his calculation.
 
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TobyQuest
Jul 8, 2019
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The solar controller plays a big part in efficency always fit mppt they are 90/95 % efficient at converting the solar panels output.
For sure. Ive just gone for the standard Victron. Even they rate themselves not only better than PWM of course but even more effective than other MPPT charge controllers. I like it too because its really small and space is at a premium
 

Jim

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Jul 19, 2007
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Because the more inefficient your system is, the less watts you will get out of it. He's mentioned the power he got through his inverter to charge the ebike, unless the 147w was already factoring in the inverter inefficiencies in his calculation.

I read it as he measured in Watts what his solar panels were producing to power his inverter.

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bigtwin

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Oct 29, 2009
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This is my solar harvest few days ago. Location, just north of Watford, midd day with a electric grill on. Panels 2x295w panasonic. Most of the time, if there is enough consumption, the panels consistently produce more than the nameplate.

Those aren’t solar panels, that's a solar farm! 😳

Ian
 

cmcardle75

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Jun 8, 2012
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Hmm. That's impossible because inverter loses are 15 percent so even if your solar panels produced a full 80w and you had zero losses through your wires or charge controller you would get 136w in perfect sunlight

I believe he has two 80W panels!

Also, panel outputs are nominal. On days like we've been having, you can expect to exceed the rated output.
 

PeteH

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Nov 22, 2007
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Unless the battery bank is "down". The Solar output will show a Voltage equal to the Solar panel, but because there is no Charge required (full batteries) the current will be zero. ie power= 0w. As the battery discharges due to load and falls below the "open" point on the solar charger, a current will flow the product of the VxA=W will show as solar charge power.

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68c

Oct 22, 2019
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Hmm. That's impossible because inverter loses are 15 percent so even if your solar panels produced a full 80w and you had zero losses through your wires or charge controller you would get 136w in perfect sunlight
The rest of the power could be going to other things than the inverter.
 
Jan 17, 2010
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Glad to see nobody believes anybody on here lol
victron smartsolar recorded 145W, what else can I say apart from battery still had to supplement the inverter to charge the battery over 3 hours but it worked.

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TobyQuest
Jul 8, 2019
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I mean its great for you if its true. Which panels are they?

What do you mean the battery had to supplement the inverter to charge the battery?
 
Jun 2, 2018
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No it was charging an e-bike battery

Why use an expensive and inefficient inverter to turn 12v dc into 240v ac just for the e-bike charger to turn it back into 39v (or similar) dc?

I installed a DC to DC charger unit for a few quid, with a variable output for charging a range of devices including an eBike. Works fine. And although I haven’t done the calcs, I’m sure it’s more efficient.

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