These panels worth fitting?

[Solar mike]

Hello

I am new here and just registered a moment ago to ask a question. Hope that's ok :)

I recently got gifted 12 solar panels hanergy SL2-120F. These are 90v and 120w.

I understand that these are not the best panels by any means but they were working when removed and are sat doing nothing at the moment.

Am I right in saying I just need an inverter to get 240v out of them? Thinking I could use it for resistance heating such as the immersion.

Is there a way I could test them to see if they are working? On a sunny day they produce 90+v as per spec but I'm not sure open voltage tells me much.

Thanks in advance.
Mike

[Rob Beckers]

Mike, there should be a label on the back that specifies Isc (short-circuit current). You can try in full sun with an Amp meter if the panels produce something around that value (cover the panel with cardboard when you connect/disconnect, it's not good for connectors to be disconnected under load, it creates sparks that burn through the plating on the pins, causing corrosion in the long run). If both Voc (open-circuit Voltage) and Isc are measuring near reasonable values the panels are likely good!

Using panels to directly drive resistance heating works sort-of. You can only match the panel's output at one light level, the rest of the light levels the load will be off and efficiency takes a nose-dive. Still, if they are free and you are willing to experiment it's worth it!

-RoB-

[Solar mike]

Thanks Rob for the info!

[Solar mike]

Using an old boiler off an electric shower (240v/8kw) with one element attached :

Got warm with one panel
Got boiling (literaly) with two panels in parallel.

Is only a tiny volume of water (couple of cups at best) but still interesting. To me anyway.

That's a sunny day UK winter, couple of hours max.

Now thinking I'll wire up six in parallel to heat up an electric towel rad in my garage or perhaps underfloor heating.

Thanks