SMA Webbox

SolarRoofSols · Feb 13, 2012

We are planning an install on 2 blocks of private flats and the client wants a remote monitoring system for it. The array details are below.

9 kw per roof fed into 2 4000TLs (total installation is 18kw/ 4 inverters)
Single phase supply (G59)
1 generation meter per site (2 in total)
The 2 sets of inverters will be 30m apart.

I was thinking 1 SMA Webbox with a repeater in one of the block of flats and then the client can utilise the free SMA portal for monitoring so they won't have to pay a monthly fee for hosting.

Does this sound like a good set up or should we have the 2 webboxes...or something else entirely?

Gavin A · Feb 13, 2012

problem with the web box is it needs a web connection, which would probably have to belong to one of the flats, and usually the flat renters own the modems etc.

We've also noticed a bit of a problem with them in that if the power is cut for any reason, on restart the web box starts up faster than the modem, fails to connect to the web because the modem's not connected, doesn't get allocated an IP address, and then won't work until the web box is turned off an on again, so not great for a situation where there's nobody on site to be sorting it out after a power cut etc.

I'd think a remote meter (we use Orsis for this) would be the better option as it's not reliant on a web connection, and actually is providing the reading from the meter that's needed for FIT purposes, not the inverter reading. Something like £30 a year network charges, but it's also probably £200 cheaper than a web box in the first place.

SolarRoofSols · Feb 14, 2012

Thanks Gavin, I had not considered the power failure issue so will look into the Orsis option, I take it it uses GSM?

Gavin A · Feb 14, 2012

yep.

and it has a web portal fairly similar to the sunny portal, with the ability to set alarms for under performance etc (although tbh we've not actually got these features set up yet so not sure how they'll function).

mmccx · Feb 21, 2012

you can get a gprs version of the webbox so you wont need an internet connection just a sim card. You could also get the counter and hook it up to the meters so the actual generation is uploaded to the portal which means your client wont have to go to the site every 3 months to get meter readings