Friday, September 9, 2011

2KW Grid-Tie system setup


This post marks my almost 2000 KWH produced so far and sold to Enemalta (my local power provider).

My Grid-Tie system basically consists of:
1. 9 (nine) 230W solar panels. IBC PolySol 230TE
2. One SMA Inverter. Sunny Boy SB 2100TL Transformerless solar inverter.

All items were bought from a local company - Crosscraft Energy which specialises in renewable energies and energy saving products. I must say that I'm truly happy with their service, expertise and after sales service. C

I've attached some photos below to demostrate my setup.
The above photo shows the nine 230W panels. Showing also in the background are another 4 smaller panels, (mounted on poles at the back) used for the off-grid system and also one of the water solar collectors (right panel).

The above photo shows three of the panels aluminium structure (as supplied by Crosscraft), bolted to eight concrete filled-in bricks acting as anchors.

Another photo from above.

The above photo shows the bottom string of panels mounted at 30 degrees to the building. A special galvanised structure was built to accommodate these panels. Special thanks go to my neighbour Mario for helping me with the structure, both building and mounting.

The above photo shows the SMA 2100 inverter. Note that contrary to many installations, I mounted the inverter in the garage (ground floor).
My reasoning was simple;
  1. Inverter is NOT exposed to weather elements such as rain, sun, heat and salt (I'm located close to the sea).
  2. My garage indoor temperature is much lower than the temperature beneath the panels where the inverters are normally mounted. This will provide my inverter with a more comfortable temperature to work in. Lower temperature  = prolonged service life, this being applicable to any electronic component!
  3. If needed, I can add extra cooling to the inverter by placing fans, something not possible and practical if the inverter is placed outside.
  4. By tapping on the inverter, the display comes on and I can know at a glance how much energy I produced, being today and/or cumulatively. If the inverter was mounted on the roof and underneath the panels, accessing it would prove to be more difficult.
  5. Less losses contrary to what most believe! My panels are all connected in series, totalling 264v DC (STC 29.4v per panel x 9). This is higher then the 230v-240v AC rms if the inverter was located on the roof. The higher the voltage, the less the power loss. Besides, I used extra thick cables to compensate for any voltage drop. Normally 4mm is used however I went for a 10mm cable run. This reduces the voltage drop by half when compared to the 4mm.

The above photo shows a section of my garage wall were I have my controls mounted. The yellow box is the Grid-Tie inverter.

I'll be posting my production statistics in a seperate post.


  1. Very interesting thanks for explanation! By any chance did you need any special permits (MEPA - Enemalta etc) or have any hassle getting connected to the grid? I'm iterested more in wind turbines since I have limited space but very detached and so quite good wind currents all through the year.

    1. Hello Tony.
      To connect a PV system system to the grid, yes you'll need permission from Enemalta, in fact they will install a second meter (on which you'll have to pay rent as well ;)
      To connect a wind turbine, you'll first need a permit from Mepa. In my case, I raised the tower/turbine much before Mepa issued any guidelines, to be exactly I had applied for the gov grant on wind turbines when Mepa did not even have any policies! Besides my turbine is classified as a 'micro-turbine', very small and considered more as a 'toy'. Mepa has policies now. Read here-
      If you're detached and have no neighbours than it's great! If I could I would have raised another one :)