Solar Panel Rails

The rails for 6 x 250w 24v panels have been installed on to the north facing roof of my carport.

Testing new Grid-tie inverter

Whilst the 'Net-meeting' law has not yet been passed in Chile, I'm nevertheless putting together my hybrid solar/wind solution to provide off-grid battery backup and the ability to feed energy into the house electrical system - grid-tie.

I've chosen to split my 6 x 250w panels into two groups. Here I'm testing a Smart Micro Grid-Tie inverter which connects directly to the solar panel. It will convert the 24-40v DC from the panel directly to 230v ac. 

There are several advantages to using this type of inverter:-

- Highly scaleable, add panels and inverters as your needs grows
- Reduces single points of failure, you are still generating power even if one panel or inverter goes down.
- Control losses normally created by long DC cable runs

In the picture above, the 60 cell 250w panel is generating 226w 230v AC in moderate sunshine and is plugged into the household supply. If the grid-power drops, the inverter automatically cuts the AC output. It was interesting to observe how the AC output varied depending on the amount of sunlight striking the panel. It seemed fairly linear all the way from 200w+ down to just 10w output in low light conditions. 

Roof and cement

No 'ReadyMix' used here, but 24 bags of cement and 6m3 of sand/pebble mix, a simple cement mixer and wheelbarrow to transport each mix to the pad. The surface was leveled and smoothed using a plank of wood! Back breaking work, it took two days to complete. 

Fitting the roof tiles

HF Low Pass Filter construction

I've started building a LPF diplexer filter rated for a 1KW SSB/CW HF transistor power amplifier

The diplexer consists of 6 relay-switched units and covers 1.8 to 30 MHz amateur radio bands. It has 1 input port and 6 antenna outputs, so no additional ant-switch is needed.

Next comes the hard part - winding the toroidal ferrite cores, and tuning them for each band.

Carport Construction p2

The basic structure of the Carport is complete; now I just need to order the roof tiles to match the house and a few days without rain to install the pine ceiling. All the exposed Oregon Pine has been painted with a non-stain wood preserver. Ethan, posing for the camera, provides a good reference of scale.

Carport Construction

I took advantage of a short break in the rain to begin construction of a carport. The roofed parking area will span 8 meters wide x 6 meters deep - ample space for two vehicles. The carport will also double as a nice shaded area over-looking our swimming pool during the hot summer months.