NHG Solar Shed

Each member is encouraged to generate, store and use their own solar energy. However, as this is not a requirement but a nice to have, the Solar Shed in the North Hamlet Garden is the main energy production facility for the community. Today the system generates around 65kW per day and our storage is around 51kWh. We have ample space and resources to take our daily generation to around 104kW and storage capacity of 72kWh. 

The solar shed cotains all the specialised electrical equipment that is used to capture, store and distribute the power that is generated to the plots and facilities in the community. Each plot has its own power point and electricity is provided via a main trunk to each of the electrical pillars and then using smaller cable delivered to each plot and facility. We have slightly oversized most of the trunks and distribution arms of the system to ensure that we can continue to build out the community facilities as they are needed without having to redo essentials like cable.

This is also the case of the water and sewerage systems that have been deployed.

All the utilities ar Kirra are underground. This added extra costs and meant that we had to dig up the roads to lay cables and pipes, but with that all behind us, you would never know that this had been done.

Power is now delivered to plots #1, #2, #3, #3a, #4, #6, #7, #8, #9, #10, #11, #12. With the exception of plots #10, #11, and #12 all the plots in the North Hamlet are complete excluding plot #5 and provisional plot #18. Plots #10, #11, and #12 are plots in the South Hamlet. Plots #14 and #15 and provisional plots #16, and #17 are yet to be completed for any utilities.

Building the Solar Shed took a bit of time, as we used the engineered adjustable stumps and built a solid deck before the shed went up. Once the shed was installed, we added a stud wall and ceiling and insulated everything and then added 12mm chipboard to all surfaces. This ensures that the shed remains cool during hot summers. Together a temperature controlled set of fans was added to extract any hot air and suck cooler air from the southern side of the shed.

Building the Solar Shed

We started by measuring out the deck that the shed was going to be mounted on, and using the augar or the excavator dug 1200mm deep holes to the sandstone for the piers. We mounted the piers and concreted them in place. Once the concrete was cured, we removed the forms and bolted the stumps to the piers.

With the concrete cured and the stumps firmly bolted to the piers, it was time to add the joists and build the floor. All the timber work here was done using reclaimed shipping container pallets. We had to pull these apart by hand and clean up all the timber. Before the joists and deck were added, a trench was excavated where the conduit was going to be installed to exit the solar shed.

All the exposed timber was painted in sump oil to help preserve it and protect it from the weather. The painted red square represents an area that should not be loaded as the timbers are not structural in that location becuase of the large hole cut for the main conduit.

With the deck installed and ready it was time to erect the absco shed and get the super-structure done.

We built the shed and as we tried to erect it the wind got up and well, it was one of those days you wished you stayed in bed. But wil a lot of swearing we finally got it up and secured to the deck.

We added a much stronger second roof to the shed which extended over the area that the generators are housed in. This is the open area on the left hand side. We also wrapped the whole building in shade cloth to help keep it a little cooler during summer. Once this was all done, we added some simple steps and a gutter to send the water into the rain catchment tanks, which are located right next to the solar shed.

Time to move onto the stud walls and the ceiling. This took a little bit of time, but wasn't complicated. The wall is clad with 12mm second hand chipboard which we got for $60. So it wasn't perfect, but it did the job nicely. Once that was all done, we added the doors and the door furniture and we were looking good to start the equipment installation. It goes without saying that the final shed wasn't square. It was confined and hard to work in with little room to add battens and move timbers around in. But we got there.

Finally time for the fun part, adding the equipment. In this installation we are using the Growatt SPF 6000 integrated charger and inverter. This is a remarkable unit that allows upto 6 units in parallel to produce both single and 3-phase power. We only needed a single unit providng single phase at this junction so thats what we installed. We have space for the remaining 5 units which we will add as we need them. Our battery selection in this case was AGM batteries. The Growatt requires some 1200Ah once all 6 units are installed, and we struggled to find any lithium batteries that were capable of that level of expansion at a reasonable price, so we went ahead and got the AGMs. In this case we have started out with 660Ah at 48v. We can double the installed batteries to achieve the required 1200Ah needed for the 6 units. At 660Ah, this will service the first 3 Growatt units. So lets get going and install some stuff... We installed an integrated battery balancer this time, and it does a great job of keeping all the batteries in sync. And the obligatory smoke detector and wifi repeater.