My Dad kindly offered to design and put together a custom solar electrical system for us. Always nice to have bored retired engineers floating around when you need them. He was planning on replacing the solar panels on the roof of his camper van anyway (upgrading to make better use of the space) and we got the (still perfectly functional) old ones.
Batteries arrived a few days after Dad did, having been off to the coast for a few weeks. Lithium, 8 cells in total to achieve 24V.
He had a friend help him switch them on the roof of the camper van, as he had some better equipment than we did. They also welded up some frames for us for the old panels.
The framing is designed to be as simple as possible, able to stand up to strong winds, and potentially mobile in case we ever want to shift the panels closer to the eventual main house. There are 4 uprights of heavy angle iron (50mm) pounded into the ground at the corners. Then a rectangular frame of lighter angle iron (25mm) to hold the panels. Finally, two pieces at the southern corners to raise the frame at an angle.
We had to add an extra upright in the middle of the wider section of panels, as they sagged a bit which bowed the frame and made it prone to swaying in the wind. An extra piece of angle iron and a bolt fixed that.
The angled pieces on the southern end are fixed with bolts and wingnuts, and though they're current set to a steep angle as it's coming in to winter there's another hole drilled in the right spot for a shallower summer angle. The extra effort involved in changing the panel angle twice a year is well worth the gain in power.
Dad keeps joking that we'll have to stage some kind of ceremony twice a year on the equinox to change the angle of the panels. I'm not sure what the appropriate attire would be for blending science and druids - I have mental images of a group of people in long flowing lab coats chanting Monty Python songs while switching the bolts.
Dad spent a few hours testing the wiring in the site shed, which we were surprised to find seemed to check out.
Kyle and I spent two days building a weather proof box to house the batteries, inverter, and so on. A wooden frame, with cross pieces positioned in specific places to allow for attachment of various parts.
Then galv sheets over the outside to clad, and a corrugated iron roof. We made one side out of leftover perspex we had lying around, as one of the parts inside the box has a display to do with battery cell balancing. I thought about doing a window, but the whole side was just easier.
Dad spent the next week while we were at work setting up all the parts and cabling. At some stage I'll get him to do a post about why he picked each particular part, and how it all went together. It'll be like an entire thesis, I'm sure. He keeps talking about first principles of battery charging, but the system he's designed is a highly customised set-and-forget. Either way, he wired up everything into our box nicely.
Then, we turned up the next weekend, and most of the wiring in the site shed just worked!
We have a dozen or so power points, several internal lights, and an external light. Over the coming few years the idea is to expand the system as needs arise, but currently we have panels that add up to about 600W, batteries at Ah, and a 3kW inverter. That translates to enough power to run most things we need for day to day living, though there's not so much extra that we won't have to watch it a bit.
After all of this was hooked up Dad and I ran cabling into the building for an inverter on/off switch and a battery level gauge, but I forgot to take photographs of that part. Which is a shame, as passing the cabling up through the walls required some amusing gymnastics. I'll take a photo next time I'm out there as we have a few bits to add to it yet.
Batteries arrived a few days after Dad did, having been off to the coast for a few weeks. Lithium, 8 cells in total to achieve 24V.
He had a friend help him switch them on the roof of the camper van, as he had some better equipment than we did. They also welded up some frames for us for the old panels.
The framing is designed to be as simple as possible, able to stand up to strong winds, and potentially mobile in case we ever want to shift the panels closer to the eventual main house. There are 4 uprights of heavy angle iron (50mm) pounded into the ground at the corners. Then a rectangular frame of lighter angle iron (25mm) to hold the panels. Finally, two pieces at the southern corners to raise the frame at an angle.
We had to add an extra upright in the middle of the wider section of panels, as they sagged a bit which bowed the frame and made it prone to swaying in the wind. An extra piece of angle iron and a bolt fixed that.
The angled pieces on the southern end are fixed with bolts and wingnuts, and though they're current set to a steep angle as it's coming in to winter there's another hole drilled in the right spot for a shallower summer angle. The extra effort involved in changing the panel angle twice a year is well worth the gain in power.
Dad keeps joking that we'll have to stage some kind of ceremony twice a year on the equinox to change the angle of the panels. I'm not sure what the appropriate attire would be for blending science and druids - I have mental images of a group of people in long flowing lab coats chanting Monty Python songs while switching the bolts.
Dad spent a few hours testing the wiring in the site shed, which we were surprised to find seemed to check out.
Kyle and I spent two days building a weather proof box to house the batteries, inverter, and so on. A wooden frame, with cross pieces positioned in specific places to allow for attachment of various parts.
Then galv sheets over the outside to clad, and a corrugated iron roof. We made one side out of leftover perspex we had lying around, as one of the parts inside the box has a display to do with battery cell balancing. I thought about doing a window, but the whole side was just easier.
Dad spent the next week while we were at work setting up all the parts and cabling. At some stage I'll get him to do a post about why he picked each particular part, and how it all went together. It'll be like an entire thesis, I'm sure. He keeps talking about first principles of battery charging, but the system he's designed is a highly customised set-and-forget. Either way, he wired up everything into our box nicely.
Then, we turned up the next weekend, and most of the wiring in the site shed just worked!
We have a dozen or so power points, several internal lights, and an external light. Over the coming few years the idea is to expand the system as needs arise, but currently we have panels that add up to about 600W, batteries at Ah, and a 3kW inverter. That translates to enough power to run most things we need for day to day living, though there's not so much extra that we won't have to watch it a bit.
After all of this was hooked up Dad and I ran cabling into the building for an inverter on/off switch and a battery level gauge, but I forgot to take photographs of that part. Which is a shame, as passing the cabling up through the walls required some amusing gymnastics. I'll take a photo next time I'm out there as we have a few bits to add to it yet.
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