Speedster
Honorary Master
I've been prepping a solar system for my home for quite a while, and have certainly learnt a ton along the way. Over the past 18 months or so I've asked perhaps too many questions (to the great annoyance of some forumites), but I've gleaned enough info to have been confident enough to finally get to work on the install a short while back. I realise there are (at least) two approaches one can take with a project like this - (1) pay someone a good sum of money to take care of it all and (2) take time to learn and do what you can yourself. Neither is right or wrong, there are certainly benefits to both, but I chose (2). In this thread I'll try to detail some of what I've learnt. Perhaps it will help another curious soul like myself. Almost certainly it will invite a ton of criticism from other citizens of MyBB-land. Hopefully this will be the next step in my quest for understanding.
I'd initially started looking at installing solar at our previous house (which already had a solar geyser) but we decided to move mid-covid which put paid to all those plans. We managed to find, and buy, a beautiful double storey house in a lovely neighbourhood. Little did I know at the time it was in a load-shedding exempt suburb, so that was a pretty neat surprise. A couple of months into the new house my mind started drifting towards solar again, but since LS was not an issue, purely as cost reduction. I got hold of an efergy and started monitoring my usage. I also put one of the geysers on a CBI astute timer, while the pool pump and borehole went on Sonoff POWR2s (all managed by Home Assistant).
The next step was preparing the roof. I have an exceedingly large jacaranda tree which shades the majority of my north-facing roof and so the only feasible option was the section of almost flat unpainted IBR roofing on the south side of the house. Upon inspection I realised this would need some maintenance as the last thing I wanted was to have to deal with leaking or loose roof sheets a couple of years down the line. I sanded down the rusted parts, applied rust-mate, galvanised primer and finally two coats of roof paint. I also replaced any loose roof nails.
While prepping the roof I investigated a number of system solutions - micro-inverters, grid-tied etc - but the maths kept leaning towards a hybrid system. I'd been on the lookout for deals and managed to pick up some almost new Pylontech US2000Bs for a really good price, as well as a Deye 8.8kW inverter. I sourced a few quotes on installation and was pretty shocked at the going rates for what is largely pretty simple DIY-able work and since cost reduction was my goal I figured I could do some of that myself. I went to work on sourcing roof mounts and found a really good supplier of Renusol mounts a stone's throw away from our house and ordered the necessary parts. Setting up the roof mounts was really easy, as the supplied hanger bolt simply replace the existing roof screws. I did need to drill slightly larger holes in the IBR as well as bigger pilot holes. The trickiest part was getting the screws in straight as the guys who installed the roof didn't pay much attention to hammering them in straight. I needed to fill up some of the holes with a mix of sawdust and wood glue and was then able to redrill the holes straight once that had dried. My roof can fit two rows, and spacing of these is also pretty important to prevent the front row shading the back row. There are a number of research papers and formulas to help get the optimal spacing, as well as some online calculators for this (e.g. https://www.renvu.com/Inter-row-Spacing-Calculator and https://www.jinyi-solar.com/Solar_Basics/solar-collector-spacing-calculator.html).
My efergy tells me our consumption is between 25kWh-30kWh most days and, with three young girls, I can only imagine this increasing. This meant I needed to get at least 5kWp of panels if I wanted sufficient production to cover my consumption on a normal day. I used the JRC Photovoltaic GIS to estimate my required panel capacity and, given the limitations on roof space, initially decided on 10 x 545W JA Solar panels. The height of these panels would however likely mean that there'd be some shading along the bottom edges of the back row of panels during the winter months (I wasn't able to increase the spacing between the panels any more). I was just about to pull the trigger on the panel order when I noticed the Canadian 595W panels were quite a bit shorter than the 540W-550W panel ranges. The 10cm or so difference would make a big difference on the shading of the back panels and so I decided to rather go this route. I'll finalise that order by the end of this week. It's important to ensure that your panel string specs (i.e. voltage and amps) are within the range specified by the inverter. The Deye has two MPPT inputs of 125-500V and 22A each, so I can put the panels as 2 strings of 5 which willl give approx 175V, 18A each.
For fellow DIY-ers, the other components one needs are what is called a PV combiner box, cabling, a battery disconnect (which contains fuses) and some AC changeover and miniature circuit breakers (MCBs). The combiner box had me stumped at first but after reading up a bit it's actually pretty simple. It consists of some form of breaker/fuse combination (they are pretty cheap on most online shops) as well as a surge protection device (SPD). You need two breaker/fuses per input string of PV (one each on +ve and -ve) and one 2 pole (2P) surge protection device (SPD) per output. The back row of panels will catch afternoon shading from the chimney so I'll be using the front row as a string to one MPPT and the back row to the second MPPT.
For the sparky's, don't get too angry with me just yet, there are some things I definitely won't be DIYing. One of these is the municipal connection, and second is I'll be getting a CoC. I started talking to an electrician and will likely arrange for him to do all the wiring and CoC (electricians don't like writing CoC on work they didn't do themselves), while I'll put up the trunking, mount the inverter and figure out a way to get the panels up on the roof.
There's lots more one can say, but this is pretty much where I'm at thus far. If all goes well the full install will be up and running before the end of the month (or hopefully even within two weeks). So that's my piece - fire away with your comments, criticisms or questions. There is certainly lots more to learn and I'm super open to suggestions for improvement.
I'd initially started looking at installing solar at our previous house (which already had a solar geyser) but we decided to move mid-covid which put paid to all those plans. We managed to find, and buy, a beautiful double storey house in a lovely neighbourhood. Little did I know at the time it was in a load-shedding exempt suburb, so that was a pretty neat surprise. A couple of months into the new house my mind started drifting towards solar again, but since LS was not an issue, purely as cost reduction. I got hold of an efergy and started monitoring my usage. I also put one of the geysers on a CBI astute timer, while the pool pump and borehole went on Sonoff POWR2s (all managed by Home Assistant).
The next step was preparing the roof. I have an exceedingly large jacaranda tree which shades the majority of my north-facing roof and so the only feasible option was the section of almost flat unpainted IBR roofing on the south side of the house. Upon inspection I realised this would need some maintenance as the last thing I wanted was to have to deal with leaking or loose roof sheets a couple of years down the line. I sanded down the rusted parts, applied rust-mate, galvanised primer and finally two coats of roof paint. I also replaced any loose roof nails.
While prepping the roof I investigated a number of system solutions - micro-inverters, grid-tied etc - but the maths kept leaning towards a hybrid system. I'd been on the lookout for deals and managed to pick up some almost new Pylontech US2000Bs for a really good price, as well as a Deye 8.8kW inverter. I sourced a few quotes on installation and was pretty shocked at the going rates for what is largely pretty simple DIY-able work and since cost reduction was my goal I figured I could do some of that myself. I went to work on sourcing roof mounts and found a really good supplier of Renusol mounts a stone's throw away from our house and ordered the necessary parts. Setting up the roof mounts was really easy, as the supplied hanger bolt simply replace the existing roof screws. I did need to drill slightly larger holes in the IBR as well as bigger pilot holes. The trickiest part was getting the screws in straight as the guys who installed the roof didn't pay much attention to hammering them in straight. I needed to fill up some of the holes with a mix of sawdust and wood glue and was then able to redrill the holes straight once that had dried. My roof can fit two rows, and spacing of these is also pretty important to prevent the front row shading the back row. There are a number of research papers and formulas to help get the optimal spacing, as well as some online calculators for this (e.g. https://www.renvu.com/Inter-row-Spacing-Calculator and https://www.jinyi-solar.com/Solar_Basics/solar-collector-spacing-calculator.html).
My efergy tells me our consumption is between 25kWh-30kWh most days and, with three young girls, I can only imagine this increasing. This meant I needed to get at least 5kWp of panels if I wanted sufficient production to cover my consumption on a normal day. I used the JRC Photovoltaic GIS to estimate my required panel capacity and, given the limitations on roof space, initially decided on 10 x 545W JA Solar panels. The height of these panels would however likely mean that there'd be some shading along the bottom edges of the back row of panels during the winter months (I wasn't able to increase the spacing between the panels any more). I was just about to pull the trigger on the panel order when I noticed the Canadian 595W panels were quite a bit shorter than the 540W-550W panel ranges. The 10cm or so difference would make a big difference on the shading of the back panels and so I decided to rather go this route. I'll finalise that order by the end of this week. It's important to ensure that your panel string specs (i.e. voltage and amps) are within the range specified by the inverter. The Deye has two MPPT inputs of 125-500V and 22A each, so I can put the panels as 2 strings of 5 which willl give approx 175V, 18A each.
For fellow DIY-ers, the other components one needs are what is called a PV combiner box, cabling, a battery disconnect (which contains fuses) and some AC changeover and miniature circuit breakers (MCBs). The combiner box had me stumped at first but after reading up a bit it's actually pretty simple. It consists of some form of breaker/fuse combination (they are pretty cheap on most online shops) as well as a surge protection device (SPD). You need two breaker/fuses per input string of PV (one each on +ve and -ve) and one 2 pole (2P) surge protection device (SPD) per output. The back row of panels will catch afternoon shading from the chimney so I'll be using the front row as a string to one MPPT and the back row to the second MPPT.
For the sparky's, don't get too angry with me just yet, there are some things I definitely won't be DIYing. One of these is the municipal connection, and second is I'll be getting a CoC. I started talking to an electrician and will likely arrange for him to do all the wiring and CoC (electricians don't like writing CoC on work they didn't do themselves), while I'll put up the trunking, mount the inverter and figure out a way to get the panels up on the roof.
There's lots more one can say, but this is pretty much where I'm at thus far. If all goes well the full install will be up and running before the end of the month (or hopefully even within two weeks). So that's my piece - fire away with your comments, criticisms or questions. There is certainly lots more to learn and I'm super open to suggestions for improvement.
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