Neuk_
Honorary Master
I checked and yesterday marked one year of us having had the PV panels, MPPT, control unit and associated hardware installed to complement our inverter and LA batteries that we had previously installed for load shedding purposes. While I am not going to go in to as much detail as @Priapus did in his one year update thread, I wanted to put down some thoughts and reflections that I hope could be of use for others. To recap what we have at the moment...
Victron Multiplus 3kVa 48v Inverter/Charger
Four OmniPower 12V 120Ah OPR Deep Cycle Rechargeable AGM/Gel Hybrid VRLA Batteries
Victron Energy SmartSolar MPPT 250/70-Tr Solar Charge Controller
Victron Venus GX
Ten CanadianSolar 360w PV panels
We started with just the inverter and LA batteries that my fiancé purchased, purely with load shedding in mind although I would have gone with a larger inverter and LFP batteries had I been given the choice. The inverter and batteries did their job for load shedding though with only our oven, bedroom AC unit and two sets of plugs in the kitchen not being available when mains electricity supply was down. Eight months on my future father-in-law had spare PV panels after installing ninety at their factory in conjunction with a 25kVa grid tied inverter so we jumped at the chance to get a few along with the necessary hardware. I contacted the installer who installed our inverter and batteries originally, arranged for him to come have a look at our roof space and advise on what would be the best way forward to install ten PV panels. Unfortunately we discovered that our available North facing roof space was far from ideal in that it wouldn't take more than three or four PV panels and would be compromised by shade in winter, forcing us to use an East and West arrangement with two strings of five PV panels which is also not ideal.
Accepting the limitations of using LA batteries and an East/West split in PV panels, I am happy with how the system has performed thus far even though it falls short of other MyBB user systems in terms of PV generation, cost saving and reduction of use of mains supply from CoJ. We have had one issue in the last year with the inverter shutting itself off, I can't remember if it was overload or temperature but it lasted for a minute and twenty six seconds while another occasion saw us rely solely on PV and batteries for a couple of days when we had a main supply break which needed a repair. Unlike other MyBB users, we were coming off a low base before installing the PV, our average daily use was around 12kWh as we have gas geysers and a gas stove, with only occasional use of the oven and bedroom AC unit and the majority of the lights we use being LED's. This winter has seen our heaviest use of mains supply electricity, mainly due to it being the first with our son and needing to keep his room warm over night using at least one electric heater which we never used before, we have a wood Morso fireplace that we use at night and a gas heater for the mornings to take the chill out the house.
We have changed how we use appliances in the house to maximise use of PV generation, so only run heavy use appliances like the dishwasher and washing machine after a certain time in the morning and only one at a time, which the inverter has managed well. Again winter is a challenge, due to the reduction in daylight hours but also the angle of the sun meaning the East and West PV configuration is less effective but also bringing in more shade due to large tree's close to our house. I'll be looking at ways to alleviate this without cutting tree's down however, partly because I prefer not to but mostly because the trees providing most of the shade are CoJ trees so we aren't allowed to even trim them. PV generation for the last year has been 2353.66 kWh with mains supply of 3603 kWh so there is definitely room for improvement in both PV generation and battery use although both will take some work and additional cost. Our peak PV generation has been 11.04 kWh in a day in early January 2021 but we have to remember that we don't have high or long duration loads like an electric geyser or pool so one of the best ways to make better use of PV generation will be to get LFP batteries with a higher capacity that we can use during non PV generation to reduce mains supply use and to better utilise the existing PV.
Plans at the moment are to replace the LA batteries with LFP when the LA's need replacing, I'll see if I can get more use out of the LA's during summer when early morning loads are light and PV generation starts earlier.
Victron Multiplus 3kVa 48v Inverter/Charger
Four OmniPower 12V 120Ah OPR Deep Cycle Rechargeable AGM/Gel Hybrid VRLA Batteries
Victron Energy SmartSolar MPPT 250/70-Tr Solar Charge Controller
Victron Venus GX
Ten CanadianSolar 360w PV panels
We started with just the inverter and LA batteries that my fiancé purchased, purely with load shedding in mind although I would have gone with a larger inverter and LFP batteries had I been given the choice. The inverter and batteries did their job for load shedding though with only our oven, bedroom AC unit and two sets of plugs in the kitchen not being available when mains electricity supply was down. Eight months on my future father-in-law had spare PV panels after installing ninety at their factory in conjunction with a 25kVa grid tied inverter so we jumped at the chance to get a few along with the necessary hardware. I contacted the installer who installed our inverter and batteries originally, arranged for him to come have a look at our roof space and advise on what would be the best way forward to install ten PV panels. Unfortunately we discovered that our available North facing roof space was far from ideal in that it wouldn't take more than three or four PV panels and would be compromised by shade in winter, forcing us to use an East and West arrangement with two strings of five PV panels which is also not ideal.
Accepting the limitations of using LA batteries and an East/West split in PV panels, I am happy with how the system has performed thus far even though it falls short of other MyBB user systems in terms of PV generation, cost saving and reduction of use of mains supply from CoJ. We have had one issue in the last year with the inverter shutting itself off, I can't remember if it was overload or temperature but it lasted for a minute and twenty six seconds while another occasion saw us rely solely on PV and batteries for a couple of days when we had a main supply break which needed a repair. Unlike other MyBB users, we were coming off a low base before installing the PV, our average daily use was around 12kWh as we have gas geysers and a gas stove, with only occasional use of the oven and bedroom AC unit and the majority of the lights we use being LED's. This winter has seen our heaviest use of mains supply electricity, mainly due to it being the first with our son and needing to keep his room warm over night using at least one electric heater which we never used before, we have a wood Morso fireplace that we use at night and a gas heater for the mornings to take the chill out the house.
We have changed how we use appliances in the house to maximise use of PV generation, so only run heavy use appliances like the dishwasher and washing machine after a certain time in the morning and only one at a time, which the inverter has managed well. Again winter is a challenge, due to the reduction in daylight hours but also the angle of the sun meaning the East and West PV configuration is less effective but also bringing in more shade due to large tree's close to our house. I'll be looking at ways to alleviate this without cutting tree's down however, partly because I prefer not to but mostly because the trees providing most of the shade are CoJ trees so we aren't allowed to even trim them. PV generation for the last year has been 2353.66 kWh with mains supply of 3603 kWh so there is definitely room for improvement in both PV generation and battery use although both will take some work and additional cost. Our peak PV generation has been 11.04 kWh in a day in early January 2021 but we have to remember that we don't have high or long duration loads like an electric geyser or pool so one of the best ways to make better use of PV generation will be to get LFP batteries with a higher capacity that we can use during non PV generation to reduce mains supply use and to better utilise the existing PV.
Plans at the moment are to replace the LA batteries with LFP when the LA's need replacing, I'll see if I can get more use out of the LA's during summer when early morning loads are light and PV generation starts earlier.
