bladerunnerpv
Well-known member
So, been agitating the grey cells about the Victron kit, some thoughts....
I think my roofs can take 10 x Perlight 425W on East facing and 11 x 425W on West facing side. Panel specs are
Vmpp 34.6V
Voc 41.7V
Impp 12.30A
Isc 13.03A
ΔIsc/°C: 0.04 %
ΔVoc/°C: -0.27 %
Perlight 425W chosen as an example because of high wattage and the high V to see what can be done. Qcell or Trina have lower V spec, so if the perlights work then they should be easier.
Positions of trees on E side and trees at bottom of neighbours garden on opposite side of road on W side is leading me to think I would be best suited by 1x4 and 1x6 on East-facing to maximise early morning sunlight, and 1x5 and 1x6 on West facing to deal with post leaf-fall dappled shading on 5 or 6 panels. But if the victron smartsolar does it's job do I need to split them like this.
The 5kVA version of the EasySolar looks like it may be a bit small for my situation. As the inbuilt MPPT only has two inputs I think it pushes me down the route of 2parallel x 5series on both E and W sides ?
Total is 4250W on each roof, which is within the 9kW limit for the kit, the inbuilt 250/100 doesn't take more than 5 of the perlights in series I think.
The DC power 4250W connected to the inverter is more than the rated AC output power 4000W so it's 6% underdimensioned for 20 panels, it can't take 21 panels.
Cost is around 13k wholesale for the EasySolar option
It wouldn't be able to supply house and charge EV at the same time in a worst case scenario?
Yes, I know, charge the EV overnight on cheaper tariff and do the house stuff during the day, but DW and DD have run their EVs nearly flat and want to go out again this evening and is DW is cooking dinner and DD is in the shower and there a power cut ;-) Unlikely I know, but you can hear it ringing in your ears can't you - you spent how much on this stuff ???
I'm trying select something to future proof needs as much as possible, if we really are all going to be driving EVs in 10 years time.
as an aside there are projections of grid substation loads from the DNOs available on the web. my local substation has about 9.5-10.5% headroom now and it drops to 5.5-6.5% by 2026/7, in other words demand is heading towards exceeding supply in the not too distant future.
See uk power networks, Find Your Grid and Primary Substation. https://ukpowernetworks.opendatasoft.com/pages/gridandprimarydashboard/
Back to the PV...
For quattro route, if I'm getting my head around it right then it's an 8k Quattro with a 4xMPPT input of Victron SmartSolar RS MPPT 450/200, panels in 1x5, 1x6, West and 1x4, 1x6 East configuration, plus 3x US5000 Pylons, although the heated Fogstar is appealing as I may end up having to put it all in the shed alongside the house.
Have been speculating about putting 2x 600W-ish on S-facing flat shed roof too for a bit more wintertime PV output. So 21x425 + 2x600 = 10.125kW,
The 8k Quattro inverter will take 16kW peak power, the 5k Quattro 10kW peak power
in which case it's an 8k Quattro with 2 x SmartSolar MPPT 250/85 to give 6xMPPT inputs,
West : 1x5, 2x3 = 11, or 1x5,1x3,1x3 and
East 1x4, 2x3 =10,
plus 1x2 from the shed panels into the spare MPPT slot. Need to review the string voltages to be sure.
It all comes in quite expensive though :-(
About £16k wholesale for 8k Quattro with a SmartSolar RS MPPT 450/200
About £16k wholesale for 8k Quattro with 2 x SmartSolar MPPT 250/85
gulp
Did I miss a trick ?
Quattro 8k feels a bit like an overspecced system for the #of panels. Each MPPT of the 450/100 or 450/200 can take 9 panels max, if it was able to take 11panels then I could go 1x11 and 1x10 on a single inverter and save some ££ albeit at expense of some potential shading issues.
Quattro UPS capability and the high continuous output power of 6400W, enough for the sunday roast, look tasty.
I don't need the generator input from the quattro unless something dire happens, or that substation can't handle the demand.
Is 6400W ok for EV charging with a 7kW Zappi though ? It also wouldn't be able to supply house and charge EV at the same time in a worst case scenario? Hmmm a 10k Quattro can output 8000W continuous...
In a nutshell the Easysolar 5k feels under-spec'd as I wouldn't be able to max out panels or have expansion potential in the future, and the Quattro 8k feels over-spec'd as only using slightly more than half the PV inputs and overpriced!
Any thoughts / suggestions ?
I'm not convinced I've got the spare time or practical skills to build my own battery, more likely to electrocute myself I reckon! Still, if needs must...
I think my roofs can take 10 x Perlight 425W on East facing and 11 x 425W on West facing side. Panel specs are
Vmpp 34.6V
Voc 41.7V
Impp 12.30A
Isc 13.03A
ΔIsc/°C: 0.04 %
ΔVoc/°C: -0.27 %
Perlight 425W chosen as an example because of high wattage and the high V to see what can be done. Qcell or Trina have lower V spec, so if the perlights work then they should be easier.
Positions of trees on E side and trees at bottom of neighbours garden on opposite side of road on W side is leading me to think I would be best suited by 1x4 and 1x6 on East-facing to maximise early morning sunlight, and 1x5 and 1x6 on West facing to deal with post leaf-fall dappled shading on 5 or 6 panels. But if the victron smartsolar does it's job do I need to split them like this.
The 5kVA version of the EasySolar looks like it may be a bit small for my situation. As the inbuilt MPPT only has two inputs I think it pushes me down the route of 2parallel x 5series on both E and W sides ?
Total is 4250W on each roof, which is within the 9kW limit for the kit, the inbuilt 250/100 doesn't take more than 5 of the perlights in series I think.
The DC power 4250W connected to the inverter is more than the rated AC output power 4000W so it's 6% underdimensioned for 20 panels, it can't take 21 panels.
Cost is around 13k wholesale for the EasySolar option
It wouldn't be able to supply house and charge EV at the same time in a worst case scenario?
Yes, I know, charge the EV overnight on cheaper tariff and do the house stuff during the day, but DW and DD have run their EVs nearly flat and want to go out again this evening and is DW is cooking dinner and DD is in the shower and there a power cut ;-) Unlikely I know, but you can hear it ringing in your ears can't you - you spent how much on this stuff ???
I'm trying select something to future proof needs as much as possible, if we really are all going to be driving EVs in 10 years time.
as an aside there are projections of grid substation loads from the DNOs available on the web. my local substation has about 9.5-10.5% headroom now and it drops to 5.5-6.5% by 2026/7, in other words demand is heading towards exceeding supply in the not too distant future.
See uk power networks, Find Your Grid and Primary Substation. https://ukpowernetworks.opendatasoft.com/pages/gridandprimarydashboard/
Back to the PV...
For quattro route, if I'm getting my head around it right then it's an 8k Quattro with a 4xMPPT input of Victron SmartSolar RS MPPT 450/200, panels in 1x5, 1x6, West and 1x4, 1x6 East configuration, plus 3x US5000 Pylons, although the heated Fogstar is appealing as I may end up having to put it all in the shed alongside the house.
Have been speculating about putting 2x 600W-ish on S-facing flat shed roof too for a bit more wintertime PV output. So 21x425 + 2x600 = 10.125kW,
The 8k Quattro inverter will take 16kW peak power, the 5k Quattro 10kW peak power
in which case it's an 8k Quattro with 2 x SmartSolar MPPT 250/85 to give 6xMPPT inputs,
West : 1x5, 2x3 = 11, or 1x5,1x3,1x3 and
East 1x4, 2x3 =10,
plus 1x2 from the shed panels into the spare MPPT slot. Need to review the string voltages to be sure.
It all comes in quite expensive though :-(
About £16k wholesale for 8k Quattro with a SmartSolar RS MPPT 450/200
About £16k wholesale for 8k Quattro with 2 x SmartSolar MPPT 250/85
gulp
Did I miss a trick ?
Quattro 8k feels a bit like an overspecced system for the #of panels. Each MPPT of the 450/100 or 450/200 can take 9 panels max, if it was able to take 11panels then I could go 1x11 and 1x10 on a single inverter and save some ££ albeit at expense of some potential shading issues.
Quattro UPS capability and the high continuous output power of 6400W, enough for the sunday roast, look tasty.
I don't need the generator input from the quattro unless something dire happens, or that substation can't handle the demand.
Is 6400W ok for EV charging with a 7kW Zappi though ? It also wouldn't be able to supply house and charge EV at the same time in a worst case scenario? Hmmm a 10k Quattro can output 8000W continuous...
In a nutshell the Easysolar 5k feels under-spec'd as I wouldn't be able to max out panels or have expansion potential in the future, and the Quattro 8k feels over-spec'd as only using slightly more than half the PV inputs and overpriced!
Any thoughts / suggestions ?
I'm not convinced I've got the spare time or practical skills to build my own battery, more likely to electrocute myself I reckon! Still, if needs must...
