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It looks simple, it is not. Firstly on the solar supply side with no batteries, the supply to the inverter maybe considered chaotic, we need to consider the f

It looks simple, it is not. Firstly on the solar supply side with no batteries, the supply to the inverter maybe considered chaotic, we need to consider the fact that the stated '13kW array' is likely to be peak output power at say midday with no cloud/dust/shadow. Therefore it is not feasable to consider a stand-alone system without batteries. We need to know the total loads power factor (pf), assuming the inverter is rated at 13kW continuous at a pf of 1.0 (purely resistive), and the rule of thumb average home load pf is .8 (slightly Inductive reactance) then your 13kW is; 13 x .8 = 10.4kW. In large motors; pool/well-water/constant-water-pressure/hot-tub pumps some older washing machines a pf of .6 may be found. Given the above, now we need to look at how chaotic the load currents are, as a rule of thumb large motors have rated start currents of 5 to 7 times the run current for 5 seconds, so 2.4kW motor (remember to de-rate the power-supply by the pf) will have a start current between 12kW and 16.8kW 12kW = 120v x 100A = 240v x 50A and 16.8kW = 120v x 140A = 240v x 70A. So if you were building a house from scratch, we would wire it with supply and load in mind.

robomartin 4y ago
All fair points. This is particularly true in the case of most of the solar systems around me, all of which are barely adequate for the homes where they are installed. This is one aspect of the solar industry nobody talks about. The other day I saw a report about this guy who was charged $50K for the installation of a dozen panels. I designed and installed my own system. I regularly supply 8 to 9 kW to the grid (peak, of course). When the grid has gone down, I can turn on the system and supply the entire house without any issues at all, even without a battery. I will probably install batteries sometime next year. The cost is still high. I need to wait until the ROI makes sense. My ultimate goal is to completely disconnect from the grid if possible. My guess is that I'll probably have to double my system size in order to be able to achieve this.
- Trouble_007 4y ago
  >this guy who was charged $50K for the installation of a dozen panels.< This sounds outrageous to me. As I'm unaware of your location, I've added a search URL[1] which will IP geo-locate to your general area, also you did not include the panel array power rating nor if batteries were included. [1] <https://html.duckduckgo.com/html/?q=price:'15k https://html.duckduckgo.com/html/?q=price:'15k>
  - Trouble_007 4y ago
    Apologizes, link was truncated (I was sure I checked it!) search: >'15kW Solar system'< @DDG : <https://html.duckduckgo.com/html/?q='15kW Solar system' https://html.duckduckgo.com/html/?q='15kW Solar system'>

robomartin 4y ago

All fair points. This is particularly true in the case of most of the solar systems around me, all of which are barely adequate for the homes where they are installed. This is one aspect of the solar industry nobody talks about. The other day I saw a report about this guy who was charged $50K for the installation of a dozen panels. I designed and installed my own system. I regularly supply 8 to 9 kW to the grid (peak, of course). When the grid has gone down, I can turn on the system and supply the entire house without any issues at all, even without a battery. I will probably install batteries sometime next year. The cost is still high. I need to wait until the ROI makes sense. My ultimate goal is to completely disconnect from the grid if possible. My guess is that I'll probably have to double my system size in order to be able to achieve this.

Trouble_007 4y ago
>this guy who was charged $50K for the installation of a dozen panels.< This sounds outrageous to me. As I'm unaware of your location, I've added a search URL[1] which will IP geo-locate to your general area, also you did not include the panel array power rating nor if batteries were included. [1] <https://html.duckduckgo.com/html/?q=price:'15k https://html.duckduckgo.com/html/?q=price:'15k>
- Trouble_007 4y ago
  Apologizes, link was truncated (I was sure I checked it!) search: >'15kW Solar system'< @DDG : <https://html.duckduckgo.com/html/?q='15kW Solar system' https://html.duckduckgo.com/html/?q='15kW Solar system'>