Gridtie Solar System Final: Balance of System, Part One

This is the final balance of system video on the grid tied solar system I originally installed in October 2008. String One is 16 Mitsubishi Electric UD185MF5 poly-crystalline panels. String Two is 14 Kyocera Solar 158G panels. Combined nameplate wattage is 5172 watts @ STC. Inverter is an SMA SB4000US, rated at 4000 watts continuous AC output. As of October 2008 to date, this system has produced 6105 kwh, with a net metered utility reading of 10012 kwh. My own deration calcs put real world output at approx 3750 watts real-time, with daily summer averages of approx 20-25 KWH. This was a fully permitted self-installed system with a total price tag of k after rebates and incentives.

11 thoughts on “Gridtie Solar System Final: Balance of System, Part One”

  1. I wa also curious about the grid suffering a power loss for example, will that effect your Energy supply being produced from your solar inverter grid to your household.

  2. Thank for your replies steve, will look deeper into the project. Am trying to put an effiecient system together for residential installation in Africa and if it works out ok might market it over there aswel. once again thanks for your knowledge.

  3. I hear ya on batteries, they aren’t created equal and are expensive for quality. That being said, this system is grid interactive which means batteries aren’t required.

  4. The down side with this type of system is that any utility interruption will also interrupt the inverter as a safety measure. In that case, a true off grid system really shines as the presence of grid power is not required.

  5. Remember, this is NOT an off grid system. When PV/inverter output is less than the actual real time load from the residence, the grid makes up the difference. When the opposite is true, the utility meter effectively runs backward.

  6. In a grid interactive system there are no batteries. It is a direct utility intertie inverter that produces as many 240V AC amps as the PV array will allow. This allows the array to make more power overall compared the the average battery based system in a maintenance charging profile (exceptions exists here of course). Because of maximum power point tracking, the inverter is able to regulate itself as PV input changes to provide the highest possible amps output.

  7. Hi Steve, I,ve being told that you always need a battery bank to get a proper domestic distribution of power through the household due to the flunctaion of the solar energy to the solar panel when connectted directly to an inverter.. pls is this the case and did you use batteries in your own project aswel. cheers.

  8. @depravedpuma…Ultimately the grounding does terminate at the ground rod as you’d normally see in residential electrical.

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