If you were doing a supply side connection you would be adding the rated service incoming from the utility plus the inverters output correct? How do power control systems affect this? Do they limit output at all depending on incoming current ? Or do you size on the maximum regardless of PCS or not?
This is an interesting question and one that, as PCSs with dynamic control start to hit the market, we may see some changes in interconnection methods. The output of the power production source (PV system) cannot exceed the rating of the service conductors. Our current method is to size the output of the production source to less than or equal to the service conductors. This way, in no case can the current on the service conductors be greater than what they are rated for. But as PCSs advance, we could have monitoring on both sides of the interconnection point. This could allow the production source to provide power for loads in the distribution panel while also sending power back to the utility. If the inverters started sending more power than the service conductors were rated for, the PCS would control the inverters to limit that power. We don't think we are there yet, but the rules in 705.11 do set us up for this potential.
If you were doing a supply side connection you would be adding the rated service incoming from the utility plus the inverters output correct? How do power control systems affect this? Do they limit output at all depending on incoming current ? Or do you size on the maximum regardless of PCS or not?
This is an interesting question and one that, as PCSs with dynamic control start to hit the market, we may see some changes in interconnection methods. The output of the power production source (PV system) cannot exceed the rating of the service conductors. Our current method is to size the output of the production source to less than or equal to the service conductors. This way, in no case can the current on the service conductors be greater than what they are rated for.
But as PCSs advance, we could have monitoring on both sides of the interconnection point. This could allow the production source to provide power for loads in the distribution panel while also sending power back to the utility. If the inverters started sending more power than the service conductors were rated for, the PCS would control the inverters to limit that power. We don't think we are there yet, but the rules in 705.11 do set us up for this potential.