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Reducing Time and Cost of an Interconnection Study




We are now changing the threshold to allow more PV projects to proceed without an interconnection requirements study (IRS).

As of February 26, 2014, single-phase projects 10 kW or smaller on circuits with less than or equal to 120 percent of daytime minimum load (DML) (up from 100 percent) will NOT require an IRS. (Daytime minimum load refers to electricity demand from 9 a.m. to 5 p.m.)
   
In some cases, protective equipment upgrades may still be needed to interconnect safely on circuits with PV between 75 percent and 100 percent of DML. We will determine if any circuit or project upgrades are needed through a quick supplemental review, at no cost to you. If the utility installs the circuit upgrades, most customers will pay only a prorated share of the cost, based on your proposed PV system size. We will let you know the projected cost of the upgrades. You will not be charged if you decide not to go forward.   
   
In some cases, on circuits with PV less than or equal to 120 percent of DML, the potential for Transient Over-Voltage can be addressed by implementing one of the approved TOV mitigation measures. Learn more.
   
  When customers wish to add PV systems larger than 10 kW up to 100 kW on circuits still under 100 percent of daytime minimum load, no IRS will be needed. Again, if circuit upgrades are needed, we will install them whenever possible and most customers will pay only a prorated share of the cost.  
   
  For circuits already equal to or greater than 100 percent of daytime minimum load, where an IRS might still be needed, our engineers will proactively use experience with the supplemental reviews (at our expense) and past interconnection studies to determine if upgrades are needed, avoiding additional interconnection studies, if possible.  If upgrades are deemed necessary, customers will only pay a prorated share.


This chart sums up the current interconnection policies:  

Aggregate PV Nameplate (kW) vs. Daytime Min Load (DML) on circuit Single Phase system,
10 kW or smaller
Single Phase system,  from
10 kW to 100 kW
Three-Phase, from
10 kW  to 100 kW
Greater than 120% of DML IRS may be required,
possible upgrades
IRS may be required,
possible upgrades
IRS may be required,
possible upgrades
100-120% of DML No IRS, possible upgrades IRS may be required, possible upgrades IRS may be required, possible upgrades
75-99% of DML No IRS, possible upgrades No IRS, possible upgrades No IRS, possible upgrades
Up to 74% of DML No IRS, no upgrades No IRS, possible upgrades No IRS, possible upgrades


In addition, to further reduce number and cost of studies needed, the company is doing a limited number of studies on several circuits over 100% of daytime minimum load and will apply the experience gained to as many  projects as possible on similar circuits.  In the past, customers who needed an interconnection requirements study would have been required to pay the entire cost and wait for that study to be finished.  

Our new practice is intended to considerably reduce the study and upgrade costs for many customers in the future.


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