How Commercial Solar Systems Work
Aggregated Metering Program
The 3 large electricity utility companies in California (PG&E. SCE. and SD&E) recently introduced a new program that allows customers to install and connect solar panels to one electricity meter but associate the solar electricity generated to multiple different electricity meters.
Below are some of the key definitions related to the program:
- NEM – Net Energy Metering, i.e. the ability to send solar-generated electricity back to the utility company for a dollar credit that can be used later
- Generating Meter – the single electricity meter to which the solar panels are directly connected
- Arrangement – A collection of meters that receives the value of the solar electricity produced
- Contiguous Parcels – an unbroken chain of land parcels solely owned/leased/rented by the same person or entity
- Other resources: PG&E, SCE, and SDG&E
Important aspects of the NEM Aggregation program include:
- There is no limit to the number of electricity meters that can be associated to a single Arrangement, however:
- All meters must be on a single parcel, or on multiple contiguous parcels
- The maximum PV system size for any one Arrangement is 1 MW, but multiple 1MW arrangements are allowed
- Public thoroughfares, such as highways, do not “break the chain” of contiguous parcels
- Individual meters can be added or removed from an Arrangement at any time
- All meter types and rate schedule can be included in an Arrangement: commercial, agricultural, residential, etc.
- The utility company might allow a new electricity meter to be installed at the PV system site
HOW IS THE ELECTRICITY GENERATED ALLOCATED?
When the solar energy system Arrangement is first turned on, for the next 12 months (and for every 12-month period thereafter) the utility company will allocate the solar electricity to the meters based on the proportion of each meter’s total kWh’s used each month.
Because the meters’ dollar balances fluctuate throughout the year, the user pays the net Energy Charges to the utility only at the end of the 12-months, not monthly.
- One centralized solar energy system
- Offsetting multiple meters
- Meters can be added or removed anytime
In the illustration below the unshaded land parcels are all solely owned, leased, or rented by the same individual/entity. Note the following:
- Parcels A, B, C, D are considered contiguous
- Parcels that touch only at a corner (parcels A and C) are considered contiguous
- Parcel E is not contiguous to any of Parcels A-D, but as a standalone parcel it is still eligible for one or more of its own Arrangements
- Roads don’t divide a parcel or break a group of parcels; Parcels C and D are still contiguous, and both meters on Parcel E can be grouped
- A parcel without a meter on it still constitutes a part of an unbroken chain (Parcel A)
WHY PREMIER RENEWABLES
The utility company uses a complicated formula to determine solar kWh’s allocation. Because the effect that the kWh allocation formula will have on a particular arrangement of electricity meters is not intuitive, it’s imperative that a thorough assessment is performed using your actual data.
Premier Renewables can provide this analysis for you, using our own proprietary software models, ensuring you get the most value out of a particular meter arrangement.
AGGREGATED METERING CASE STUDY
Excelsior – Hanford, CA – 200kW
This project was installed under PG&E’s new aggregated metering program. The 200kW PV system interconnects at one meter but produces enough solar energy to offset 3 seperate well pump meters on the property. The customer is able to reduce all electricity bills for their agricultural operation with a single PV system. If you are interested to see if this program would work for you, contact us today.
Agricultural operations who are interested in installing a solar power system while maximizing their ROI should act quickly. Aggregated Metering is required to be offered by electrical utility companies only until the total capacity of renewable energy generated surpasses 5% of the utility’s aggregated demand. The capacity is quickly increasing and will only continue to accelerate with Aggregated Metering as an option.