There are 3 possible types of RESOP grid connections:

This is where there is no load (home or building) involved, and just the generation system connecting to the grid. Not relevant to residential PV customers.

Indirect Parallel
This is the old fashioned way of connecting the PV system to the grid on the grid side of the existing (import) meter. Not a good alternative as an additional customer account is needed (therefore a monthly cost) and the connection is more dangerous to make for the installer.

Indirect Series
This is the new and preferred connection type. PV system output is fed through an (export) meter, and then fed into the home's existing electrical panel. No additional customer account is needed, and it is much safer for the installer. The only problem is that the LDC must now do a bit of arithmetic to figure out what the true consumption figure was. I can step you through the calculation if anybody cares to know it. I previously thought that Toronto Hydro was just being a very progressive LDC in allowing residential PV generators customers with Indirect Series connections to work with just one customer account, but in fact, this was laid out for all Ontario LDCs in OEB Compliance Bulletin 200703 which dates back to April 27, 2007! (attached)

In the 2nd last paragraph of page 3, the bulletin states "an imbedded retail generation facility that is indirectly connected in series is not, in my view, a separate customer of the distributor. In this case, the load and the generator are not treated independently for settlement purposes". This means that if LDCs allow customers to use Indirect Series connections, but don't allow these customers to remain with just their existing LDC account, they are in violation of the Compliance Bulletin and need to have this pointed out to them. This is great news, because now it isn't us saying "please do this for us" it is "unless you offer such, you are in violation of OEB Compliance Bulletin 200703". The only question here, is whether LDCs are required to offer Indirect Series connections, and if so, by when. I have a format inquiry placed with the OEB Compliance Office to try to get an answer to this.

For Toronto Hydro customers, their website gives some more information on the connection types, on their page:
What Are The Metering Connection Options
(no navigate there manually, go to Toronto Hydro's Home page, then "Residential", then "Generation Connection".

Here is what they state:

What are the metering connection options?
Generators have a choice of three metering connections:

1. Direct

2. Indirect Parallel

3. Indirect Series

In the direct connection, a separate service connects the generator to Toronto Hydro’s system. A bi-directional meter is required for the generator. This is a separate service and incurs the fixed monthly customer charge.

An indirect parallel connection permits the generator and its bi-directional meter to be installed in parallel with the load service meter of the customer. The point of parallel connection is upstream of both meters but before the connection with Toronto Hydro. As this is a separate service, the generator requires a bi-directional meter and it incurs the monthly customer charge.

An indirect series connection connects the generator in series with the customers load behind the service meter. It is not a separate service but the same service and therefore does not incur the fixed monthly customer charge. The service meter needs to be changed to a bi-directional meter. The generator meter must be an interval meter with a dedicated telephone communication line to the meter as per Toronto Hydro’s Conditions of Service section 3.5.7.

Please note that settlement of energy produced is not the same across each of the three methods. Please refer to Section 6 of the OPA Standard Offer Program Final Rules.
For indirectly parallel-connected generators of 10kW or less, bi-directional meters do not have to be of the interval type. In other cases, an interval meter with a dedicated communication line to the meter is required as per Toronto Hydro Conditions of Service section 3.5.7.

The cost of metering varies depending on specific site details. Toronto Hydro will provide the customer with the meter cost information once the customer has finalized their SOP application with the OPA and has provided Toronto Hydro with a copy.

Copy of OEB Compliance Bulletin


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