EV Customer (on TOU) Already Has or Adding Solar

If you already have an EV on a separate TOU meter and you have or plan to install solar panels:

If you already have an EV on a separate TOU meter, and you have or plan to install solar panels with enough capacity to meet some or all of your EV charging needs, it may be more financially advantageous for you to switch to one of the following options:

Option 1. Opt out of the TOU Rate permanently and charge at the time of day that maximizes use of your solar electricity. 

At no cost, CMLP can remove the second meter measuring usage for EV charging on- and off-peak and install UL rated jumpers in the meter socket. Off-peak EV charging at a lower rate than the standard Residential Rate will no longer be available under this option.

For more information, see our guidance for those who wish to have the flexibility to charge their car anytime during the day.


Option 2: Opt out of the TOU Rate permanently and enroll in the EV Miles Program instead.

This option allows you to use solar electricity to charge your car until 12 noon each weekday and all weekend, while still providing you with bill credits for programming your car to charge exclusively during off-peak hours: 10 PM to 12 noon, Monday through Friday and all weekend. Minor exceptions are allowed in case of emergency.

As in Option 1, CMLP can remove the second meter measuring usage for EV charging on- and off-peak and install UL rated jumpers in the meter socket, at no cost.

Option 3: Opt out of the TOU Rate during high solar production months.

If there are months of the year when your solar panels will produce more electricity than your house needs, there is an option that allows you to opt out of the TOU Rate and charge your car at the regular Residential Rate at any time of the day or night during those months.

First, if your second meter is located on the load side (house side) of your house meter, CMLP will require you to relocate it to the line side (street side) of your house meter. CMLP’s incoming overhead or underground feeder wires deliver electricity to the “line side” (street side) of your house meter. The electricity passes through the meter to wires on the “load side” (house side) of the meter. These wires convey the electricity to the interior electrical panel that distributes it via circuits throughout your house.

This move ensures that the second meter will not mistake electricity produced by your solar panels for electricity delivered by CMLP and erroneously charge you (rather than refund you) for the electricity your panels are producing.

The move is necessary because the meters currently used by CMLP do not have the technological capability to track how much power is being used during off-peak vs. on-peak periods, and simultaneously track whether power is being delivered to you from the grid vs. being sent back to the grid from your solar panels. 

The side effect of moving the second meter to the line side of your house meter is that only electricity delivered by CMLP will charge your EV. Electricity generated by your solar panels will power your house, but not your EV.

In order to allow you to work around the technological limitations of our meters, the second part of Option 3 involves installing a transfer switch with your second meter when it is moved to the line side of your house meter. During months when you have excess solar electricity for charging your car, throw the switch to disable the second meter and discontinue separate measurements of how much power is used during on-peak and during off-peak hours.

Once the switch is thrown, solar electricity produced by your panels will feed your car as well as your home. Any electricity that CMLP delivers to you while the 2nd meter is disabled, either for EV charging or for household needs, will be measured by your house meter and charged at the regular Residential Rate. The current Residential Rate is based on three tiers of monthly usage:

a) First 600 kWh:                   15.5¢ / kWh
b) Next 316 kWh:                   16.9¢ / kWh
c) Any use above 916 kWh:   19.7¢ / kWh

Your electrician can give you an estimate to install a separate line for an additional meter socket on the line side of your house meter. This can cost from hundreds to thousands of dollars. Including the transfer switch in the electrical work to accommodate move your second meter to the line side of your house meter is expected to add hundreds of dollars to the cost.  (See meter socket wiring diagrams for 200 amp and 320 amp systems here)

Working with CMLP's electrician, your electrician can advise you on the best placement of the meter socket. Your electrician can contact our electrician, Marty Boermeester, at 978-318-3141, with questions and to meet at your home before or during the job to discuss the work planned.

Although you would need to pay your electrician for the extra line and meter socket work, CMLP will move the second meter from the load side to the line side of your house meter at no cost.

If you choose Option 3, CMLP strongly suggests that you join our peak demand reduction Google group, which will allow us to send you an email when peak demand is predicted. Thirty percent of your electric bill is directly related to the amount of electricity Concord uses for just one hour during the entire year. That one hour, the peak demand hour, occurs on a hot weekday afternoon during the summer months, typically between the hours of 12PM – 6PM. When you refrain from charging your EV during peak hours, everyone benefits with lower electric rates, since there are higher costs associated with these peaker power plants.