How to Upgrade an Electric Service Panel to Solar

Your electric service panel generally does not have to be upgraded when adding solar power, but solar power does require several changes in connected equipment. Solar panels generate direct current electricity, so you will need an inverter to convert to the alternating current used in houses. When connected to the electric service panels, solar power is also connected to the electric utility grid and the electric company has regulations regarding such connections.

If it has room for an additional breaker, your electric service panel is ready for solar power.
  1. Check your electric service panel to make sure that there is a spare breaker or room for an additional breaker. Check your solar panel rated output current, output voltage and maximum power. Select your grid-connect inverter based on the solar panel voltage, current and maximum power. Make sure the inverter has a power failure feature that cuts the connection from the solar panels to the grid during a power failure, so that the current generated by your system does not endanger utility workers.

  2. Install the grid-connect inverter according to the manufacturer's instructions, near the electric service panel. Run the cable from the solar panels to the input side of the inverter, and connect the positive and negative wires to the corresponding terminals on the inverter. Connect the output of the inverter to the electric service panel. Check the rated output current and connect the output cable to a spare breaker with adequate current rating, or install a new breaker with a current rating high enough to handle the inverter output current.

  3. Connect the solar panels to the cable. Use the multimeter to check currents and voltages on both sides of the inverter to make sure they match the ratings. Switch off the main breaker to simulate a power failure, and check to make sure that the inverter has cut the connection to the solar panels and is no longer supplying voltage on the output.

  4. Install a kilowatt-hour meter as required by your local electric utility. Check with your utility to see whether it allows a reduction in your electricity bill by the amount of power supplied into the grid from your solar panels or whether it requires an additional kilowatt-hour meter to determine the value of the solar power. Install the additional meter next to the existing power meter of the electric utility. Keep track of the readings of the meters, and check your next electricity bill to make sure the solar power is included.

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