When your solar PV system is installed you may need to have a new meter installed.

If you have a traditional accumulation meter (with a spinning disk) this will need to be replaced with an interval meter or smart meter. This is because an accumulation meter does not record the energy you export to the grid or the electricity you import from the grid. An interval meter or a smart meter provide half hourly readings of the electricity you consume and the surplus electricity you generate.

The states and territories have committed to the progressive rollout of smart metering across Australia from 2007. While a smart meter is similar to an interval meter in that it records electricity usage in 30-minute intervals remotely to your electricity company, smart meters have a range of additional capabilities. So if your new meter is an interval meter, it will need to be replaced again with a smart meter when this rollout occurs.

Depending on where you live, your interval meter may be a gross meter or a net meter.

If you are on a gross feed-in tariff scheme, your gross meter separately measures the total electricity consumed by your household and the total electricity generated by your solar PV system. Your electricity company reads the meter and determines the total amount of electricity generated by your solar panels, regardless of whether it goes into the grid or is used by your household.

If you are on a net feed-in tariff scheme, your net meter measures your household's electricity and the electricity generated by your solar PV system together. Your electricity company reads the meter and calculates any surplus electricity fed back into the grid.

Your new meter must be installed by a relevant qualified professional. This may be organised by your accredited designer/installer; or your electricity retailer; or electricity distributor. Ask to find out who will organise this for you.

The installation of a new meter may affect your electricity billing rates:

• The new meters are provided by your electricity distributor. The cost of this is passed from the electricity distributor to your electricity retailer. Generally, this cost is recovered by your electricity retailer through increased network charges on your monthly electricity bill.
• You may move from an off-peak tariff to a time-of-use (TOU) tariff. A TOU tariff is a pricing structure that changes depending on the time of day you consume power. In peak demand periods (day), charges will be higher than consumption during lower demand periods (night). So while electricity is most expensive during the day, this will be offset by your solar PV system producing energy during this time also.
• If you move from an off-peak tariff to a time-of-use (TOU) tariff, this will particularly affect your dedicated off-peak loads, such as hot water, space heating and air-conditioning.

You should check with your electricity retailer about any tariff changes that will occur as a result of installing solar and carefully weigh up the advantages and disadvantages before making a decision. This should be considered before you install your solar PV panels.