What does a bi-directional meter do?
A bi-directional meter is like a standard electricity meter, except that it’s designed to measures electricity flow in two directions. When you install grid connected solar power system, you need a meter that can tell you not just how much energy you’ve consumed but also how much you’ve fed back into the grid.
Most states have feed in tariffs, premium rates consumers get paid for the clean energy their solar power systems contribute back into the grid. Data from the bi-directional meter is used by your electricity company to tell how much power they need to pay you for.
Most electricity meters currently installed on houses can not measure electricity from a grid connect solar system being returned to the mains grid. Some meters, such as electro-mechanical (or spinning disc) meters may accurately measure power but the data is not always accepted by electricity companies.
Most bi-directional meters will be "interval" or "smart" meters. These meters record consumption and feed-in data in half hour blocks. Interval meters are either remotely or manually read, depending on the model. Manually read interval meters download data into hand held probes, carried by meter readers at the end of every billing period. With remotely read interval meters, data is sent back to the distributor using a device like a mobile phone. Some remotely read meters can even de-energise and re-energise remotely, removing the need for a distributor to come and pull out the fuse.
Depending on where you live, installation of a bi-directional meter may be free. We can tell you if this will be the case in your situation. For example, in Victoria from July 2009 onwards every home will be receiving a new smart meter in a staged rollout.