Bidirectional meter
Definition. A bidirectional meter measures electricity flowing in both directions across the connection point, keeping separate registers for units imported from the network and units exported to it, and it is mandatory for a net-metered installation.
Also called: Net meter · Green meter · Import-export meter
Where you see it: At the service entrance on a net-metered premises, and reflected on the bill as separate import and export readings.
Why an ordinary meter will not do
A conventional electronic meter has a ratchet that prevents the register from running backwards. Feeding it exported energy does not credit you; on many models it simply refuses to count, and on some it registers a tamper flag.
The bidirectional meter is a different device with separate registers, and it is installed and sealed by the DISCO as part of the net-metering approval.
Checking that export is registering
Note the export register on a clear day at noon with household load minimal, then again an hour later. It should have advanced by roughly the array's output for that hour.
If it has not moved while the inverter reports generation, the fault is between the inverter and the meter — a wiring polarity error at commissioning is the usual cause, and it is worth catching in the first month rather than the sixth.
Frequently asked questions
Who pays for the bidirectional meter?
The consumer, as part of the net-metering application. It also carries a higher meter rent than a standard single-phase meter.
Can I read the export figure myself?
Yes. The meter cycles through screens, and import and export totals are separately displayed. Photographing both on the reading date is the simplest protection against a settlement dispute.
Related terms
- Net metering — How net metering settlement actually works in Pakistan, the difference between netting units and netting rupees, and what the licence application involves.
- Meter reading — How to read a Pakistani electricity meter correctly, which digits to ignore, and how to check the reading printed on your bill against the device on your wall.
- Smart meter — What Pakistan's AMI rollout changes for a consumer, what a smart meter can and cannot do, and whether smart meters really produce higher bills.
- Meter rent — What the meter rent line covers, why it differs between single-phase and three-phase connections, and whether buying your own meter removes it.
Go further
Back to the full 44-term glossary, or open your own bill with the reference number lookup.