As energy consumption and environmental awareness continue to grow, so too does the demand for renewable energy resources. These resources, such as solar and wind power, require special metering solutions. Traditional meters only measure the flow of energy in one direction and are not able to accurately record the amount of energy being generated by the private power generation.
What is a bidirectional meter?
A bidirectional meter is a specialized type of electronic energy meter used to measure the flow of energy in both directions. This makes them ideal for renewable energy applications, such as solar and wind power, which can generate electricity when connected to the grid.
How do bidirectional meters work?
Bidirectional meters use what is called a net meter design. This design allows for the measurement of energy flow in both directions. The energy consumption and generation are measured separately. Bidirectional meters provide separate registers for
- Active energy import (user consumption)
- Active energy export (user generation)
- Reactive energy Quadrant QI
- Reactive energy Quadrant QII
- Reactive energy Quadrant QIII
- Reactive energy Quadrant QIV
Each register has individual OBIS codes. OBIS is the Object identification system, defined in the DLMS/COSEM protocol. It’s a unified system for local- or remote meter access. The quadrant definition in DLMS is according to IEC 62053-23.
The benefits of bidirectional meters
They offer a number of benefits for both the user and the power company. For the user, bidirectional meters offer the ability to monitor their power usage in real time. This allows them to make informed choices about their power usage and can help them save money. For the power company, bidirectional meters offer the ability to more accurately bill the user for the power usage.
For a real net-metering in Europe, some trials are on the way, but it’s questionable, who covers the operational grid costs. Other countries have different regulations.
According to the Renewable Energy Act in e.g. the USA or the Philippines, its Implementing Rules and Regulations, and the Energy Regulation Commission’s net metering recommendations, electric utilities must only bill their customers for the kWh difference (or net) between their usage and any solar excess they export to the grid. So, a solar owner may use the excess solar production throughout the day to balance off an equivalent amount of evening consumption.
A bidirectional energy meter can record energy usage, monitor power generation, and estimate the cost of energy. The meter allows for more flexibility and information in electrical usage. Different countries have varying net metering laws.
Do not hesitate to get in touch with us if you have any related questions for metering or testing.
Editor's note: This article was originally published in November 2022 and has been updated for comprehensiveness.