Energy metering

How is energy metering done today?

Natural gas consumers have traditionally been billed for their energy usage measured in kWh. However, the gas meters used to measure this consumption are only capable of measuring the volume of gas passing through them. The great majority of the meters in use today are not capable of measuring volume while, taking into account the required corrections for variations in temperature and pressure.

To arrive at energy consumption, gas distributors need to know the standard volume as well as the calorific value of gas that each consumer receives: Energy = Standard volume * Calorific Value
 

Today, this problem is solved by installing gas chromatographs at injection points in the grid and making general assumptions about the temperature and pressure of the gas delivered to consumers. Likewise, it is also assumed that all consumers beyond the injection points receive gas of identical quality. 

How does the future in energy metering look like?

The current trend in the global energy supply is to replace fossil fuels with renewable energy. In the context of natural gas, this transition is expected to take the form of gradually replacing natural gas with biomethane and hydrogen, before potentially switching to pure hydrogen.

Consequently, many countries are now publishing their hydrogen strategies and adapting policies to prepare for this transition; hence the requirement for all boilers sold in the UK and Netherlands from 2025 to be hydrogen-ready. At the same time, multiple pilot projects are being launched around the world to test the readiness of networks for the arrival of renewable gases – especially hydrogen, whose properties significantly differ from those of natural gas.

The production of renewable gases is set to be much more decentralized than the current gas supply. The introduction of these renewable gases into the grid is predicted to greatly multiply the number of injection points and lead to diverse calorific value of the gas distributed to the end-users.

With the problem expected to worsen and affect more users in the future, a new approach is needed for gas billing. The most comprehensive solution is to put an end to the separate measurement of flow and calorific values and to task meters with measuring energy directly. Sensirion’s thermal-mass technology is uniquely well equipped for this task. Sensirion’s gas meter modules measure the volume of natural gas, biomethane, hydrogen and hydrogen blends while intrinsically correcting for temperature and pressure. 

A natural extension of Sensirion’s technology allows for direct energy metering with a perspective of OIML R140 class B (1%) or C (2%) accuracy in calorific value measurement and class 1.5 accuracy for volume flow measurement (OIML R137). Once the regulations permit direct energy metering with B or C class accuracy CV measurement, Sensirion will offer an economic solution compatible with hydrogen and biomethane to combine volume and calorific value measurement in a gas meter.