Energy audit

Lecture content:

1. Why is energy accounting needed?
2. Types of energy in an energy audit
3. Heat energy accounting units of a heating system
4. Water accounting units
5. Monitoring coolant consumption
6. Electricity accounting
7. Natural gas accounting
8. Conclusions
9. Active links (NPA, standards, resources)
10. Glossary
11. Questions for self-testing

1. Why is energy accounting needed?

Because without accounting we cannot manage consumption.

Integrated metering is not a single meter, but a single automated system that:

• collects indicators from all primary metering devices – electricity, water, heating, gas;
• transmits information to a data collection device and then – to the server;
• where processing and analysis take place.

As a result, the user receives:

• a complete picture of energy consumption;
• analytics that show inefficiencies and make it possible to optimize the operating parameters of building systems;
• and all this works throughout the entire life of the building.

2. Types of energy in an energy audit

There are two types of energy in an energy audit: primary and supplied.

• Primary energy is energy from renewable or non-renewable sources that has not yet undergone any transformations.
  Example: gas, coal, solar or wind energy.
• Supply energy is the actual consumption of the energy carrier that has passed through the distribution boundary.
  The boundary is determined by the act of delimitation of the balance ownership of the networks.

Main:

• primary is the source, the “raw material”;
• supplied is what actually entered the building and for which the consumer pays.

3. Heating system thermal energy metering units

What do we always pay attention to?

1. Flow meters and their passports.

• Proper installation = accuracy of measurements.
• First, we study the technical documentation.

2. Stabilization sections.

• If the flow is stabilized, the accuracy of measurements is much higher.

3. Temperature sensors.

• Channel sensor → must reach the middle of the pipeline, then it shows the real temperature of the coolant.
• Surface sensor → often measures only the temperature of the pipe surface → transmits incorrect data.
• Therefore, we check the correct installation, cable condition, and data transmission quality.

4. Thermomonometer.

• Required when designing ITP and metering units.

5. Types of thermal energy units.

• Compact – all in one housing.
• Separate design – calculators can be moved to the control cabinet or installed directly on the flow meter.

4. Water metering units

• Cold water: the meter is installed only if there is a ball valve, filter, check valve and holes for sealing.
• Hot water: multi-zone meters with temperature sensors. If the temperature is below 40 °C → the impeller does not rotate → consumption is not counted.

5. Monitoring coolant flow

How is it done?

• A portable ultrasonic flowmeter is used.

What is this device?

• This is a time-pulse flowmeter.
• It has the characteristics of a stationary device, but is convenient to use as a portable one.

What does it measure?

• Works with most single-phase liquids.
• Can be used even where there is a second phase:

• • clean liquids,
  • wastewater,
  • suspensions,
  • water-oil mixtures,
  • liquids with a small content of gas bubbles.

Additional features:

• Has two inputs for temperature sensors to calculate the energy of the heat flow carried by the liquid.

Who uses it?

• Mainly energy auditors at large industrial enterprises.

Important:

• Flow meters and heat meters must regularly undergo metrological verification.

6. Electricity metering

• Single-tariff and multi-tariff lmeters. Most apartments now have at least two-tariff meters installed, which allow you to save money by consuming electricity at night.

• Portable meters. They are needed to determine the consumption of an individual device.

When it comes to technical audits and large capacities, a power quality analyzer is used. It monitors the energy consumption of the installation without interfering with the network.

• A modern three-phase analyzer combines:

• multifunctionality and a simple interface;
• simultaneous measurement of four-channel current and voltage;
• estimating peak values, unbalance coefficients, and power.

The device shows:

• real-time oscillograms,
• harmonic coefficient histograms,
• instantaneous changes in parameters.

Due to its reliable design and generation of alarm signals, such an analyzer provides a complete comprehensive analysis of electricity quality.

7. Natural gas metering

Natural gas is one of the key resources. It is used for cooking, for heating and water heating.

• Household meters:
  • are installed in apartments or private houses,
  • record the amount of gas used at the distribution boundary.

• Industrial meters:
• • operate in medium and high pressure systems.
  • A gas metering unit (GMU) is a set of devices that:
  • • records the amount of gas consumed,
    • ensures settlements between the supplier and the consumer,
    • controls and records gas parameters.
  • Gas volume corrector:
  • • automatically recalculates meter readings,
    • converts to standard conditions,
    • takes into account pressure and temperature.Interesting fact:
  • Ukraine is probably the only country in Europe where people pay for gas volume.
  • In the same Germany, the consumer pays for quantity heat, which is actually obtained from burning gas.

  Ukraine remains unique among European countries – consumers pay for the volume of gas, while in Germany payment is made for the heat released during its combustion.

   

  8. Conclusions

  Energy consumption audit is a comprehensive procedure that:

  • allows to determine real energy losses;
  • provides reliable accounting of all resources;
  • creates the basis for increasing the energy efficiency of residential and commercial buildings;
  • helps to optimize costs and increase user comfort.

   

  Active Links

  • State Agency for Energy Efficiency and Energy Saving of Ukraine: https://saee.gov.ua/
  • Energy Performance of Buildings. EU policies and initiatives to achieve a fully decarbonised building stock by 2050: https://energy.ec.europa.eu/topics/energy-efficiency/energy-performance-buildings_en
  • International Energy Agency (IEA) – Energy Efficiency: https://www.iea.org/
  • ISO 50001 – Energy Management Systems: https://online.budstandart.com/ua/catalog/doc-page.html?id_doc=90178