Supermarkets

Objectives

The main objectives were to achieve maximum energy efficiency and maintain the level of comfort for customers. These two objectives can be divided into the following:

• Electric energy supervision and management of each centre: to optimise energy consumption in each centre and reduce the bill through both lower consumption and reducing the amount of power contracted.
• Comparison of energy consumption between centres: to control those that deviated from the average ratios.
• Monitoring and controlling electrical energy billing parameters: to simulate electrical energy billing and draw up cash flow forecasts.
• Finding out the actual consumption during different time periods to contract the best company and energy tariff.
• Improving energy efficiency and reducing inefficient energy consumption (reactive energy).
• Improving customer satisfaction through better control of the energy factors of the installations, ensuring correct air conditioning and lighting quality levels.

Solution

CVM-MINI energy measurement and control units were installed in the stores, one for each line: general consumption, air conditioning, fridges, ovens and the rest of the store.

An OPTIM capacitor bank was also connected to the header of each installation, to compensate inefficient energy (reactive energy). These banks resulted in a 15% saving on the electricity bill.

All the data relating to the CVM-MINIs were included in the EDS energy manager which includes an integrated web server. This unit supplies the data locally to a computer installed in the SCADA PowerStudio energy management software. The same EDS energy manager sent the data to the central computer via the normal Internet installation. Alternatively, the EDS 3G version was installed if there was no telephone line in the area, so that the data could be sent wirelessly.

Information per store and a summary of all the data:

• Quantification in kWh per hour of consumption with the store open and closed.
• Knowledge of actual consumption in relation to the objectives set in each area enabled more accurate correction and better final energy adjustment.
• If the instantaneous power in hours for "Stored Closed" exceeded 20% of the contracted power, an alarm was activated.

By monitoring the actual power consumed, it was possible to reduce the amount of power contracted in some centres, achieving a reduction of €12,000 a year on the electricity bill.

With the integration of the energy consumptions of all the centres into the central computer, the best ratios between the centres in equivalent areas could be compared, and improvements in consumption could be implemented, by improving units and their control, and implementing more rational electric energy management schedules.