Understanding how electricity is consumed in a company or building is essential in order to develop an electricity-saving policy and reduce energy costs.
The electricity bill shows the monthly energy consumption of an industrial facility. Contracting electricity appropriately with an energy supplier can lead to significant economic savings. For this reason, every company should keep an energy accounting system that defines electricity contracting criteria within the liberalised Spanish electricity market.
Energy Saving and Efficiency Measures
Elimination of reactive energy
Power factor correction, or reactive energy compensation, provides unquestionable advantages from both a technical and economic perspective, as this type of energy is penalised on the electricity bill.
The main advantages of this measure for a company include:
- Reduction in the electricity bill amount.
- Increase in available power capacity.
- Reduction in conductor cross-section.
- Decrease in losses due to the Joule effect (heating) in conductors and transformers.
- Reduction in voltage drops.
The most common way to eliminate reactive energy is by installing capacitor banks at the main switchboard of the electrical installation.
Adjustment of the contracted power term
In industries and buildings with contracted power greater than 15 kW, a device known as a maximum demand meter (maximeter) is installed. This device records the maximum power consumed during the billing period. Based on this recorded value, the power term of the electricity bill is calculated.
It is essential to adjust the contracted power to actual consumption in order to avoid unnecessary costs:
- If the consumed power (as recorded by the maximeter) is significantly lower than the contracted power, billing will be based on the contracted power.
- If the consumed power (maximeter) significantly exceeds the contracted power, a penalty will be charged for exceeding the contracted limit.
Therefore, to optimise contracted power, it is necessary to analyse historical maximum demand data (maximeter records) and calculate the contracted power that minimises the annual cost of the power term.
Maximum power demand in an installation occurs due to the random simultaneity of different loads operating at the same time. Controlling and reducing this peak demand makes it possible to contract a lower power level, thereby reducing the electricity bill.
Review of the variable term of the electricity bill: contract type and energy price
Depending on how much electricity is consumed and at what times, an energy supplier may offer more or less favourable pricing. The more information a company has regarding its power demand and usage schedules, the more competitive offers it can obtain from different suppliers.
Currently, there are various contract types, ranging from single-period tariffs to three-period or six-period tariffs for higher power levels. Companies should carry out a detailed study comparing offered prices against their historical consumption data in order to select the most advantageous option.
