Before connecting to the power grid, you need to declare the maximum power you will be drawing, which is referred to as contracted power. This declaration allows the energy supplier to determine the appropriate connection and protection. Importantly, the contracted power is the basis for calculating charges for energy consumption. If a business incorrectly estimates its power demand or doesn’t control the operation of its devices properly and exceeds the contracted power, it may face additional costs as the energy provider will levy additional charges.
Distribution system operators (DSOs) continuously monitor the active power consumed or fed into the grid by a facility. The excess of the contracted power is calculated hourly, but it uses the average values recorded every 15 minutes. This means that momentary exceedances of the contracted power due to events like device startups are not taken into account. Penalties are calculated based on this data.
As a result of multiple power exceedances during the same hour, the Distribution System Operator (DSO) takes into account only the moments when the facility exceeded the power by the largest values. The penalty is calculated using several methods, and one of them involves the product of a fixed component of the network rate and the sum of the ten highest power exceedances recorded.
To reduce additional costs, it’s necessary to choose the rated power appropriately. Optimization can involve using a fixed or variable rated power. Sometimes, using variable power can lead to savings of several dozen percent compared to a fixed rated power. However, it’s important to be aware that with this practice, the savings will vary depending on the month.
Another way to optimize the rated power is to intervene in the energy system, for example, by using a power guard, a cogeneration unit, or photovoltaics. However, if the company chooses not to intervene in the energy system in any way, the scope of cost optimization will be limited to the analysis of the rated power, which is conducted by Energy Trend using a success fee model – payment expressed as a percentage of the financial savings achieved.