Energy price - Why as much, or what is a load curve good for?

More than 90% of price of electric energy is determined by the purchase price. Nevertheless, these prices may differ by supply point. How is that possible?

To understand this, it is necessary to know that supply points with a contracted low-voltage capacity exceeding 3x80 A (≈50 kW) are obliged to install remote data access. This means a phone line and a modem in practice, which make remote access to metering data possible. Not only is this practical and comfortable, since meter reading does not entail on-site assistance, but it is necessary for a more important reason as well. Namely, this technology makes it possible to extract the metering data recorded by the meter every 15 minutes on a monthly basis.

These are called time-series data, and those are “time series” supply points. Plotting these 15-minute data in a time-value coordinate system we get the load curve, which shows the daily energy consumption curves on the given meter site. At locations whose capacity is below the above mentioned contracted capacity, it is unfeasible to install remote meter reading due to the great number of such meter sites. Therefore, in these cases the most suitable profile has to be applied from a pool of real metering samples based on the most frequent activities. These are the so-called “profiled” supply points. Profiles are thus load curves themselves, but instead of being site-specific, they are typical, general curves.

What is a load curve good for?

The public utility system that ceased last year involved so-called peak- and off-peak periods, based on well thought of energy economy considerations. The two periods’ different yet regulated energy prices made it possible to balance daily nationwide load by inciting consumers to use less energy in high load periods due to its higher price.

With the liberalization of the market this system ended, and the new electricity bills of time-series meter sites don’t indicate periods any more. Owing to the availability of a 15-minute load curve, there is a much more efficient opportunity for energy conservation than with the previous double-zone system. Accordingly, the energy prices of the competitive market are calculated on the basis of the consumption patterns - load curves - of individual consumers, and this explains why the energy prices differ for each time-series supply point.

The reason is, that in practice a lower energy price is calculated on the basis of a load curve which shows that the majority of consumption occurred during the night or weekend periods - that is, periods of less load with respect to national energy economy - while only some of it occurred during the high-load peak period.

The precision of custom energy price calculation is further increased by taking into consideration the evenness of consumption. In theory, a continuous and even consumption load would be the most beneficial. Even though this is hardly feasible, it is worth aiming for the closest possible approximation of an even consumption in order to achieve the most favourable energy price. Thus — in case it requires no disproportionate expenditure — it is advisable to make as much effort as possible to rationalize and upgrade, in order to reduce daily fluctuation.