When the variables to be measured and the required meters are installed, the process of energy and battery monitoring can begin.
The frequency at which the data is collected depends on the desired accuracy of the analyzes and forecasts. The desired frequency for energy monitoring is usually daily, per hour or quarter.
Define the standard consumption pattern
The energy consumption is plotted against the predefined variables (production, temperature, etc.), and a regression line is drawn through the values. This line is a monitored representation of the standard energy usage, and here’s a lot of information to be extracted:
-The y-axis intersection shows the minimum energy usage (base load) in the absence of the variable (no production, no degree days, etc.).
-The slope of the line is a representation of the efficiency of the energy-consuming process. It shows the relationship between the usage of energy and the relevant variable.
-The distribution of the measuring points indicates the degree of variation that occurs in the connection between energy consumption and the influence factors.
The height of the zero axis (intersection with the y axis) is an important value. A high zero load may indicate an error in the usage process, which uses too much energy while there is no production (or other impact factor). A strong spread of measurement points can indicate that there are more factors that significantly affect energy consumption. It can also be an indication of a lack of control over the process.
Monitoring of deviations
One of the most common ways is by using the CUSUM method, a graph showing cumulative sum of these differences. This graph is created as follows:
-First, the difference between the calculated and the actual values is determined (difference between the regression line and the measured value)
-Next, the CUSUM is plotted against a time. From this graph, the energy manager can get more information. Fluctuations around the zero point are indicative of a process that is usually expired. Striking variations, with sharp increases or decreases, are generally indicative of changes in the factors where the process depends.
The CUSUM graph, the directional coefficient is important. This angle of inclination is the key indicator of the savings achieved. A constant negative slope (descending line) indicates constant savings. A change of directional coefficient is an indication of change (s) in the process. A CUSUM analysis can quickly calculate the total savings over a period and can very well monitor the effects of savings measures.
Declaration of Causes
Energy consultants, together with building or technical managers, can analyze and explain the CUSUM, which causes the changes in energy consumption. This can be a behavioral change, a change in the process, external influences, etc. These changes should be monitored and the causes identified. In this way energy-saving measures and desirable behavior can be stimulated. Measures or behaviors that lead to increased energy use can also be made instantly, after which adjustment can take place.
When setting targets, two aspects are determined:
-The desired amount of energy saving
-The time frame in which savings can be achieved.