New building, PLN 100,000 a year to save on fixed charges
A modern, “energy-efficient” building. It seemed that nothing could be improved.
The client is a large organisation in laboratory testing. The building is an office and laboratory building in central Poland. It opened one year before the audit. It has two usable floors and one technical floor, six air handling units with heat recovery, district heating and LED lighting with controls. There is also a solar PV system of about 50 kWp on the roof.
The building works around the clock on weekdays and in two shifts on Saturdays. The question was: where can a building this new still save energy?
The yearly cost of electricity and heat was about PLN 870,000 net.
There was no energy monitoring and no building management system (BMS). Decisions were based on intuition, not on data.
The building is better than the Polish building standards in force (WT 2021). Classic insulation upgrades would not pay back.
The contract settings with suppliers were fixed at the design stage. Nobody had ever checked them against the real use of the building.
Four steps: from invoices to an hourly profile
Site visit and inventory
A review of the heat source, the heat substation, the air handling units, the cooling units, the lighting and the PV system. We checked the design documents against the real state.
Invoices and cost structure
We split 12 months of electricity and heat bills into their parts: active energy, capacity charge, contracted capacity, variable distribution and reactive energy. We separated the costs that depend on use from the costs paid regardless of use.
Hourly profiles and load duration curves
Data from the network operators for a full year: yearly, monthly, weekly and daily profiles. We used 1-hour steps for electricity and 3-hour steps for heat. The load duration curve showed how many hours a year the building really needs the declared capacity.
Building model and assessment of measures
A model of the building in energy calculation software (Audytor OZC), with walls, roofs and the need for heat and cooling. Then we priced each measure: savings, cost, simple payback and life cycle cost (LCC).
The client paid for capacity it never used
The contracted electrical capacity was 400 kW, and the yearly peak was 112.6 kW. The building used more than 100 kW for only 11 hours a year (0.13% of the time). Heat looked the same: 473 kW of ordered capacity against a maximum of 201.1 kW. That maximum was one reading, on the morning after the Christmas break.
87% of the yearly potential did not need any investment at all. It only needed new contract settings, based on measured data.
Four decisions that save
PLN 100,000 a year
Building management system (BMS): the building had no energy monitoring. A BMS gives a history of how the systems work, live alarms and a basis for further analysis.
Reserve for the next season: after a full season of the PV system, the contracted capacity can drop by another ~20 kW. That is about PLN 3,500 a year. An energy storage system can then be chosen to match the summer peaks.
What we did not recommend: new lighting, because LED with controls was already in place. Better insulation would not help either, as walls and roofs already beat the standards of the time. Reactive energy was well managed, with no charges for it.
In new, well-designed buildings, the biggest money is rarely in the walls. It is in contracts set “just in case” at the design stage and never checked against the real use of the building.
Are you paying for capacity you do not use?
Invoices and hourly data from your network operator are enough to check if your building has a similar reserve. Tell us what kind of building it is, and we will tell you where to start.
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