Capacity tariff risk often looks technical, but many spikes are operational. They happen when several systems start in the same 15‑minute window because schedules were set for convenience, not for spreading demand. In Belgium your monthly peak is the highest quarter-hour average in the month-so shifting even a few heavy loads by 10–20 minutes can avoid a new peak and lower the capacity component on the next invoice. Simple sequencing rules, with clear ownership, can reduce risk without capex.
Step 1: map your first-hour load stack
Focus on the first 60–90 minutes of each operating day-this is when most avoidable peaks occur. List systems that start automatically or by routine: HVAC boost, process lines, compressors, kitchen equipment, EV charging, water heating, ventilation. For each, note whether it must start at a fixed time or can be delayed by 10–20 minutes. The goal is to avoid having more than two major loads in the same 15‑minute interval.
Step 2: apply a simple stagger rule
Apply one rule first: no more than two heavy loads in the same 15‑minute window unless operationally required. Use 10–20 minute offsets for flexible systems (EV charging, hot water recovery, non-critical ventilation or warmup). Keep it simple in the first rollout-consistent application matters more than fine-grained optimisation.
A 10–20 minute shift is often enough to move a load out of the peak-forming interval and reduce the monthly capacity charge without affecting operations.
Step 3: review and lock ownership weekly
Weekly review
- 1. Compare expected startup sequence vs actual practice.
- 2. Note exceptions and whether they were avoidable.
- 3. Estimate month-to-date peak trend and financial effect.
- 4. Confirm who approves schedule changes going forward.
Without ownership, schedules drift back and peak risk returns.
4. Getting buy-in from operations and keeping the rule alive
Peak reduction only works if the stagger rule is actually followed. Involve operations early: explain that one 15‑minute window sets the whole month's capacity charge and that shifting a few non-critical loads by 10–20 minutes can avoid a big cost. Make the rule simple and visible-e.g. a one-page "startup sequence" or a short checklist for the person who opens up or runs the first shift. If possible, tie it to a shared goal (e.g. "keep peak under X kW this month") so there is a clear success measure.
Review weekly for the first month or two: did the sequence happen as planned? If not, was it avoidable? Adjust the rule or the ownership if schedules keep drifting; without reinforcement, old habits return and the peak creeps back up.
5. Measuring impact: what to track before and after
Before / After
Before
Note your last three months' peak (kW) and the capacity line on the invoice.
After
Compare: did the peak drop or stay stable? Even 5–10 kW can mean meaningful € savings.
Before you introduce stagger rules, note your last three months' peak (in kW) and the capacity line on the invoice if visible. After one to two months with the new sequence, compare: did the peak drop or stay stable? Even a small drop (e.g. 5–10 kW) can mean a meaningful € saving depending on your tariff. If you have access to interval data from your DSO, you can also see whether the highest interval moved or flattened. Document the "before" and "after" so you can show management and operations that the change had an effect-and so you know whether to keep, tighten, or relax the rule.
If the peak does not budge, check that the rule is really being applied (e.g. no silent bypass of the sequence) and that the loads you staggered are actually significant. Sometimes the real spike comes from a different window (e.g. afternoon) that you have not yet addressed.
6. What if we cannot shift our main loads?
Focus on loads that can move
Some loads truly have to start at a fixed time-e.g. production must begin at 07:00, or the building must be at temperature before staff arrive. In that case, focus on the loads that can move: EV charging, hot water recovery, ventilation boost, non-critical HVAC precool or preheat, standby equipment, or any "nice to have" that does not need to be in the first 15 minutes. Even shifting two or three medium loads out of the peak window can lower the aggregate by 10–20 kW, which may be enough to avoid a new monthly peak or to bring the peak back into last month's range.
When scheduling hits its limit
If almost nothing can move, you have hit the limit of pure scheduling. The next levers are technical: timers, load-shedding or demand-response systems, or shifting some consumption to off-peak hours (e.g. preheating or batch processes at night). For many SMEs, though, there is still low-hanging fruit in "loads we never thought to stagger"-so map everything first before concluding that scheduling cannot help.
7. Communicating peak performance to management
Management often sees only the bottom-line energy cost and may not understand why the bill went up when "we didn't use more". Prepare a one-page summary: last month's peak (kW), this month's peak (kW), and the capacity line (€). Explain in one sentence that the capacity charge is driven by the highest 15‑minute draw, not by total kWh. Then report what you are doing: "We've introduced a stagger rule for [X]; we expect the next peak to be in the [Y] kW range." If you have interval data or a before/after comparison, include a simple chart or table. That turns peak from a black box into a managed metric.
Update the summary monthly so that when the next invoice arrives, you can say "peak was X kW, as expected" or "peak was higher because [event]; we're [action]." Consistent reporting builds trust and makes it easier to get support for further investments (e.g. timers, monitoring) if you need them later.
When to escalate beyond scheduling
If peaks remain high after applying and sustaining stagger rules, consider deeper options: control-system tuning, timers, or infrastructure changes. For most SMEs, scheduling is the right first step-fast, reversible, and often sufficient to remove the worst concentration patterns and avoid the highest capacity penalties.