Optimization of tariff curves / subscribed power

Optimizing tariff curves and contracted power involves aligning your energy contract (tariff options, hourly rates) and your power profile (contracted kVA) with the actual usage of your site. The goal is to pay the right price by reducing overconsumption penalties, smoothing peak loads, and choosing the most suitable tariff structure (differentiated hours, dynamic signals, demand response clauses). This approach isn't purely administrative; it relies on load curve analysis and technical measures (control, sequencing, storage).

Pricing and power optimization: operational definition

The process begins with a detailed analysis of the load curve (10/15/30 min) to distinguish between base load, peak load, seasonality, and time-of-use periods. This data is then compared to the current contract: contracted power (kVA), time-of-use periods (base/peak-off-peak/tempo or equivalent dynamic), overrun conditions, and the structure of fixed/variable terms.

Next, an arbitration plan is developed:

- Settings and sequencing (stagger HVAC/DHW/lighting restarts, pre-heating/pre-cooling).

- Removal and smoothing of peaks (BMS/EMS rules, non-critical load shedding).

- Storage (thermal/electrical) if relevant for peak shaving.

- New contract: adjust the subscribed power, choose a time option better correlated to the profile, negotiate clauses (power, indexation, penalties).

The whole thing is monitored by dashboards (kW/kWh, overruns, costs avoided) to ensure the sustainability of the gains.

Optimizing contract and power: advantages, limitations, and areas for attention

Interests

• Immediate cost reduction: elimination of overruns and a better time-based option.
• CAPEX avoided: by reducing peaks, there is less need for oversizing.
• Budget predictability: pricing structure aligned with the actual profile.
• Speed: many gains through adjustments and control, without heavy work.

Boundaries

• Data sometimes incomplete (bad timing, missing sensors).
• Non-controllable loads (critical processes) limit demand response.
• Reversible gains if the instructions are not maintained (usage drift).
• Heterogeneous contracts and clauses that are sometimes complex to compare.

Points to consider

• Reliable measurement quality and time stamping to detect true spikes.
• Comfort & IAQ: no erasure that degrades usability or health.
• Coordination of HVAC/lighting/equipment: avoid simultaneous restarts.
• Supervision: alarm thresholds, monitoring of exceedances, monthly reviews.
• Negotiation: check penalties, contracted power per period, indexation terms.
• Annual review: re-calibrate power/option if the profile changes (new occupants, PV, PAC).

Anecdote — “The 8:30 a.m. train that cost Bordeaux too much”

In Bordeaux, a mixed-use building saw its energy bill inflated by recurring peak usage times precisely at 8:30 a.m. Analysis revealed simultaneous activation of ventilation, heating, hot water, and lighting. With a simple sequencing (ventilation at 7:50 a.m., preheating at 8:05 a.m., lighting at 8:25 a.m.) and a slight reduction in the initial temperature setting, the peak usage dropped by 20%. The building manager was able to reduce the contracted power upon renewal, resulting in savings per kWh and, more importantly, on the power bill. The moral of the story: sometimes, a 30-minute difference can save thousands of euros per year.