Respuesta rápida
A maxímetro records your highest 15-minute average power demand and bills it on 3.0TD (Spanish SME/commercial) tariffs. The 85–105% rule: if your peak is under 85% of contracted power, you still pay for 85% (waste); between 85–105% you pay the actual peak (optimal); over 105% you pay the contract plus double the excess (penalty). Right-sizing often saves €300–€1,200/year.
En 30 segundos
- ✓Locate the 'Billing Data' section in your PDF invoice.
- ✓Identify the 'Potencia Facturada' (Billed Power) vs 'Potencia Contratada' (Contracted Power).
- ✓Check if your billed power is consistently 85% of your contracted power (the minimum billing rule).
Stop paying for 'Ghost Power'
Our AI performs a forensic autopsy on your bill to see if your maxímetro readings suggest you should lower your contracted power.
Why you can trust it
- Free and no signup
- AI trained on the Spanish market (~30s)
- Privacy-first: ephemeral processing (we don't store your bills)
Transparencia y fuentes
Autoría
Equipo ahorr.ai
Auditoría energética (España)
Actualizado: 21 de abril de 2026
Metodología orientada a decisión: separar coste fijo/variable, detectar extras y comparar opciones con números claros.
Metodología
- →Separamos coste fijo (potencia/término fijo), energía y cargos/impuestos.
- →Buscamos sobrecostes típicos: potencia sobredimensionada, servicios extra, lecturas estimadas.
- →Damos pasos accionables (qué tocar primero) con ejemplos orientativos, no promesas.
- →Enlazamos fuentes oficiales y marcamos lo que puede variar por comercializadora.
Información orientativa (España). Comprueba condiciones con tu comercializadora: precios, peajes, cargos e impuestos pueden variar.
What is a maxímetro: the definition without the jargon
Forget complex electrical engineering. The maxímetro is simply a 'high-water mark' for your electricity usage.
The definition in one sentence
A maxímetro is a device (integrated into modern meters) that records the maximum power you demand at any given time, allowing for billing based on actual peaks rather than just a fixed limit.
Where it appears on the bill
Look for the 'Potencia' or 'Lecturas' section. You will see values for P1, P2, P3 (and up to P6 in 3.0TD tariffs). Next to your 'Contracted' power, you'll see the 'Maximum Demand' or 'Maxímetro' reading.
Why it matters: money, decisions, and typical traps
In the Spanish market, the maxímetro is the heart of the 3.0TD tariff, used by most SMEs and large homes.
The most common error
Many businesses contract 'just in case' power. If you contract 20 kW but your maxímetro only ever hits 10 kW, you are still billed for 17 kW (85% of 20). You are literally gifting money to the provider.
The clue almost no one looks at
If your billed power is exactly the same every month and matches 85% of your contracted power, you have a 'Power Vampire' in your contract. You are oversized.
How to check it in 60 seconds (Auditor's Checklist)
You don't need a technician to find the truth. Your PDF invoice has the evidence.
What to look for in the PDF
Search for the term 'Maxímetro' or 'Potencia Maxestada'. Compare these values across the different time periods (P1-P6). Usually, one period will be much higher than others.
What to note for comparison
Note down the highest peak of the last 3 months. If that peak is lower than your contracted power, there is a clear opportunity to optimize and save.
If you want certainty: autopsy your bill and decide with numbers
Manual checks are fine, but an automated forensic audit is faster and more precise.
What ahorr.ai detects
Our engine scans the relationship between your peaks and your contracted power. It flags if you are paying the 85% minimum unnecessarily or if you are paying 'Excesos' (penalties) that could be avoided by slightly raising your limit.
What to do with the result
Once you have the report, you can call your provider with the exact numbers. No guessing, no 'maybe'. Just the facts.
Forensic Checklist: Is your Maxímetro working for or against you?
- ✓Locate the 'Billing Data' section in your PDF invoice.
- ✓Identify the 'Potencia Facturada' (Billed Power) vs 'Potencia Contratada' (Contracted Power).
- ✓Check if your billed power is consistently 85% of your contracted power (the minimum billing rule).
- ✓Look for 'Excesos de potencia' (Power excesses) penalties in the breakdown.
- ✓Compare the peak recorded by the maxímetro in the last 12 months with your current contract limit.
- ✓Decide: If peaks are always below 85%, you are overpaying for 'ghost' power.
Maxímetro Billing Logic: The 85-105% Rule
| Real Peak vs. Contracted | What you are billed | Impact on your Wallet |
|---|---|---|
| Below 85% | 85% of Contracted Power | Inefficient: You pay for power you don't use. |
| Between 85% and 105% | The exact peak recorded | Optimal: You pay exactly for your maximum demand. |
| Above 105% | Contracted + Penalty (Double the difference) | Critical: High penalties; you need to increase power or manage loads. |
This rule is standard for 3.0TD tariffs (SMEs) and some legacy high-power domestic contracts.
The British Cafe Owner's Oversized 3.0TD in Alicante
A British expat running a small cafe in central Alicante had contracted 20 kW on a 3.0TD tariff when the building was renovated years ago. The maxímetro had never registered above 11.5 kW across all 6 periods in two years. Because of the 85% rule, they were being billed for 17 kW every month — paying for 5.5 kW of 'ghost' power.
Hallazgos
- ✓Contracted 20 kW vs. real peak of 11.5 kW (billed 17 kW thanks to the 85% floor).
- ✓5.5 kW of phantom capacity paid every month across 6 periods.
- ✓Right-sized to 14 kW — saving around €680/year in fixed term.
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Create your energy profile manually and we'll tell you what to look for in your specific tariff.
Preguntas frecuentes
Transparent and Private
Free, no signup required, and we never store your bills. Just pure data to help you save.
Disclaimers
- Informational tool; not financial advice.
- We don’t guarantee savings: these are estimates.