Insights
Market and technical insights
Our reading of what is changing for data centres and large energy consumers in Spain, with our own models and the criteria we apply in every energy study.
Grid access
Demand is queuing for grid capacity
Access to the transmission grid granted to new demand reached about 18.5 GW in October 2026. Data centres hold the largest share, about 6.3 GW, but none of it is in service yet, and their requests exceed 22 GW. For industry the question is the same: how to grow within the capacity a site already has.
Before asking for more grid, measure how the existing connection is used. Storage and EMS can create headroom within the contracted capacity.
Regulation
Data centres: renewable power, hour by hour
The Royal Decree on data-centre sustainability is still being processed. The revised text sent to the Council of State in October 2026 eases the first draft, but keeps the principle: consumption must be matched with renewable generation hour by hour.
| Draft, August 2026 | Revised text, October 2026 | What it means technically | |
|---|---|---|---|
| Scope | Grid access of 1 MW or more | Grid access of 10 MW or more; reporting from 500 kW IT | More sites affected than expected; measurement and reporting from day one |
| Hourly renewable matching | 80 % from the start | Optional transition up to 5 years: 60 % in peak hours to 2028, then 70 % peak and 60 % mid-peak; requires joining the automatic power-reduction scheme | Storage and EMS needed to move solar energy to the evening and night, and to manage curtailment |
| Age of linked renewables | Up to 18 months | Up to 36 months; no limit for PV without a prior PPA | Wider choice of plants and PPAs; minimum PPA term cut from 10 to 6 years |
| Efficiency | PUE ≤ 1.15, WUE ≤ 0.1 | PUE ≤ 1.25 as a transitional ceiling; top EU water class | Cooling design and EMS control become part of the compliance case |
Status at the time of writing: text under review by the Council of State, not final.
Our model
What it takes to reach 80 % hour by hour
Illustrative model: a 10 MW IT data centre (12.5 MW with PUE 1.25) supplied by 60 MWp of solar on a sunny day. Solar alone covers about half of the hours. A battery moves the surplus of the middle of the day to the evening and night.
| Battery added to 60 MWp PV | Load matched hour by hour (sunny day) |
|---|---|
| No battery | 47 % |
| 20 MW / 60 MWh | 66 % |
| 20 MW / 90 MWh | 75 % |
| 20 MW / 120 MWh | 85 % |
| 20 MW / 150 MWh | 89 % |
Auditor’s note: one sunny day is the best case. Annual compliance must be checked with 8,760 hourly values, winter weeks, battery degradation and a mix of solar and wind supply.
Prices
More hours at zero or negative prices
In the first quarter of 2026 Spain recorded 397 hours with negative wholesale prices, against 48 in the same quarter of 2025. Midday energy is increasingly cheap; evening energy is not.
Storage that charges at midday and discharges in the evening captures that spread, and helps meet hourly matching at the same time.
Large energy consumers
Peak shaving: paying for the power you really need
Illustrative model of an industrial plant with production peaks above 8 MW. A 2 MW / 4 MWh battery keeps demand below 6.5 MW, so contracted power and demand charges can be reduced.
- Maximum demand
- 8.5 MW → 6.5 MW (−24 %)
- Energy shifted by the battery
- 3.9 MWh per day
- Battery
- 2 MW / 4 MWh, one cycle per day
Audit criteria
What we measure in an energy study
| Indicator | Reference | Why it matters |
|---|---|---|
| Power factor (cos φ) | Reactive energy is charged below 0.95 | Direct cost on the bill; correction often pays back quickly |
| Voltage harmonic distortion (THD) | EN 50160: up to 8 % at the supply point | Overheating of transformers and cables, nuisance trips |
| Current harmonics from drives, rectifiers and UPS | IEC 61000 / IEEE 519 guidance | Defines filters and the PCS specification |
| Voltage sags and interruptions | Counted and classified per EN 50160 | Lost production; ride-through requirement for storage |
| Maximum demand per tariff period | Contracted power P1 to P6 vs measured peaks | Contract optimisation and peak-shaving potential |
| Load factor and peak-to-average ratio | Measured on interval data | Battery sizing and business case |
| PUE (data centres) | Transitional ceiling 1.25 in the revised decree | Cooling and EMS strategy |
Electro-intensive industry
Support that depends on good data
Certified electro-intensive consumers can recover up to 85 % of the charges for renewable and cogeneration support paid on their electricity, through annual calls of the Ministry of Industry. Accurate metering and energy reporting make these files easier to prepare and defend.
Data: Red Eléctrica, OMIE, MITECO, Ministry of Industry and public announcements. Models, tables and analysis: STEG Technological Platform. Illustrative models are not a sizing for any specific site.
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