Analysis
What is changing in energy for data centres and large industry in Spain
We follow the grid, regulation and the electricity market because they decide whether a project can connect, comply and be financed. Here we summarise the data, our models and the technical criteria we apply.
Public data from Red Eléctrica, OMIE, MITECO and the Ministry of Industry, October 2026.
Grid access
The grid is no longer a formality. It is the scarce resource
Transmission-grid access granted to new demand adds up to about 18.5 GW. Data centres hold the largest share, about 6.3 GW, but none of it is in service yet, and the sector's requests exceed 22 GW. Industry faces the same question: how to grow with the power it already has under contract.
Our approach: before asking for more grid, measure how the existing connection is used. Storage and EMS can create headroom within the capacity already available.
Regulation
Spain's data-centre decree: renewable power, hour by hour
The Government has softened the August draft and sent a revised text to the Council of State. The core principle stays: consumption will have to be covered by renewable generation matched hour by hour.
| Topic | Draft, August 2026 | Revised text, October 2026 | Technical reading |
|---|---|---|---|
| Scope | Grid access of 1 MW or more | Grid access of 10 MW or more; reporting duty from 500 kW IT | More sites affected than expected; metering and reporting from day one |
| Hourly renewable matching | 80 % from the start | Optional transition of up to 5 years: 60 % in P1 until 2028, then 70 % in P1 and 60 % in P2; requires joining the automatic power-reduction scheme | Storage and EMS are needed to carry solar energy into the evening and night and to manage reductions |
| Age of linked renewables | Up to 18 months | Up to 36 months; no limit for PV without a prior PPA | More plants and PPAs available; minimum PPA term down from 10 to 6 years |
| Efficiency | PUE ≤ 1.15 and WUE ≤ 0.1 | PUE ≤ 1.25 as a transitional ceiling; top EU water class | Cooling design and EMS control become part of compliance |
Status at the time of writing: text at the Council of State, not yet final.
Solar-Tec model
How much battery it takes to reach 80 % hour by hour
Illustrative model: a 10 MW IT data centre (12.5 MW with PUE 1.25) and 60 MWp of PV on a sunny day. PV alone covers roughly half of the hours; the battery moves the midday surplus into 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 % |
Audit note: a sunny day is the best case. Annual compliance is checked with all 8,760 hourly values, winter weeks, battery degradation and a mix of solar and wind.
Market
Midday gets cheaper. The evening does not
In the first quarter of 2026 Spain recorded 397 hours with negative wholesale prices, against 48 in the same quarter of 2025.
Storage that charges at midday and discharges in the evening captures that spread and, at the same time, helps meet hourly matching.
Large consumers
Peak shaving: pay only 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 excess-power charges can be reduced.
- Maximum demand
- 8.5 MW → 6.5 MW (−24 %)
- Energy shifted
- 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 usually 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 15-minute data | Battery sizing and business case |
| PUE (data centres) | Transitional ceiling of 1.25 in the revised text | Cooling and EMS strategy |
Electro-intensive industry
Support that depends on good data
Consumers certified as electro-intensive can recover up to 85 % of the renewable and cogeneration support charges they pay on their electricity, through the Ministry of Industry's annual calls. Rigorous metering and energy reporting make the file easier to prepare and defend.
Data: Red Eléctrica, OMIE, MITECO, Ministry of Industry and public announcements. Models, tables and analysis: Solar-Tec. Models are illustrative and do not replace the sizing of a specific site.
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