Larger rooftop photovoltaic projects for businesses across mainland Spain and the Balearic Islands, including systems above 100 kW. The service covers warehouses and logistics facilities, factories and processing plants, cold storage, larger hotels, supermarkets and retail portfolios, agricultural and food production buildings, business parks, multi-building sites and multi-site operators.
Commercial Solar Spain reviews and coordinates enquiries. Technical assessment, system design, proposals and project delivery are handled by our installation partner, who is identified to you before technical assessment begins. You contract directly with that company.
Request a Large Commercial Solar Assessment · See commercial solar installation in Spain
What counts as a large commercial project
"Large commercial solar" is a practical description rather than a legal category. There is no single capacity at which a project becomes large.
The 100 kW figure is worth understanding because certain economic and administrative arrangements change there. It is not a maximum installation size, not a planning threshold, not the definition of an industrial project, and not evidence that a system is commercially suitable. Plenty of projects below 100 kW are substantial capital decisions and some above it are straightforward.
One technical point matters at this scale. The relevant Spanish threshold is measured by inverter installed capacity rather than module capacity in kWp. A proposal should state both figures separately.
The largest system that fits is not automatically the right one
Roof area sets a possible maximum. The commercial capacity depends on the overlap between generation and demand. Generation used on site displaces imported electricity, while excess output is exported at a different value or curtailed under a without-surplus configuration.
As capacity grows, more generation may fall into hours when demand is already met. The correct point can only be found by testing capacity options against interval consumption. Our guide to sizing a commercial solar system around business electricity use explains the method, while the Datadis consumption data guide explains how interval records are obtained and used.
Incremental capacity and incremental return
Whole-system payback does not show how the final portion of capacity performs. Ask what the additional capacity costs, what annual benefit it adds and the payback on that difference. Two or three capacities should be modelled on consistent assumptions so the incremental capital and benefit are visible.
The outcome depends on the load profile. Sustained seven-day demand may absorb additional output effectively, while a five-day operation may export or curtail more of each capacity increase. A proposal presenting one capacity only does not demonstrate that alternatives were tested.
Self-consumed, exported and curtailed generation
Three quantities carry different values, and a large-project proposal should keep them separate.
Self-consumed electricity is used on site as it is produced and reduces what you import at that moment. Its value depends partly on the applicable tariff period, as explained in how Spanish business electricity tariffs work.
Exported surplus goes to the network. Where the installation qualifies it may be compensated through the electricity bill; otherwise it is sold under producer and market arrangements. Either route values it below the cost of imported electricity.
Curtailed generation arises where the installation operates without surplus. Output is held below site demand and the excess is never produced. It has no value at all.
Ask for all three in kWh, together with the self-consumption rate and solar coverage rate. Those percentages measure different things and must be labelled.
What changes above 100 kW
Above 100 kW, simplified surplus compensation is unavailable where the associated production capacity exceeds that figure. Surplus must therefore be sold under producer and market arrangements, or the installation configured to operate without export.
Larger with-surplus projects may require producer registration, market representation and additional administrative arrangements, each carrying cost and time. A without-surplus configuration is a different position: it avoids the export-related obligations, though other requirements may still apply depending on capacity and location.
The precise route depends on the configuration and should be established before a programme or budget is fixed. The detail is set out in commercial solar above 100 kW in Spain, with the wider process covered under permissions, grid connection and legalisation.
Site, structural and electrical due diligence
The technical questions are similar to those on any commercial project, but the financial consequence of an unresolved issue grows with the project. Structural capacity, roof condition and remaining service life must be established before design is fixed. Suspected asbestos-containing material requires specialist investigation and should not be treated as an ordinary mounting question.
The electrical assessment must establish the connection point, switchboard position, cable routes and available capacity. Where export is restricted, output may need to be limited below site demand, changing both system size and return.
Roof-specific considerations are covered under industrial and warehouse solar, while what a commercial solar feasibility study includes explains the wider assessment scope.
Programme and operational planning
The programme should address access, lifting, deliveries, working areas and any interruption required for connection or commissioning. On an operating site, timing may need to align with a maintenance window or planned shutdown.
It should also separate installer-controlled work from distributor, municipal and regional procedures. A completion date given before the regulatory route is established remains provisional.
Multi-building and multi-site assessment
Several sites can be reviewed together, but each requires its own technical and consumption assessment. Differences in operating hours, roof condition and connection capacity can produce a clear order of priority.
Where several buildings share a site, possible connection and allocation arrangements depend on the metering and proposed configuration. That question must be resolved technically before it is included in a budget.
What a large-project proposal should contain
Request panel capacity and inverter installed capacity separately, with more than one capacity scenario modelled on consistent assumptions. Each scenario should show generation, self-consumed, exported and curtailed kWh, the self-consumption and solar coverage rates and the value applied to each category.
Also request incremental capital and annual benefit between scenarios, full costs with and without IVA, written exclusions, external programme dependencies and the assumed regulatory route. For a larger capital decision, NPV and IRR assumptions and sensitivity testing provide a fuller view than payback alone.
Evaluating the return
Simple payback is a useful first filter but ignores value after the payback point, degradation, inverter replacement and the time value of money.
Net present value and internal rate of return are the appropriate measures, because they can be compared directly against other uses of the same capital. The discount rate should reflect your actual cost of capital rather than a convention borrowed from a proposal template.
Where debt is involved, project return and equity return are different figures. Electricity-price escalation also deserves scrutiny because it can dominate a long projection. The methodology is set out in commercial solar payback and return on investment, with indicative ranges covered under commercial solar costs in Spain.
What to send with your enquiry
The more of this that is available, the more useful the review:
- Business name and site location
- Property and operational use, and whether the building is owned or leased
- Operating hours and shift patterns, including weekend working and any annual shutdown
- Annual electricity consumption or annual spend
- Recent electricity bills, and interval consumption data if you hold it
- CUPS reference for each supply point, optional
- Approximate roof area
- Roof type and approximate age, if known
- Any known structural or electrical constraints
- Planned operational or electrical changes, such as additional plant or fleet charging
- Whether the enquiry covers one site or several
The CUPS is the supply point reference on your electricity bill, beginning ES. It identifies the site and the distributor serving it. It does not by itself provide access to your consumption data, which requires your separate authorisation.
How the project runs
Enquiry and review. You send the site details. We review the enquiry against our installation partner's project criteria.
Partner identified. We tell you which company would deliver the project, and you decide whether to proceed. Nothing is passed on for technical assessment before that point.
Technical assessment and proposal. The installation partner surveys the site, models capacity scenarios against your consumption, establishes the structural, electrical and regulatory position and issues a proposal.
Contract, delivery and commissioning. Entered into directly between you and the installation company, which handles construction, the applicable procedures, testing and handover.
How this works
Commercial Solar Spain is a commercial enquiry and coordination brand. We are not the installer, and we are not a comparison service, a marketplace or an independent adviser. We work with one installation partner, and that partner delivers every project.
There is no charge to you for the introduction. We may receive a fee from the installation partner when an introduced project proceeds.
We will not tender your project to several companies because we work with one. We encourage you to benchmark the proposal against alternatives and normalise every bid onto the same scope before comparing prices. Our guidance on comparing commercial solar quotations explains the process and applies to us as much as to anyone else.
Frequently asked questions
Is there a minimum size for this service? There is no legal threshold defining a large commercial project. We review the site, consumption profile and proposed scope against the installation partner's project criteria.
Is 100 kW a legal limit on system size? No. Spanish self-consumption rules do not impose a general maximum. What changes above 100 kW is which economic and administrative arrangements are available, and the practical limits come from the property, the electrical installation, the connection point and the economics.
Is the threshold based on panels or inverters? Inverter installed capacity, not module capacity in kWp. The two figures are often different, so both should appear in any proposal.
Will a larger system produce a better return? Not necessarily. It depends on how much of the additional generation the site can use as it is produced. Ask for the incremental capital and incremental annual benefit on each step up in capacity, shown separately from the whole-system figure.
Do we have to export surplus? No. An installation can be configured to operate without surplus, in which case excess generation is curtailed rather than exported. Whether that is preferable depends on the value of the surplus against the cost and complexity of selling it.
Can several sites be considered together? Yes. Send the basic information for each, although every building will require its own technical assessment.
How long does a larger project take? There is no standard programme. Surveys, engineering, procurement, construction and any distributor or administrative procedures all contribute. A reliable timetable depends on the route applying to the specific project.
What should we insist on seeing in the proposal? Multiple capacity scenarios on identical assumptions, self-consumed and exported electricity separated with the value applied to each, incremental analysis between scenarios, a written exclusions list, and NPV and IRR with the assumptions and sensitivity testing shown.
Request a large commercial solar assessment
Send your site details, or details for each site where the enquiry covers several. We will review it against our installation partner's project criteria, and if it is suitable we will identify the installation company and confirm the next step before anything proceeds to technical assessment.
Request a Large Commercial Solar Assessment
For businesses, industrial property owners and multi-site operators in mainland Spain and the Balearic Islands.