Types of Solar Panels in Spain: What Your Quote Might Include

If you receive a solar quote in Spain today, the panels on it will almost certainly be monocrystalline. These panels are made from a single, continuous crystal of silicon, which gives them their characteristic uniform dark black appearance.

Monocrystalline panels have become the industry standard because they offer the best balance of efficiency, durability and cost. A typical modern mono panel converts around 20–22% of the sunlight hitting it into electricity. This matters because higher efficiency means you need fewer panels to reach your target system size — which is especially important if you have limited roof space.

Within the monocrystalline category, there are several cell technologies you may see on quotes:

• PERC (Passivated Emitter and Rear Cell): The most common technology in residential panels. A reflective layer on the back of each cell bounces unabsorbed light back through the silicon for a second pass, boosting efficiency by 1–2%.
• Half-Cut Cells: Instead of using standard full-size cells, these panels use cells that have been cut in half. This reduces electrical resistance and heat, and critically makes the panel more shade-tolerant — if one half is shaded, the other half continues to produce.
• TOPCon (Tunnel Oxide Passivated Contact): A newer premium technology appearing on 2024–2025 quotes. TOPCon panels achieve efficiencies of 22–24% and perform better in low-light conditions (early morning, late afternoon, overcast days). They cost slightly more but are increasingly common on higher-end installations.
• HJT (Heterojunction Technology): The highest-efficiency mass-produced panels available, reaching 24%+. HJT panels have excellent temperature performance — they lose less output in extreme heat, which is particularly relevant for summer in southern Spain. However, they are significantly more expensive.

You may still occasionally see polycrystalline panels mentioned. These are recognisable by their distinctive blue, speckled appearance. They are made from multiple silicon crystals melted together, which makes them cheaper to produce but less efficient (typically 15–17%).

Polycrystalline panels were the standard choice for residential installations until around 2018–2019. Today, the price gap between mono and poly has narrowed so much that there is almost no reason to choose polycrystalline panels for a new installation. If an installer is quoting you polycrystalline panels in 2025, you should ask why — it may indicate they are using old or budget stock.

Bifacial panels can generate electricity from both the front and the rear of the panel. The rear side captures reflected and diffused light bouncing off the surface beneath the panel. In ideal conditions, the rear side can contribute an extra 5–15% of energy production.

Whether bifacial panels are worth the extra cost depends entirely on your installation:

• They work well on: White flat roofs (common in Andalucía), pergola or carport structures, ground-mounted arrays, and any installation where the panel is raised at least 30cm above a light-coloured reflective surface.
• They add little value on: Dark tiled roofs where panels are mounted close to the surface with minimal airflow or light reaching the rear side.

Many Spanish villas have white flat terraces that are excellent for bifacial panels. But if an installer is quoting you bifacial panels on a traditional dark clay tile roof, the extra cost is unlikely to pay for itself.

Read our detailed guide to bifacial panels →

Solar panels are rated in Watts peak (Wp), which represents the maximum power output under ideal laboratory conditions. Over the past five years, panel wattages have increased dramatically:

• 2019: Typical residential panel was 300–330 Wp
• 2022: 400–415 Wp became standard
• 2025: Many installers now quote 440–580 Wp panels

Higher wattage generally means higher efficiency, but there is an important physical trade-off: higher-wattage panels are physically larger. A 580 Wp panel might measure 2.3m × 1.1m, which may not fit well on smaller roof sections, around dormer windows, or on roofs with vents and chimneys.

What matters on your quote is the total system size in kWp (kilowatts peak) and how that relates to your actual electricity consumption. Ten panels at 440 Wp (4.4 kWp) will produce essentially the same amount of energy as eight panels at 550 Wp (4.4 kWp). The difference is how many panels fit on your roof and the cost per watt.

Be wary of installers who emphasise high wattage as a selling point without explaining why it matters for your specific property. Sometimes, using a greater number of smaller panels gives better coverage and more design flexibility.

Efficiency is the percentage of sunlight energy that a panel converts into electricity. Most modern residential panels fall between 20% and 24%. But what does a 2–3% efficiency difference actually mean in practice?

For a typical 10-panel installation in Málaga:

• At 20% efficiency: approximately 7,800 kWh/year
• At 22% efficiency: approximately 8,580 kWh/year
• At 24% efficiency: approximately 9,360 kWh/year

The difference between 20% and 22% is real but modest — about 780 kWh/year, worth roughly €80–120 annually at current electricity prices. The question is whether the premium price of higher-efficiency panels is justified by the additional energy produced over the panel's lifetime.

For most homeowners, choosing a reputable brand with 20–22% efficiency is the sweet spot. Premium 24%+ panels (like HJT technology) make sense mainly when roof space is very limited and you need maximum output from every square metre.

Every solar panel comes with two separate warranties, and it is important to understand the difference:

• Product Warranty (Manufacturing Defects): Covers physical faults — cracked glass, delamination, junction box failure, defective cells. Typically 12–15 years for budget brands, 25–30 years for premium brands like SunPower, REC, or Maxeon.
• Performance Warranty (Degradation): Guarantees that the panel will still produce a minimum percentage of its original rated output after a certain number of years. A typical guarantee is 87.4% output after 25 years, meaning the panel is allowed to lose about 0.5% of output per year.

What to watch for on your quote: Some budget panels offer only a 10-year product warranty. Since inverters and batteries may need replacing after 10–15 years, having panels that are only warranted for 10 years means your entire system is effectively on a shorter warranty clock. A 25-year product warranty gives you much better long-term protection.

Also check the warranty provider — if the manufacturer is a small Chinese company with no European office, enforcing a warranty claim could be extremely difficult. Established brands with European distribution centres (like Longi, JA Solar, Canadian Solar, Trina, REC, SunPower) are much safer choices.

Before you sign a solar quote, make sure you can answer these questions about the panels:

• Brand and model: Is it clearly stated? Can you look up the datasheet online? Avoid quotes that just say "Tier 1 panels" without specifying the exact make and model.
• Wattage per panel: What is the Wp rating of each panel?
• Number of panels: How many panels are included, and does the roof layout diagram show exactly where each one goes?
• Total system size (kWp): This is the number of panels × wattage. A 10-panel system with 440 Wp panels = 4.4 kWp.
• Product warranty: How many years, and who is the warranty provider?
• Performance warranty: What minimum output is guaranteed after 25 years?
• Cell technology: PERC, TOPCon, HJT? Half-cut cells?
• Shading analysis: Has the installer assessed shading from trees, chimneys, neighbouring buildings, or satellite dishes?

If any of these details are vague or missing from your quote, that is a red flag. A reputable installer will always specify the exact equipment.