Sol Viva

Solar Scams, Shortcuts & Red Flags in Portugal

John Wallace
Dec 15, 2025By John Wallace

As solar demand grows, so does the number of low-quality installers and questionable deals. Protecting homeowners is part of Sol Viva’s mission — and here are the biggest red flags to watch out for.

Red Flag 1: Unrealistic savings claims

If someone promises:

  • “Zero electricity bills”
  • “1-2 year payback”
  • “We guarantee 100% coverage”
    …walk away. These claims are not realistic.

Red Flag 2: No structural roof assessment

A proper installer checks:

  • Roof material
  • Age
  • Orientation
  • Fixing method
  • Load-bearing capability

Skipping this step leads to dangerous installations.

Red Flag 3: Mismatched equipment

Examples:

  • A 6 kWp inverter with 12 kWp of panels
  • Batteries that cannot communicate with the inverter
  • Cheap panels with premium inverters

Always check compatibility.

Red Flag 4: Missing warranty documents

You should receive:

  • Panel model & warranty
  • Inverter model & warranty
  • Battery warranty
  • Installation warranty (minimum 2 years)

If not, do not sign.

Red Flag 5: Unsafe cabling

A professional installation includes:

  • UV-protected cable
  • Correct cable size
  • Proper AC/DC isolation
  • Earthing & surge protection

Shortcutting any of these is dangerous.

Red Flag 6: Registration Not Included 

In Portugal, all grid-connected solar systems must be registered with DGEG.

Many installers:

  • Do not register the system,
  • Or tell homeowners that registration “isn’t needed”,
  • Or leave the paperwork to the customer with no guidance,
  • Or incorrectly register the system, causing export errors and billing issues.

This leads to:

  • Legal non-compliance
  • Blocked export capability
  • Incorrect metering
  • No insurance coverage for system faults
  • Problems when selling the home
  • A proper installer always includes:

Registration with DGEG

  • Communication with your utility
  • Configuration of export limits
  • Final validation
  • Delivery of all registration documents to the homeowner

If registration is not explicitly listed on the proposal, walk away.