Solar Power for Dummies: The Complete Guide 2026

Are you thinking of switching to solar energy but find the technical terms a bit confusing? This guide demystifies photovoltaics and takes you step by step through your self-consumption project.

What is photovoltaics? The basics you need to know

Photovoltaics refers to the direct conversion of sunlight into electricity using photovoltaic cells integrated into solar panels. This physical phenomenon, known as the ‘photovoltaic effect’, was discovered in 1839 by the French physicist Alexandre-Edmond Becquerel.

How does a solar panel work?

A solar panel consists of several dozen photovoltaic cells, usually made of crystalline silicon. When photons from sunlight strike these cells, they release electrons, thereby creating a direct current (DC). This current is then converted into alternating current (AC) compatible with the domestic electricity grid via an inverter.

“A 450 Wp panel produces an average of 450–550 kWh per year in Belgium, equivalent to the annual consumption of a modern fridge.”

The different types of photovoltaic panels

Important note: Wattuneed focuses on high-efficiency technologies (TOPCon, ABC) offering the best value for money. Amorphous panels, although flexible, have too low an efficiency (6–10%) and are no longer recommended in 2026 given the availability of modern flexible monocrystalline alternatives.

Detailed comparison of technologies available at Wattuneed

Focus on cutting-edge technologies

🏆 AIKO N-Type ABC: The All Back Contact revolution

The AIKO Neostar 2S 460Wp at €108.35 represents the pinnacle of photovoltaic technology in 2026. Unlike traditional panels where the electrical contacts are visible on the front (reducing the active surface area), ABC technology places all contacts on the back.

Key benefits:

• Record efficiency of 23.1%: Produces 15–20% more than a standard PERC panel over the same surface area
• Intelligent shading management: Each cell operates independently. A falling leaf affects only one cell; the rest continue to generate power
• Zero PID/LID degradation: Stable performance guaranteed for 30 years at a minimum of 85%
• Internationally acclaimed: Intersolar Innovation Award + Red Dot Design Award 2023

Who is it for? Roofs with limited space, shaded installations, high-end projects requiring maximum performance.

💎 Leapton N-Type TOPCon: The best value for money

At just €84.95 for 450Wp, the Leapton N-Type TOPCon bifacial panel offers an exceptional efficiency of 22.52% with double-sided production that can increase output by 5 to 25% depending on the installation.

Our 2026 recommendation: This is the panel offering the best performance-to-price ratio on the market. For just €0.25 more than the PERC, you gain 2 percentage points in efficiency and 50Wp in power!

💰 Longi PERC: The reliable budget option

At €84.70 for 400Wp, the Longi Hi-MO 5m remains an excellent option for tight budgets. Proven PERC technology with 20.5% efficiency and a 25-year warranty.

The essential components of a photovoltaic system

A complete solar installation requires several complementary components to operate efficiently and safely.

1. Solar panels: the heart of the system

They capture solar energy and convert it into electricity. For an average 150 m² house in Belgium, you’ll need between 10 and 20 450 Wp panels, equating to a 4.5 to 9 kWp system depending on your electricity needs.

Actual prices for Wattuneed 2026 panels:

• Longi PERC 400Wp: €84.70 incl. VAT
• Leapton N-Type TOPCon 450Wp: €84.95 incl. VAT ⭐ Recommended
• AIKO N-Type ABC 460Wp: €108.35 incl. VAT (maximum performance)

2. The inverter: the brain of the system

The inverter converts the direct current produced by the panels into alternating current that can be used in your home. There are three main types:

• String inverter: A single centralised inverter for all panels (the most common)
• Micro-inverter: One inverter per panel, ideal for shaded roofs
• Hybrid inverter: Allows the system to be connected to storage batteries

3. Solar batteries (optional but recommended)

Lithium batteries allow you to store the electricity generated during the day for use in the evening or at night, thereby increasing your self-consumption rate from 30–40% to 70–85%. A Delong Top 5.12 kWh lithium battery costs around €968 incl. VAT at Wattuneed.

4. Mounting and fixing systems

Essential for securely fixing the panels to your roof, these must comply with Eurocode standards and be suitable for your roof type (tiles, slates, steel roofing sheets, flat roof). Expect to pay €400–€800 depending on the configuration.

5. Safety and monitoring accessories

• DC circuit breaker: Panel-side protection (€30–50)
• Surge protector: Protection against power surges (€80–150)
• Monitoring system: Real-time tracking of your energy production via a mobile app

“Monitoring allows you to detect any faults immediately and optimise your self-consumption by adjusting the use of your appliances to times of high production.”

Sizing your system: how many panels do you need?

Correctly sizing your system is crucial to ensuring profitability and efficiency. It depends on several factors:

Step 1: Analyse your electricity consumption

Check your electricity bills from the last 12 months to find out your annual consumption in kWh. In Belgium, the average consumption is:

• 2-person household: 3,500 kWh/year → 7–8 panels (3–3.6 kWp) → ~€680 for equipment only
• 4-person household: 5,000 kWh/year → 11–12 panels (5–5.4 kWp) → ~€1,020 for equipment only
• 6-person household: 7,000 kWh/year → 16–18 panels (7–8 kWp) → ~€1,440 for equipment only

* Prices based on the Leapton 450Wp panel at €84.95 incl. VAT, excluding inverter, batteries and accessories

Step 2: Assess your roof’s solar potential

Step 3: Use the sizing tools

Wattuneed provides free online calculators to help you accurately estimate your needs and optimise your investment. 🔗 Access the tools

The different types of photovoltaic systems

1. Self-consumption with surplus resale

You prioritise using the electricity you generate and sell any surplus back to the grid. This is the most cost-effective model in Belgium in 2026 with the digital meter system.

2. Total self-consumption without feed-in

All the electricity generated is consumed on-site. Requires a backflow prevention system and is particularly suitable for installations with batteries.

3. Off-grid (stand-alone) system

A 100% self-sufficient installation with no connection to the electricity grid, essential for holiday homes, motorhomes or areas without grid access. Requires precise battery sizing.

4. The Plug & Play kit for beginners

A very simple solution that plugs directly into a domestic power socket. Perfect for getting to grips with solar power before embarking on a more ambitious project.

How much does a solar panel installation cost?

Prices have fallen considerably in recent years, making solar power accessible to all budgets. Here are the actual Wattuneed prices for 2026.

Actual prices of Wattuneed kits (2026)

Prices of individual Wattuneed components

• Longi PERC 400Wp panel: €84.70 incl. VAT
• Leapton N-Type TOPCon 450Wp bifacial panel: €84.95 incl. VAT ⭐ Recommended
• AIKO N-Type ABC 460Wp panel: €108.35 incl. VAT (maximum performance)
• Solenso 350VA micro-inverter: €60.00 incl. VAT (special offer, standard price €139.40)
• Astro-E 800W micro-inverter: ~€200–250 incl. VAT
• Deye 3.6 kVA hybrid inverter: ~€800–1,200 incl. VAT
• Delong Top 5.12 kWh lithium battery: €968.00 incl. VAT
• Deye 6 kVA inverter + 5.12 kWh battery pack: €1,293.80 + €968.00 = €2,261.80 incl. VAT
• Roof mounting system: €400–800 depending on configuration
• Complete cabling kit: €100–250

Important for Belgian customers: A Bebat environmental levy of €144.50 excl. VAT applies per lithium battery purchased (legal requirement for battery management).

“With complete kits starting from €319, solar power has never been more affordable. An investment of €3,706 for a 10-panel kit with a battery provides significant energy self-sufficiency and a return on investment within 7–9 years.”

Example of profitability calculation

Case study: Family of four in Belgium

• Annual consumption: 5,000 kWh
• System chosen: 10-panel 4.5 kWp kit + 5.12 kWh battery
• Investment: €3,706.89 incl. VAT
• Estimated annual production: 4,500 kWh
• Self-consumption rate with battery: 75%
• Annual saving (€0.30/kWh): 4,500 × 0.75 × 0.30 = €1,012/year
• Payback period: €3,706 ÷ €1,012 = 3.7 years
• Savings over 25 years: €1,012 × 25 - €3,706 = €21,594

Financial support and regulations

In Belgium

Wallonia:

• No planning permission required since 2022 (power ≤ 250 kWp)
• Variable local authority grants (€300–€1,500 depending on the local authority)
• 6% VAT for installations ≤ 10 kWp on homes less than 10 years old
• Digital meter with prosumer tariff reformed in 2024
• Plug & Play kits permitted from 17 April 2025

Flanders:

• Digital green certificates until 2030
• Prosumer tariff abolished since 2021
• Variable municipal subsidy

Brussels:

• Green certificates for 10 years
• Regional tax exemption

In France

• Self-consumption grant: €280–370/kWp for installations ≤ 9 kWp
• Reduced VAT rate of 10% for installations ≤ 3 kWp
• EDF purchase obligation: increased from €0.3/kWh in 2012 to rates of €0.06–0.13/kWh for surplus electricity
• MaPrimeRénov ': up to €2,500 as part of a comprehensive renovation

DIY or professional installation?

Advantages of professional installation

• ✅ Ten-year warranty on the work
• ✅ Compliance with electrical and building standards
• ✅ Access to grants and certificates
• ✅ Third-party liability insurance
• ✅ Customised sizing and advice

Self-build: who is it for?

A self-build installation can reduce costs by 30–50%, but requires:

• Electrical skills (electrical certification recommended)
• Good physical fitness (working at height)
• Time (3–5 days for a 5 kWp installation)
• Approval by an accredited body (Consuel in France)

Example DIY budget (equipment only):

• 12 Leapton 450Wp panels: 12 × €84.95 = €1,019.40
• Deye 3.6 kVA hybrid inverter: ~€1,000
• Delong 5.12 kWh battery: €968
• Mounting brackets + cabling + safety equipment: ~€500
• Total: ~€3,487 instead of €5,000–7,000 with installation

Complete solar kits make DIY installation much easier by providing all the compatible components along with detailed installation diagrams. 🔗 View the kits

Wiring diagrams and installation guides

Wattuneed provides detailed diagrams for all types of installations: self-consumption with or without batteries, three-phase systems, off-grid installations. 📐 View diagrams

Servicing and maintenance: what do you need to know?

Photovoltaic systems require very little maintenance, which contributes to their long-term cost-effectiveness.

Recommended maintenance tasks

• Cleaning the panels: 1–2 times a year (natural rainfall is often sufficient in Belgium)
• Visual inspection: twice a year (cracks, peeling, dirt)
• Electrical inspection: Every 2–3 years by a professional
• Production monitoring: Daily via app (detection of faults)

Component lifespan

What to do in the event of a fault?

Monitoring allows any drop in production to be detected immediately. The most common faults involve:

• Inverter (70% of faults): Error code displayed, after-sales service within 48–72 hours
• Fuses or circuit breakers (15%): Simple replacement
• Wiring (10%): Visual inspection of connections
• Faulty panel (5%): Replacement under warranty

Wattuneed offers dedicated technical support to quickly diagnose and resolve any issues. 🆘 Access support

Frequently Asked Questions (FAQ)

Do solar panels work on cloudy days?

Yes! Panels produce around 10–25% of their maximum capacity on cloudy days and up to 50% on partly cloudy days. Although Belgium does not get much sunshine, it offers a solar potential of 950–1,100 kWh/kWp/year.

How cost-effective is a solar panel installation?

In 2026, the average payback period in Belgium is 7–9 years for a 5 kWp system. With Wattuneed kits, the payback period can be reduced to 3–5 years for battery-optimised configurations. Over 25 years, the total savings amount to €15,000–25,000 depending on your consumption.

What is the difference between PERC, TOPCon and ABC?

PERC (€84.70/400W): Proven technology with rear passivation, 20.5% efficiency, excellent value for money.

TOPCon (€84.95/450W): N-type technology with an oxide tunnel layer, 22.52% efficiency, bifacial production (+5–25%), best choice for 2026.

ABC (€108.35/460W): All Back Contact, all contacts on the rear, record efficiency of 23.1%, optimal shading management, zero PID/LID, for limited spaces.

Can you be completely self-sufficient with solar panels?

Total self-sufficiency is technically possible but requires significant oversizing (batteries of at least 15–20 kWh) and costs 2–3 times more than a standard installation. The self-consumption model with the grid connection retained remains the most economically viable option.

Do you need to register your solar panel installation?

In Belgium, all installations must be registered with the network operator (ORES, RESA, SIBELGA depending on your area). Plug & Play kits < 800 VA have been authorised since April 2025 without RGIE inspection as they are considered appliances rather than installations. In France, Plug & Play installations < 800 VA must be registered via the Enedis portal.

Are the panels resistant to hail and storms?

Yes, IEC 61215-certified panels (Longi PERC, Leapton TOPCon, AIKO ABC) can withstand hail impacts of 25 mm at 83 km/h and winds of up to 200 km/h if correctly fixed in accordance with Eurocode standards. Snow load test 5400 Pa and wind load test 2400 Pa.

Can I install panels on an asbestos roof?

No, legislation prohibits any work on roofs containing asbestos without prior removal by a certified contractor. This costs €20–40 per square metre but often provides an opportunity for a fully subsidised renovation.

Your next steps to get started

You are now ready to launch your solar project! Here are the practical steps to follow:

1. Assess your energy consumption using our online calculator
2. Check the orientation and condition of your roof
3. Choose your starter solution:
   • Beginner: 450Wp Plug & Play Kit at €319
   • Intermediate: 900Wp Kit at €1,102
   • Complete: 10-panel kit + battery for €3,706
4. Select your panel technology:
   • Best value for money: Longi PERC 400W at €84.70
   • Best value for money: Leapton TOPCon 450W at €84.95 ⭐
   • Maximum performance: AIKO ABC 460W at €108.35
5. Compare quotes from several installers (at least 3) if you opt for a professional installation
6. Check what financial assistance is available in your area
7. Order your kit or schedule the installation
8. Register your installation with the relevant authorities

For beginners, we recommend starting with a 450Wp Plug & Play kit at €319 to familiarise yourself with solar energy production before considering a full installation.

Wattuneed SPRL
Rue Henripré 12, 4821 Andrimont, Belgium
Tel: +32 87 45 00 34 – info@wattuneed.com
www.wattuneed.com | Technical support