With global demand for renewable energy on the rise, solar panels have emerged as one of the most accessible and scalable solutions for clean electricity generation. But what exactly is a solar panel? How does it work? What types are available? This article will walk you through the fundamentals of solar panels, their components, and why they are increasingly used in homes, businesses, and industrial applications across the globe.
What Is a Solar Panel?
A solar panel, also known as a photovoltaic (PV) panel, is a device that converts sunlight into electricity. It achieves this through the photovoltaic effect, a process in which solar energy is absorbed by semiconductor materials—usually silicon—and transformed into direct current (DC) electricity.
Solar panels are made up of many solar cells, connected in series and sealed within protective layers of tempered glass and an aluminium frame. When sunlight hits these cells, electrons are knocked loose and flow through an electrical circuit, generating electricity.
The Photovoltaic Effect
The photovoltaic effect was first discovered in 1839 by Alexandre Edmond Becquerel. It refers to the creation of voltage or electric current in a material upon exposure to light.
Here’s a simplified explanation of how it works in a solar panel:
- Sunlight hits the solar cells.
- Photons (light particles) transfer energy to electrons in the silicon atoms.
- These excited electrons break free from their atomic bonds.
- An electric field within the cell pushes these electrons through a circuit.
- This flow of electrons creates electric current (DC).
This electricity can then be used immediately, stored in batteries, or converted to alternating current (AC) using an inverter for use in homes and businesses.
Key Components of a Solar Panel System
A solar panel system is more than just the panels themselves. Here’s what typically makes up a full system:
1. Solar Panels
- Arrays of solar cells that convert sunlight into electricity.
- Rated by their output in watts (W); common residential panels range from 350W to 450W.
2. Inverter
- Converts DC electricity into AC electricity.
- Types: string inverter, microinverter, hybrid inverter.
3. Mounting Structure
- Secures solar panels to the roof or ground.
- Can be fixed tilt or adjustable for maximum sun exposure.
4. Battery Storage (Optional)
- Stores excess electricity generated during the day.
- Useful for backup during power outages or night-time usage.
5. Monitoring System
- Allows you to track performance and energy production in real time.
Types of Solar Panels
There are three main types of solar panels, each with distinct characteristics:
1. Monocrystalline Solar Panels
- Made from a single crystal structure.
- Highest efficiency rates: 18%–23%.
- Sleek black appearance.
- Higher cost but better space efficiency and longevity.
2. Polycrystalline Solar Panels
- Made from multiple silicon fragments melted together.
- Efficiency: 15%–17%.
- Blue in colour.
- More affordable but slightly less efficient.
3. Thin-Film Solar Panels
- Made using different materials like cadmium telluride (CdTe) or amorphous silicon (a-Si).
- Efficiency: 10%–13%.
- Lightweight and flexible.
- Ideal for large-scale installations or irregular surfaces.
How Much Electricity Can a Solar Panel Produce?
A typical solar panel produces between 350W to 450W of power under Standard Test Conditions (STC). However, actual energy output depends on several factors:
- Sunlight hours: Average is 4–6 hours/day in sunny climates.
- Orientation and tilt angle.
- Shading from trees or buildings.
- Temperature (panels are less efficient in extreme heat).
Example:
A 400W panel receiving 5 hours of peak sunlight per day generates:
400W × 5 hrs = 2,000Wh/day or 2 kWh/day.
If you install 10 such panels:
2 kWh × 10 panels = 20 kWh/day.
That’s enough to power the average Singapore household, which uses between 15–20 kWh/day.
Solar Panel Efficiency and Performance
Efficiency refers to how much sunlight a solar panel can convert into usable electricity.
| Type | Efficiency (%) | Space Needed |
|---|---|---|
| Monocrystalline | 18–23% | Least |
| Polycrystalline | 15–17% | More |
| Thin-Film | 10–13% | Most |
Higher efficiency = fewer panels for the same output.
Degradation rate is also important. Most panels degrade at 0.5% per year, retaining ~90% efficiency after 20 years.
Installation Options
1. Rooftop Installation
- Most common for residential systems.
- Must evaluate roof direction, tilt, and shading.
2. Ground-Mounted
- Ideal for large properties or commercial spaces.
- Easier to clean and cool.
3. Floating Solar (Floating PV)
- Installed on water bodies.
- Reduces land use and helps cool the panels for higher efficiency.
Costs and Savings
In Singapore, the average cost for solar installation ranges from S$1,500 to S$2,000 per kWp for residential systems.
| System Size | Estimated Cost | Monthly Savings |
|---|---|---|
| 3 kWp | S$4,500–S$6,000 | S$120–S$180 |
| 5 kWp | S$7,500–S$10,000 | S$200–S$300 |
| 10 kWp | S$15,000–S$20,000 | S$400–S$600 |
ROI usually occurs within 5–7 years, with warranties up to 25 years.
Government Incentives in Singapore
Although direct subsidies are limited, support comes in forms such as:
- Open Electricity Market (OEM) – Sell excess electricity back to the grid.
- SolarNova Programme – Government initiative to increase solar adoption in public sector.
- Green Mark Certification – Buildings with solar are awarded higher green ratings.
Benefits of Solar Panels
✅ Lower Energy Bills
- Generate your own electricity and reduce reliance on grid power.
✅ Environmentally Friendly
- 1kWp system offsets ~1 tonne of CO₂ annually.
✅ Energy Independence
- Protects against rising utility prices and blackouts.
✅ Increases Property Value
- Homes with solar systems are seen as modern and sustainable.
Challenges to Consider
❌ High Upfront Cost
- Though long-term savings are significant, the initial capital can be steep.
❌ Weather Dependence
- Reduced efficiency during rainy or overcast days.
❌ Not Suitable for All Roofs
- Requires enough space, correct orientation, and minimal shading.
Maintenance and Lifespan
Solar panels require minimal maintenance:
- Cleaning: Every 3–6 months if dust or bird droppings are frequent.
- Inspection: Annually to check mounting, wiring, and inverter performance.
- Lifespan: Typically 25–30 years with warranties often covering 80–90% performance.
Future Trends in Solar Technology
- Bifacial Panels: Capture sunlight from both front and rear surfaces.
- Perovskite Solar Cells: Potential for higher efficiency and lower cost.
- Building-Integrated PV (BIPV): Solar integrated into roofs, windows, and facades.
- Solar + Battery Packages: Increased adoption of home energy storage solutions.
Conclusion
Solar panels represent a powerful and sustainable way to harness the energy of the sun for electricity. Whether you’re a homeowner looking to reduce bills or a business aiming to improve ESG credentials, installing a solar panel system can deliver long-term financial and environmental benefits. With advancements in technology, falling prices, and government support, there’s never been a better time to consider going solar.