Solar Photovoltaic (PV) technology converts sunlight directly into electricity using semi-conductors. While the concept is simple, the engineering behind a reliable system involves several critical components working in harmony.
A good PV system is not just panels on a roof. Performance depends on how the panel array, inverter, batteries (if included), protection devices, and wiring are designed to work together under real Kenyan conditions such as dust, voltage instability, and varying weather.
The Solar Panel: Mono vs. Poly
Most modern installations use one of two types of crystalline silicon cells:
- Monocrystalline: Made from a single, pure silicon crystal. They are highly efficient, perform better in low light, and have a sleek black appearance. This is our standard at Iselle.
- Polycrystalline: Made from multiple fragments of silicon melted together. They are cheaper to produce but less efficient and have a blue-marbled look.
In practice, monocrystalline panels dominate modern premium and mid-range installations because they provide better output per square meter. That matters when roof space is limited or when the project needs enough solar generation to support both daytime loads and battery charging.
Panel ratings are test conditions, not daily guarantees
Panel wattage (for example, 550W) is measured under standard test conditions. Real production changes with irradiance, temperature, shading, orientation, and system losses. This is why engineering-led sizing uses yield assumptions and site conditions rather than multiplying panel wattage by sunlight hours and calling it done.
The Inverter: The Brain of the System
Solar panels produce Direct Current (DC) electricity, but your home runs on Alternating Current (AC). The Inverter is the device that performs this conversion.
High-end hybrid inverters also manage the "logic" of your power: deciding when to pull from the sun, when to use the batteries, and when to fall back on the grid.
Beyond conversion, the inverter also interacts with protection devices, battery communication, and monitoring systems. In hybrid systems, inverter sizing must match both your peak demand and your backup strategy. A high-capacity battery does not help if the inverter cannot deliver the required output power at the right time.
Why "hybrid" matters in outage-prone environments
Grid-tied systems without backup batteries usually shut down during outages for safety reasons. Hybrid systems can continue powering selected loads because they are designed with battery storage and essential-load separation. This is one reason hybrid design has become the preferred route for many homes and businesses seeking reliability, not just bill savings.
Efficiency & Degradation
Solar panels don't last forever, but they are incredibly durable. A Tier-1 panel typically comes with a 25-year linear power warranty. You can expect about 0.5% degradation per year, meaning after 20 years, your panels will still produce roughly 90% of their original rated power.
Efficiency and degradation are important, but so is the quality of installation. Poor mounting, cable routing, shading management, and protection can reduce system performance long before panel degradation becomes a real factor. Good engineering protects both output and equipment lifespan.
System losses to remember
- Temperature losses (hot panels produce less power than their STC rating)
- Inverter conversion losses
- DC and AC cable voltage drop
- Dust, dirt, and partial shading losses
- Battery charging/discharging losses in hybrid systems
Optimizing Performance
To get the most out of your PV array:
- Orientation: In Kenya (Southern Hemisphere), panels should generally face True North to capture maximum daily irradiance.
- Cabling: Using thick, UV-resistant DC cables reduces "voltage drop"—energy lost as heat before it even reaches your inverter.
- Cleaning: Dust and bird droppings can create "hot spots" that permanently damage cells. A monthly rinse with water is often all that's needed.
Optimization also includes operational choices. For hybrid systems, running flexible loads during peak solar hours improves self-consumption and reduces battery cycling. For commercial sites, monitoring data helps spot abnormal performance early before it becomes a larger maintenance issue.
If you are just starting, pair this guide with System Sizing 101 and Battery Capacity & Life Basics so you can compare system options using both power and runtime expectations.