Solar PV Microinverters

Panel-Level MPPT: Microinverters use Maximum Power Point Tracking (MPPT) for every individual panel. This means each panel is operating at its absolute peak performance at all times.

Mitigation of Mismatch Losses: This is the biggest gain. If you have any shading (from a tree, chimney, or roof vent), a mismatch in panel output (due to dirt, snow, or minor manufacturing differences), or panels facing different directions, the microinverters isolate the issue. The strong panels continue to produce at full power, resulting in a higher total system yield compared to a string inverter, where the entire string's output would be dragged down by the weakest panel.

Shade Performance: Excellent in shaded conditions or on complex roofs (multiple orientations) because each panel works independently, preventing shading on one panel from affecting the others.

System Lifespan: Longer lifespan and warranty, typically 20–25 years, often matching the solar panels themselves.

Failure Mode: If one unit fails, only that single panel's production is lost (Partial Loss), and the rest of the system continues to operate.

Monitoring: Provides panel-level monitoring, allowing you to track the performance of every individual panel.

Best For: Shaded roofs, complex rooflines, and installations where future system expansion or maximum longevity is desired.

Cost: Have a higher upfront cost but may offer greater long-term value due to increased energy yield and a longer lifespan.

Shade Performance: Poor performance in shaded conditions, as the output of the entire "string" is reduced to match the lowest-performing panel.

System Lifespan: Shorter lifespan, typically 5–12 years, meaning they will need to be replaced once or twice during the life of the solar panels.

Failure Mode: If the single unit fails, the entire solar system shuts down (Total Loss).

Monitoring: Provides system-level monitoring (total output), making it harder to spot a single underperforming panel.

Best For: Simple, unshaded, south-facing roofs, or projects with a tighter initial budget.

Cost: Have a lower upfront cost, but may incur higher long-term replacement costs.

Efficiency: Microinverters can lead to 5% to 25% higher annual energy production in systems with shading or panel-to-panel performance mismatch compared to a string inverter.

Repair: String inverters are generally easier to repair as the single unit is typically located at ground level. Replacing a microinverter often requires roof access.

Microinverters: Major brands, such as Enphase, typically offer a 25-year limited product warranty in the UK as standard. This demonstrates the manufacturer's confidence that the unit is built to last for the entire expected life of your solar panels.

Traditional String Inverters: In contrast, traditional string inverters usually come with a shorter warranty of 5 to 12 years, meaning they are typically expected to be replaced at least once, or possibly twice, during the lifespan of the solar panels.

Cooler Operating Conditions: They are sealed and often installed in the shade underneath the panels, which can protect them from the elements and high heat stress.

Lower Voltage Stress: They deal with the lower DC voltage of a single panel, which is less electrically stressful than handling the high, combined DC voltage of an entire string of panels.

Traditional String Systems: Solar panels are wired in a long series, which causes the DC voltage to stack up, often reaching very high levels (e.g., 300V to over 600V) on the roof and in the cables that run into the house to the central inverter. High-voltage DC is dangerous, especially if wiring is damaged, as it can sustain a continuous electrical arc.

Microinverter Systems: The microinverter, mounted directly underneath each solar panel, immediately converts the high-voltage DC generated by that single panel into low-voltage AC (typically 230V AC, the same as standard household electricity).

Safety Outcome: Only safe, low-voltage AC wiring runs across the roof and enters the building. This removes the main cause of electrical arc faults and dramatically reduces the risk of a solar-related fire.

Emergency Response: In the event of a fire, the system needs to be quickly de-energised to allow firefighters to safely access the roof.

Microinverter Advantage: When the main AC power is shut off (by the homeowner or emergency services), the microinverters stop producing power at the panel level almost instantly. This ensures that the wiring on the roof is not carrying dangerous voltages, complying with rapid shutdown safety standards.

Traditional Risk: In a string system, a wiring fault or damage in one panel or connector can put the entire high-voltage string at risk of an arc fault.

Microinverter Advantage: Because each microinverter operates independently, a fault, such as a damaged connector or overheating component on one panel, is typically contained to that single module. The fault will not affect the rest of the array, preventing a localised issue from escalating into a system-wide hazard.

Fewer Failure Points: Microinverter systems generally use less complex wiring than string systems, reducing the overall number of high-risk DC connections that could degrade or be installed incorrectly.

Pinpoint Monitoring: The ability to monitor the performance of every individual panel makes it easy to remotely detect a potential issue (like a drop in current or a temperature warning) before it becomes a serious safety hazard, allowing for proactive maintenance.

Separate Components: The battery storage system has its own battery inverter/charger unit.

Connection Point: This unit connects directly to your home's existing AC electrical system (the main switchboard or a dedicated circuit).

Power Flow: