When matching solar panels to a water pump system, the specific brand of the panel is secondary to its electrical characteristics. The critical engineering goal is to ensure the total Vmp (Voltage at Maximum Power) of the solar string falls within the inverter’s peak efficiency window, and the total string Voc (Open Circuit Voltage) remains safely below the inverter’s maximum DC input at the site’s lowest recorded temperature.
1. The “Panel-Agnostic” Advantage
At HOBER, our AC pump solarization technology is designed to be Indépendant du panel. Whether you are using Monocrystalline, Polycrystalline, or the latest Bi-facial high-efficiency modules from any global tier-1 manufacturer or local supplier, the system performance is guaranteed as long as the voltage sizing is correct.
Installer Tip: This allows you to source the “glass” (solar panels) locally to save on shipping costs while relying on HOBER for the system’s “brain.”
2. The Sizing Ratio: Why 1.4x?
A common mistake is matching 7.5kW of solar panels to a 7.5kW pump.
- The Problem: Solar radiation is not constant. You lose power to heat, dust, and atmosphere.
- The HOBER Standard: We recommend an Over-sizing Ratio of 1.3x to 1.5x.
- Exemple: For a 15kW (20HP) pump, you should aim for 21kWp to 22.5kWp of solar PV input. This ensures the pump runs at full 50Hz/60Hz frequency even during non-peak sun hours.
3. The Voltage Calculation (The Engineering Core)
Forget the brand name; focus on the data sheet.
A. Vmp Matching (The Frequency Engine)
To push an AC pump to its full rated speed, the inverter needs a specific DC input. For 380V Pumps: Your string Vmp should be between 530V and 600V.
Formula: Total Vmp = Number of Panels in Series × Panel Vmp (STC)
B. Voc Protection (The Safety Margin)
This is where inverters are destroyed. Total string Voc must jamais exceed the Inverter’s Max DC Input (typically 800V for 380V models).
The Low-Temp Factor: In cold desert mornings (e.g., Saudi Arabia or Chile), Voc spikes. Always leave a 15% safety buffer. If the inverter limit is 800V, target a design Voc of 680V – 700V.
4. Recommended String Configurations (Generic)
| Panel Wattage (e.g.) | String Setup (Series) | Total PV Power | Target Pump |
|---|---|---|---|
| 550W Mono | 18 Panels | 9.9 kWp | 5.5kW – 7.5kW Pump |
| 650W Bi-facial | 18 Panels | 11.7 kWp | 7.5kW Pump |
Panel-Agnostic means freedom of choice. HOBER handles the MPPT tracking and protection, allowing you to maximize project margins with local procurement.
