2 kW Wind + 2 kWp Solar Hybrid System Off-grid, on-grid with battery, and on-grid without battery

2026-10-27
2 kW Wind + 2 kWp Solar Hybrid System Off-grid, on-grid with battery, and on-grid without battery

Solar Hybrid System

2 kW Wind + 2 kWp Solar Hybrid System


Off-grid, on-grid with battery, and on-grid without battery


Overview


This design combines a 2 kW wind turbine with a 2 kWp solar PV array. Sun and wind are often available at different times of day and in different seasons, so the two sources complement each other and deliver more stable energy than either alone. Three configurations are shown below, depending on whether the site has a grid connection and whether battery storage is needed.

Design basis


The figures below are a worked example. Replace them with measured site data before installation.

ParameterValueNotes
Wind turbine2 kW, 48 V PMG, direct driveAverage wind 5–6 m/s at hub height
Wind energyAbout 9.6 kWh/day20% capacity factor (assumed)
Solar PV array2 kWp (4 × 500 W panels)Two strings of two panels in series
Solar energyAbout 6.4 kWh/day4.0 peak sun hours; performance ratio 0.80 (assumed)
Total generationAbout 16 kWh/dayAverage day; varies by season
Daily load6 kWh/dayFrom load audit
Surplus energyAbout 10 kWh/dayCharges battery, then exported or dumped
Peak load3 kWSets inverter size

Solar PV sizing


•Array: 4 panels × 500 W = 2.0 kWp, in two parallel strings of two panels in series.
•Voltage: about 80 V (Vmp) and 100 V (Voc) per string at 25 °C. Check Voc at the coldest expected temperature (about 10–15% higher) against the controller limit.
•Off-grid: a 60 A solar MPPT controller at 48 V gives margin over the 42 A needed for 2 kW.
•DC cable: 4–6 mm² outdoor-rated PV cable, at least 1000 V DC, with 15 A fuses per string.

System configurations:

 Off-grid with batteryOn-grid with batteryOn-grid, no battery
PurposeFull power without a gridSelf-consumption and backup during outagesLowest cost; export to grid
Battery48 V 300 Ah LiFePO₄ (14.4 kWh; about 12.2 kWh usable; 2 days of load)48 V 200 Ah LiFePO₄ (9.6 kWh; about 8.6 kWh usable; covers an 8 h outage at 1 kW)None
Inverter4 kW pure sine wave, 48 V DC to 230 V AC4 kW hybrid, 48 V battery input, at least 2.5 kWp PV input, grid-tie and backupTwo grid-tie inverters, 2 kW each (wind and solar)
Grid outageNot applicableEssential loads stay powered from battery, solar and windSupply stops (anti-islanding)
AutonomyAbout 2 days with no wind or sunAbout 8 h of essential loadsNone

Off-grid (wind + solar + battery)

•2 kW wind turbine with overspeed brake, 12–18 m tower.
•Wind MPPT controller (48 V, 60 A) with dump-load output and a 2–3 kW dump load for surplus wind energy.
•Solar MPPT controller (48 V, 60 A), 4 × 500 W panels, PV isolator and string fuses.
•Battery bank 48 V 300 Ah LiFePO₄ with integrated BMS; 4 kW pure sine wave inverter; DC protection and AC distribution with 30 mA RCD.

Figure 1: Off-grid wind and solar system, connection diagram
Figure 1: Off-grid wind and solar system, connection diagram

On-grid with battery backup (wind + solar)

•2 kW wind turbine with brake or shunt, 12–18 m tower, and a 48 V MPPT wind controller.
•4 × 500 W solar panels (2.0 kWp) connected to a 4 kW hybrid inverter with grid-tie, battery charging and automatic backup changeover.
•Battery bank 48 V 200 Ah LiFePO₄ with integrated BMS; bidirectional net meter; main AC board; backup switch for essential circuits.

 

Figure 2: On-grid wind and solar system with battery backup, connection diagram
Figure 2: On-grid wind and solar system with battery backup, connection diagram

 

On-grid without battery (wind + solar)

•2 kW wind turbine (grid-tie type, AC output) on a 12–18 m tower.
•2 kW wind grid-tie inverter and 2 kW solar grid-tie inverter (4 kW total), both certified to grid code with anti-islanding.
•4 × 500 W solar panels (2.0 kWp), bidirectional net meter, and a grid isolation switch accessible to the utility.

Figure 3: On-grid wind and solar system without battery, connection diagram
Figure 3: On-grid wind and solar system without battery, connection diagram

 

Controller summary:

ControllerOff-grid (battery)On-grid with batteryOn-grid (no battery)
Wind MPPT controllerRequiredRequiredNot required (wind grid-tie inverter)
Solar MPPT charge controllerRequiredIncluded in hybrid inverterNot required (solar grid-tie inverter)
Turbine brake / shuntRequiredRequiredRequired
Dump load controllerRequiredOnly if export is forbiddenNot required
Off-grid inverter controlRequiredNot requiredNot required
Grid-tie inverter controlNot requiredRequired (hybrid)Required (two units)
Battery management systemRequiredRequiredNot required
Automatic backup changeoverNot requiredRequired (hybrid)Not required
Export limit controllerNot requiredOnly if utility requiresOnly if utility requires

Safety essentials
•Confirm local rules for tower height, setbacks, building permits, roof loading and grid connection before work starts.
•Earthing: 10 Ω or less; PV frames and the tower must be bonded to it. Test before energising.
•Check PV string Voc against the controller maximum at the coldest expected temperature.
•Isolate PV at the DC isolator before working on panels. Never disconnect a live DC string under load.
•Never work on a running turbine. Apply the brake before climbing the tower.
•Install surge protection (SPD) on the turbine, PV and AC sides.

Disclaimer
This is a general design guide for a combined 2 kW wind and 2 kWp solar system, based on the assumptions stated above. It is not a substitute for a site-specific engineering design. Equipment ratings, cable sizes, protection settings, structures and grid approvals must be confirmed against manufacturer datasheets, local electrical codes and utility requirements.

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