With rising electricity tariffs and strong solar incentives in Singapore, more homeowners of landed properties are exploring rooftop solar as a sustainable energy source. One of the most common questions they face is: “Is a 5kW inverter enough to power my entire home?”
In this in-depth guide tailored for Singapore’s landed property context, we’ll explore whether a 5kW inverter can meet the energy demands of your household, what factors to consider, and when it makes sense to size up. Whether you’re powering a terrace house, semi-detached, or bungalow, this article gives you the clarity to make an informed decision.
What Is a 5kW Inverter?
A 5kW inverter can convert up to 5,000 watts of direct current (DC) electricity—generated from your solar panels—into alternating current (AC), which powers your lights, appliances, and air-conditioning.
A kilowatt (kW) measures how much power your home uses at any moment—1 kW equals 1,000 watts. A 5kW inverter can supply up to 5,000 watts of electricity at once from your solar panels, which is enough to run some appliances like lights, fridge, and aircon.
But in a landed home, where you might use multiple high-powered appliances together (like an oven, water heater, and aircon), your usage can exceed 5kW. When that happens, your inverter can’t keep up, and your system will either draw power from the grid or waste excess solar energy.
Understanding Energy Consumption in Landed Homes
Landed homes in Singapore tend to be larger and more power-hungry than flats. Here’s a breakdown of typical monthly energy consumption based on home type:
| Property Type | Monthly Usage Estimate (kWh) |
|---|---|
| Terrace House | 900 – 1,300 |
| Semi-Detached | 1,200 – 1,800 |
| Detached/Bungalow | 1,500 – 3,000+ |
Let’s use a semi-detached house with a monthly usage of 1,500 kWh as an example. This translates to:
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Daily usage: 1,500 ÷ 30 = 50 kWh/day
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Peak hourly load: 50 kWh ÷ 5 hours of peak use = 10,000W or 10 kW
A 5kW inverter, limited to 5,000W instantaneous output, would fall short during high-demand periods.
Typical Appliance Load in Landed Properties
Landed homes often use multiple energy-intensive devices simultaneously:
| Appliance | Power Draw (Watts) |
|---|---|
| Split aircon (x3 units) | 3,000 – 5,000 |
| Electric oven | 2,000 – 2,500 |
| Induction hob | 1,800 – 2,400 |
| Water heater | 3,000 |
| Washer + dryer combo | 1,800 – 2,500 |
| Pool pump (if any) | 600 – 1,200 |
| Lighting + outlets | 400 – 800 |
When multiple high-draw appliances are running concurrently, it’s easy to hit or exceed 7–10 kW in peak load—well above what a 5kW inverter can handle alone.
Solar Yield in Singapore for 5kW Systems
Singapore receives strong and consistent solar irradiance throughout the year. The expected output from a 5kWp solar system is roughly:
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Annual generation: ~6,500 to 7,200 kWh
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Monthly generation: ~540 to 600 kWh
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Daily generation: ~18 to 20 kWh
If your landed home consumes 1,500 kWh/month, a 5kW system offsets around 35–40% of your energy—significant savings but far from full self-sufficiency.
Note: A 5kW inverter does not limit how much electricity your solar panels generate over time—it limits instantaneous usage. If your panels produce 6,000W at noon but your inverter maxes out at 5,000W, 1,000W is either wasted, curtailed, or fed to the grid.
When Is a 5kW Inverter Suitable for Landed Homes?
✅ Suitable if:
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You use appliances sequentially, not simultaneously.
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Your peak usage is below 5,000W.
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You’re mainly targeting bill offset, not full independence.
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You have space for a ~5kWp array (about 22–25 sqm with 400–450W panels).
A 5kW inverter paired with a 5kWp system works well for homeowners prioritising daytime loads such as:
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Air-conditioning in home offices
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Fridge, washer, and lighting
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EV charging scheduled during off-peak solar hours
When to Upgrade to a Larger Inverter (6kW–10kW)
❌ Upgrade if:
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You have heavy simultaneous loads: multiple aircons, induction hob, oven, dryer.
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You’re installing >6.5kWp worth of panels.
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You own or plan to own an electric vehicle (7.4kW to 11kW wall box chargers).
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You’re installing batteries (which require higher throughput).
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You want future-proofing (e.g., adding solar thermal or pool heating).
A good rule of thumb: match the inverter size to 80–100% of your panel array size. But don’t oversize—SP Group limits single-phase inverters to 5kW export unless you obtain additional approval for three-phase connections.
Pros of a 5kW Inverter
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✅ Lower Initial Cost: S$1,300–S$1,800 on average (excluding installation)
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✅ Simplified Grid Approval: SP Group permits up to 5kW export for residential homes without load analysis
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✅ Optimised ROI: Best return when paired with a 5kWp array (~S$15k–S$20k fully installed)
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✅ Smaller Footprint: Compact units ideal for tight M&E risers or utility closets
Cons of a 5kW Inverter
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❌ Limited Scalability: Not suitable for >6kWp systems
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❌ Curtailment Risk: If panels generate more than inverter can handle, some solar is wasted
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❌ Undersized for Peak Loads: Can’t support heavy draw appliances running simultaneously
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❌ Incompatibility with Battery Backup: Most modern battery systems (e.g., Tesla Powerwall, Huawei Luna) require hybrid inverters with higher capacity
Sizing Strategy: 5kW vs 6kW+ Systems
| Criteria | 5kW Inverter | 6–10kW Inverter |
|---|---|---|
| Max Solar Panel Array | 5.5 – 6.5 kWp | 7.5 – 12 kWp |
| Suitable for EV Charging? | No | Yes |
| Peak Load Coverage | Limited to 5,000W | Up to 10,000W |
| SP Group Approval Needed? | No | Yes (if >5kW export) |
| ROI Payback Period | ~5 – 6 years | ~6 – 7.5 years |
| Ideal for Future Expansion? | No | Yes |
Battery Compatibility Considerations
If you’re planning to install battery storage (e.g., 10kWh to 20kWh), opt for a hybrid inverter system of 6kW and above. A 5kW inverter often lacks the capacity and battery interface required for future energy storage integration.
Singapore’s energy market is evolving towards more grid independence and smart home capabilities. Upgrading to a hybrid 8–10kW inverter can position your home for energy arbitrage and export incentives.
Conclusion: Is 5kW Enough for a Landed House?
Not always. For many landed properties in Singapore, especially those exceeding 1,200 kWh/month or with high peak loads, a 5kW inverter may be insufficient on its own. It can support modest setups and partial load offset but may require careful load management or eventual system upgrades.
Bottom Line:
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For light to moderate energy users: Yes, a 5kW inverter works well.
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For heavy users, EV owners, or future expanders: Go larger.
Planning a Solar System for Your Landed Home?
At First Solution Group, we specialise in turnkey solar installations tailored to Singapore’s landed residential market. Whether you’re planning a 5kW system or a large 10kW+ hybrid setup, our consultants handle everything—from URA roof checks to SP Group approvals.
🔧 Contact us today for a free on-site assessment and personalised quote. Let us help you build a smart, sustainable energy future for your home.