Off-Grid Solar System Philippines: What Size Do You Really Need?
off-grid solar systems are popular in the Philippines, especially in rural provinces or island areas where power interruptions are frequent. It helps you reduce electricity bills, gain energy independence, and live a greener lifestyle.
But here’s the real question: What size off-grid solar system do you need?
Let’s dive into what an off-grid solar power system is, how to size your solar system, and how to build your own off-grid setup in the easiest way.
What Is an Off-Grid Solar System?
What is meant by off-grid solar systems? An off-grid solar system is a standalone setup that allows you to generate and store your own electricity without relying on the local utility grid. It typically consists of solar panels, a battery bank, a charge controller, and an inverter.
Unlike on-grid systems that send excess power back to the grid, off-grid solar systems store energy in batteries for later use—making them ideal for remote locations or areas with unstable power supply.
If you’ve ever seen an off-grid solar system diagram, it basically flows like this: sunlight → solar panels → charge controller → battery → inverter → appliances. Each component plays a vital role in generating your own continuous, renewable power.
In the Philippines, where brownouts are still common, off-grid solar systems are an eco-friendly alternative to generators for home backup, providing clean, quiet power with no ongoing cost.
How to Size Your Off-Grid Solar Power System
Designing your own off-grid solar power system starts with accurate sizing. If your system is too small, you’ll run out of power fast. Too large, and you’ll overspend. Let’s go step by step to find your ideal setup.
Calculate Your Daily Energy Consumption
The first step in off-grid solar system sizing is to know how much energy you use daily.
List all appliances you plan to run, their wattage, and how many hours they operate per day. Multiply watts by hours to get watt-hours (Wh) per appliance, then total them all.
Example:
Appliance | Wattage (W) | Hours/Day | Energy (Wh) |
LED Light | 15 | 5 | 75 |
Fan | 50 | 8 | 400 |
Refrigerator | 100 | 24 | 2,400 |
Laptop | 60 | 4 | 240 |
Total Daily Energy Need | 3,115 Wh (≈3.1 kWh) | ||
Now, add 20–30% more to cover inverter losses or cloudy days. Estimated total = 4 kWh/day.
You can also use an off-grid solar system sizing calculator online to simplify this process. Once you know your total energy use, the next step is to match it with your local sunlight conditions.
Understand Peak Sun Hours in Your Location
The Philippines enjoys 4–6 peak sun hours daily on average (roughly between 10 a.m. and 4 p.m.), depending on location and season.
Example averages:
Luzon: ~4.5 hours
Visayas: ~5 hours
Mindanao: ~5.5 hours
To calculate your solar panel requirement: Solar Panel Wattage (W) = Daily Energy Use (Wh) ÷ Peak Sun Hours (h)
For a 4,000 Wh daily need and 5 sun hours: 4,000 ÷ 5 = 800 W.
So you’ll need around 800 W of solar panels (or slightly more for safety). You can explore available solar panels to find efficient and portable options.
Determine Battery Bank Capacity
With your solar panel size estimated, you’ll also need to calculate how much battery capacity you’ll require to stay powered at night or during cloudy days.
To size your battery: Battery Capacity (Wh) = Daily Energy Use (Wh) × Days of Autonomy ÷ Depth of Discharge (DoD)
If you want 2 days of backup and use lithium batteries (DoD 90%): 4,000 × 2 ÷ 0.9 = 8,888 Wh (≈9 kWh total).
That means you’ll need around 9 kWh of usable battery capacity, which could be achieved by connecting multiple lithium batteries or using an off-grid solar battery system with modular capacity.
How to Build an Off-Grid Solar System
Once you know your off-grid solar system size, the next step is building it. You can either DIY your setup or use modern all-in-one power stations.
DIY an Off-Grid Solar System from Scratch
If you’re a hands-on, build your own off-grid solar system using separate components:
Solar Panels –Capture sunlight and convert it into direct current (DC) electricity that powers your system. The total output depends on your panel wattage and daily sun exposure.
Charge Controller – Manages the flow of electricity from the solar panels to the batteries, preventing overcharging and protecting your battery’s lifespan.
Battery Bank – Stores the solar energy collected during the day, allowing you to use it at night or during cloudy weather. Lithium batteries (especially LiFePO₄) are more efficient and long-lasting than lead-acid ones.
Inverter – Converts stored DC electricity from the batteries into alternating current (AC), which is what most household appliances use.
Wires, Switches, and Protection Gear – Connect all components securely while ensuring safe power flow and monitoring. Include proper fuses, circuit breakers, and meters to prevent overloads and track system performance.
While this gives you full control, it involves technical wiring, voltage matching, and maintenance. Beginners might find this challenging without electrical knowledge. Plus, sourcing each part separately—like comparing solar panel prices in the Philippines—takes time.
Build an Off-Grid Solar System with a Portable Power Station
If DIY isn’t your thing, a portable power station is your best shortcut to an off-grid solar system. These all-in-one devices combine a battery, inverter, charge controller, and multiple output ports in one compact unit.
For example, the EcoFlow DELTA Pro 3 Portable Power Station is a powerful off-grid solution. With a 4 kW output and a 4 kWh LFP battery expandable up to 12 kWh, it can run essential home appliances like refrigerators, fans, and even air conditioners. It also supports fast solar charging up to 2,600W, so you can recharge it quickly during sunny hours.
EcoFlow DELTA Pro 3 Portable Power Station
Connect it with the EcoFlow 400W Portable Solar Panel—a highly efficient, foldable, and IP68-rated waterproof panel. With a few plug-and-clicks, you’ll build an off-grid solar system in no time.
These modern all-in-one systems make building an off-grid solar power system for homes simple, safe, and scalable. During typhoons or blackouts, you can use it as a home power backup. Even better, your off-grid solar system can reduce your electricity bills by tapping into endless solar energy.
Conclusion
So, what size solar system do you need to run off-grid? It depends on your energy use, sunlight hours, and how many backup days you want.
For most Filipino homes, an off-grid solar system between 1–3 kW of solar panels and 5–10 kWh of batteries can power essentials like lighting, fans, and refrigerators.
For a faster, cleaner, and safer setup, DELTA Pro 3 portable power stations paired with solar panels offer complete off-grid solar systems with batteries, balancing between convenience and power.
FAQs
What size off-grid solar system do I need?
The right size depends on your total daily power usage and how many days of autonomy you want. Most off-grid Filipino households typically need 1–3 kW of solar panels and 5–10 kWh of batteries. Use an off-grid solar system sizing calculator or consult local installers to fine-tune your design based on your exact appliance list and sun exposure.
Can off-grid solar system work without batteries?
Technically, yes—but it’s not ideal. Without batteries, you can only use power when the sun is shining, and any excess goes unused. A complete off-grid solar system with batteries ensures a steady energy supply even at night or during brownouts, which is vital in the Philippines, where weather and power stability can fluctuate. Batteries also protect appliances from sudden power drops.
Can AC run on off-grid solar power?
Yes! Modern off-grid solar inverter systems can easily run energy-efficient air conditioners, especially when paired with a powerful battery like EcoFlow portable power stations. You’ll just need to ensure your inverter capacity (e.g., 2,000–3,000W) matches the AC’s starting wattage. This setup lets you stay cool even during power outages without relying on noisy fuel generators.
How many solar batteries do I need to go off-grid?
The number of batteries depends on your daily energy use and desired backup days. For example, if you use 4 kWh per day and want 2 days of autonomy, you’ll need about 8–9 kWh of total storage. Modular systems like the EcoFlow DELTA Pro 3 make expansion easy—just add extra batteries when your needs grow. Always size slightly higher for cloudy days.