Let say : 4 workers stay at the Quarters.
To use DC Solar Power ONLY.
🔌 Basic Power Needs (DC Only)
Example.
⚡ Room Lights – 3 rooms
- 1 DC bulb per room × 3 rooms = 3 bulbs
- Assume each LED bulb = 5W – 7W
- Operation: 8 hours/night (but unlikely as they will have to sleep, the most they use will be from 7pm – 12 mid night, = 5 hours.
- 👉 Total:
3 × 5W × 8h = 120Wh
⚡ Kitchen & Outside Lights (Outside light may use seperate unit light such as Flood Lighting)
- 1 bulb in kitchen and 1 bulb outside
- Same 5W LED, 8 hours/night
- 👉
2 × 5W × 8h = 80Wh
🌀 Table Fans
- 3 rooms × 1 DC fan/room = 3 fans
- Small 12V DC fan = 15W
- Operation: 8 hours/night
- 👉
3 × 15W × 8h = 360Wh
📱 Handphone Charging
- Assume 4 phones × 10Wh/phone per full charge
- Daily charging =
4 × 10Wh = 40Wh
TOTAL LOADING (based on full 8 hours usage)
Lights: 120Wh
Kitchen/out: 80Wh
Fans: 360Wh
Phones : 40Wh
TOTAL: 600Wh/day..but need to add power margin – 25% margin (for wire losses, real-life inefficiencies): 👉 600Wh × 1.25 = 750Wh/day total required energy.
☀️ Solar Panel Sizing
In Malaysia, most areas typically get ~4.5 hours/day of effective sunlight (PSH – Peak Sun Hours).
To find required panel wattage:
Required energy: 750Wh/day
Available sunlight: 4.5h/day
Solar Panel Size Needed = 750Wh / 4.5h = 167W
Panel Setup:
- 2 x 150W 12V polycrystalline or monocrystalline panels
- Mount on roof, tilted ~15°-20° for drainage
🔋 Battery Capacity
You want enough to store at least 1 day of use, preferably 2 days (for rainy/cloudy days).
You need to store 750Wh, ideally ×2 for buffer: 👉 750Wh × 2 = 1500Wh
Since you’ll be using 12V battery:
Battery Ah = Total Wh / Voltage
= 1500Wh / 12V = 125Ah
Battery Setup:
- 1 x 12V 150Ah deep cycle battery (preferably GEL or LiFePO₄)
- Or 2 x 12V 100Ah in parallel
⚙️ Charge Controller
To se a 12V solar panel + 12V battery setup. No inverter needed.
Use an MPPT or PWM charge controller, sized to your panel current.
For 300W @ 12V → that’s 25A max.
✅ Recommended Controller:
- MPPT 30A 12V charge controller
- Safer and more efficient than PWM
- Good brands: Victron, Epever, or even JFY for budget builds
🔧 Cables, Accessories & Misc
Here’s the rest of what you’ll need:
- DC wires (solar to controller, controller to battery, battery to lights/fans)
- Use at least 4mm² solar cables, especially from panels to controller
- Fuse between panel and controller (30A) and between battery and load (40A)
- Battery box, mounting brackets for panels
- MC4 connectors, crimping tools, junction box if needed
🧰 Summary – System Components List
| Component | Quantity | Spec / Notes |
|---|---|---|
| Solar Panel | 2 pcs | 150W, 12V Monocrystalline |
| Charge Controller | 1 pc | MPPT 30A, 12V |
| Deep Cycle Battery | 1–2 pcs | 12V 150Ah or 2×12V 100Ah |
| DC LED Bulbs | 5 pcs | 12V, 5W |
| DC Table Fan | 3 pcs | 12V, 15W |
| USB Charger Hub | 1 pc | 12V to 5V converter, 4 ports |
| Mounting Kit | 1 set | Brackets, screws |
| Solar Cable | 10–15 m | 4mm² or 6mm² |
| Fuse & Breakers | 2–3 pcs | 30A (panel), 40A (battery) |
| Battery Box | 1 pc | Plastic or wood |
What This System Can’t Do – Upon adding the Inverter.
- It can’t handle fridge, rice cooker, or TV — purely lights + fans + phones.
- During several days of rain, charging may drop — battery might need backup charging (generator or car alternator).
- DC-only systems are efficient but more limited; if your needs grow, add an inverter + bigger battery bank later.
What types of suitable Inverter?
🌀 Modified vs Pure Sine Wave Inverter
Here’s the brutal truth:
| Type | Pros | Cons | Use Case |
|---|---|---|---|
| Modified Sine Wave | Cheap, easy to find | Can damage sensitive electronics, noisy fans, flickering lights | Only good for basic resistive loads like simple bulbs |
| Pure Sine Wave | Clean, smooth AC like TNB supply | Expensive but worth it | Fans, chargers, TVs, fridges, pumps |
Upgrade usage:-
TV
Blender
Rice cooker
Mini fridge
Any future AC-powered appliances
🔌 Wattage Capacity – How Big an Inverter?
Let’s say one day you want to power:
| Appliance | Power (W) | Notes |
|---|---|---|
| 1 ceiling fan | 70W | 1 or 2 fans |
| 1 LED TV | 60W | |
| Phone charger(s) | 20W | 2–4 phones |
| 1 small fridge | 100W | + startup surge ~300W |
| 1 rice cooker | 300W–500W | For future-proofing |
| Total Running | ~600W | Running load |
| With Surge | ~1000W | Must account for startup |
✅ Inverter Recommendation Summary
| Spec | Recommended |
|---|---|
| Type | Pure Sine Wave |
| Voltage | 12V input (matches battery) |
| Wattage (continuous) | 1000W |
| Surge capacity | At least 2000W |
| Features to look for | Built-in fuse, low voltage cut-off, cooling fan, display panel |
Good brands in Malaysia/Southeast Asia: Must Power, Suoer, Growatt (for hybrid setups), Victron (premium), or EPEver.
