While Peninsular Malaysia has near-universal grid coverage, parts of rural Sabah and Sarawak still lack reliable grid electricity. For these areas, and for mainland Malaysians tired of frequent voltage dips and brownouts, off-grid solar is no longer a fringe option — it is a practical, cost-effective alternative.
Off-Grid vs Grid-Connected Solar: Which One Do You Need?
| Factor | Off-Grid Solar | Grid-Connected (Solar ATAP) |
|---|---|---|
| Grid access required | No | Yes |
| Battery storage | Essential (2–5 days autonomy) | Optional |
| System cost | Higher (batteries add 30–50%) | Lower |
| Power reliability | High (no grid dependency) | Depends on TNB grid stability |
| SEDA/TNB approval needed | No | Yes |
| Best for | Remote areas, farms, vacation chalets, rural Sabah/Sarawak | Urban/suburban connected properties |
The Five Core Components of an Off-Grid Solar System
1. Solar Panels (PV Modules)
The same Tier-1 panels used in grid-connected systems work perfectly for off-grid applications. For Sabah and Sarawak, where rain can reduce irradiance on some days, we recommend slightly oversizing the panel array by 20% compared to daily consumption to ensure the battery bank fully recharges even on overcast days.
Market references for off-grid Borneo conditions (not stocked by Trexon; off-grid is quoted per site): Longi Hi-MO 7 (N-Type, excellent low-light performance) or Trina Vertex S+ (dual-glass, resistant to coastal humidity).
2. Off-Grid Inverter / Inverter-Charger
Unlike grid-tied inverters that shut down during grid outages (anti-islanding protection), off-grid inverters operate completely independently. They also incorporate a battery charger (to charge from solar) and often a generator input for backup charging. Key brands available in Malaysia (market references with estimated prices; not stocked by Trexon, off-grid systems are quoted per site):
- Victron Energy MultiPlus-II: Widely used for off-grid. Reliable, programmable, extensive monitoring (RM 3,500–6,000 for 5kVA unit)
- Growatt SPF 5000 ES: Good value, used in Sabah installations (RM 2,800–4,200)
3. Battery Bank
This is the largest variable cost in an off-grid system. Battery technology has improved dramatically:
| Battery Type | Lifespan (cycles) | Depth of Discharge (DoD) | Cost (RM/kWh) | Recommended? |
|---|---|---|---|---|
| LiFePO4 (Lithium Iron Phosphate) | 4,000 – 6,000 cycles | 95% | RM 1,200 – 1,800/kWh | Yes — recommended |
| AGM Lead-Acid | 500 – 800 cycles | 50% | RM 400 – 600/kWh usable | No — poor lifespan in heat |
| Gel Lead-Acid | 600 – 1,000 cycles | 50% | RM 500 – 700/kWh usable | Only for very tight budgets |
| NMC Lithium | 3,000 – 4,000 cycles | 90% | RM 2,000 – 3,500/kWh | Only if budget allows |
For Malaysian off-grid systems, LiFePO4 lithium batteries are strongly recommended. In the high ambient temperatures of Borneo (27–35°C), lead-acid batteries can degrade much faster than in temperate climates. LiFePO4 handles heat significantly better and delivers 10–15 years of reliable service in tropical conditions.
4. Solar Charge Controller (MPPT)
The charge controller regulates the power flowing from panels to batteries. Always use an MPPT (Maximum Power Point Tracking) controller, not PWM. MPPT controllers are typically more efficient than PWM in real-world conditions. For off-grid systems above 3kW, Victron SmartSolar MPPT controllers are widely used.
5. Generator Backup (Recommended)
Even a well-designed off-grid system can face extended periods of cloud cover (3–5 consecutive overcast days during monsoon season in Sabah and Sarawak). A diesel or LPG generator sized at 20–30% of your inverter capacity provides critical backup and battery top-up capability. Cost: RM 1,500–4,000 for a reliable 3kVA petrol generator.
Off-Grid System Sizing: How to Calculate Your Battery Bank
Step 1: Total Daily Energy Consumption
List every appliance and its daily usage:
- LED lights (10 bulbs × 10W × 6 hours) = 600 Wh/day = 0.6 kWh
- Refrigerator (200W × 8 hours effective run time) = 1.6 kWh/day
- Ceiling fans (3 × 80W × 10 hours) = 2.4 kWh/day
- TV (150W × 5 hours) = 0.75 kWh/day
- Washing machine (500W × 1 hour) = 0.5 kWh/day
- Air conditioner (1,000W × 6 hours, used strategically) = 6.0 kWh/day
- Total Daily Consumption: 11.85 kWh/day
Step 2: Calculate Battery Bank Size
For 2 days' autonomy (ability to run without any solar input for 2 days, common for areas with 2–3 days of heavy rain):
- Energy needed: 11.85 kWh × 2 days = 23.7 kWh
- With LiFePO4 at 95% DoD: 23.7 ÷ 0.95 = 24.9 kWh battery bank → round up to 25 kWh
- Battery bank cost: 25 kWh × RM 1,500/kWh = RM 37,500 (LiFePO4)
Step 3: Size the Solar Array
Use 3.5 peak sun hours as the planning basis for Sabah and Sarawak, conservatively for rainy months:
- Daily consumption: 11.85 kWh
- Array size: 11.85 ÷ 3.5 PSH ÷ 0.80 efficiency = 4.2 kWp → Install 5 kWp (adds about 18% buffer for charging battery in monsoon)
Complete Off-Grid System Cost Estimates (2026)
| System Size | Battery (LiFePO4) | For Household | Estimated Total Cost (RM) |
|---|---|---|---|
| 3 kWp + 10 kWh battery | 10 kWh (2-day autonomy) | Small 2-room (no A/C) | RM 28,000 – 38,000 |
| 5 kWp + 20 kWh battery | 20 kWh (2-day autonomy) | Standard 3-room (1 A/C) | RM 52,000 – 68,000 |
| 8 kWp + 30 kWh battery | 30 kWh (2-day autonomy) | Family home (2–3 A/C) | RM 75,000 – 100,000 |
| 15 kWp + 50 kWh battery | 50 kWh (2-day autonomy) | Homestay / small resort | RM 140,000 – 185,000 |
Illustrative Scenario: A Village Microgrid in Sabah
Illustrative scenario — not a Trexon project. The village and figures below are hypothetical.
Picture a 30-household village in the Keningau area relying on a shared diesel generator costing RM 4,500/month in fuel and maintenance, replaced by a 25kWp community solar microgrid with 80kWh LiFePO4 battery storage.
What the numbers could look like after 12 months:
- Monthly diesel fuel savings: RM 3,900 (87% reduction)
- Generator run time reduced from 18 hours/day to 2 hours/day (backup only)
- Village LED street lighting installed (previously no street lighting)
- New refrigerators for food storage — reduced spoilage losses
- System cost: RM 185,000 | Payback period: 3.9 years vs diesel baseline
Government Support for Off-Grid Solar in Sabah and Sarawak
Rural electrification is run by federal and state agencies, and programmes change over time:
- Ask your district office and your utility (SESB in Sabah, Sarawak Energy in Sarawak) which rural electrification programmes are open for your area before you buy.
Planning an off-grid solar project in Sabah or Sarawak? Contact us for a quote. Trexon is a Peninsular RPVSP, so East Malaysia installations are carried out through local partners, who quote and install for you.
