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Solar Panel Calculator
Panel count, wattage & cost for your home or business. BD & global.
💰 Savings · ROI · Payback · Net Metering
Solar Savings Calculator
Calculate your monthly electricity savings from solar, estimated payback period, and full 25-year return on investment. Includes BPDB net metering, annual electricity price escalation, and panel degradation modelling.
Solar Savings Calculator
Monthly savings · Payback period · 25-year ROI · Net metering
e.g. 3 kWp for average BD home
BD average: ৳8–10/kWh (BPDB 2025)
Total installed cost
Historical BD rate: 5–10%/yr
BD average: 4.5–5.5 hrs/day
Net Metering (sell excess to grid)
Net metering in Bangladesh: BPDB allows approved residential customers to sell excess solar power back. Export rate is typically lower than grid rate. Contact your local BPDB office for approval.
Monthly Savings
৳3,103
360 kWh/mo
Year 1 Savings
৳37,230
annual
Payback Period
—
enter cost
25-yr ROI
—
৳1,653,520 total
| Year | Annual kWh | Annual Savings | Cumulative |
|---|---|---|---|
| Year 1 | 4,380 | ৳37,230 | ৳37,230 |
| Year 5 | 4,293 | ৳44,355 | ৳203,573 |
| Year 10 | 4,187 | ৳55,208 | ৳456,958 |
| Year 15 | 4,083 | ৳68,717 | ৳772,345 |
| Year 25 | 3,884 | ৳106,461 | ৳1,653,520 |
How to Use
- 1Enter your solar system size in kWp.
- 2Enter your current grid electricity rate (BD average: ৳8.5/kWh).
- 3Enter total installation cost for payback calculation.
- 4Set annual electricity price increase (historical BD: 5–10%).
- 5Toggle net metering if you sell excess power to BPDB.
- 6Review monthly savings, payback year, and 25-year ROI.
Example Calculation
- System: 3 kWp hybrid
- Grid rate: ৳8.5/kWh · Peak sun: 5 hrs/day
- Annual generation: ~4,380 kWh
- Year 1 savings: ~৳37,230
- System cost: ৳240,000
Payback: ~6.4 years · 25-yr savings: ~৳1.6M · ROI: ~567%
Formula Used
Annual generation = System kWp × Peak sun hrs × 365 × 0.80 × (1 − 0.005)^(year−1). Annual savings = Generation × Grid rate × (1 + price increase)^year. Payback = year when cumulative savings ≥ system cost. ROI = (25-yr savings − cost) ÷ cost × 100%.
Frequently Asked Questions
How much can I save per month with solar in Bangladesh?
A 3 kWp solar system in Bangladesh generates approximately 450 kWh per month. At BPDB's average residential rate of ৳8.5/kWh, that saves about ৳3,825 per month. Over a year that's ৳45,900 — growing each year as electricity prices rise.
What is the payback period for solar in Bangladesh?
For a typical 3 kWp hybrid system costing ৳210,000–270,000, the payback period is 4–7 years depending on your electricity bill, local electricity rate, and whether you have BPDB net metering. After payback, electricity is essentially free for the remaining 18–20 years of panel life.
How fast do electricity prices rise in Bangladesh?
BPDB has increased electricity tariffs multiple times in recent years. The historical average increase is approximately 5–10% per year. This calculator lets you set your own projection — higher rates mean better solar ROI.
What is BPDB net metering?
BPDB net metering allows approved solar customers to sell excess electricity back to the grid. Typically, 70% of your generation is self-consumed (saving at retail rate) and 30% is exported to BPDB at a lower rate. This calculator models that split automatically when you enable net metering.
Does solar panel efficiency degrade over time?
Yes — most solar panels degrade at about 0.5% per year. After 25 years, a panel rated at 400W will produce approximately 88% of its original output. This calculator applies the standard 0.5% annual degradation to give you an accurate 25-year savings projection.