How many years does it take for solar panels to pay for themselves in Sri Lanka?

For a typical grid-tied home system in 2026, simple payback is usually 3 to 6 years. A 5 kW Net Metering system on a Rs 950,000 quote that offsets a heavy monthly bill often pays back in under 3.5 years. Smaller systems or lower electricity usage push it toward 5 to 7 years. Enter your own quote above for a specific figure.

Is rooftop solar worth it in Sri Lanka in 2026?

For most households with a mid-to-high monthly bill, yes. Because panels last 20+ years and this tool holds tariffs flat (a conservative assumption), a system that pays back in 4 years then produces roughly 16 more years of savings. If CEB tariffs rise, the real payback is faster than shown here.

What is the difference between Net Metering, Net Accounting and Net Plus?

Net Metering banks your surplus units as credit (1-for-1) but never pays cash, best when generation matches your usage. Net Accounting offsets your bill and pays cash for surplus at the Rs 22.00/kWh export credit. Net Plus sells every unit generated at the PUCSL feed-in tariff while you keep paying your own bill, best when the system is bigger than your usage.

How much can a 5 kW solar system save per month in Sri Lanka?

A 5 kW system generates roughly 600 kWh a month at the SLSEA typical yield of 4.0 kWh/kW/day. Under the tariff approved from 11 May 2026, a household that was buying those units above 180 pays Rs 100 each for them, so offsetting 600 units is worth up to about Rs 60,000 a month, less if part of the generation is exported rather than used. The exact figure depends on where your usage sits on the tariff and how much of it falls in daylight hours.

What is the CEB export tariff rate for solar in Sri Lanka?

Under the PUCSL Net Plus Tariff Order (effective 1 January 2024), systems ≤ 10 kW earn Rs 27.00/kWh for years 1–7 and Rs 22.00/kWh for years 8–20 on a 20-year contract. Net Accounting surplus is paid at Rs 22.00/kWh. Always confirm the current rate with your CEB/LECO branch before signing.

What specific yield (units per kW) does this calculator assume?

It defaults to 4 kWh per installed kW per day, the SLSEA typical for Sri Lanka. Dry-zone districts (Jaffna, Mannar, Trincomalee) can exceed 4.8; the wet-zone hill country sits nearer 3.9. You can edit the specific-yield field to match your installer's estimate or your district.

Does the payback include electricity tariff increases?

No. Version 1 deliberately holds both the domestic tariff and the feed-in rate flat across all 20 years. Since CEB tariffs have historically risen, this makes the payback estimate conservative, your real payback is likely a little faster than the number shown.

Why does my quote's payback differ from an installer's promise?

Installers sometimes assume higher yield, a higher tariff, or future tariff hikes to shorten the headline payback. This tool is transparent: it shows generation, the per-unit tariff used, and the full 20-year cash flow. Adjust the assumptions to match your installer's, and the numbers will reconcile.

Sri Lanka · Finance

Sri Lanka Solar Panel Payback Calculator

Enter your rooftop solar quote, size, cost, monthly units and CEB scheme, and see how many years it takes to pay back plus the 20-year net saving. Uses PUCSL and CEB rates, no signup, sources cited below.

By Induwara Ashinsana· Co-Founder, Ryzera TechnologiesUpdated Jul 12, 2026

Estimate your solar payback

PUCSL / CEB rates

CEB rooftop scheme

Net Metering: Surplus units roll over as credit (1-for-1) but are never paid in cash. Your saving is the electricity you no longer import. Best when generation is close to your own usage.

System size

Rooftop PV capacity from your quote.

Installed cost

Total turn-key price incl. panels + inverter.

Monthly usage

kWh

Average units on your CEB bill.

Common sizes

Assumptions

Tariff

Auto: Rs 75.70/kWh (PUCSL blocks). Edit to override.

Specific yield

kWh/kW/day

SLSEA typical ≈ 4.0 for Sri Lanka.

Panel degradation

%/yr

Typical 0.5% output loss per year.

Simple payback

2 yr 1 mo

Monthly saving (yr 1)

Rs 37,850

First-year saving

Rs 454,200

20-year net saving

Rs 8,134,000

After subtracting system cost

Which scheme pays back fastest?

Net MeteringSelected

2 yr 1 mo

20-yr net Rs 8,134,000

Net Accounting

2 yr 0 mo

20-yr net Rs 8,557,911

Net Plus

4 yr 10 mo

20-yr net Rs 2,365,611

20-year cash flow

Year	Generation	Saving	Cumulative
1	7,300 kWh	Rs 454,200	-LKR 495,800
2	7,264 kWh	Rs 454,200	-LKR 41,600
3break-even	7,227 kWh	Rs 454,200	Rs 412,600
4	7,191 kWh	Rs 454,200	Rs 866,800
5	7,155 kWh	Rs 454,200	Rs 1,321,000
6	7,119 kWh	Rs 454,200	Rs 1,775,200
7	7,084 kWh	Rs 454,200	Rs 2,229,400
8	7,048 kWh	Rs 454,200	Rs 2,683,600
9	7,013 kWh	Rs 454,200	Rs 3,137,800
10	6,978 kWh	Rs 454,200	Rs 3,592,000
11	6,943 kWh	Rs 454,200	Rs 4,046,200
12	6,908 kWh	Rs 454,200	Rs 4,500,400
13	6,874 kWh	Rs 454,200	Rs 4,954,600
14	6,839 kWh	Rs 454,200	Rs 5,408,800
15	6,805 kWh	Rs 454,200	Rs 5,863,000
16	6,771 kWh	Rs 454,200	Rs 6,317,200
17	6,737 kWh	Rs 454,200	Rs 6,771,400
18	6,704 kWh	Rs 454,200	Rs 7,225,600
19	6,670 kWh	Rs 454,200	Rs 7,679,800
20	6,637 kWh	Rs 454,200	Rs 8,134,000

Generation ≈ 7,300 kWh in year 1 at 4 kWh/kW/day. Self-consumed units are valued at Rs 75.70/kWh; Net Accounting surplus is paid at Rs 22.00/kWh. Payback in Sinhala: ආපසු ගෙවීමේ කාලය.

Sources cited: PUCSL Net Plus Tariff Order (01 Jan 2024) for feed-in rates, CEB Soorya Bala Sangramaya scheme rules, the PUCSL domestic block schedule for the avoided-import tariff, and SLSEA typical yield. Full links and the methodology are below this calculator.

How it works

The calculator models 20 years of generation and savings for a rooftop PV system under Sri Lanka's three Ceylon Electricity Board rooftop schemes. Every rate is drawn from the Public Utilities Commission of Sri Lanka (PUCSL) tariff orders and the CEB Soorya Bala Sangramaya programme, last cross-checked on 2026-07-12. The steps are:

Annual generation = system size (kW) × specific yield (kWh/kW/day) × 365. The default yield is 4 kWh/kW/day, the Sri Lanka Sustainable Energy Authority (SLSEA) typical; you can edit it for your district.
Self-consumed units = the smaller of annual generation and annual consumption. These units are valued at your effective per-unit tariff, auto-derived by walking the PUCSL domestic block schedule (energy charge ÷ units) so it reflects where you actually sit on the tariff ladder. The field is editable.
Surplus units = generation above your consumption. How they are valued depends on the scheme: Net Metering banks them as credit with no cash payout; Net Accounting pays Rs 22.00/kWh; Net Plus buys all generation at the PUCSL feed-in tariff while you keep paying your own bill.
Feed-in tariff (Net Plus) is tiered by system size. For ≤ 10 kW systems it is Rs 27.00/kWh in years 1–7 and Rs 22.00/kWh in years 8–20, per the PUCSL Net Plus Tariff Order effective 1 January 2024.
Degradation reduces generation each year: output in year n = year-1 output × (1 − degradation)^(n−1), with a 0.5% default.
Payback is the first year cumulative savings reach the installed cost, interpolated within that year. The 20-year net saving is the sum of all 20 years of savings minus the system cost.

To stay conservative, version 1 holds both the domestic tariff and the feed-in rate flat for the full 20 years, no tariff-inflation forecast. Because CEB tariffs have historically risen, your real payback is likely a little faster than shown. This is a financial payback tool, not a panel-sizing or engineering tool, and it excludes battery storage and solar-loan interest. For a month-by-month bill simulation, use the Solar Net Metering calculator.

Worked examples

5 kW · Net Metering · heavy user

Rs 950,000 quote, 500 kWh/month

Generation Y1: 5 × 4.0 × 365 = 7,300 kWh/yr
Annual usage: 500 × 12 = 6,000 kWh
Effective tariff (500 kWh block walk): Rs 37,850 ÷ 500 = Rs 75.70/kWh
Self-consumed: min(7,300, 6,000) = 6,000 kWh
Year-1 saving: 6,000 × 75.70 = Rs 454,200 (≈ Rs 37,850/mo)
Simple payback: 950,000 ÷ 454,200 = 2.1 years

3 kW · Net Accounting · exports surplus

Rs 600,000 quote, 250 kWh/month

Generation Y1: 3 × 4.0 × 365 = 4,380 kWh/yr
Annual usage: 250 × 12 = 3,000 kWh
Effective tariff (250 kWh): Rs 12,850 ÷ 250 = Rs 51.40/kWh
Self-consumed: 3,000 kWh; surplus: 1,380 kWh
Saving Y1: 3,000 × 51.40 + 1,380 × 22.00 = 154,200 + 30,360 = Rs 184,560
Simple payback: 600,000 ÷ 184,560 = 3.3 years

8 kW · Net Plus · pure export

Rs 1,600,000 quote (bill paid separately)

Generation Y1: 8 × 4.0 × 365 = 11,680 kWh/yr
Feed-in tariff (≤ 10 kW, yr 1–7): Rs 27.00/kWh
Year-1 earnings: 11,680 × 27.00 = Rs 315,360
Simple payback: 1,600,000 ÷ 315,360 = 5.1 years
From year 8 the rate steps down to Rs 22.00/kWh for the rest of the 20-year contract.

Frequently asked questions

Sources & references

Feed-in and export rates and the domestic block schedule were last cross-checked against the PUCSL and CEB sources on 2026-07-12. Solar tariffs and schemes are revised periodically, always confirm the current figures with your CEB or LECO branch before signing an installation contract.

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