किन्नुअघि पैसाको हिसाब Before you invest

सोलारमा लगाएको पैसा कति वर्षमा उठ्छ? When will your solar system pay back?

सिस्टमको कुल खर्च, वर्षको उत्पादन, आफैं प्रयोग हुने हिस्सा, जोगिने बिजुली दर, grid मा पठाएको ऊर्जाको मूल्य र मर्मत खर्च राखेर simple payback निकाल्नुहोस्। Enter total system cost, annual generation, self-use, avoided electricity value, export value, and maintenance to estimate simple payback.

आफ्नो quote र ऊर्जा राख्नुहोस् Enter your quote and energy

लगानी र उत्पादन Investment and generation

आफूले तिर्ने कुल सिस्टम खर्च Total system cost you will pay

प्यानल, inverter, structure, wiring, जडान र meter सहितको हालको quote राख्नुहोस्। Use a current quote including panels, inverter, structure, wiring, installation, and metering.

वर्षको सोलार उत्पादन Annual solar generation

kWh/yr

installer को site estimate, एक वर्षको meter data वा Yantrix को उत्पादन calculator प्रयोग गर्नुहोस्। Use an installer site estimate, a year of meter data, or the Yantrix output calculator.

ऊर्जाको मूल्य Value of the energy

सोलारबाट आफैं प्रयोग हुने हिस्सा Solar energy used on site

आफैं प्रयोग गर्दा प्रति युनिट जोगिने रकम Avoided grid cost per self-used kWh

औसत बिल दर होइन। सोलारले घटाउने युनिटमा पर्ने हालको NEA energy rate राख्नुहोस्। Do not use the whole-bill average. Enter the current energy rate avoided by those units.

grid मा पठाएको प्रति युनिट पाउने रकम Credit received per exported kWh

हालको लिखित agreement वा bill मा भएको दर मात्र राख्नुहोस्। नपाउने भए 0। Use only the rate in a current written agreement or bill. Keep zero if no credit applies.

वर्षको मर्मत र चलाउने खर्च Annual maintenance and operating cost

पैसा उठ्ने अनुमान Payback estimate

Simple paybackSimple payback 15.0 वर्षyears हरेक वर्ष उस्तै net saving मान्दाif annual net savings stay constant

वर्षको net savingAnnual net savingsRs 40,000

महिनाको औसतMonthly averageRs 3,333

बिलमा जोगिनेAnnual bill savingsRs 45,000

export बाट आउनेAnnual export valueRs 0

घरमै प्रयोगUsed on site4,500 kWh/yr

grid मा पठाइनेExported1,500 kWh/yr

ध्यान दिनुहोस्Honesty note

यो simple payback हो। ऋणको ब्याज, पैसाको समय मूल्य, tariff फेरबदल, उत्पादन घट्दै जाने असर, inverter replacement, कर, downtime र resale value यसमा छैन। ठूलो लगानीको अन्तिम निर्णयका लागि discounted cash-flow र installer का लिखित सर्त पनि हेर्नुहोस्। This is simple payback. It excludes loan interest, time value of money, tariff changes, degradation, inverter replacement, tax, downtime, and resale value. Check discounted cash flow and written installer terms before a major investment.

हिसाब कसरी हुन्छ?How the calculation works

आफैं प्रयोग भएको सोलारले grid बाट किन्नुपर्ने ऊर्जा घटाउँछ। बाँकी ऊर्जा grid मा पठाइन्छ, तर त्यसको मूल्य हालको agreement मा जे छ त्यही हुन्छ। Self-used solar avoids buying grid energy. The remainder is exported, but it has value only at the rate in the current agreement.

self-used kWh = annual generation × self-use %
exported kWh = annual generation − self-used kWh
bill savings = self-used kWh × avoided grid rate
export value = exported kWh × export credit rate
annual net savings = bill savings + export value − annual maintenance
simple payback years = total system cost ÷ annual net savings

Annual net savings शून्य वा ऋणात्मक भए simple payback हुँदैन। सबै cash flow हरेक वर्ष उस्तै रहने मान्यतामा मात्र भाग गरेर वर्ष निकालिएको हो। If annual net savings are zero or negative, there is no simple payback. Dividing cost by savings assumes the same cash flow every year.

नमुना हिसाबWorked example

यो बजारको औसत होइन। उदाहरणका लागि सिस्टम खर्च Rs 600,000, वर्षको उत्पादन 6,000 kWh, self-use 75%, जोगिने दर Rs 10/kWh, export credit 0 र वर्षको मर्मत Rs 5,000 राखिएको छ। This is not a market average. The example uses a Rs 600,000 system, 6,000 kWh/year, 75% self-use, Rs 10/kWh avoided cost, zero export credit, and Rs 5,000 annual maintenance.

6,000 × 75% = 4,500 kWhघरमै प्रयोग हुने ऊर्जाenergy used on site

6,000 − 4,500 = 1,500 kWhgrid मा पठाइने ऊर्जाenergy exported

4,500 × Rs 10 = Rs 45,000वर्षमा जोगिने बिलannual bill savings

Rs 45,000 + Rs 0 − Rs 5,000 = Rs 40,000वर्षको net savingannual net savings

Rs 600,000 ÷ Rs 40,000 = 15.0 yearssimple paybacksimple payback

स्रोत र मान्यताSources and assumptions

AEPC, Planning a Solar Project, checked 23 Aug 2026. AEPC provides the official Nepal rooftop planning and feasibility workflow.
AEPC, Leveraging Investment in Sustainable Energy, checked 23 Aug 2026. It documents rooftop self-consumption and surplus energy sent through net metering in Nepal projects.
Nepal Electricity Authority, Consumer Tariff Rates, checked 23 Aug 2026. Use the current energy rate actually avoided on your bill, not a universal average.
Ministry of Energy, Water Resources and Irrigation, grid-connected alternative electricity procedure 2078, first amendment, checked 23 Aug 2026. Confirm current export and interconnection terms before assigning exported energy a value.
NIST, Recommended Practice for Measuring Simple and Discounted Payback, checked 23 Aug 2026. For uniform annual cash flow, simple payback is initial cost divided by annual benefits net of annual costs; the method omits the time value of money.

Rs 600,000, 6,000 kWh, 75%, Rs 10/kWh र Rs 5,000 सबै नमुना input हुन्। कुनै पनि रकमलाई नेपालभरको default वा vendor quote नमान्नुहोस्। Rs 600,000, 6,000 kWh, 75%, Rs 10/kWh, and Rs 5,000 are example inputs. None is a Nepal-wide default or vendor quote.