Monthly bill and monthly units are different inputs
A bill amount can include energy charges, fixed charges, fuel adjustments, duties, taxes, and bill credits. In Telangana, eligible households may also receive a zero bill for qualifying monthly use under Gruha Jyothi. Dividing a bill amount by a guessed tariff would not recover exact energy use.
If a household knows its monthly energy use in kWh (often called units), annual use can be represented as monthly use multiplied by 12. This is still not enough by itself to determine solar savings.
Inputs used in the current scenario
Use the proposal's estimate
Enter average monthly generation for the quoted DC capacity. SolarWise does not invent a Hyderabad yield. Actual output depends on roof direction, shade, weather, equipment and installation.
Estimate self-use
Enter the share of generation expected to be used in the home. The model limits self-used units to monthly household consumption and compares cited tariff components before and after.
Assign no export value
Surplus is valued at ₹0 in this scenario. A TGERC proceeding lists ₹2.57/kWh for named arrangements, but later-order currentness and household billing applicability need confirmation.
Formulas in the current model
Annual household use = monthly kWh × 12. The quote's implied annual yield = installer-estimated monthly generation × 12 ÷ quoted module capacity. The energy-balance size reference = annual household use ÷ quote-implied annual yield per kWp. This is a comparison reference, not a recommended engineering design; roof suitability, sanctioned load, hourly load and DISCOM feasibility still matter.
Estimated self-used kWh/month = the lower of monthly household consumption or quoted monthly generation × entered self-consumption percentage. Surplus generation receives no export credit in this model.
The tariff comparison applies the listed LT-I domestic energy rate rows to the entered consumption, plus the applicable per-kW fixed charge and monthly customer charge before and after modeled self-use. Annualized savings = the monthly difference × 12. The row-based energy-band interpretation and customer-specific bill interactions require confirmation against actual TGSPDCL bills; output is therefore illustrative. FSA/FCA, electricity duty, arrears, adjustments, Gruha Jyothi and export settlement are excluded. Savings are suppressed when Gruha Jyothi is selected as yes or unsure.
Simple payback = the user-entered gross quote ÷ annualized modeled tariff-component reduction, shown only when the modeled reduction is positive. It is before any CFA, not discounted cash flow, and excludes maintenance, inverter replacement, financing, degradation, tariff changes, seasonal output variation and export value.
Subsidy reference is not deducted
The calculator shows the MNRE capacity schedule as a separate reference only. It does not determine household eligibility, approval, or payment, and it does not subtract the reference amount from the gross quote or payback. Read the CFA guide and confirm eligibility through official channels.
What SolarWise does not assume
- A fixed generation yield or installer price for every Hyderabad roof.
- A CFA schedule amount as an installation discount or approved payment.
- That all exported units earn the same rate, or that fixed charges vanish.
- That a household receives Gruha Jyothi or qualifies for a tax reimbursement.
- That a system size based on annual kWh is an engineering design or utility approval.
Data status
This is an illustrative quote scenario using user-entered technical and price values. The tariff is a FY 2026–27 official reference checked 15 October 2026. If the utility, metering arrangement, scheme status or required inputs are unsupported or uncertain, dependent savings stay unavailable rather than being replaced by a national average.
Read the current source register for the Hyderabad pilot or calculate a quote scenario.