Savings calculator
Rooftop Solar PPA, CAPEX, Group Captive and Open Access — side by side for your bill.
Upload your latest DISCOM bill. We read your load, units, tariff and bill amount and prepare a quotation instantly. Add your roof area below for accurate sizing.
Base rate, excluding surcharge and cess
5% refundable deposit. With handover, deposit returns at expiry and the client pays O&M thereafter. Without handover, the PPA is assumed renewed on the same discount through Year 25; deposit returns then.
Illustrative state-neutral assumptions, not a tariff quote or tax opinion. 40% is normal WDV depreciation under Section 32, not additional depreciation. Eligibility, commissioning date, taxable profits, 115BAA conditions and current state OA charges require professional validation. Captive ownership/consumption are aggregate annual SPV tests, not a requirement that this facility consume 51% of its own demand.
27-year investment horizon
Highest positive after-tax NPV among feasible routes at the selected discount rate.
58.4% of annual consumption
27-year net cash savings
₹26.21 Cr
58.4% of annual consumption
27-year net cash savings
₹24.77 Cr
94.6% of annual consumption
27-year net cash savings
₹30.42 Cr
94.6% of annual consumption
27-year net cash savings
₹27.23 Cr
₹ lakhs · Includes initial outflows, tax effects and deposit returns
Saksham Powergen India
Group Captive · 1,350 kWp · 27-year evaluation
Initial cash ₹1.58 Cr: plant ₹0, SPV equity ₹1.58 Cr, refundable deposit ₹0. NPV ₹6.36 Cr at 10%. Year 1 net operating cash benefit ₹44.37 L.
Highest positive after-tax NPV among feasible routes at the selected discount rate. Selected brief: Group Captive. Subject to site and regulatory diligence.
Facility: monthly bill ₹15.00 L, grid ₹9/kWh, consumption 1,66,667 kWh/month (estimated from bill ÷ tariff), roof 80,000 sq ft, load 1,500 kVA (1,350 kW). Tax 30% base; grid escalation 4%; annual degradation 0.7%; generation 4 kWh/kWp/day; CAPEX ₹45,000/kWp; O&M 1.5% escalating 5%; Year 12 replacement 10%. Generator tariff ₹4.56; escalation 0%; losses 4%; wheeling ₹0.45, STU ₹0.35, other ₹0.1, CSS ₹1.5, AS ₹0.75/kWh; captive exemptions assumed verified. IRR is customer investment return, not developer PPA revenue return. LCOE is pre-tax discounted supply cost, not after-tax savings. Tax shield assumes sufficient taxable profits; ordinary WDV depreciation only. No debt, residual value, SPV dividends, replacement depreciation or roof lease costs modeled; charges held constant except stated escalation. Validate current state OA rules, equity proportionality and tax eligibility before committing.
Indicative decision memo · 13th Floor, Embassy 247 Park, HCC, LBS Road, Vikhroli West, Mumbai 400079
| Year | Delivered kWh | Grid ₹/kWh | Energy + O&M | Tax shield | Net cash flow | Cumulative |
|---|---|---|---|---|---|---|
| 0 | Initial cash outflow | ₹-1.58 Cr | ₹-1.58 Cr | |||
| 1 | 18,92,160 | 9 | ₹1.07 Cr | ₹0 | ₹44.37 L | ₹-1.14 Cr |
| 2 | 18,78,915 | 9.36 | ₹1.06 Cr | ₹0 | ₹48.80 L | ₹-64.78 L |
| 3 | 18,65,762 | 9.73 | ₹1.05 Cr | ₹0 | ₹53.34 L | ₹-11.44 L |
| 4 | 18,52,702 | 10.12 | ₹1.05 Cr | ₹0 | ₹58.02 L | ₹46.58 L |
| 5 | 18,39,733 | 10.53 | ₹1.04 Cr | ₹0 | ₹62.83 L | ₹1.09 Cr |
| 6 | 18,26,855 | 10.95 | ₹1.03 Cr | ₹0 | ₹67.77 L | ₹1.77 Cr |
| 7 | 18,14,067 | 11.39 | ₹1.02 Cr | ₹0 | ₹72.86 L | ₹2.50 Cr |
| 8 | 18,01,369 | 11.84 | ₹1.02 Cr | ₹0 | ₹78.10 L | ₹3.28 Cr |
| 9 | 17,88,759 | 12.32 | ₹1.01 Cr | ₹0 | ₹83.48 L | ₹4.12 Cr |
| 10 | 17,76,238 | 12.81 | ₹1.00 Cr | ₹0 | ₹89.02 L | ₹5.01 Cr |
| 11 | 17,63,804 | 13.32 | ₹99.65 L | ₹0 | ₹94.73 L | ₹5.95 Cr |
| 12 | 17,51,457 | 13.86 | ₹98.96 L | ₹0 | ₹1.01 Cr | ₹6.96 Cr |
| 13 | 17,39,197 | 14.41 | ₹98.26 L | ₹0 | ₹1.07 Cr | ₹8.03 Cr |
| 14 | 17,27,023 | 14.99 | ₹97.58 L | ₹0 | ₹1.13 Cr | ₹9.15 Cr |
| 15 | 17,14,934 | 15.59 | ₹96.89 L | ₹0 | ₹1.19 Cr | ₹10.35 Cr |
| 16 | 17,02,929 | 16.21 | ₹96.22 L | ₹0 | ₹1.26 Cr | ₹11.61 Cr |
| 17 | 16,91,009 | 16.86 | ₹95.54 L | ₹0 | ₹1.33 Cr | ₹12.93 Cr |
| 18 | 16,79,172 | 17.53 | ₹94.87 L | ₹0 | ₹1.40 Cr | ₹14.33 Cr |
| 19 | 16,67,417 | 18.23 | ₹94.21 L | ₹0 | ₹1.47 Cr | ₹15.80 Cr |
| 20 | 16,55,745 | 18.96 | ₹93.55 L | ₹0 | ₹1.54 Cr | ₹17.34 Cr |
| 21 | 16,44,155 | 19.72 | ₹92.89 L | ₹0 | ₹1.62 Cr | ₹18.96 Cr |
| 22 | 16,32,646 | 20.51 | ₹92.24 L | ₹0 | ₹1.70 Cr | ₹20.66 Cr |
| 23 | 16,21,218 | 21.33 | ₹91.60 L | ₹0 | ₹1.78 Cr | ₹22.44 Cr |
| 24 | 16,09,869 | 22.18 | ₹90.96 L | ₹0 | ₹1.86 Cr | ₹24.30 Cr |
| 25 | 15,98,600 | 23.07 | ₹90.32 L | ₹0 | ₹1.95 Cr | ₹26.25 Cr |
| 26 | 15,87,410 | 23.99 | ₹89.69 L | ₹0 | ₹2.04 Cr | ₹28.29 Cr |
| 27 | 15,76,298 | 24.95 | ₹89.06 L | ₹0 | ₹2.13 Cr | ₹30.42 Cr |
Animated PPA Academy & best-fit finder →Read the full guide to Captive, Group Captive and Open Access solar →
PPA routes
Same facility, three ways to buy solar power on a PPA. Demand 1,66,667 kWh/month, load 1,350 kW.
₹6.75/kWh
landed vs grid ₹9.00
₹5.65/kWh
landed vs grid ₹9.00
• Equity is not assumed refundable; dividends and exit value excluded. Aggregate SPV tests must be verified annually.
₹7.11/kWh
landed vs grid ₹9.00
| Landed cost build-up (₹/kWh) | Rooftop OPEX PPA | Group Captive Solar PPA | Third-Party Open Access PPA |
|---|---|---|---|
| Generator / PPA tariff | ₹6.75 | ₹4.56 | ₹3.80 |
| Transmission loss gross-up | ₹0.00 | ₹0.19 | ₹0.16 |
| Wheeling charge | ₹0.00 | ₹0.45 | ₹0.45 |
| STU / transmission charge | ₹0.00 | ₹0.35 | ₹0.35 |
| Other OA (SLDC, banking) | ₹0.00 | ₹0.10 | ₹0.10 |
| Cross-subsidy surcharge | ₹0.00 | Exempt | ₹1.50 |
| Additional surcharge | ₹0.00 | Exempt | ₹0.75 |
| Landed cost | ₹6.75 | ₹5.65 | ₹7.11 |
| Site | Your own rooftop (behind the meter) | Off-site solar park, power wheeled via grid | Off-site solar park, power wheeled via grid |
| Upfront | Zero capex; 5% refundable deposit | 26% of total plant investment (SPV equity) | Zero; payment security (LC / BG) |
| Tariff | Grid tariff less 25–30% discount | Fixed generator tariff + wheeling & losses | Generator tariff + all open access charges |
| Regulatory charges | None — no wheeling, CSS or AS | CSS & AS exempt if captive rules met | Wheeling, losses, CSS and AS payable |
| Tenure | 5–7 years, plant handed over free | 25 years; shares bought back at exit | 25 years, no plant ownership |
| Contracts | PPA + rooftop licence | PPA + Share Subscription & Shareholders' Agreement | Bilateral PPA + wheeling & banking agreement |
| Constraint | Roof area (~100 sq ft per kWp) | ≥26% ownership, ≥51% consumption yearly | Green OA ≥100 kW (state rules apply) |
Open access charges are editable in the assumptions above and vary by state; verify with the DISCOM/SLDC before signing.
Share your details and, if you like, your latest electricity bill. Our team will assess the procurement options for your facility. Your advisor will contact you within 24 hours. Figures are indicative.