Cash · 100% Self-Fund
Cash THB 48-52M for 2 MW · no interest · 100% asset ownership · no BOI for self-use solar since 1 July 2025 · no covenants · no reporting burden · fits cash-rich CFOs with hurdle ≤ 12%.
4-Way CFO Guide · MLR 2026 · 25-Yr NPV
Factory Solar Financing Guide 2026 Compare 4 Options · Cash vs Loan vs Lease vs PPA
Choose between Cash · Thai Bank Loan (EXIM / KBank K-Energy / Krungsri / SCB / BBL) · Operating Lease · Solar PPA. Grounded in Bank of Thailand MLR 2026 + current BOI status + 25-yr NPV for a 2 MW factory. Answers the CFO's single question: which route maximizes NPV?
15 dimensions25-yr NPV5 Thai banks
16-min read · updated 2026-04-24
Disclaimer
All loan interest rates, lease rentals, PPA rates, and NPV figures are illustrative. Based on Bank of Thailand MLR 2026-Q1 (~7.125%) + each bank's quarterly rate announcement + BOI Announcement 3/2568 + ERC TOU peak THB 3.88-3.95/kWh. Always consult a bank officer, tax advisor, and Thai CPA before committing.
Answer in one paragraph
Thai factories have 4 solar-financing routes. Cash (highest ROI, no debt; requires THB 48-52M for 2 MW). Thai Bank Loan (EXIM Green 5.5-7% cheapest; KBank K-Energy 6.5-8.5%; Krungsri / SCB / BBL; preserves working capital; interest tax shield). Operating Lease (5-10 yr; flexible; TFRS 16 on-balance). Solar PPA (zero CapEx; off-balance; operator bears 100% risk). None of the routes earns BOI for self-use solar any more (applications from 1 July 2025, Announcement 3/2568). CFOs with full cash pick Cash; partial pick Loan; uncertain pick Lease; cash-constrained pick PPA.
The 4 Routes: Cash · Loan · Lease · PPA
Each route fits a different CFO profile. The wrong choice can mean a 25-yr NPV loss of THB 30-40M. This guide helps the CFO decide using real numbers from Bank of Thailand + BOI + ERC (all figures illustrative — see disclaimer above). Not sure which route to take? Start with our 5-option financing decision tree.
Thai Bank Loan · 70-80% LTV
20-30% down + 7-10 yr loan @ 5.5-8.5% (EXIM Green cheapest; KBank K-Energy / Krungsri / SCB / BBL). Factory owns the asset + interest tax shield (no BOI for self-use solar). Preserves working capital. DSCR ≥ 1.2 covenant.
Operating Lease · 5-10 yr
Flat rental, THB 300-440K/mo for 2 MW, 5-10 yr. End-of-term: return / buyout / renew. TFRS 16 on-balance (ROU asset + lease liability). No BOI under either Operating or Finance Lease.
Solar PPA · 0 CapEx
Operator (IPP) funds 100%. Factory pays THB 2.70-3.55/kWh fixed 15-20 yr (10-30% below grid). Operator bears O&M + performance + FX risk. TFRS 16 service (off-balance) → D/E unchanged → pre-IPO friendly. No BOI. 25-yr NPV +34M.
15-Dimension Comparator
15 CFO-facing dimensions. Green = best in that row · amber = mid · blue = situational. Most important for CFOs: upfront, BOI, balance-sheet, 25-yr NPV, who-wins.
| Dimension | Cash | Thai Bank Loan | Operating Lease | Solar PPA |
|---|---|---|---|---|
| Upfront capital | 100% · THB 48-52M (2 MW) | 20-30% down payment (THB 10-15M) | 10-15% security deposit (THB 5-8M) | THB 0 |
| Monthly payment | None (asset free-and-clear) | THB 500-650K/mo (7-10 yr) | THB 300-440K/mo (5-10 yr) | Pay-per-kWh · ~THB 513K/mo avg |
| BOI eligibility (self-use solar) | No · self-use solar not promoted since 1 July 2025 (Announcement 3/2568) | No · same as Cash (interest still tax-deductible) | No · lease structure does not change BOI status | Not the factory · an operator selling ≥200 kW per point may hold A2 (7.1.2) |
| Balance-sheet impact | Asset + no debt (no D/E impact) | Asset + term loan liability (raises D/E) | ROU asset + lease liability (TFRS 16 on-balance) | Off-balance-sheet (service contract) |
| Asset ownership | Factory Day 1 · permanent | Factory Day 1 · bank lien until payoff | Lessor · buyout or return at end | Operator · transfers THB 1 at yr 15-20 |
| Commitment term | N/A (own asset) | 7-10 yr (some projects 15 yr) | 5-10 yr · early-exit schedule | 15-20 yr · early termination 30-50% penalty |
| Interest / implicit rate (2026) | 0% · opportunity cost = internal hurdle rate 10-12% | 5.5-8.5% MLR-linked (EXIM cheapest · KBank K-Energy next) | Implicit 8-11% (includes O&M + risk premium) | Effective 9-12% (operator IRR embedded in THB/kWh) |
| Prepayment flexibility | N/A (no debt) | Usually free after yr 3 (some banks charge 1-2% prepayment) | Pre-agreed buyout schedule · NPV-based | Hard · NPV buyout + 30-50% penalty |
| Performance / generation risk | Factory bears (EPC warranty 12-24 mo) | Factory bears (asset pledged to bank) | Shared per SLA · lessor covers uptime | Operator 100% · Performance Ratio guarantee |
| Currency risk (USD equipment) | Factory bears all (module + inverter USD) | Factory bears · some banks offer FX hedge add-ons | Lessor bears (embedded in rental) | Operator bears 100% |
| Depreciation / tax shield | Straight-line over asset life (no BOI since Jul 2025) | Same as Cash + interest tax-deductible (double shield) | 100% OpEx rental (Operating Lease) or ROU depreciation (Finance) | 100% OpEx electricity tax-deductible |
| Approval time | Instant (board-level decision) | 45-90 days (collateral + credit review) | 30-60 days (lessor credit review) | 60-120 days (operator DD + site survey) |
| End-of-term outcome | Asset runs 20-25 more yr (high residual) | Lien released · asset free-and-clear | Return / buyout / renew | Transfer at THB 1 or renew 5-yr |
| Covenant / restriction | None | Financial covenants: DSCR ≥ 1.2 · D/E ≤ 2.5 · min EBITDA · cross-default clause | Use restriction + insurance covenant + return condition | Grid access commitment · off-taker obligation · no competing solar |
| Who this model fits | CFO with unrestricted cash > CapEx + BOI + hurdle ≤ 12% | Cash-rich company wanting tax shield + preserve liquidity | Mid-tenor factory · uncertain 5-10 yr plan | Cash-constrained + OpEx simplicity + stable site |
Thai Bank Green Loan Rates · 2026-Q1
Bank of Thailand MLR reference ~7.125% (2026-Q1). Each bank publishes its own MLR + margin per product. Rates indicative — confirm with bank officer before committing. Cites each bank's public product page.
| Bank | Product | Rate | Basis | Max term | Eligibility | Approval time | Source |
|---|---|---|---|---|---|---|---|
| EXIM Thailand | EXIM Green Loan | 5.5-7.0% | MLR-1.5 to MLR-0.5 (preferential) | Up to 10 yr | Exporter or factory with Green Industry / BOI / ISO 14001 · CapEx ≥ THB 5M | 60-75 days | www.exim.go.th |
| Kasikornbank (KBank) | K-Energy Saving Loan | 6.5-8.5% | MLR-0.5 to MLR+1.5 | Up to 7 yr (10 yr for select projects) | SME or corporate · CapEx THB 1-200M · KBank customer profile | 45-60 days | www.kasikornbank.com |
| Bank of Ayudhya (Krungsri / BAY) | Krungsri SME Solar / Energy Saving Loan | 6.75-8.75% | MLR-0.25 to MLR+1.75 | Up to 7 yr | SME · CapEx THB 1-100M · payback ≤ 7 yr estimated | 45-75 days | www.krungsri.com |
| Siam Commercial Bank (SCB) | SCB Green Finance / Sustainable Loan | 6.75-8.25% | MLR-0.25 to MLR+1.25 | Up to 7 yr | Corporate or SME · ESG screening + THB 10M minimum CapEx | 60-90 days | www.scb.co.th |
| Bangkok Bank (BBL) | Industrial Term Loan (general) | 7.0-8.75% | MLR to MLR+1.75 (no green discount) | Up to 10 yr | Standard corporate client · DSCR ≥ 1.2 · no ESG required | 45-90 days | www.bangkokbank.com |
Bottom line: EXIM Green Loan cheapest (5.5-7%; exporter or green-certified required). KBank K-Energy is second (6.5-8.5%; broad eligibility). Krungsri / SCB / BBL similar. BBL has no green discount but faster approval for legacy BBL clients.
BOI and Each Financing Route
There is no "BOI Section 30/31 stacking" for self-use solar: Section 30 of the Investment Promotion Act is import-duty relief on raw materials, and BOI stopped promoting solar installations for applications filed from 1 July 2025 (Announcement 3/2568). So none of Cash, Loan, Lease or PPA earns BOI for self-use solar; the differences are depreciation, interest and TFRS 16 accounting. See BOI and solar for details.
Cash · asset 100% factory-owned · normal depreciation · no BOI for self-use solar
Loan · same as Cash + interest tax-deductible · no BOI for self-use solar
Operating Lease · rental tax-deductible · Finance Lease · ROU depreciation · neither earns BOI
PPA · no BOI for the factory · an operator selling ≥200 kW per point may hold A2 (7.1.2) itself · trade-off = Operator covers risk + O&M almost entirely
25-Yr NPV · 2 MW Factory · 4 Scenarios
NPV (Net Present Value) = sum of future cashflows discounted to present. The CFO's primary tool for comparing long-horizon investments. Assumptions: 2 MW generating 2.2M kWh/yr · grid TOU THB 3.95/kWh · PPA rate THB 2.80/kWh · Loan 7.5% 7-yr (KBank K-Energy midpoint) · 12% discount · 20% CIT · All figures illustrative. Note: this table was built with an 8-yr BOI CIT exemption for Cash + Loan, which no longer applies to self-use solar (Announcement 3/2568), so the Cash/Loan figures are overstated and are being recalculated — use the table for the shape of each route only.
| Year | Cash NPV (THB) | Loan NPV (THB) | Lease NPV (THB) | PPA NPV (THB) | Notes |
|---|---|---|---|---|---|
| Year 0 (start) | -฿50M | -฿12M | -฿6M | ฿0 | Cash 50M · Loan 12M down · Lease 6M deposit · PPA 0 |
| Year 5 | +฿10M | +฿5M | +฿8M | +฿9M | All models positive; Cash leads (+10M NPV); Loan still burdened by debt service |
| Year 10 | +฿38M | +฿30M | +฿22M | +฿18M | Cash/Loan figures still carry the old 8-yr BOI assumption (no longer available), so they are overstated · Lease buyout window |
| Year 15 | +฿58M | +฿52M | +฿32M | +฿26M | Cash - Loan gap narrows · Lease / PPA fall behind materially |
| Year 25 (system life) | +฿74M | +฿68M | +฿42M | +฿34M | 25-yr NPV: Cash +74M · Loan +68M · Lease +42M · PPA +34M (12% discount) |
Bottom line: the Cash/Loan figures in the table still carry the old 8-yr BOI assumption, which no longer applies, so they are overstated and being recalculated. Use the table for the shape of each route only: Cash needs the most upfront capital; Loan preserves liquidity with an interest tax shield; Lease and PPA need little or no capital. Ask CapSolar for a site-specific model.
Decision Tree · 4 CFO Scenarios
Pick the condition matching your factory — get a recommended route with rationale. Based on a 2 MW factory. Scale with the PPA vs Self-Invest calculator.
3 Key Risk Dimensions
Before committing, the CFO must answer the board on 3 risks: currency, interest rate, covenant.
1 · Currency risk (USD equipment vs THB revenue)
Modules + inverter are 70-80% of CapEx and priced in USD (Jinko, Longi, Trina, Sungrow, Huawei). THB weakens 10% → CapEx rises ~7%. Cash / Loan = factory bears it; some banks offer FX hedge add-ons. Lease / PPA = Operator / Lessor bears it, baked into rental / PPA rate. Tip: if FX volatility > ±5%, lock hedging before PO.
2 · Interest rate volatility (MLR)
Thai MLR tracks BOT policy rate. 2022-2024 rose from 5.50% → 7.125%. MLR-linked loans need sensitivity: +100bps MLR → +THB 0.5-0.8M/yr interest on a 2 MW loan. Mitigations: fixed-rate tranche or interest rate swap (for loans > THB 50M). Lease / PPA rates are fixed (no rate risk, but opportunity cost if MLR falls).
3 · Covenant risk (loan + lease restrictions)
Typical loan covenants: DSCR ≥ 1.2 · D/E ≤ 2.5 · min EBITDA · cross-default. A miss can trigger default on other loans. Lease covenants: use restriction + insurance + return condition. PPA covenants: grid access commitment + no competing solar. PPA exit penalty = 30-50% of remaining NPV. CFO must read term sheet + legal review before signing.
HowTo · 5-Step Financing Decision Framework
Step 1 · Audit the balance sheet
Identify unrestricted cash · free cashflow · current D/E · DSCR · target IPO (if any). Most important: do you have cash > CapEx THB 48-52M for 2 MW? What is your hurdle rate (typically 10-12%)?
Step 2 · Check tax position (BOI no longer applies)
Self-use solar is no longer promoted by BOI (applications from 1 July 2025, Announcement 3/2568), so BOI no longer decides the route. Check instead whether the factory has enough taxable profit to use depreciation and interest deductions, and what its hurdle rate is. See BOI and solar.
Step 3 · Get term sheets from 2-3 banks
Compare EXIM Green (if eligible) + KBank K-Energy + Krungsri / SCB / BBL. Review headline rate + fees + DSCR covenant + prepayment penalty. Negotiate margin -25bps if you have a multi-product relationship.
Step 4 · Run 25-yr NPV + sensitivity
Use PPA vs Self-Invest calculator with real numbers. Test 3 scenarios: base · MLR +100bps · PPA rate -10%. If Cash-Loan NPV gap ≤ 5-10% → pick Loan (preserve liquidity). If Cash NPV > Lease/PPA ≥ 30% → pick Cash. If no cash at all → pick between Lease vs PPA per balance-sheet goal.
Step 5 · Legal + CPA review + sign
Loan: legal review covenants + cross-default + hedging clause. Lease: CPA review TFRS 16 classification (Operating vs Finance). PPA: legal review grid access + termination penalty. Always have a tax advisor review the tax treatment (self-use solar has no BOI any more). CapSolar free consultation delivers a 4-scenario financial model in 5 business days.
Author note
By Frank Lee · Founder, CapSolar. Our team has delivered 80+ MWp across 150+ projects in Thailand. I've negotiated loan term sheets with 20+ CFOs (EXIM / KBank / Krungsri). The most common mistake: listing full CapEx in the EBITDA projection but forgetting to count the solar savings — DSCR comes out low and the bank declines. This guide trains the CFO to think like the Banker before submitting the loan application.
Reviewed by: Chief Engineer · CapSolar (2026-04-24)
Frequently Asked Questions
EXIM Green Loan (5.5-7%) is 100-150bps cheaper than KBank K-Energy (6.5-8.5%). But EXIM requires exporter status OR Green Industry cert / BOI / ISO 14001 + minimum CapEx THB 5M. KBank K-Energy has broader eligibility. If you qualify for EXIM, use EXIM. Otherwise, KBank K-Energy is #2. 100bps × THB 38M × 7 yr ≈ THB 1.9M interest saved.
No — because there is no BOI benefit left to lose. BOI stopped promoting self-use solar for applications filed from 1 July 2025 (Announcement 3/2568), whether you pay cash or borrow, and the old route was never 8 years (it was a 3-year CIT exemption capped at 50% of the investment). What a loan does add is a tax shield: interest is deductible against 20% CIT, which keeps Loan close to Cash on 25-yr NPV.
For a THB 38M 7-yr loan (KBank K-Energy), MLR +100bps = rate 7.5% → 8.5%, adding ~THB 1.3-1.5M total interest over loan life. NPV impact (at 12% discount) ~THB 0.9-1.1M — still less than the 25-yr Cash-Loan gap (6M). If worried, take a fixed-rate tranche (some banks allow 40-50% fixed + rest MLR) or an interest rate swap (for loans > 50M).
Grid TOU peak THB 3.88-3.95/kWh. PPA at THB 2.80 saves ~28% per kWh generated, totaling ~THB 2.5M/yr on a 2 MW system. But Cash / Loan save the full grid rate (~THB 8.7M/yr gross) + depreciation shield — so 25-yr NPV is higher. PPA competes only when CFOs need 100% off-balance-sheet (pre-IPO) or have zero cash. Beyond cost, solar also hedges against volatile energy prices — see factory energy security in the Hormuz crisis.
DSCR = Debt Service Coverage Ratio = EBITDA ÷ (annual interest + principal). Banks want ≥ 1.2, meaning EBITDA covers debt service by 120%. New factories use projected EBITDA + solar savings. Below 1.2, banks request personal guarantee from directors or extra collateral. Tip: include solar savings in EBITDA projection (~THB 8M/yr for 2 MW) — materially boosts DSCR.
Three options: (1) USD loan to currency-match equipment cost (but THB revenue re-introduces risk). (2) THB loan + forward contract directly with the bank to lock the rate at PO date (KBank, Krungsri, SCB offer 6-12 month forwards). (3) Currency swap (more complex, for deals > THB 100M). Option 2 is most common. Forward premium ~1-2% of USD portion — bake into CapEx budget upfront.
What changed for BOI and self-use solar? Read BOI and Solar — Announcement 3/2568 · For the 3-way EPC / PPA / Lease decision tree → EPC vs PPA vs Lease. See the full financing options comparison → 2026 Solar Financing Options Matrix.
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Further Reading
- Tier pricing breakdown — size your loan to match your tier
- Permit timeline impact on financing drawdown
- Bangkok-specific case study: 600 kWp warehouse financing
- BOI worked example — what Announcement 3/2568 changed
- Solar O&M costs — the factor often missing from financing models
- Calculate solar ROI — plug in your real financing numbers
- Net Metering Thailand — grid export revenue for your NPV model
- Warehouse & logistics solar — a strong financing case
- Net Billing vs Net Metering — the distinction that changes your financing model
- Direct PPA explained — zero-capex financing model for factories
- Solar procurement checklist — documents banks and lessors require
- Battery storage (BESS) — impact on solar loan structures
- EGAT DPPP — Alternative Clean Energy Procurement
- Dental clinic solar — SME financing for small commercial operations
- Vet hospital solar — high ROI from 24-hour power demand
- Factory energy security — solar as a hedge against price & supply shocks
- 2026 factory solar price — the cost baseline for financing models