TOPCon vs Mono PERC Solar in Indian Heat 2026 Compare

On an Indian rooftop in summer, the panel is not running at the 25°C on its datasheet. Rooftop panel temperatures sit at 60 to 70°C for four months a year across most of India, and the temperature coefficient gap between TOPCon (Tunnel Oxide Passivated Contact, N-type silicon) and Mono PERC (Passivated Emitter and Rear Cell, P-type silicon) translates directly into generation, ROI (Return on Investment) and payback months. If you compared a Mono PERC quote at ₹24/W with a TOPCon quote at ₹26/W, the cheaper one wins in cool climates but loses you money across most of India. TOPCon is now widely offered on Indian rooftops, and the reason to choose it is heat behaviour, not headline efficiency.

This page is about heat and climate performance only. It breaks the decision down on the only six variables that matter for Indian conditions, runs the 25-year generation math for a hot state (Rajasthan) and a coastal city (Mumbai), and gives a clear use-case verdict at the end.

Direct answer. In Indian heat, TOPCon loses less output than Mono PERC because of its better temperature coefficient (-0.30%/°C against -0.34%/°C). That means roughly 1.6 to 2% more electricity in summer and about 2.5 to 3% more across 25 years. This page covers heat performance only; for the full three-way comparison including HJT, use the hub guide.

If you are sizing a rooftop in the next 90 days, the framework below tells you exactly when paying the TOPCon premium is worth it and when it is not.

Why Temperature Matters Much More in India Than Europe

Solar panel datasheets quote performance at STC (Standard Test Conditions): 25°C cell temperature, 1,000 W/m² irradiance, AM1.5 spectrum. Those numbers describe a German laboratory, not an Indian rooftop in May. The gap between the laboratory and the rooftop is where most of the buyer confusion sits, and it is where the TOPCon-vs-PERC argument actually plays out.

Across the Indo-Gangetic plain and most of central and western India, peak summer ambient temperatures hit 42 to 48°C. Rooftop solar modules run roughly 18 to 22°C hotter than ambient air because they sit on a heat-absorbing roof, in direct sun, with limited airflow underneath. That puts real cell temperature at 65 to 70°C during the highest-irradiance hours of the day, exactly when the panel should be producing peak watts. Every degree above 25°C reduces panel output by the panel’s temperature coefficient. Multiply the gap (40 to 45°C above STC) by the coefficient and you get the real-world derating that distinguishes one panel from another.

European installations rarely see cell temperatures above 50°C. The Indian rooftop operates a full 15 to 20°C hotter for months at a stretch. The same panel that loses 8% in Munich loses 13 to 15% in Jaipur, and the cell technology that handles that heat better wins on every metric that matters: kWh (kilowatt-hour) yield, ₹/kWh lifetime cost, and warranty headroom. This is why Indian buyers should weight temperature coefficient much more heavily than buyers in Germany, the United Kingdom, or even most of the United States.

For a broader three-way comparison including HJT (Heterojunction Technology), read our Mono PERC vs TOPCon vs HJT guide.

The 6-Variable TOPCon vs Mono PERC Heat Scorecard

This is the framework we use across every residential and commercial quote at Heaven Green Energy. Six variables, scored side by side. Five of them are direct datasheet pulls; one (₹/W) comes from current tier-1 module pricing. If you score a panel set on these six variables you can stop arguing about marketing brochures and decide on numbers.

Variable 1: Temperature Coefficient (Pmax)

This is the percentage of output a panel loses for every 1°C the cell temperature rises above 25°C. Lower (more negative) is worse. Mono PERC tier-1 modules from Waaree, Adani, Tata, Vikram, and Premier list temperature coefficients of −0.34%/°C on average, with some older lines at −0.36%/°C. TOPCon equivalents from the same manufacturers list −0.30%/°C, with premium N-type lines reaching −0.29%/°C. The 0.04-point gap looks small until you multiply by a 40-degree temperature delta, that produces a 1.6-point output gap during every peak summer hour for the life of the system.

Variable 2: Peak Summer Generation

At a realistic Indian summer cell temperature of 65°C (44°C ambient + 21°C heat rise), Mono PERC loses (65−25) × 0.34 = 13.6% vs STC nameplate. TOPCon loses (65−25) × 0.30 = 12.0%. Net edge for TOPCon during the hottest 3 to 4 months: about 1.6%. Spread across the year and combined with TOPCon’s lower first-year degradation, the annual yield advantage works out to about 2% in hot states (see the Jaipur example below).

Variable 3: NOCT Performance

NOCT (Nominal Operating Cell Temperature) is the cell temperature reached at 20°C ambient, 800 W/m² irradiance, 1 m/s wind. Lower NOCT means the panel runs cooler under the same conditions, and therefore loses less to thermal derating. Modern TOPCon panels list NOCT at 43 to 44°C; comparable Mono PERC sits at 44 to 45°C. A 1 to 2°C structural advantage compounds with the temperature coefficient advantage above to widen the real-world gap.

Variable 4: Degradation Rate

Year 1 degradation is the LID/LeTID (Light-Induced and Light-and-elevated-Temperature-Induced Degradation) drop that happens early in a panel’s life. Mono PERC loses about 2% in Year 1; TOPCon loses about 1%. After Year 1, Mono PERC degrades linearly at 0.45%/year to Year 25; TOPCon at 0.4%/year. At Year 25, a Mono PERC panel is at roughly 87% of nameplate; TOPCon is at roughly 89%. That 2-point gap is locked-in lifetime generation.

Variable 5: Warranty Headroom

Most tier-1 Mono PERC panels carry a 12-year product warranty and 25-year linear performance warranty guaranteeing ≥84.8% output at Year 25. TOPCon panels typically carry a 30-year linear performance warranty with a slower warranted degradation rate; Adani Solar, for example, gives 12 years of product warranty on both technologies, with 25 years of performance cover on Mono PERC and 30 years on TOPCon at 0.40% degradation a year. Product warranty terms vary by maker, so read the datasheet. The extra 5 years of performance cover plus the cleaner degradation curve reduces the long-tail risk that owners of older Mono PERC panels are now facing.

Variable 6: ₹/W Cost

Adani Solar’s published 2026 prices, before GST, put its 540 to 560 Wp (Watt-peak) Mono PERC DCR modules at ₹23.35–₹23.86/W and its 610 to 640 Wp TOPCon DCR modules at ₹23.25–₹24.76/W, so the DCR premium for TOPCon is about ₹1/W or less. Non-DCR modules, which do not qualify for PM Surya Ghar subsidy, are much cheaper: ₹12.70–₹13.20/W for Mono PERC and ₹13.70–₹14.20/W for TOPCon. Installer quotes add margin on top, so compare the gap between the two options, not just the headline ₹/W.

Variable	Mono PERC	TOPCon	TOPCon edge
Temperature coefficient (Pmax)	−0.34%/°C	−0.30%/°C	0.04 points
Cell technology	P-type silicon	N-type silicon	Better at high temp
Peak summer loss (65°C cell)	13.6%	12.0%	1.6 points
NOCT	44 to 45°C	43 to 44°C	~1°C cooler
Year 1 degradation	~2%	~1%	1 point
Linear degradation Y2–Y25	0.45%/yr	0.40%/yr	0.05 points/yr
Product warranty	12 years (Adani)	12 years (Adani)	Varies by maker
Performance warranty	25 yr ≥ 84.8%	30 yr at 0.40%/yr (Adani)	+5 years
₹/W (Adani DCR list, 2026, pre-GST)	₹23.35–₹23.86	₹23.25–₹24.76	About ₹1/W or less

The pattern is consistent: TOPCon wins five of six variables. Mono PERC only wins, narrowly, on upfront ₹/W. The whole financial argument reduces to one question, does the recurring generation advantage repay the upfront premium fast enough? Section 5 below runs that math for two very different Indian climates.

Cell Tech Difference, N-type vs P-type, and Why It Matters in Heat

Both Mono PERC and TOPCon use monocrystalline silicon wafers. The difference is in the dopant and the contact passivation. P-type wafers were traditionally doped with boron (many current PERC lines, Adani’s included, use gallium instead to curb light-induced degradation), while N-type wafers are doped with phosphorus. N-type silicon has lower boron-oxygen defect density, which directly translates to lower LID, better behaviour at high temperature, and lower bulk recombination, all three of which favour Indian rooftops.

Mono PERC is a P-type architecture. Its breakthrough in the 2010s was adding a dielectric passivation layer on the rear of the cell to reduce electron recombination at the rear surface. That step lifted efficiency from ~17% to ~21% and made it the global default for almost a decade.

TOPCon adds a tunnel oxide layer between the silicon and the metal rear contact, plus a thin doped polysilicon layer. This combination passivates the contact itself, not just the bulk surface, recombination losses drop further, and the cell tolerates heat better. TOPCon cells use N-type silicon, which is more expensive to produce but inherently more stable. The result is a cell that hits 23 to 24% efficiency under STC and holds onto more of that efficiency at the temperatures Indian rooftops actually see.

The practical implication is that N-type TOPCon cells age more gracefully. Boron-oxygen complexes in boron-doped P-type silicon are the main driver of LID (Light-Induced Degradation), the steep drop in output during the first weeks of field exposure. N-type wafers do not form these complexes, so they sidestep the bulk of that early loss. Combine that with the polysilicon contact passivation and you get a cell that starts higher and falls more slowly, both of which compound over 25 years of Indian sun.

Manufacturing-wise, TOPCon uses LPCVD (Low-Pressure Chemical Vapour Deposition) or PECVD (Plasma-Enhanced Chemical Vapour Deposition) to lay down the polysilicon layer, which raises capex per gigawatt of capacity. Indian manufacturers, Adani Solar among them, have added TOPCon capacity in recent years, and TOPCon models now sit on the ALMM alongside Mono PERC, in both DCR and non-DCR versions.

If you want a fuller side-by-side that also covers HJT, read Mono PERC vs TOPCon vs HJT. For brand-level comparisons inside each architecture, see Adani vs Tata solar panels, Adani vs Waaree, and Waaree vs Tata.

Real Generation Math, Rajasthan vs Mumbai

Take two identical rooftops, both with a single 540 Wp panel, one in Jaipur (hot, dry, 5.9 PSH/day) and one in Mumbai (hot, humid, coastal, 4.8 PSH/day). Compare what each panel actually produces in Year 1 across Mono PERC and TOPCon. This is where the temperature coefficient stops being a number on paper and becomes ₹ in the bank.

Year 1, Jaipur, Rajasthan (Hot State)

Jaipur runs roughly 7 months of ambient above 30°C and 4 months above 40°C. Average rooftop cell temperature across the year is approximately 50°C. Applied to a 540 Wp panel:

Metric	Mono PERC	TOPCon
STC nameplate	540 W	540 W
Average cell temp loss (50°C)	8.5%	7.5%
Effective average output	494 W	500 W
Year-1 LID/LeTID loss	2%	1%
Real Year-1 output	484 W	495 W
Annual generation (Jaipur 5.9 PSH)	1,043 kWh	1,066 kWh
Generation advantage	,	+2.2%

Year 1, Mumbai (Coastal/Humid)

Mumbai’s ambient temperature peaks at 35 to 37°C and stays above 28°C for most of the year, but high humidity and cloud cover reduce the time spent at extreme cell temperature. Average annual cell temperature is approximately 42°C.

Metric	Mono PERC	TOPCon
STC nameplate	540 W	540 W
Average cell temp loss (42°C)	5.8%	5.1%
Effective average output	509 W	513 W
Year-1 LID/LeTID loss	2%	1%
Real Year-1 output	499 W	508 W
Annual generation (Mumbai 4.8 PSH)	874 kWh	890 kWh
Generation advantage	,	+1.8%

The pattern is clear: TOPCon’s advantage in Mumbai (~1.8%) is real but smaller than in Jaipur (~2.2%). The hotter the climate, the bigger the TOPCon edge. The average cell temperatures used above are estimates for illustration.

Want a panel-by-panel quote based on your city’s actual irradiance and temperature profile? Heaven Green Energy generates a 25-year generation forecast for your exact rooftop before you commit. Get your free quote →

25-Year Generation Total + Lifetime ROI Delta

Annual gaps compound across 25 years because TOPCon also degrades more slowly. Below are the 25-year cumulative generation totals for the same two cities using the Year 1 baseline above and the linear degradation rates from the scorecard.

25-Year Generation, Jaipur 540 Wp Panel

Year	Mono PERC (kWh)	TOPCon (kWh)	Cumulative gap
1	1,043	1,066	+2.2%
5	1,024	1,049	,
10	1,001	1,028	,
15	977	1,006	,
20	954	985	,
25	930	964	,
25-yr total	24,700	25,400	+700 kWh (+2.9%)

Annual output of one 540 Wp panel in Jaipur over 25 years

Data for: Annual output of one 540 Wp panel in Jaipur over 25 years

Period	Mono PERC	TOPCon
Year 1	1,043 kWh	1,066 kWh
Year 5	1,024 kWh	1,049 kWh
Year 10	1,001 kWh	1,028 kWh
Year 15	977 kWh	1,006 kWh
Year 20	954 kWh	985 kWh
Year 25	930 kWh	964 kWh

25-Year Generation, Mumbai 540 Wp Panel

Year	Mono PERC (kWh)	TOPCon (kWh)	Cumulative gap
1	874	890	+1.8%
10	839	858	,
25	780	805	,
25-yr total	20,700	21,200	+500 kWh (+2.5%)

Lifetime ROI Delta, 5 kW System (10 Panels)

Scale the per-panel totals to a typical 5 kW residential system (10 panels) and apply blended retail tariff savings.

Metric	Jaipur 5 kW	Mumbai 5 kW
25-yr extra kWh (TOPCon over PERC)	7,000 kWh	5,100 kWh
Blended retail tariff	₹7.20/kWh	₹8.50/kWh
Lifetime extra savings	₹50,700	₹43,500
TOPCon premium (about ₹1/W × 5,400 W)	₹5,400	₹5,400
Net lifetime gain	+₹45,300	+₹38,100
Payback of TOPCon premium	about 3.3 yrs	about 4 yrs

At a premium of about ₹1/W, even in cooler Mumbai the TOPCon premium repays itself in about 4 years and returns roughly ₹38,000 net over the system’s life. In Jaipur it repays in about 3.3 years and returns roughly ₹45,000. At a ₹2/W premium the paybacks stretch to about 6.5 and 8 years, so the size of the premium you are quoted matters as much as the climate. The Bureau of Indian Standards (BIS) IS 14286 module standard now covers both technologies; either way the panel meets IEC (International Electrotechnical Commission) and BIS performance requirements.

Cost Premium, When Heat Makes TOPCon Pay Off Faster

The payback gap between hot and mild cities follows average cell temperature. Use this rough map, with indicative cell temperatures, to decide whether to lean TOPCon or stay PERC.

Region	Avg cell temp	TOPCon edge	Recommended choice
Rajasthan (Jaipur, Jodhpur, Udaipur)	50 to 55°C	Largest	TOPCon
Gujarat (Ahmedabad, Surat, Rajkot)	50 to 54°C	Large	TOPCon
Madhya Pradesh (Indore, Bhopal)	48 to 52°C	Large	TOPCon
Telangana, Andhra Pradesh (Hyderabad, Vijayawada)	48 to 52°C	Large	TOPCon
Delhi NCR, Haryana, Punjab	47 to 51°C	Large	TOPCon
Tamil Nadu (Chennai, Coimbatore)	46 to 50°C	Moderate	TOPCon
Maharashtra inland (Pune, Nashik)	45 to 48°C	Moderate	TOPCon
Mumbai, Goa (coastal humid)	42 to 45°C	Smaller	Either
Bengaluru (mild high-altitude)	40 to 43°C	Smaller	Either
Hill states (Himachal, Uttarakhand hills)	35 to 40°C	Smallest	PERC OK

A second factor is what each extra unit displaces. Residential slab tariffs are set by monthly consumption, so in a high-consumption home every extra midday unit that TOPCon’s lower derating delivers comes off your top slab. The PERC panel covers the same load, just slightly less of it, and the gap shows up directly in your bill the very first summer.

For dust-and-heat-specific guidance on solar in Rajasthan, see Solar in Rajasthan dust and heat. For a buyer’s framework that goes beyond cell tech to mounting, BoS (Balance of System), and installer selection, see How to choose solar modules.

Common Mistakes in Heat-Sensitive Panel Selection

These are the recurring errors we catch when reviewing third-party quotes for clients across the cities we serve. Each one is preventable in a 5-minute datasheet check, and each one shows up in real bills the very next summer. A buyer who avoids all seven gives up no warranty, no ALMM eligibility and no Suryaghar subsidy, they simply land on the panel that matches their climate and tariff. Print this list, take it to your quote review meeting, and ask the installer to address each item in writing.

1. 1
   Comparing only STC efficiency. A 21.2% Mono PERC and a 21.5% TOPCon look close on paper. In real Indian conditions the TOPCon wins by about 2% a year in hot cities because it holds output at high cell temperature and loses less in Year 1.
2. 2
   Ignoring the temperature coefficient line on the datasheet. Most installers skip it. It is the single number that drives lifetime ₹/kWh in India.
3. 3
   Choosing PERC purely because it is a little cheaper per watt. Across 25 years the cheaper panel can cost you around ₹50,000 in foregone generation on a 5 kW system in a hot state.
4. 4
   Paying the TOPCon premium in Bengaluru or coastal Goa. Below 43°C average cell temperature, the math weakens. Either tech works; don't overpay.
5. 5
   Treating "bifacial" as the headline differentiator. Rooftop bifacial gain is usually modest on a low-mounted residential array. Check the cell technology and temperature coefficient first, rather than choosing on glass-glass vs glass-backsheet alone.
6. 6
   Mixing TOPCon and Mono PERC panels in the same string. Different I-V curves cause module-level current mismatch and you lose 2 to 4% to the lowest-performing module. Always stay with one cell tech per string.
7. 7
   Not asking for the ALMM line item. Both technologies are widely ALMM-listed in 2026, but specific Wp ratings within a model line are listed individually, and for PM Surya Ghar the module must also be DCR. The wrong sub-line breaks subsidy eligibility.

TOPCon vs PERC in Heat, Verdict by Climate and Use Case

The honest verdict depends on three things, your climate zone, your roof’s exposure to direct sun, and how long you plan to own the property. Use the matrix below.

A third and final consideration is resale value. Homes with documented TOPCon installations and 30-year performance warranties can make for better resale conversations than identical homes with older Mono PERC arrays, particularly in metro markets where buyers now know to ask the question. The warranty paperwork, the ALMM-listed serial numbers and the generation logs from the monitoring app together form a sellable asset, not just a utility upgrade.

Verdict. For most Indian rooftops in 2026, anywhere with sustained summer cell temperatures above 50°C, TOPCon is the right answer when the premium is small. At about ₹1/W (Adani’s DCR list gap) the premium pays back in roughly 3 to 4 years and delivers around ₹40,000 to ₹45,000 of net lifetime upside on a 5 kW system. Mono PERC stays the right call for cool-climate hill installations, very large unconstrained ground or rooftop arrays where ₹/W dominates the decision, and short-tenure owners (under 5 years) who will not capture the lifetime delta.

How Heaven Green Energy Chooses Panel Tech for Indian Heat

We do not push one technology by default. The recommendation flows from your address, your roof, and your tariff. For every project we run the same six-variable scorecard above and document a written recommendation for the buyer.

• Residential, hot states (Rajasthan, Gujarat, MP, Telangana, Maharashtra inland): default to TOPCon from Adani Solar (its TOPCon range is 610 to 640 Wp). Payback of premium 3 to 4 years at about ₹1/W.
• Residential, cool/coastal (Mumbai, Goa, Bengaluru, Chennai coastal): both technologies on the quote. Buyer picks based on tenure and cash flow.
• Commercial rooftops (50 kWp+): TOPCon almost always wins because the ₹/W gap narrows and accelerated depreciation magnifies the lifetime savings.
• Hill installations (Himachal, Uttarakhand, Sikkim): Mono PERC unless customer specifically wants TOPCon for warranty length.
• Solar pumps and off-grid (rural Rajasthan, Gujarat): TOPCon, peak summer reliability matters when there is no grid backup.

Every panel we install is ALMM-listed, BIS-certified to IS 14286, IEC 61215 and IEC 61730 compliant, and supplied with a digital datasheet pack so you have the temperature coefficient and warranty terms documented before commissioning. For full module options, browse our solar modules range, or talk to the team for residential and commercial projects directly.

Beyond the cell choice, we document the system specification end-to-end, inverter MPPT (Maximum Power Point Tracker) range matched to the chosen module’s Voc and Isc, string length checked against the lowest-recorded local winter temperature, mounting structure rated to local wind-zone classifications under IS 875 Part 3, and earthing per IS 3043. Every Heaven Green installation comes with a 25-year performance support contract, an annual cleaning visit aligned with the local dust season, and a thermal-imaging hotspot audit at the end of Year 2 to catch any cell-level defects before they propagate.

If you want a personal recommendation for your city and roof, get a free quote and we will return a written panel-tech recommendation with 25-year generation projections within 24 hours.

Frequently Asked Questions

Is TOPCon really better than Mono PERC in Indian heat, or is it just marketing?

It is genuinely better, and the difference is measurable on every tier-1 datasheet. The temperature coefficient gap is 0.04 percentage points per degree Celsius, which produces a 1.6% peak-summer output advantage at 65°C cell temperature. Lower NOCT and slower Year-1 degradation widen that gap further. Across 25 years in a hot state like Rajasthan, TOPCon produces about 3% more total kWh from the same nameplate wattage. That is not marketing, it is physics and chemistry of N-type silicon plus the tunnel oxide passivation layer.

How much more does TOPCon cost than Mono PERC in 2026?

Less than most quotes suggest. Adani Solar’s published 2026 prices, before GST, are ₹23.25–₹24.76/W for its DCR TOPCon modules (610 to 640 Wp) and ₹23.35–₹23.86/W for its DCR Mono PERC modules (540 to 560 Wp), a premium of about ₹1/W or less, roughly ₹5,400 or less on a 5 kW (5,400 W) system. Non-DCR modules, which do not qualify for PM Surya Ghar subsidy, are ₹13.70–₹14.20/W for TOPCon and ₹12.70–₹13.20/W for Mono PERC.

Does TOPCon work for PM Suryaghar subsidy?

Yes, if it is a DCR module. PM Suryaghar (the central rooftop subsidy scheme administered by MNRE) does not favour one cell technology, but the module must be made with Indian cells (DCR) and be on the ALMM; non-DCR TOPCon does not qualify. A DCR panel, Mono PERC or TOPCon, qualifies for the full ₹78,000 subsidy on a 3 kW or larger residential system. Heaven Green Energy uses DCR, ALMM-listed Adani Solar modules for Suryaghar installations across Gujarat and beyond.

How do I tell if a quoted panel is TOPCon or Mono PERC?

Check the datasheet. TOPCon panels list “N-type” silicon, “TOPCon” or “TOPCon 2.0” cell architecture, a temperature coefficient near −0.30%/°C, and often a 30-year performance warranty. Mono PERC panels list “P-type” silicon, “PERC” cell architecture, a coefficient near −0.34%/°C, and usually a 25-year performance warranty. The Wp rating alone does not tell you, a 540 Wp panel could be either. Always ask for the datasheet PDF and the ALMM line item.

Is HJT a better choice than TOPCon in Indian heat?

HJT (Heterojunction Technology) has a slightly better temperature coefficient (−0.26%/°C) and lower degradation than TOPCon, but it costs 15 to 25% more than Mono PERC versus TOPCon’s small premium. For most Indian rooftops the marginal output gain of HJT over TOPCon does not justify the cost. HJT makes sense only on space-constrained premium rooftops where the absolute highest output per square metre is required. Read our Mono PERC vs TOPCon vs HJT comparison for the full three-way analysis.

Does TOPCon need different mounting or inverters than Mono PERC?

No. Both technologies use the same module form factors, MC4 connectors, and DC voltage ranges. Any standard string or hybrid inverter rated for the system’s DC voltage and current will work with either. Mounting works the same way, though module dimensions and weight differ by model, so check the datasheet. The only difference your installer sees is the datasheet they reference for string-sizing and Voc calculation, where TOPCon’s slightly different temperature coefficient marginally widens the safe string length on cold mornings.

What is the payback period for the TOPCon premium in different Indian cities?

It depends on the premium you are quoted. At about ₹1/W (the gap on Adani Solar’s DCR list prices), a 5 kW system pays back the premium in about 3.3 years in Jaipur, returning roughly ₹45,000 net over 25 years, and in about 4 years in Mumbai, returning roughly ₹38,000. Other hot cities sit close to Jaipur, and cooler or hill locations take longer. At a ₹2/W premium those paybacks roughly double.

Will Mono PERC panels still be sold and supported in India after 2027?

Yes, for at least another decade. Mono PERC remains widely manufactured in India by Waaree, Adani, Tata, Vikram, Premier and dozens of tier-2 brands. The 25-year performance warranties on panels installed in 2026 will be honoured by these manufacturers regardless of which cell technology becomes dominant. Spare parts and replacement modules will remain available, the cell technology is mature and the supply chain is broad. The shift to TOPCon is gradual, not a cliff.