--- title: "Hiwatt Solar HW-M12/120H-590 590W Solar Panel - Specs & Review | ComparePV" description: "Hiwatt Solar HW-M12/120H-590 590W solar panel. Specs: 20.80% efficiency, Monocrystalline cells, dimensions, warranty and temperature coefficient." source: "https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-590" updated: 2026-09-11 --- # Hiwatt Solar HW-M12/120H-590 Middle of its segment, modest efficiency 6,404 panels in the 490-690 W band, all technologies ## Identity - **Manufacturer:** Hiwatt Solar - **Model:** HW-M12/120H-590 - **Series:** HW-M12/120H(585-605) - **Rated power:** 590 W - **Cell technology:** Monocrystalline ## How it compares Compared against 490-690 W band, all technologies (6404 panels). | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Power (Wp) | 590 W | 585 W | Typical | | | Module efficiency | 20.80% | 22.25% | Weak - bottom 9% | 10,457 | | Power density | 208.5 | 222.5 | Weak - bottom 10% | 10,359 | | Temperature coefficient | -0.340 | -0.300 | Typical | 8,778 | | Weight (kg) | 30.9 kg | 31.2 kg | Typical | | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 11% | 9,798 | ### Full peer table | Measure | This panel | Segment median | Standing | Rank | | --- | --- | --- | --- | --- | | Module efficiency | 20.80% | 22.25% | Weak - bottom 9% | 10,457 | | Power density | 208.5 | 222.5 | Weak - bottom 10% | 10,359 | | Temperature coefficient | -0.340 | -0.300 | Typical | 8,778 | | Weight per kWp | 52.4 | 52.8 | Typical | 5,853 | | Performance warranty | 25 yrs | 30 yrs | Weak - bottom 11% | 9,798 | ### Watch out for - **20.80% module efficiency** - Bottom 9% of the 490-690 W band, against a median of 22.25%. Ranked 10,457th in the whole database. - **208.5 watts per square metre** - Bottom 10% of the 490-690 W band, against a median of 222.5. Ranked 10,359th in the whole database. - **25 year performance warranty** - Bottom 11% of the 490-690 W band, against a median of 30 yrs. - **Best for:** Residential, commercial, utility-scale and shaded-installations. - **Not ideal for:** Tight roof space, roofs where every square metre has to count and owners who want a long output guarantee. ## Specification ### Electrical - **Rated power (Pmax):** 590 W - **Efficiency:** 20.80 % - **Voltage at Pmax (Vmp):** 34.00 V - **Current at Pmax (Imp):** 17.35 A - **Open-circuit voltage (Voc):** 41.10 V - **Short-circuit current (Isc):** 18.42 A - **Max system voltage:** 1500 V ### Temperature - **Temperature coefficient of Pmax:** -0.340 %/degC - **Temperature coefficient of Voc:** -0.250 %/degC - **Temperature coefficient of Isc:** 0.040 %/degC - **NOCT:** 43 degC ### Cell and construction - **Cell type:** Monocrystalline - **Cell count:** 120 ### Physical - **Length:** 2172 mm - **Width:** 1303 mm - **Thickness:** 35 mm - **Weight:** 30.9 kg - **Area:** 2.83 m2 - **Power density:** 208.5 Wp/m2 ### Warranty and degradation - **Product warranty:** 12 years - **Performance warranty:** 25 years - **First-year degradation:** 2.00 % - **Annual degradation:** 0.55 % - **Output after 30 years:** 484 W ## Rank in the whole catalogue | Measure | Position | | --- | --- | | Efficiency | 10457 of 14005 | | Power density | 10359 of 14005 | | Temperature coefficient | 8778 of 14005 | | Weight | 5853 of 14005 | | Warranty | 9798 of 14005 | ## Pros - **N-type TOPCon cell technology** - N-type cells exhibit first-year LID below 1%, compared to the typical 2-3% for P-type PERC. Combined with lower LeTID rates, the series maintains more stable output over its 25-year operational life, directly improving LCOE for the end investor. - **Half-cut 120-cell layout** - Splitting cells in half reduces per-cell operating current, lowering resistive losses and hot-spot risk. Under partial shading conditions — common in urban rooftop and prosumer installations — half-cut modules deliver measurably higher energy yield than full-cell equivalents at the same rated power. - **High power density 585-605 Wp** - At up to 21.4% module efficiency, the series allows more kWp to be installed on space-constrained rooftops. Peer comparables JS Solar JS210MHC120 reach an identical 21.4% and LEDVANCE M585~605P60UB-SF-F3 achieves 21.37%, placing Hiwatt among the top performers in this power class. - **Structural PID resistance (N-type)** - N-type cells are structurally immune to Potential Induced Degradation due to their reversed polarity relative to P-type. In commercial systems with negative string-inverter grounding or long string configurations, this eliminates the need for additional anti-PID retrofit devices, reducing BoS costs. ## Cons - **Not BNEF Tier-1 / non-bankable** - Hiwatt Solar does not appear on the BNEF bankable manufacturer list (Q1 2026). For commercial projects above 0.5 MW financed through bank debt or leasing, the absence of Tier-1 status can block project approval by lender risk departments or require more expensive credit insurance. - **Efficiency gap vs. GCL SIROT NT10/72GDF** - Peer comparable GCL SIROT NT10/72GDF achieves 23.42% module efficiency at the same 605 Wp — 2.02 percentage points above Hiwatt's maximum of 21.4%. This translates to approximately 9.4% more energy yield per unit of roof area, a material disadvantage on projects with strict m² constraints. - **No bifacial variant available** - The HW-M12/120H series is monofacial (is\_bifacial: false), while most competing TOPCon panels in this power class — JA Solar, Trina Solar, GCL — now offer bifacial as standard. The monofacial design foregoes 5-25% additional rear-side energy gain (depending on ground albedo), particularly relevant for ground-mount and flat-roof installations. - **Temperature coefficient -0.34%/°C** - The datasheet specifies a Pmax temperature coefficient of -0.34%/°C — less favorable than premium TOPCon peers reaching -0.30 to -0.31%/°C. At a typical cell temperature of 65°C during summer peak hours, Hiwatt loses ~13.6% of rated output vs. ~12.0% for best-in-class TOPCon modules, partially eroding the N-type technology advantage. ## About this series The Hiwatt Solar HW-M12/120H(585-605) series consists of high-power modules based on **N-type cells in a half-cut configuration**, designed to maximize energy yield in situations where every square meter counts. The use of **TOPCon technology** helps to minimize production losses in demanding conditions and maintain the stability of the system over a longer period. The half-cell design improves the module's performance under partial shading and reduces the risk of losses due to local overheating, which translates to more predictable yields in real-world installations. For the investor, this means **lower energy costs over the lifetime (LCOE)** and better suitability for projects where roof space or the number of mounting points are limited. This series is suitable for commercial, industrial, and larger prosumer installations, where key factors are: fast scalability, reliable performance in hot conditions, and **PID resistance** due to controlled processes and materials. Compared to many standard P-type modules, this is a practical choice for those who prioritize stability and high yields, rather than just focusing on table values. ## Notable figures - Efficiency of 20.8% is 1.0pp below the \*\*database\*\* median (21.8%) - Power density of 208.5 W/m² is 9.6 W/m² below \*\*database\*\* median (218.1 W/m²) - needs more roof space - At -0.34%/°C, loses 0.04pp more power per degree than \*\*database\*\* median (-0.30%/°C) - At 30.9 kg (4.4 kg above \*\*database\*\* median of 26.5 kg), requires checking roof load capacity - Ranked #10457 out of 14005 panels for efficiency in the database ## Questions ### What warranty does the Hiwatt Solar HW-M12/120H(585-605) series come with? The HW-M12/120H(585-605) series includes a 12-year product warranty covering material and workmanship defects, plus a 25-year linear power output warranty. After 25 years of operation, the module is expected to retain approximately 84.8% of its rated power. This is a standard coverage level for high-power class modules and supports long-term LCOE calculations. ### How does the TOPCon technology in the HW-M12/120H series differ from standard PERC cells? TOPCon uses N-type cells with an additional tunnel oxide passivation layer that reduces carrier recombination. In practice this translates to higher module efficiency (the HW-M12/120H series achieves 20.7–21.4%), a lower temperature coefficient, and no LID (Light Induced Degradation) effect. PERC modules rely on P-type cells and are more susceptible to degradation in the early years of operation. ### Is the Hiwatt Solar HW-M12/120H up to 605 W suitable for a pitched roof installation? Yes, modules in this series are designed for both rooftop and ground-mounted systems. Dimensions are approximately 2172 × 1303 × 35 mm and weight is around 30.9 kg per unit. Before installation, verify the roof's load-bearing capacity and adjust mounting points to meet local wind and snow load requirements. The series is particularly recommended where high power density per square meter is a priority. ### How does the HW-M12/120H series perform in high temperatures during summer? N-type TOPCon cells have a lower temperature power coefficient than standard PERC modules – typically around -0.29%/°C compared to -0.35%/°C for P-type technology. This results in lower production losses on hot days, which matters most on dark or poorly ventilated roof surfaces. The half-cut cell layout also reduces localized hotspot heating and minimizes related output losses. ### Are the Hiwatt Solar HW-M12/120H(585-605) panels bifacial? No, the HW-M12/120H(585-605) series is monofacial – energy is harvested from the front surface only and the modules do not benefit from reflected albedo light the way bifacial panels do. For typical rooftop installations this is not a drawback, since roof albedo is generally low. Bifacial modules are worth considering primarily for ground-mounted systems with highly reflective surfaces. ### Is Hiwatt Solar a Tier 1 manufacturer, and is this series worth the investment? Hiwatt Solar is not currently listed on the Bloomberg NEF Tier 1 bankability ranking, which may be relevant for utility-scale project financing. For commercial and prosumer installations this is generally less critical – the products carry IEC certifications and anti-PID performance guarantees. Before purchasing, compare the distributor's warranty terms, verify local after-sales service availability, and assess supply-chain stability. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/HW-M12120H-585-605-ca181a59eab8.pdf) ## Alternatives | Panel | Power | How it differs | | --- | --- | --- | | [Longi Solar LR7-60HVH-560M](https://comparepv.com/panel/longi-lr7-60hvh-560m) | 560 W | Cooler, lighter, +4.0 pp | | [AIKO AIKO-A640-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a640-mae72mw) | 640 W | +50 W, cooler, +4.0 pp | | [Longi Solar LR7-60HVH-555M](https://comparepv.com/panel/longi-lr7-60hvh-555m) | 555 W | Cooler, lighter, +3.8 pp | | [AIKO AIKO-A635-MAE72Mw](https://comparepv.com/panel/aiko-aiko-a635-mae72mw) | 635 W | Cooler, +3.8 pp, +5 yr warranty | | [AIKO AIKO-A630-MAH72Dw](https://comparepv.com/panel/aiko-aiko-a630-mah72dw) | 630 W | Cooler, +3.6 pp, +5 yr warranty | | [Longi Solar LR7-60HVHL-550M](https://comparepv.com/panel/longi-lr7-60hvhl-550m) | 550 W | Cooler, lighter, +3.6 pp | | [Hiwatt Solar HW-M12/120H-585](https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-585) | 585 W | Very close match | | [Hiwatt Solar HW-M12/120H-595](https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-595) | 595 W | Very close match | | [Hiwatt Solar HW-M12/120H-600](https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-600) | 600 W | +10 W, +0.4 pp | | [Hiwatt Solar HW-M12/120H-605](https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-605) | 605 W | +15 W, +0.6 pp | | [Gamko New Energy GKA210N120](https://comparepv.com/panel/gamko-new-energy-gka210n120) | 680 W | +90 W, +3.2 pp, +5 yr warranty | | [Gamko New Energy GKA210N120-675](https://comparepv.com/panel/gamko-new-energy-gka210n120-675) | 675 W | +85 W, +3.1 pp, +5 yr warranty | | [Q-SUN Solar QN-670HJT-01](https://comparepv.com/panel/q-sun-solar-qn-670hjt-01) | 670 W | +80 W, cooler, +2.9 pp | | [Gamko New Energy GKA210N120-670](https://comparepv.com/panel/gamko-new-energy-gka210n120-670) | 670 W | +80 W, +2.9 pp, +5 yr warranty | | [Q-SUN Solar QN-665HJT-01](https://comparepv.com/panel/q-sun-solar-qn-665hjt-01) | 665 W | +75 W, cooler, +2.7 pp | | [Gamko New Energy GKA210N120-665](https://comparepv.com/panel/gamko-new-energy-gka210n120-665) | 665 W | +75 W, +2.7 pp, +5 yr warranty | --- Source: https://comparepv.com/panel/hiwatt-solar-hw-m12-120h-590 Not in this file, on the page: a thirty-year output simulator and alternatives filtered by how closely they match these dimensions.