Commercial Solar Inverter Brands Compared on Datasheet Figures
Updated 23 October 2026 · SEO Dons Editorial
What do makers' pages state for common three-phase ranges?
The table below reproduces what each maker's own product page stated on 22 October 2026 for one commercial three-phase range. It ranks nothing. "Not stated" means the page checked did not give the figure; it does not mean the product lacks the feature, because full figures may sit in PDF datasheets. Efficiency figures are as each maker states them. Inverters with a battery port are covered in the hybrid inverter guide.
| Maker and range | Rated AC output | MPP trackers | DC input window | Maximum efficiency | European efficiency | Checked |
|---|---|---|---|---|---|---|
| Fronius Tauro 50-3-D | 50 kW (max. 50 kVA) | 3 | MPP range 400-870 V | 98,5 % | 97,8 / 98,3 / 97,9 / 97,7 at 400 / 600 / 800 / 870 V DC | 22 Oct 2026 |
| Fronius Tauro ECO 100-3-P | 100 kW (max. 100 kVA) | 1 | MPP range 580-930 V; DC input 580-1000 V | 98,5 % | 98.2 / 97.7 / 97.3 at 580 / 800 / 930 V DC | 22 Oct 2026 |
| SMA STP 50-40 (CORE1 operating manual) | 50,000 W; 50,000 VA | 6 | MPP range 500-800 V; max. input 1000 V | > 98.1% | > 97.8% | 22 Oct 2026 |
| GoodWe MT, GW50KN-MT to GW80K-MT | "50-80 kW" range | 4 | Max. input 1100 V | 98.7% to 99.0%, by model | Not stated | 22 Oct 2026 |
| Solis S5-GC(50-60)K | 50K and 60K models | 5/6 | MPPT range 180-1000 V | 98.7% | Not stated | 22 Oct 2026 |
| SolaX X3-MEGA G2 | 40, 50 and 60 kW | Up to 6 | MPPT range 180-1000 V | Up to 98.4% | Not stated | 22 Oct 2026 |
| Deye SUN-40/45/50K-G04 | 40K, 45K and 50K models | Up to 4 | MPPT range 200-1000 V | Up to 98.7% | 98.1% | 22 Oct 2026 |
| FoxESS T Series and V Series | T 3~30 kW; V 30~75 kW | Not stated | Not stated | T Series 98.6% | Not stated | 22 Oct 2026 |
What do the makers say about warranty and monitoring?
| Maker (page) | Warranty as stated on the page checked | Monitoring named on the page checked | Checked |
|---|---|---|---|
| Fronius (UK warranty page) | Separate models: inverters under 50 kW, register for 10 years; inverters of 50 kW and above, register for 5 years. Further paid extension up to 15 years. Registration within 30 months of delivery. | Solar.web | 22 Oct 2026 |
| SMA (Sunny Tripower X page) | Standard warranty 5 years; extension to 10, 15 and 20 years on request to SMA | Sunny Portal powered by ennexOS | 22 Oct 2026 |
| SolaX (UK warranty page, X3-MEGA G2 row) | 5 years standard; 5 years plus 1 year of parts cover when the inverter is connected to SolaX cloud and data uploaded | SolaX cloud | 22 Oct 2026 |
| Solis (UK warranty page) | Period set out in Appendix A of the warranty document; extension application within 12 months of commencement; extended cover limited to hardware repair or replacement | Not named | 22 Oct 2026 |
| GoodWe, Deye | Not stated on the product pages checked | Not named | 22 Oct 2026 |
| FoxESS | Not stated on the page checked | "smartphone app or web portal" | 22 Oct 2026 |
How should each column be read?
- Rated AC output. Read both kW and kVA. Fronius lists the Tauro 50-3-D at "50 kW" and "50 kVA"; the three-phase inverter guide explains why the connection is compared in kVA.
- Maximum and European efficiency. Maximum efficiency is a single figure. Fronius lists European efficiency separately at four DC voltages, 97,8 / 98,3 / 97,9 / 97,7, so two pages are only comparable when they state the same voltage and method.
- MPP trackers and DC window. These decide how strings are grouped and how many modules sit in a string. Even within one family, figures change by model: GoodWe's MT page lists maximum input current per MPPT of 44 A for the GW80K-MT and 33/33/22/22 A for the GW50KN-MT.
- Warranty. Terms carry conditions. Fronius ties its cover to registration on Solar.web, SolaX ties its extra year of parts cover to cloud connection and data upload, and Solis requires an extension application within 12 months of commencement. Compare the conditions, not just the years.
- Monitoring. Check whether string-level data is reported, how alarms reach the site and whether the data can be exported. The inverter types guide covers what good monitoring shows.
How do you check a model in a quote against the ENA register?
The Energy Networks Association (ENA) provides a register that its generation page calls the LCT Register and its menus link as the Type Test Verification Report Register. It is a repository "where equipment manufacturers can submit information about their products and make their own declarations of compliance with EREC G98 or EREC G99". Entries change, so they are not reproduced here. Use this sequence:
- Get the exact model name. A suffix changes the product. GoodWe's MT page lists the GW80K-MT with a 400 V nominal output and 98.8% maximum efficiency, and the GW80KHV-MT with a 540 V nominal output and 99.0%.
- Search the register for that exact name and read the status. The ENA says an entry is marked "compliant" where the information "is found to be correct and complete".
- Do not treat a missing entry as proof of non-compliance. The ENA notes "it is not mandatory for manufacturers of generation products with a capacity greater than 3.68kW/phase to use this register". It adds that manufacturers must, on request, "be able to demonstrate compliance supported by appropriate evidence", so ask the maker for that evidence.
- Keep the maker's certificate and the register entry apart. The Solis UK page, for example, lists a download titled "Solis_certificate_G99_S5-GC(50-60)K_UK_V01". That is the maker's document, not the register entry.
- Match the ratings. SSEN's G98 page asks for an "Inverter Type Test Certificate" whose power rating "must match the inverter rating shown on the schematic diagram". Quote, certificate and drawing should all name the same model and rating.
- Ask for the device reference number. National Grid Electricity Distribution lists "The device reference number(s) of any new or existing generation devices that you wish to connect" among the items needed to notify.
What do datasheet figures not show?
Yield on a given roof, field reliability, spare-parts and service arrangements, and what a maker's support will do in year eight. Those need references, the maintenance contract and the yield model for the actual site. This page makes no claim about any maker's security or reliability. When comparing quotes for a commercial PV system, the commercial PV systems page lists what a full specification should name, and quotes can be requested through the site's enquiry form.
Sources
- Maker pages, each used only for facts about that maker's own products, checked 22 October 2026: Fronius Tauro 50-3-D, Tauro ECO 100-3-P and UK warranty models; SMA STP 50-40 technical data and Sunny Tripower X; GoodWe MT Series; Solis S5-GC(50-60)K and UK warranty; SolaX X3 MEGA G2 and UK warranty; Deye SUN-40/45/50K-G04; FoxESS PV inverters.
- Connecting generation to the electricity networks, Energy Networks Association, checked 22 October 2026.
- Micro generation (G98), National Grid Electricity Distribution, and Installation of up to 3.68kW per phase at one property, SSEN, checked 22 October 2026.
Common questions
Which commercial solar inverter brand is best?
This page does not rank brands. Datasheets show what a maker publishes; they cannot show field reliability, service or fit to a particular roof. The more useful question is which exact model suits the site's supply, string layout, monitoring needs and warranty conditions.
Why do two pages for the same inverter family show different efficiency figures?
Because the model suffix, the DC voltage or the test method differs. GoodWe's MT page lists maximum efficiency from 98.7% to 99.0% across its models, and Fronius lists European efficiency separately for each DC voltage.
Does a higher maximum efficiency mean more energy over a year?
Not by itself. Maximum efficiency is one operating point, while annual energy depends on how the inverter performs across load and DC voltage. Ask for the efficiency curve of the exact model at the planned string voltage, and the modelled yield.
Is a G99 certificate on a maker's page the same as the register entry?
No. A certificate download is the maker's document. The ENA register is a separate repository where manufacturers lodge declarations, and the ENA says lodging is not mandatory above 3.68 kW per phase. Ask for both, and match the model names.