GoodWe ESA vs Sigenergy SigenStor: specs, warranty and WA eligibility compared

The GoodWe ESA is a hybrid solar inverter and a stack of lithium iron phosphate battery modules assembled as one floor-standing tower, with whole-home backup built into the inverter. Single-phase versions run from 3 to 10 kW and three-phase from 5 to 30 kW, each taking one to twelve modules of 5 to 9 kWh. It launched in Australia in October 2025. Every inverter size on its current datasheets sits on Synergy's Supported Solutions List as a provisional listing.

Installers most often quote it against the Sigenergy SigenStor: the same idea, an energy controller and stacked modules in one tower, from a company founded in 2022. On the datasheets the differences are narrow, and the 10-year warranties share a structure. The gaps are hardware and paperwork.

The brand-level GoodWe vs Sigenergy comparison covers the two makers' wider ranges.

How do the GoodWe ESA and the SigenStor compare side by side?

On capacity, chemistry and warranty length they match. They part on backup hardware, EV charging, years in Australia and what a paid warranty extension covers.

Check the model numbers on your quote against Synergy's list. Model codes change between datasheet revisions, and GoodWe reissued both ESA datasheets in September 2026.

Are the GoodWe ESA and the SigenStor eligible for the WA battery rebate?

Yes, as at 24 September 2026. Both appear on the Clean Energy Council's inverter and battery lists, and both sit on Synergy's Supported Solutions List as provisional listings, which is what the WA rebate checks.

The Clean Energy Council approved the ESA's single-phase inverters in July 2025 and its three-phase inverters in February 2026. All six battery module codes are on its list as well: the 5 and 8 kWh modules in both hardware versions from August 2025, the 6 and 9 kWh modules from July 2026. SigenStor configurations on the 5.0 and 8.0 modules have been listed since June and October 2024, those on the newer 6.0 and 10.0 modules since April 2026. Newer modules, newer listings.

For the WA rebate the gate is Synergy's Supported Solutions List. A system has to appear under the DER-Storage category before it can join Synergy Battery Rewards, and joining a virtual power plant is a condition of the WA Residential Battery Scheme rebate.

On 24 September 2026 that list carried SigenStor configurations from the 5S single-phase units through the 10T, 15T and 25T three-phase units, and the ESA at every inverter size on its current AU datasheets. All provisional. Earlier ESA datasheets carried 10 kW and 30 kW model codes that never reached the list; the September 2026 sheets top out at 9.999 kW and 29.999 kW, and those are the listed codes.

Neither product carries the green tick Synergy uses to mark a solution "ready to be activated under a VPP program", so on that count they are level. A provisional listing is still a listing, and the list itself states that every DER-Storage entry meets the scheme's technical requirements. Before you sign, ask the installer whether this exact model number is marked VPP-ready on Synergy's list today and, if not, on what date the system can be enrolled in Battery Rewards. Get the answer in writing, because the rebate is paid to the accredited installer rather than to you, and only once the installation and enrolment steps complete. The WA rebate eligibility checklist lists every step.

Rebate arithmetic is the same for both. Synergy customers receive $130 per kWh of usable capacity, capped at $1,300, which lands at 10 kWh, with a 5 kWh minimum. Two ESA GW5.1 modules give 10 kWh usable; two SigenStor BAT 5.0 modules give 10.4 kWh. Either reaches the cap. Households with a combined income under $210,000 can add the scheme's no-interest loan of up to $10,000 on top, for either system. The federal certificate support on top steps down on 1 January 2027 and is set by the installation date, not the contract date, covered in rebate timelines and the January step-down. Both systems also have to meet the WA connection rules from 1 May 2026, which the installer handles as part of the Western Power application.

How do the warranties compare?

The two warranties match on the big terms. Both run 10 years on the battery and both guarantee 70% of usable energy at the end. Each also ends early if a throughput cap is reached first, and the caps differ. Throughput is the total energy the battery delivers over its life, and a full cycle is one complete discharge of the usable capacity. GoodWe caps throughput at 3.0 MWh per kWh of usable capacity, which is 3,000 full cycles, and one full cycle a day uses that up in a little over eight years. Sigenergy's current AU and NZ warranty sets the cap per module: 19.76 MWh on the BAT 5.0, 22.19 MWh on the BAT 6.0, 29.64 MWh on the BAT 8.0 and 33.29 MWh on the BAT 10.0. That works out to 3.7 to 3.8 MWh per kWh, or 3,700 to 3,800 full cycles, just past ten years at one a day.

On a two-module 10 kWh system that is roughly 30 MWh of covered throughput against 40 MWh. GoodWe's own cap assumes no more than one full cycle a day on average. Cycle less than that and the calendar ends either warranty first; cycle a battery fully every day and GoodWe's cap ends its warranty in year nine while Sigenergy's runs the full ten. Sigenergy's EV charging module is the one part on a shorter term, three years. The mechanics are explained in how battery warranties work.

Coast. GoodWe excludes damage from exposure to sea coasts or saltwater unless GoodWe approved the installation in writing beforehand, and that approval is at GoodWe's discretion. For a home in Cottesloe, Scarborough, Fremantle, Rockingham or any other suburb near the coastline, ask the installer to obtain GoodWe's written coastal approval before install day and to give you a copy. After a claim is too late. Sigenergy's current AU and NZ warranty has no coastal distance clause. An earlier version excluded installs within 500 metres of the coastline, so check which version your installer hands you. Each excludes rust on the enclosure caused by harsh conditions.

Connection. Sigenergy's 10-year warranty depends on the system staying online for firmware updates. After 90 days offline the system drops into a safe operation mode, and after a year offline the warranty shortens to five years from activation. GoodWe's battery warranty has no equivalent clause.

Claim windows. GoodWe wants a fault reported within two weeks of it appearing and a claim lodged within one month. Sigenergy wants the claim within 30 days of the failure date, lodged through the mySigen app. Miss either and the maker treats the claim as abandoned. These are the makers' own warranties. The consumer guarantees under Australian Consumer Law apply as well, automatically, and neither document can take them away.

Extensions. Each maker sells one, and they cover different parts. Sigenergy's takes the battery, controller and gateway to 15 years, bought within 12 months of installation, and ends at 60% of usable energy or a higher throughput cap (21.89 MWh on a BAT 5.0). Its device list names the 8, 10 and 12 kW single-phase controllers only, so a three-phase buyer should ask the installer for Sigenergy's written confirmation that the extension covers the controller on the quote. GoodWe's covers the ESA inverter only. Its AU and NZ price list, valid to 31 December 2026, takes a single-phase ESA inverter from 10 to 15 years for $549 to $989 plus GST depending on size. The extension has to be bought within 12 months of the production date or six months of installation, and the list has no line for the battery modules. So the ESA battery's cover ends at 10 years whatever you buy, while a SigenStor's can run to 15.

Check which models each document names: the current Sigenergy AU and NZ warranty names every SigenStor configuration from the 3S to the 30T with one to six modules of either generation. GoodWe's battery warranty is narrower and has changed. The version on GoodWe's Australian site, dated September 2026, names the four G20 modules only. The July 2025 version named the G21 modules too. If your quote carries a G21 code, ask which version comes with it and keep a copy. The battery warranty comparison puts both alongside the other brands sold in Perth.

Which one gives you backup power, and how?

Both, but differently. The ESA has backup built into the inverter: whole-home, 63 A on single-phase and 80 A on three-phase, switching in under 4 ms, with no separate gateway to buy or mount.

The SigenStor delivers backup through the Sigen Energy Gateway, a separate wall unit that sits between the grid and the house; the AU models are the Home SP, the HomePro SP-F and, for three-phase, the Home TP. With the gateway fitted, the changeover is 0 ms and the system supports either whole-home backup or a selected set of circuits. Without it, there is no backup. The gateway is IP55 rated and weighs 22.5 to 25.5 kg, so it needs its own wall space near the switchboard and adds a line to the quote. If a SigenStor quote does not itemise the gateway, ask whether backup is included at all.

Which suits you depends on the loads you need to keep running, for how long, and whether a second wall box near the switchboard is acceptable. Whole-home vs essential backup walks through that decision for a Perth household.

What about EV charging and vehicle-to-home in WA?

Only the SigenStor has EV charging inside the stack. The Sigen EV DC Charging Module comes in 12 kW and 25 kW versions with a CCS2 plug. It charges the car straight from the DC bus and is built for two-way charging. Sigenergy says vehicle-to-home and vehicle-to-grid are available worldwide but gated on the standards in each market and on a per-vehicle support list it has not yet published.

The ESA has no charging module. GoodWe's answer is its separate HCA wall charger, connected on the AC side like any other charger.

On the Perth grid, two-way charging is allowed under Western Power's rules, though most homes cannot use it yet. Western Power treats a bidirectional charger as an embedded generator: the hardware has to meet its connection requirements, hold Clean Energy Council registration, and go through the embedded generation connection application for written approval. The tariff side already exists. Synergy's Distributed Energy Buyback Scheme counts an electric vehicle set up to export as a home battery, so approved vehicle-to-grid exports earn the same buyback as any other export: 10 cents a unit in the 3pm-9pm peak window, 2 cents outside it. Eligibility for the buyback is set by Synergy, so check its current DEBS terms before counting on the credit. The missing pieces are approved hardware and a vehicle on Sigenergy's support list. The SigenStor's DC module delivers 12 kW or 25 kW of solar-direct charging today. Vehicle-to-home stays out of reach for a Perth home until those approvals exist; the hardware may support it later. Using an EV as a home battery covers what has to change first.

What is inside each battery module?

Lithium iron phosphate cells, packed into modules that stack in a column. Compare quotes on usable capacity, the energy you can draw from a module; the nominal figure on a brochure counts the whole cell and runs a little higher.

The cycle ratings are not comparable. GoodWe qualifies its figures as "specific laboratory conditions" with no depth, temperature or rate published beside them. Sigenergy's 10,000 is the cell maker's number at 25°C, half-rate charging, down to 60% state of health. Neither is a warranty term. The warranties above are what you can hold either company to.

Only the BAT 6.0 and 10.0 carry the 314 Ah cells; the BAT 5.0 and 8.0 use 280 Ah cells. The Clean Energy Council lists both generations. Ask which one you are being quoted.

On GoodWe's side, the 5 and 8 kWh modules also come in two hardware versions. The G20 has a built-in heater and charges down to minus 18°C; the G21 has none and stops charging below 2°C. Each is on the Council's list, and the difference rarely matters in Perth, but the warranty naming does, covered above.

Per-module output only matters until the inverter becomes the limit. The ESA's GW5.1 and GW8.3 deliver twice the continuous power of the matching SigenStor modules, and the newer pairs are a near tie, but a three-module stack on a 10 kW controller delivers what the controller allows, whatever the modules add up to. Size the inverter to the loads you run after dark, then the modules to the energy you use.

GoodWe's own pages give ceilings of 48, 54 and 108 kWh. They fit together. A column takes up to six modules, 54 kWh with the 9 kWh module. An inverter takes up to twelve, six in any one column: the 108 kWh in the headline. The 48 kWh at the October 2025 launch was six 8 kWh modules, before the 9 kWh module was listed in July 2026. So the working ceiling is six modules per column; get that in writing for your module. Sigenergy's rule is one to six modules per energy controller: 46.8 kWh usable with BAT 8.0 modules, 52.8 kWh with BAT 10.0.

Neither datasheet prints an AC-to-AC round-trip efficiency. GoodWe quotes battery-to-AC conversion at up to 98%, which is a different measurement, and Sigenergy's AU documents give no battery-only figure at all. Treat the efficiency line on any quote for either system as an inverter figure; no whole-system figure is published.

Width is 800 mm for the ESA tower and 767 mm for the SigenStor modules. Each is IP66 rated, and each module stops charging above 55°C. The single-phase ESA inverter derates above 40°C ambient, so for a north-facing garage wall ask the installer what continuous output it holds on a 40°C afternoon and whether a shaded wall is available. Sigenergy's controller is rated to 60°C without a published derating point.

Who stands behind each product in Australia?

Each maker sells here through its own Australian company, GoodWe Australia in Melbourne and Sigenergy Australia in Sydney, the importer named on its warranty.

GoodWe says its Australian team dates from 2012; the register shows GoodWe Australia from October 2015. Sigenergy Australia appears on the register from August 2023, and its first products were certified for sale here in June 2024.

The GoodWe brand review and the Sigenergy brand review go deeper on each company.

What should you check on a Perth quote for either system?

• The exact inverter and module model numbers, rather than the brand name, checked against Synergy's Supported Solutions List on the day you sign.
• Which module generation you are getting: GW5.1 and GW8.3 or GW6.0 and GW9.0 for the ESA; BAT 5.0 and 8.0 or BAT 6.0 and 10.0 for the SigenStor. The cycle rating, cell size and listing date differ between generations.
• For a SigenStor with backup, that the Sigen Energy Gateway is itemised on the quote with its own model number and price.
• The distance from your meter box to the ocean, against each warranty's coastal clause.
• For an ESA, the module code. If the quote says G21, ask which warranty version applies and keep a copy, because the September 2026 document names G20 modules only.
• The warranty version you are handed. Sigenergy's coastal clause and throughput caps changed between versions, and GoodWe reissued both its battery and inverter warranties in September 2026.
• A firm installation date, because the federal certificate rate changes on 1 January 2027.

Which home suits the ESA, and which the SigenStor?

On the datasheets, the ESA fits a household that wants whole-home backup without a second box and the higher output of the GW5.1 and GW8.3 modules. GoodWe's local company dates from 2015, Sigenergy's from 2023. The SigenStor fits a household that wants EV charging inside the stack or a paid extension that covers the battery as well as the electronics. Prices vary by installer and by module count, so compare the installed cost for the same usable kWh, the same backup arrangement and the same inverter size before you compare brands. The SigenStor 10T product page carries the current configurations and Perth quote data.