For years we mostly fitted Huawei for Marblanc Solar clients. But that has changed. Across our installations in 2026, we’re installing a lot more Sigenergy with Deye as a strong third option.
The best solar inverter for most Spanish homes is the Sigenergy SigenStor, because it handles Spain’s unstable grid voltage without the light flicker other inverters show on backup power. Huawei stays excellent for reliability and whole-home backup, while Deye suits large three-phase systems and the cheapest battery storage.
Below I’ll compare all three on price, specs, backup and reliability – and explain the one question that matters more than any brand name.
This piece is my personal opinion based on personal experience as the site manager for Marblanc Solar, a solar installation company in Spain. I was not paid to produce this article.
What is the best solar inverter in Spain?
The best solar inverter for most Spanish homes is the Sigenergy SigenStor, which holds a steady output through Spain’s over- and under-voltage swings where other inverters flicker on backup power. Huawei remains a top pick for reliability and whole-home backup. Deye suits large three-phase systems and tight battery budgets.
As I said above, I used to recommend Huawei for its superior safety features. But Sigenegy entered the market in 2024 in Spain and it’s quickly become a top choice we recommend to clients.
How we chose these three brands
We install across the Costa del Sol and the Costa Blanca, on real properties with real supply problems. That field experience decided this shortlist, not a brochure.
Huawei still tops the independent Wood Mackenzie inverter ranking, scoring first globally at 93.9, just ahead of Sungrow, in the H1 2025 rankings. So why do we now lead with Sigenergy for Spanish homes? Because a global ranking measures the product, and our job is to match the product to the property.
On backup systems here, Sigenergy wins on the one thing that bothers our clients daily.
We began fitting Sigenergy in early 2026, among the first companies in Spain to do so. Demand came from our Irish and UK expat clients first – they knew the brand from home. At the time there was no established Spanish supply chain, so we worked directly with the supplier to bring the material in. We were a pioneer with it here.
The pedigree helped us trust it early. Sigenergy was founded in 2022 by former Huawei executives – its founder ran Huawei’s own solar-inverter business, the division he built into the world’s largest. In Ireland, one of our biggest expat markets, independent consultancy SunWiz ranked Sigenergy the number-one home energy-storage brand in 2025, with roughly a third of the sub-1000 kWh market.
That partnership has gone further than most. Sigenergy has invited our survey engineers Alan Manning and COO Adam Millington to China in October 2026 to see production first-hand, and Marblanc holds VIP partner status with the brand.
“Our clients asked for Sigenergy before most Spanish installers had heard of it. We backed it, and it has become our default.”
— Adam Millington, co-owner
Sigenergy vs Huawei vs Deye compared
Sigenergy, Huawei and Deye differ most in what they are built for. Sigenergy suits homes with battery backup on Spain’s unstable grid. Huawei suits reliability-first installs needing whole-home backup. Deye suits large three-phase systems and the cheapest battery storage per kWh.
Here’s how the three compare on the specs that decide a residential install. The prices are the units we have actually quoted in 2026 – and because they’re different sizes, treat them as anchor points, not a like-for-like race.
| Feature | Sigenergy SigenStor | Huawei SUN2000 | Deye SUN-SG series |
| Type | Hybrid, all-in-one (solar + battery + energy management, stackable) | Hybrid (solar + battery) | Hybrid (solar + battery) |
| Phase support | Single and three phase | Single and three phase | Single and three phase |
| Max efficiency | 98.4% (EC 12.0 TP) | 97.8% (SUN200-6K-LB0); up to 98.4% on other models | 97.6% (SUN-20K-SG01HP3) |
| MPPT channels | Up to 4 | 2 on residential single-phase | 2 on the 20 kW three-phase |
| Battery compatibility | SigenStor stackable LFP (own ecosystem), 6 kWh upward | LUNA2000 stackable LFP | Wide third-party LFP (BYD, Pylontech, Dyness) plus own packs |
| Backup capability | Whole-home or partial via LoadHub; seamless on/off-grid switching | Whole-home via SmartGuard, up to 63 A across three phases | Hybrid backup; strong on large three-phase loads |
| Monitoring app | mySigen | FusionSolar | Solarman / Deye app |
| Warranty | 10 years | 10 years | 5 years extendable |
| Marblanc 2026 quote (inverter only) | ~€3,000 (13.2 kW) | ~€1,000 (6.6 kW) | ~€2,500 (20 kW) |
Source: Marblanc 2026 signed proposals (price, efficiency, capacity anchors); manufacturer datasheets and Clean Energy Reviews (feature rows).
The three quoted units are different sizes, so the headline prices are not a fair comparison. Per kW they sit much closer: about €149/kW for the Huawei, €132/kW for the Deye and €228/kW for the Sigenergy, with the Sigenergy premium buying the all-in-one design and the voltage handling.
Sigenergy
Sigenergy’s SigenStor is an all-in-one unit – inverter, battery and energy management in one stackable system. It runs up to four MPPT channels, so it copes with complex roofs across several angles. For us its real strength is steadier output on an unstable supply, which is why it has become our default for backup installs.
Huawei
Huawei remains a superb inverter and we still fit it happily. Its SmartGuard system backs up a whole villa – up to 63 amps across three phases – and its fire and surge protection are genuinely excellent. Its Safe Roof feature monitors connector temperature and shuts the system down if anything overheats, which prevents fires before they start.
Deye
Deye is our third option and it earns its place on big systems. Its three-phase range handles high loads well, and it works with a wide range of third-party batteries, which keeps storage costs down. It is the cheapest of the three for battery storage per kWh.
Why grid voltage matters more in Spain than you would expect
Grid voltage matters more in Spain because the supply swings well beyond its legal range on many properties. We have measured single-phase supplies from around 210 V up to 260-270 V against a 230 V nominal. On systems running backup load, that swing makes lights flicker.
This is the part no other guide covers, and it is the reason our recommendation changed. It is a supply problem we see across brands, not a fault with any one manufacturer.
| Nominal supply voltage | 230 V, single phase |
| Legal tolerance (EN 50160) | ±10% (207-253 V) |
| Highs measured by Marblanc | 260-270 V |
| Lows measured by Marblanc | ~210 V |
| Effect on backup systems | Light flicker under over- and under-voltage |
| Marblanc’s default for backup | Sigenergy SigenStor |
Voltage band per EN 50160, the European standard for supply voltage quality applied in Spain; installations are governed by the REBT (Royal Decree 842/2002).
What voltage should a Spanish electricity supply be?
A Spanish electricity supply should be 230 volts, single phase, with a legal tolerance of plus or minus 10 percent. That gives a permitted range of 207 to 253 volts under the EN 50160 standard. Readings above 253 V sit outside the legal limit.
In practice, plenty of properties don’t stay inside that band. We regularly see readings above 253 V at the top of the day and near 210 V under load. The grid here is simply less stable than many homeowners expect.
How unstable voltage affects a backup system
Unstable voltage affects a backup system by making the inverter’s output waver – lights flicker when the grid runs high, and dim when it drops low. We see this on Huawei and other inverter brands. The Sigenergy SigenStor holds a steady output through both swings.
On a normal grid-tied day you’d rarely notice. It’s on backup load – when the inverter is doing more of the work – that the problem appears. Sigenergy’s handling of that condition is the main reason it became our backup default.
This section covers voltage stability only – for how the backup hardware itself works, see how a backup box keeps your power on.
Does grid voltage instability damage your inverter or appliances?
Grid voltage instability can stress inverters and sensitive appliances over time, but modern inverters protect themselves. They carry over- and under-voltage protection that disconnects the system when the supply leaves its safe range. The everyday effect on backup homes is flicker, not damage.
That protection is why an inverter sometimes drops offline on a bad-voltage day rather than risk itself. It’s the system doing its job. The difference with Sigenergy is that it rides out more of those swings without dropping the quality of the output.
What should you look for in a solar inverter?
When choosing a solar inverter, look at eight things: capacity, voltage compatibility, warranty, efficiency, expandability, MPPT channels, monitoring and battery compatibility. The one that catches most people out is future battery compatibility, because adding a battery later can mean replacing a non-hybrid inverter.
Take them in two groups – the essentials everyone should check, then the technical details that matter for trickier roofs and future plans.
The essentials
| Term | Definition |
| Inverter capacity (DC-to-AC ratio) | The inverter must be sized to your panels. Too small and you lose power at peak sun – a flat line on your app called clipping, where output hits an artificial ceiling. |
| Voltage and current compatibility | Every inverter has a voltage and current range it handles safely. Outside that range, a system can underperform, shut down, or not work at all. |
| Warranty and service life | The inverter works harder than any other part and wears out first. Ten years is the standard to look for; a shorter warranty risks an early, costly replacement. |
| Efficiency rating | Efficiency is how much solar power the inverter turns into usable energy rather than losing as heat. Higher efficiency means more of your generation reaches the house. |
The technical details
| Term | Definition |
| Future expandability | Some inverters cap the number of panels they support. Choose one with headroom so you can add panels later without replacing the whole unit. |
| MPPT channels | MPPT (Maximum Power Point Tracking) lets the inverter optimise each panel string. More channels handle roofs with different angles or shading without one shaded string dragging down the rest. |
| Smart monitoring | A good monitoring app shows real-time generation and use, and alerts you to faults. Without it, a problem can go unnoticed for months and cost you in lost production. |
| Future battery compatibility | If a battery might come later, choose a hybrid, battery-ready inverter now. Otherwise you may have to swap the whole inverter just to add storage. |
Case Study: Retrofitting Battery onto Mijas Solar System
A client in Mijas with an existing small solar system installed by another provider wanted to add battery storage to capture excess daytime generation. However, because the original installer selected a non-hybrid inverter without battery ports or expansion headroom, the existing unit could not support a battery or additional solar panels.
To make the property battery-ready and expand solar output, we had to replace the old inverter with a new hybrid inverter.
We then were able to add three JaSolar 595W panels (bringing total capacity to 4.485 kW), and a 5 kWh Huawei LUNA2000 battery. Choosing a hybrid, expandable inverter from day one avoids the extra expense of swapping out an incompatible unit when storage needs grow.
Results:
- Cut electricity costs by over €600 per year.
- Earns ~€8 per month in electricity credits via virtual battery surplus export.
- Achieved full energy independence at night with complete system reliability.
Case Study: Planning Ahead for Battery Expansion in Sotogrande
A client in Sotogrande initially installed a 14.5 kW solar system (34 all-black 440W panels spread across nine roof sections) using a Huawei 15kW hybrid inverter. The client intentionally selected a hybrid, expandable inverter from day one to keep future battery integration open.
A few months after the initial solar panel installation, the client returned to upgrade the system with two 14kWh solar batteries (28 kWh total capacity).
Unlike the Mijas project where a non-hybrid inverter had to be completely replaced, choosing the correct hybrid inverter from the start meant adding batteries was a straightforward, plug-and-play upgrade. The client avoided the extra cost, labor, and disruption of having to rip out an incompatible unit or pay for extensive wiring upgrades.
Results:
- Reduced annual electricity costs by over €5,000 (over 80% savings).
- Seamless, plug-and-play battery upgrade without inverter replacement or extra installation costs.
- Reduced electricity bills to €0 by August 2025 after adding the battery storage.
Which solar inverter brand is the most reliable?
The most reliable solar inverter depends more on installation quality than on brand. Across 500-plus installations, Marblanc has never had a Huawei inverter fail, and we rate Sigenergy and Deye highly too. Undersized cabling and poor setup cause more failures than the badge on the box.
Let me be plain about this, because it’s where a lot of money gets wasted. A brilliant inverter fitted badly is still a bad installation.
Our move to Sigenergy is not a reliability judgement against Huawei. Huawei has been faultless for us. Sigenergy simply handles Spanish backup conditions better, and that’s a different question from which brand breaks.
Does inverter brand matter more than installation quality?
Inverter brand matters less than installation quality for reliability. A premium inverter on undersized cabling still fails. At one solar installation in El Rosario, Marbella, we were called in for a second opinion and found another installer had used 4 mm² cable where 6 mm² was needed – an overheating and fire risk.
That’s why I’d tell anyone to vet the installer harder than the brand. A good installer sizes the system properly, uses quality materials, and sets it up so you never think about it again.
How much do solar inverters cost in Spain?
A solar inverter in Spain typically costs €1,000 to €3,000, around 15% of a full installation quote. Price depends mainly on capacity and whether it’s a hybrid model. Our 2026 quotes run from ~€900 for a 6.6 kW Huawei to ~€3,000 for a 13.2 kW Sigenergy.
| Model | Capacity | Phase | Marblanc quote (inverter only) | Per kW |
| Huawei SUN200-6K-LB0 | 6.6 kW | Single | €983 | ~€149/kW |
| Deye SUN-20K-SG01HP3 | 20 kW | Three | €2,636 | ~€132/kW |
| Sigenergy SigenStor EC 12.0 TP | 13.2 kW | Three | €3,011 | ~€228/kW |
Source: Marblanc 2026 signed proposals. Units differ in size, so compare per kW, not on headline price.
The inverter is only one line on a full quote. For the complete breakdown, see what a solar installation costs in Spain – this page covers the inverter itself.
How much of your total solar cost is the inverter?
The inverter is roughly 15% of a full solar installation cost in Spain. Panels, battery, mounting, cabling and labour make up the rest. On a typical quote, the inverter choice moves the total far less than the battery decision does.
So while the brand matters for performance, it’s rarely the number that decides your budget. The battery is where the big money moves.
Are Sigenergy batteries cheaper than Huawei?
Sigenergy batteries are cheaper than Huawei’s on our own quotes – about ~€370 per kWh for a 9.04 kWh Sigenergy pack against ~€600 per kWh for a 5 kWh Huawei pack, roughly a 38% difference. Per-kWh cost falls as capacity rises, which explains part of the gap.
That saving is a real part of why we recommend Sigenergy even on systems that start without a battery – if storage comes later, it comes cheaper. Larger packs from other brands can undercut both on pure per-kWh cost, so the right battery still depends on the system. You can see our solar battery installation options for the full range.
Which solar inverter should you choose?
The right solar inverter depends on your property and your plans. Choose Sigenergy for battery or backup systems on Spain’s unstable grid. Choose Huawei for proven reliability and whole-home backup. Choose Deye for large three-phase systems and the cheapest battery storage.
Matching the inverter to the job – the scenarios we see most, and what we fit for each.
| Scenario | We recommend | Why | Typical example |
| Battery or backup system on an unstable supply | Sigenergy | Holds steady output through voltage swings; better app and manufacturer support | A Marbella villa with a backup box on a 260 V supply |
| Reliability-first, whole-home backup | Huawei | Never failed across 500+ Marblanc installs; SmartGuard backs the whole house at up to 63 A across three phases | A large villa that needs everything backed up |
| Large or three-phase system, tight battery budget | Deye | Strong on high three-phase loads; cheapest battery storage per kWh | A large rural or commercial-scale property |
| Panels now, battery later | Sigenergy | Recommended even without a battery; add stackable storage later without swapping the inverter | A homeowner starting with a solar-only system |
If you’re weighing up a battery tariff alongside the hardware, switching to a virtual battery tariff is worth a look too.
Which inverter is best for a battery or backup system?
For a battery or backup system in Spain, the Sigenergy SigenStor is our default. It holds a steady output through the grid’s over- and under-voltage swings, where other inverters flicker. We recommend it even on non-battery systems, because storage can be added later without changing the inverter.
Which inverter is best for a large or three-phase system?
For a large or three-phase system, Deye is a strong choice. Its three-phase range handles high loads, and its battery storage is the cheapest per kWh of the three brands we install. Huawei and Sigenergy also offer capable three-phase models for these systems.
Frequently asked questions
What are the three main types of solar inverter?
There are three main types of solar inverter: string, hybrid and microinverters. String inverters connect all panels to one central unit. Hybrid inverters add battery management to that. Microinverters sit under each panel. Most Spanish homes now use a hybrid, so a battery can be added later.
What are microinverters?
Microinverters are small inverters fitted under each solar panel, converting DC to AC at the panel rather than at one central unit. Also called module-level inverters, they let each panel work independently, which helps on shaded or multi-angle roofs. Enphase is the best-known brand.
What is the typical lifespan of a solar inverter?
A solar inverter typically lasts 10 to 15 years, shorter than the 25-plus years of the panels it serves. Heat is the main factor that shortens inverter life. Most systems need at least one inverter replacement over their lifetime.
Can you run an inverter 24 hours a day?
A solar inverter can run 24 hours a day, and grid-tied models normally do. They draw very little at night and drop to standby when there’s no solar or battery output. Hybrid inverters stay active overnight to manage battery charge and backup.
What about Tesla inverters?
Tesla’s Powerwall is an all-in-one battery and inverter rather than a standalone string inverter. Marblanc is a Tesla Powerwall certified installer and fits them on request. For this three-way comparison, we’ve focused on Sigenergy, Huawei and Deye.
Book a free solar survey
The right inverter isn’t really a blog-post decision – it’s a survey decision. Which brand suits your home depends on your phase supply, how stable the grid is at your exact address, and whether a battery is coming later. Those are things we measure on site, not things you can read off a page.
So we offer a free, no-obligation solar survey to any homeowner in Marbella, across the Costa del Sol, or anywhere in Spain. A qualified survey engineer visits in person and inspects your roof with an aerial drone, checking its health and the space you have to work with.
We then come back with two or more proposals and walk you through them on a laptop, using our Pylon design software. You’ll watch live how your costs and long-term savings shift as we add or remove panels, switch roof sections, or bring in a battery. Before we leave, you get an itemised quote generated on site – no waiting days for it.
Your free survey includes a home visit*, drone inspection, 3D performance model, two custom proposals, and a break-even estimate for each.
Ready to find the right inverter for your property? Book your free solar survey, or get in touch with any questions.
*For homeowners in remote locations or where demand is high, we may offer a digital version of the survey.
