EcoFlow’s naming has confused a lot of people. There are five products in the STREAM range, they do different things, and picking the wrong one is an expensive mistake. I have been running the STREAM Ultra X at home in Peterborough since spring 2026 and have spent a lot of time with the rest of the range. Here is exactly what each model is, what it costs, and who it is actually for — including what the new UK regulations from 27 August 2026 mean for each one.
If you want the short version: the STREAM Microinverter is the product that will qualify for DIY socket connection under the new UK rules. The battery-integrated models (Ultra, Ultra X, Pro, AC Pro) are more capable but require a hardwired installation for now.
The EcoFlow STREAM range at a glance
There are five products. Two are pure microinverters with no built-in battery. Three are battery-integrated systems that combine storage, solar input, and an inverter in one unit.
The Microinverter models: STREAM Microinverter (£149 standalone).
The battery-integrated models: STREAM Pro (1.92kWh, £799), STREAM Ultra (1.92kWh, four MPPT inputs, £999), STREAM Ultra X (3.84kWh, four MPPT inputs, £1,249), STREAM AC Pro (battery storage only, no solar inputs, £699).
EcoFlow was named as an official UK government partner for the plug-in solar rollout in March 2026. That matters for certification timelines — their products are expected to be among the first through the IPS v2.0 certification process.
EcoFlow STREAM Microinverter
Price: £149 standalone. Around £949 in a bundle with two panels.
This is the simplest product in the range and the one that matters most under the new regulations. It is a standalone microinverter — panels connect to it via MC4, it converts DC to AC, and the AC output feeds into your home’s circuits. No built-in battery. No smart meter diverter built in. Just panels to microinverter to house.
The STREAM Microinverter is the product most likely to achieve IPS v2.0 certification and qualify for DIY socket connection from 27 August 2026 onwards, once it completes the notified body approval process. It is solar-only with no battery import capability, which is exactly what the Interim Product Specification requires. Until certification is confirmed and the product appears on the ENA G98 Type Test Register, the hardwired route via a registered electrician still applies.
It works on its own or as a solar input to any STREAM battery unit. If you buy it now and want to add battery storage later, you do not replace the microinverter — you plug it into the back of a STREAM Ultra or Pro. That upgrade path makes it a sensible starting point if budget is the priority.
Output: 800W maximum. Two MPPT inputs, up to 1,000W DC panel input. Compatible with panels from 15V to 60V open-circuit voltage, up to 14A. This means standard 400W to 500W panels work well on each input. Do not exceed 60V — wire panels individually, not in series.
Warranty: 5 years on the microinverter. Shorter than the Hoymiles HMS-800 (12 years) and Anker SOLIX RS40P (12 years), which is a genuine consideration if you are comparing on long-term cost of ownership.
EcoFlow STREAM Pro
Price: £799.
The entry-level battery-integrated STREAM. It combines a 1.92kWh lithium iron phosphate battery, a built-in microinverter, and three MPPT solar inputs in one weatherproof unit. It sits between the pure microinverter and the Ultra in terms of capability.
Three MPPT inputs means up to 1,500W of direct panel input — three panels at 500W each. That is more solar flexibility than the Microinverter alone gives you, and the battery means you capture daytime generation and discharge it in the evening when consumption peaks. At the current Ofgem rate of 26.11p per kWh, a fully charged STREAM Pro battery (1.92kWh) contains around 50p worth of electricity — charged for free from solar.
Grid output: 800W to the house mains. AC outlet output: 1,200W. Pair with a second STREAM Ultra or AC Pro and total output rises to 2,300W, which is enough to run most household appliances simultaneously.
The STREAM Pro does not qualify for the new IPS v2.0 socket-connection route because it has an integrated battery that can import and store electricity from the house. It requires a hardwired installation by a CPS-registered electrician. That requirement will likely remain until a separate regulatory framework for plug-in battery systems is confirmed — which has no date yet.
Best for: homeowners who want battery storage and solar input at the lower end of the budget, and who are happy with a hardwired installation.
EcoFlow STREAM Ultra
Price: £999.
The most popular model in the range. It has the same 1.92kWh battery as the Pro but with four MPPT inputs instead of three, allowing up to 2,000W of direct solar panel input — four panels at 500W each. For most UK gardens with four panels, this is the one that makes sense.
Four independent MPPT inputs matter because each panel gets its own maximum power point tracking. Shading on one panel does not drag the others down. If your panels are split across different orientations — say, two facing south and two facing west — each panel works independently at its own optimum. I run four panels on mine, one per MPPT, and the independence is noticeable on days when one section of fence is in partial shade.
Grid output: 800W. AC outlet: 1,200W (2,300W paired). Battery expandable up to 11.52kWh by linking up to six units. The battery charges from panels or from the grid — on Octopus Intelligent or similar overnight tariffs at 7p to 9p per kWh, a fully charged 1.92kWh battery costs around 13p to 17p to charge from the grid overnight and saves 50p at daytime rates. That arbitrage is where a significant chunk of annual savings comes from.
The EcoFlow smart meter, either the EcoFlow Smart Meter or the EcoFlow x Shelly variant, is the accessory that makes the system genuinely smart. Clipped to your main supply tails, it monitors whole-house consumption in real time and tells the Ultra when to discharge and at what rate. Without it, the system works on a base load setting which is less efficient.
Same regulatory position as the Pro: requires hardwired installation, does not qualify for socket connection under IPS v2.0.
Best for: the most common upgrade from pure microinverter. If you have four panels and want battery storage, this is the benchmark product in the range.
EcoFlow STREAM Ultra X
Price: £1,249.
The premium model. Same four MPPT inputs and same grid and AC output specifications as the Ultra, but with a 3.84kWh battery — exactly double the capacity. That extra storage changes the daily use case significantly. Where a 1.92kWh Ultra battery fills up by mid-morning on a good summer day and then throttles solar input, a 3.84kWh Ultra X keeps absorbing solar through more of the day before it fills.
At 3.84kWh, a fully charged Ultra X contains roughly £1 worth of electricity at current rates. Charged from solar that is free. For a house with an average daily consumption of 8 to 10kWh, an Ultra X fully charged from panels covers 35 to 48% of daily usage — a meaningful contribution without any overnight grid charging.
The Ultra X is rated IP65 for outdoor installation, wall-mounts on a standard bracket, and runs passively cooled. Real-world capacity matches the spec closely — reviewers report no significant degradation over months of use, and the passive cooling performs well even on warm days provided it is not in direct sunlight.
I am running the Ultra X at home and the extra capacity versus the Ultra is noticeable in how it handles summer days. On a clear day in June with four 465W panels, the battery reaches around 80% charge by early afternoon rather than filling up by mid-morning, which means more of the midday peak generation actually gets stored rather than throttled.
One thing that trips people up: the Ultra X cannot be used as a pure socket-connection device under IPS v2.0 any more than the Ultra or Pro can. The battery disqualifies all three from the socket route. Hardwired installation is required.
Best for: anyone who wants to maximise self-consumption and can justify the extra £250 over the Ultra. The doubling of storage is a meaningful real-world upgrade, not just a spec sheet difference.
EcoFlow STREAM AC Pro
Price: £699.
This is the odd one out and the most misunderstood product in the range. The AC Pro has a 1.92kWh battery but no MPPT solar inputs at all. It cannot connect to solar panels directly. What it does is accept AC input — from a microinverter plugged into its back port, from the grid, or from another STREAM unit via the AC connection.
The AC Pro is essentially a battery expansion unit. Connect it to a STREAM Ultra or Ultra X and you add 1.92kWh of additional storage to the system. Connect it to a STREAM Microinverter and you get a battery-backed microinverter setup — the microinverter generates AC from the panels, the AC Pro stores it, the system discharges when the house needs it.
It is also the cheapest way to add battery storage to an existing non-EcoFlow microinverter setup. If you already have a Hoymiles HMS-800 or APsystems EZ1-M, you can plug it into the AC Pro’s input port and gain battery storage without replacing the inverter. This makes the AC Pro potentially interesting in the context of the new regulations — pair a certified microinverter kit (socket-connected legally from 27 August) with an AC Pro (hardwired via an electrician) and you get both the legal socket connection and battery storage in a split setup.
Best for: expanding storage on an existing STREAM system, or adding battery storage to a third-party microinverter setup.
Which EcoFlow STREAM model should I buy?
The answer depends on two questions: do you want battery storage, and are you buying before or after the first certified socket-connection products appear?
If you want the simplest, cheapest entry point and are waiting for a certified socket-connection product, the STREAM Microinverter is what to watch. Once it achieves IPS v2.0 certification and appears on the ENA register, it will be the most accessible legal DIY solar product EcoFlow sells. At £149 for the inverter plus around £160 to £200 for two decent 400W to 465W panels, you can build a working system for under £400.
If you want battery storage and are prepared for a hardwired installation, the STREAM Ultra at £999 is the benchmark for most UK homes with four panels. The Ultra X at £1,249 is worth the extra if you can accommodate the larger battery and want to maximise self-consumption. The Pro at £799 suits homes with three or fewer panels or tighter budgets.
The AC Pro at £699 makes most sense as a second unit to expand an existing system rather than as a first purchase.
All of the battery-integrated models require a hardwired installation by a CPS-registered electrician and a G98 notification to your DNO. For everything about the regulatory requirements, see our rules and regulations page. For the full STREAM FAQ covering MPPT limits, smart meter setup, loop charging, and common issues, see the EcoFlow STREAM FAQ.
EcoFlow STREAM accessories worth knowing about
The EcoFlow Smart Meter is the accessory that most improves the system’s real-world efficiency. Without it, the STREAM defaults to a fixed base load setting, which is less accurate and often results in small amounts of grid draw. With the smart meter clipped to your main supply tails, the system tracks whole-house consumption and matches discharge precisely. The EcoFlow x Shelly variant is more accurate (±1%) and is the one to get if you are buying new.
EcoFlow Smart Plugs allow specific appliances — washing machine, dishwasher, EV charger — to be triggered automatically when solar surplus is available. Combined with the smart meter, this is how you push self-consumption above 70% without battery storage.
The parallel cable allows two STREAM Ultra or Pro units to be daisy-chained, combining their output to deliver up to 2,300W back to the house — enough to run a dishwasher, washing machine, and kettle simultaneously from stored solar.
EcoFlow STREAM and the new UK regulations
From 27 August 2026, certified plug-in solar systems can be connected to a standard 13A socket without an electrician under SI 2026/848. EcoFlow was named as an official government partner and is expected to be among the first brands through the IPS v2.0 certification process.
The critical point: only the STREAM Microinverter, as a solar-only product with no battery, is likely to qualify for the new socket-connection route. The Ultra, Ultra X, Pro and AC Pro all contain batteries and are explicitly excluded from the IPS v2.0 framework as currently written. They remain excellent products, but they require a hardwired installation regardless of what happens on 27 August.
The full picture on what the new regulations mean, which products will qualify, and what to check before buying is in our dedicated article: Plug-In Solar Is Legal in the UK from 27 August 2026.
If you have questions about your specific setup or are trying to decide between models, leave them in the comments below. I have used most of this range hands-on and am happy to give a straight answer.