Deye SUN-6K-SG05LP1-EU (6 kW) - single-phase hybrid inverter

The sites where six kilowatts is exactly the right size

Six kilowatts on a single phase is the point where a household no longer has to ration power by hand during an outage: fridge, gas boiler, borehole pump, lighting, two air conditioners and kitchen appliances all run at once with headroom to spare. In consumption terms this suits a house using 15 to 20 kWh a day, typically 120 to 200 m² with gas or solid-fuel heating and an ordinary set of appliances. On the commercial side the same rating covers a shop with three or four refrigerated cabinets, a coffee bar with an espresso machine and an ice maker, or a small workshop with a compressor. What this model will not do, even with a large battery bank: it cannot serve a three-phase supply and it will not carry electric space heating — a 9 kW boiler or a directly fed heat pump stay out of reach, and for those the catalogue has the LP3 and HP3 families. One more limit worth knowing before installation: six kilowatts is the ceiling of the inverter's own generation, not of the house — while the grid is up, consumption can be considerably higher thanks to pass-through.

An array of up to 7800 W across two 13 A trackers

The two independent MPPTs handle 13 A of operating current each and accept a single string per tracker, which is enough for modern 450 to 600 W modules whose working current rarely exceeds 14 A under standard conditions. Up to 7800 W of panels can be connected against the inverter's 6 kW rating, a deliberate 30 % oversizing of the array: it harms nothing, since the surplus is simply clipped at midday a few times a year, while in winter and under cloud it adds exactly the percentage that is otherwise missing. The MPPT window runs from 125 to 425 V with a 500 V limit and a 150 V start-up point, so a typical string of ten to twelve modules sits mid-range — and in winter it is worth checking open-circuit voltage in frost, because it rises by 10 to 15 %. Two trackers bring freedom in planning: east and west, the main roof and an extension, a roof and a carport — each sub-array keeps its own tilt and works independently. Tracking efficiency is 99.9 %, so the search for the maximum power point introduces almost no loss; far more is lost on poor connections and undersized cable from roof to inverter.

Six kilowatts against 120 A of battery current: the bank now sets the limit

The battery channel is built around 48 V with a 40 to 60 V range and a charge and discharge current of up to 120 A, roughly 6.1 kW at 51.2 V. That is where the system becomes balanced: the inverter can deliver 6 kW and the battery can supply as much, so neither side sits idle. There is a catch worth remembering when choosing modules, though — many low-voltage batteries, the SE-G5.1 (item 1947) among them, are rated at 50 A continuous, and a single such module will cap the system at about 2.5 kW no matter what the inverter label says. For this model you either take modules rated 100 to 120 A, such as the SE-F5 (item 1944) or the RW-F10.2 (item 1930), or you parallel two or three weaker ones so that their currents add up. AGM and GEL banks are supported too, but lead is constrained even harder: sustained discharge above 0.3C damages it, so six kilowatts from a lead bank is practically unreachable without enormous capacity.

A 12 000 W peak and the real currents at the output

In island mode the inverter holds 12 000 W for ten seconds — double the nominal rating, and that is the decisive figure for sites with pumps and compressors. A 1.5 kW borehole pump demands 4 to 6 kW at start-up, and if it fires at the same moment as an air conditioning compressor the combined peak easily passes seven or eight kilowatts: this is the reserve that keeps the inverter out of protection. Rated output current at 220 V is 27.3 A, already a serious figure for domestic wiring — the output cable and breaker should be sized for 32 A rather than left as they were before the inverter arrived. Harmonic distortion stays under 3 %, and under 1.5 % on linear loads, so sensitive electronics, boiler controls and variable-speed pumps run without complaint. Apparent power of 6600 VA also implies something practical: with poor power factor loads — older motors, welders, transformer supplies — the real ceiling sits closer to 6 kW than to 6.6.

Forty amps of pass-through and cooperation with the grid

Maximum grid input current is 40 A, about 9 kW of pass-through: while mains power is present the house may consume more than the inverter can itself produce, and that is normal hybrid behaviour. This arrangement lets the water heater and the hob stay on the general supply while only the essentials go onto the backed-up circuit: boiler, fridge, lighting, internet, pump. The inverter can also charge the battery from the grid during chosen hours — a function that matters as much as sunshine in Ukrainian conditions: with a known outage schedule the bank refills overnight and stands full by evening. Priorities are configurable in detail: house first, then battery, then grid, or down to an hourly timetable, depending on whether a feed-in tariff applies and how frequent the outages are. One installation detail: the current transformer that measures self-consumption must sit on the main incoming line, otherwise the inverter sees only part of the load and manages the flows incorrectly.

Cooling, efficiency and what the location must provide

Maximum efficiency of 97.6 % and a European figure of 97 % mean about 180 W turns into heat at full load — not much in itself, but noticeable inside a closed niche with no ventilation. Cooling in this revision is intelligent: the fan is temperature-controlled, so in cool weather the unit is practically silent and full fan speed appears only under sustained load in heat. The 420 by 680 by 233 mm enclosure and 32 kg mass are identical to the smaller five-kilowatt model, so the wall space needed is the same and so are the requirements: solid masonry, two people for the lift, and 20 to 30 cm of clearance above and below for convection. IP65 permits mounting outdoors under a canopy, yet in this climate a technical room is wiser: the inverter runs from -25 to +60 °C, but a housing heated by direct summer sun means lost output exactly when the panels are at their best. Noise is quoted below 30 dB, quiet for a hallway or a boiler room, though a bedroom on the other side of the wall still calls for a different spot.

How it differs from its neighbours in this catalogue

Against the SUN-5K-SG03LP1-EU (item 2050) the difference is more than one kilowatt: trackers here are 13 A instead of 11, the array goes to 7800 W rather than 6500, grid transit is 40 A instead of 35, output current 27.3 A instead of 21, and cooling is intelligent rather than permanently forced. Enclosure, weight and battery current are the same, so with identical batteries it is the 6K that leaves more margin for inrush. If a water heater, air conditioners and a workshop are all in the plan, look instead at the SUN-8K-SG01LP1-EU (item 2047) with its 190 A battery current or the SUN-16K-SG01LP1-EU (item 2055) with three MPPTs and 290 A — that is a different class of task. The smaller SUN-3K-SG04LP1-EU (item 2048) runs a 24 V bus and is incompatible with 48 V batteries, so comparing it with this model on price alone is misleading: the architectures differ. And a hard boundary: grid-tie units such as the SUN-5K-G (item 2086) or the SUN-10K-G (item 2068) support no battery at all and stop working when the grid goes down, so they can never substitute for a hybrid.

Tell us which appliances must stay alive during an outage and we will work out whether six kilowatts is enough and which battery modules suit it.