Deye SUN-2K-G (2 kW) - single-phase grid-tie inverter

The smallest inverter in the series: who actually needs it

Two kilowatts corresponds to an array of up to 2.6 kW, meaning four to six modern panels and 12 to 15 m² of surface, and that size gets chosen in three typical situations. First: there is little roof — a balcony, a garage, an extension, a small flat roof where nothing larger physically fits. Second: consumption is modest but reliably daytime — a summer house with a fridge and a pump, a kiosk, a parcel point, a small office — and then even two kilowatts cover the bulk of the daytime load. Third, and often overlooked: a second separate roof plane, where the main array already runs on another inverter and adding panels to the existing strings is awkward because the orientation differs. What this model fundamentally does not do: it is grid-tie, so it supports no battery and does not operate during an outage, which rules it out as a backup source in any scenario.

A short string is no obstacle: start-up from 80 V

There is one tracker here, with up to 13 A of operating current and a 550 V maximum input, but for a small array something else matters more — a start-up voltage of just 80 V and an MPPT window from 70 to 500 V. In practice the inverter begins working with three or four modules in the string, while five or six panels put the voltage comfortably mid-range. By comparison, inverters with a window starting at 150 V need at least six or seven modules, and on a small roof that simply does not add up. The low start-up threshold also brings an early working day: the unit wakes at dawn when array voltage is still low and keeps going into dusk. The limitation of that single tracker: all panels must be the same model with the same orientation and tilt, because any mismatch within one string clips the yield down to the weakest member.

9.1 A output: the simplest connection in the whole series

Rated output current is 9.1 A at 220 V and 8.7 A at 230 V with a maximum of 10 A: a load on the level of an ordinary domestic circuit, so a dedicated 2.5 mm² cable and a 16 A breaker cover the requirement with room to spare. That simplicity is the model's main practical advantage: no need to upgrade the service, rerun cable, fit heavy breakers or recalculate the thermal behaviour of the board. Apparent power is 2.2 kW, so brief excursions above the nameplate on a clear midday are handled by the inverter itself. Harmonic distortion stays below 3 %, which for a household network means the inverter does not interfere with sensitive equipment. If a feed-in arrangement is planned, remember that a bidirectional meter and operator approval are required regardless of power — for two kilowatts the paperwork is the same as for ten.

An honest look at the economics of two kilowatts

A 2.6 kW array in this climate yields roughly 2.5 to 3 MWh a year, and the entire benefit depends on how much of that you consume yourself rather than export. Where a fridge, a pump, lighting and appliances run during the day, self-consumption reaches 70 to 80 % and the system pays for itself at a sensible rate. If the premises stand empty until evening, most of the energy goes to the grid at the export rate and the payback period lengthens considerably — something worth calculating before the purchase rather than after. The second component is installation cost: in a small system it takes a larger share, so two kilowatts make sense when the roof and the board are already prepared, or when nothing larger fits. And one more thing: this inverter has no battery channel, so the plan of adding storage later does not work with it — the inverter itself would have to be replaced with a hybrid.

Installation and operating conditions

The 280 by 310 by 184 mm housing weighs 4.8 kg — identical to the 3 and 3.6 kW models — so one person completes the mounting in half an hour. Cooling is natural with no fan; noise does not exceed 35 dB, which is effectively silence, so the inverter lives happily in a hallway, a cupboard or a stairwell. IP65 protection and humidity tolerance to 100 % non-condensing permit an external wall, though direct summer sun on the housing is better avoided: derating begins above +45 °C. The operating range of -25 to +65 °C and altitude up to 2000 m without restriction cover any site in the country, mountain districts included. The DC isolator is integrated, panels connect through MC4 connectors and the output through a sealed IP65 connector, so no extra boxes are needed.

Monitoring and protection

Despite being the smallest unit in the series, the interface set here is complete: RS485, RS232, Wi-Fi and LAN, plus an LCD 1602 text display on the housing and a mobile app. For a small system that is more than a formality: the app's curves reveal whether yield has dropped because of dusty panels or partial shading, which a short string feels particularly keenly. Protections are standard: earth-fault and grid monitoring, DC reverse-polarity protection, short-circuit protection and type II surge arresters on the DC and AC sides. Certification matches the larger models of the series — IEC/EN 62109-1/2, IEC 61727, IEC 62116, VDE4105, VDE0126, AS4777.2, CEI 0-21 — so the official connection is processed in exactly the same way. Night-time self-consumption is under one watt and the manufacturer warranty runs five years.

How it differs from its neighbours in this catalogue

Within the series the choice is simple and depends only on how many panels your roof takes: the SUN-3K-G (item 2083) delivers 3 kW with an array of up to 3.9 kW, the SUN-3.6K-G (item 2084) gives 3.6 kW and up to 4.7 kW, both in the same 4.8 kg housing with one tracker. If the panels face two different directions you need the SUN-5K-G (item 2086) with its two independent MPPTs, and for a large array the SUN-10K-G (item 2068) with two 26 A trackers. Efficiency differences across the series are minimal (97.3 % against 97.5 %), so the decision rests purely on array size rather than conversion efficiency. Only one thing is worth keeping in mind: the two-kilowatt model has the least headroom, so if there is any chance of extending the array next year, taking 3 or 3.6 kW straight away is cheaper than reworking the system later. And if power during outages is required, this series should be ruled out entirely: a hybrid such as the SUN-3K-SG04LP1-EU (item 2048) is what that calls for.

Tell us how many panels fit on your roof and what actually runs during the day, and we will say whether two kilowatts suffice or a larger model is worth it.