Deye SUN-15K-G03 (15 kW) - three-phase grid-tie inverter

Fifteen three-phase kilowatts without a battery: who it is for

The SUN-15K-G03 is the smallest three-phase grid-tie inverter in this catalogue, and it is bought with one purpose: cutting the electricity bill at a site that consumes during daylight. Typical buyers: a shop with refrigerated cabinets, a small workshop, an office building, a car wash, a bakery, a greenhouse operation, a farmyard with pumps. An array of up to 19.5 kW yields roughly 20 to 22 MWh a year at these latitudes, and if two thirds of that energy is consumed on site the saving is noticeable from the first month. The essential point to grasp before buying: this is a grid-tie inverter, it supports no battery and shuts down together with the grid during an outage — it cannot keep the site running in a blackout by design. If both are needed, look at the hybrids: the SUN-15K-SG05LP3-EU-SM2 (item 2060) with a 48 V battery or the SUN-15K-SG01HP3-EU-AM2 (item 2058) with a high-voltage one.

Fifteen kilograms for fifteen kilowatts

The 333 by 472 by 203 mm housing weighs 15 kg — an inverter two people hang on a wall in half an hour, with no lifting gear and no separate frame to prepare. For comparison, a hybrid of the same rating weighs 30 to 52 kg, because it carries a battery channel, chokes and a larger heatsink. Low weight directly affects the final installation price, particularly when the inverter goes on a technical floor, in a utility room or on an external wall under a canopy. Cooling is intelligent and typical noise stays within 40 dB, so siting it near workplaces causes no problems. Operating altitude reaches 4000 m with no derating, which in practice means no restrictions anywhere in this country, mountain sites included.

Two trackers with different capacity

The photovoltaic input is asymmetric: the first MPPT accepts one string at 13 A of operating current, the second two strings at 26 A. The array is therefore split roughly one to two, and that is worth allowing for while laying out the panels: the smaller group — a slope, a canopy, a roof section with a different orientation — goes to the first input and the main group to the second. Total array power reaches 19.5 kW against the inverter's 15 kW rating, the standard 30 % oversizing that covers winter and overcast days. The MPPT window is 200 to 850 V with a 1000 V maximum input and start-up from 250 V: this is a high-voltage input, so strings are long at fourteen to twenty modules and the cable from the roof can be thinner than in low-voltage systems. Short-circuit current is 19.5 A on the first input and 39 A on the second.

98.5 % efficiency and what it means in practice

Maximum efficiency is 98.5 % with a European figure of 97.5 %: grid-tie inverters are always more efficient than hybrids because they have no battery converter, and at fifteen kilowatts one percentage point means 150 W that never turns into heat. Maximum power point tracking exceeds 99 % efficiency, output distortion stays below 3 % and night-time self-consumption is under one watt. Rated output current is 22.7 A per phase at 220 V and 21.7 A at 230 V with a maximum of 25 A: there is no backup circuit here, the inverter connects in parallel with the service through its own 32 A per phase breaker. A three-phase output means balanced phase loading — exactly what the network operator requires when approving generation. For a site with a three-phase service it also means lower cable losses than a single-phase system of the same rating.

What an official connection requires

A grid-tie inverter is always connected through approval by the network operator, and the certification set here is complete: IEC/EN 62109-1/2, IEC 61727, IEC 62116, EN 50549, VDE4105 and the other standards a distribution operator asks for. A bidirectional meter is mandatory: without it, energy exported to the grid simply is not recorded, and for a site with 19.5 kW of panels that is real money. Anti-islanding protection is built in and works to IEC 62116: when the grid disappears the inverter disconnects within a fraction of a second, which protects repair crews on the line. The remaining protections are standard: earth-fault monitoring, grid parameter monitoring, DC reverse-polarity protection and type II surge arresters on both sides. The frequency range is 50/60 Hz and the voltage 3L/N/PE 220/380 or 230/400 V, so the inverter works in older 380 V networks and newer 400 V ones alike.

Monitoring and maintenance

Communication comes through RS485, RS232, Wi-Fi and LAN simultaneously, all built into the housing, so connecting to an app or a company metering system needs no extra modules. For a commercial site that matters: per-tracker yield, daily and monthly curves, an event log and fault notifications are all available remotely, with no trip to the roof. The practical value of two tracker curves: if one string starts producing less because of soiling, shading or a failed module, it shows up immediately rather than at the end of the season. Maintenance amounts to checking terminal torque, inspecting the MC4 connectors and keeping the panels clean; the inverter itself contains no serviceable parts. The manufacturer warranty is five years, and an operating range of -25 to +65 °C with derating above +45 °C covers any conditions found in this climate.

How it differs from its neighbours in this catalogue

The larger SUN-20K-G04 (item 2046) has two 32 A trackers with three strings each — six strings — and an array of up to 26 kW at 23 kg, which suits sites where panels are scattered across many surfaces. The SUN-25K-G05 (item 2049) delivers 25 kW with a 32.5 kW array at just 20 kg, while the SUN-30K-G04 (item 2051) offers 30 kW and a 39 kW array but weighs 44.5 kg with noise up to 50 dB. Within the grid-tie line the choice is driven solely by array size and the generation capacity your agreement with the operator allows. If you need power during outages, no model of the G series will do — that is a fundamentally different architecture and calls for a hybrid. There is no fifteen-kilowatt single-phase grid-tie unit in this catalogue: the top of the single-phase grid-tie series is the SUN-10K-G (item 2068).

Tell us how many panels your roof holds and what generation capacity the network operator has approved, and we will advise whether fifteen kilowatts is enough.