Outdoor enclosures for
photovoltaics & wind power

Generating plants need enclosures for the open field

Between module rows and beneath wind turbines stands power electronics that will never see the inside of a building: string inverters and central inverter periphery, DC combiners, SCADA and park controllers, grid and system protection and auxiliary power distribution. The enclosures for this must do two things at once: dissipate the heat loss of the electronics — and keep out the solar radiation that heats the sheet metal to over 70 °C in summer.

The double-walled SZD aluminium series solves this passively: the rear-ventilated air gap carries radiant heat away before it reaches the equipment; ventilation, heat exchangers or a cooling unit add active cooling according to heat load. The grid and distribution side is covered on the sister page Energy & smart grid.

Typical applications

Requirements — clearly classified

Standards in the generation park

The electrical side of a park is governed by the grid connection rules — VDE-AR-N 4110 (medium voltage) and 4120 (high voltage) determine which grid and system protection, metering and control equipment belongs at the grid connection point. The enclosure must hold this equipment reliably in the open field: degrees of protection to EN 60529 (IP 54/55), impact resistance IK10, distribution boards to IEC 61439, empty enclosures to IEC 62208.

For a service life of 20+ years, corrosion protection is what counts: anodised, seawater-resistant aluminium of the SZD series, design according to the corrosivity categories of EN ISO 12944, salt spray testing to ISO 9227 per project — for coastal sites also as a marine version or in stainless steel.

Which enclosure for which task in the park?

Typical project: ground-mounted PV plant with grid connection

Starting point: a ground-mounted PV plant needs decentralised string combiners between the module rows, cabinets for inverters and communication — and, at the grid connection point, the equipment required by the connection rules: grid and system protection, metering, telecontrol. Everything stands outdoors, from summer sun to freezing fog.

The solution: double-walled SZD enclosures whose rear ventilation dissipates the solar load, with ventilation or a cooling unit against the inverter waste heat and a heater against condensation. The park communication sits on a 19-inch level in the outdoor server cabinet. Special sizes adapt the cabinets to cable route widths and foundation grids; they are delivered wired from the factory, with foundation and drilling templates supplied in advance.

Wind power: equipment at the tower base and the transfer station

In wind turbines, the enclosure equipment sits in two places. Inside the tower, SZE enclosures handle control, auxiliary power distribution and converter periphery — in an internal climate with temperature changes and high humidity, which is why a thermostat-controlled heater against condensation is part of the basic equipment. Outside, at the transfer station and park cabling, the same rules apply as in a PV park: double-walled SZD enclosures for grid and system protection, metering and telecontrol, plus the 19-inch level for park communication.

Special sizes pay off twice here: tower doors, existing stations and foundation grids dictate the dimensions — ZPAS builds the cabinets to fit, instead of adapting the plant to the catalogue. For maintenance teams, what counts is door hinging, access protection and per-cabinet documentation that is still correct when servicing years later.

Planning checklist: enclosures for PV & wind power

These points should be clarified before the tender:

• Site climate: determine the corrosivity category to EN ISO 12944 — inland, coastal or offshore-related use decides between aluminium and stainless steel.
• Solar load: plan a double-walled design with rear ventilation — it lowers the internal temperature without any energy input.
• Heat load: quantify the power loss of the inverters — it determines ventilation, heat exchanger or cooling unit.
• Communication: define 19-inch requirements for SCADA, routers and park controllers early — including space for a UPS.
• Foundation & cables: foundation or plinth mounting, cable entry from below with reserve for repowering.
• Certificates: name the required product-related certificates (IP, IK, material) early — they are supplied with each order.

Why ZPAS

Because generating plants are project business: ZPAS supplies everything from a single enclosure to a park-wide roll-out from its own production — with prepared cut-outs, mounting levels and cooling. A first configuration takes minutes in the outdoor enclosure configurator.