Summary
- A 244kWp ground-mounted solar array at Yexio Heiligenhaus is expected to generate around 220MWh annually.
- The output will be consumed directly onsite, reducing grid imports while the panels are generating.
- At a continuous 2MW load, the stated production would equal about 1.3% of annual facility electricity demand.
Yexio has installed a 244kWp ground-mounted solar array at its data centre in Heiligenhaus, North Rhine-Westphalia, with forecast annual generation of approximately 220MWh.
Hochtief Solarpartner delivered the installation, which will feed its output directly into the facility rather than operating as a separate export project. The data centre currently provides around 2MW of capacity and has been designed to expand to 4MW.
The facility forms part of Yorizon Cloud’s planned Germany West region and was developed through a partnership involving Hochtief PPP Solutions and Thomas-Krenn. Direct liquid cooling sits within the technical design, alongside the newly installed behind-the-meter generation.
Useful output against a much larger load
A data centre consumes electricity around the clock, giving onsite solar a ready load during daylight hours and limiting the amount that needs to be exported. The array can lower grid imports while it is producing, provided the facility load remains above the inverter output.
Annual generation of 220MWh corresponds to an average output of roughly 25kW across the year. If the site operated continuously at its current 2MW capacity, it would consume 17,520MWh, leaving the solar array equivalent to about 1.3% of that demand.
The array still provides measurable energy rather than an unquantified renewable claim. It can reduce purchased electricity, avoid a portion of distribution losses, and make productive use of available land, while the facility retains direct control of the generated power.
Its scale also defines the boundary of the contribution. A 244kWp installation cannot replace a multi-megawatt grid connection, and output falls at night, in winter, and during poor weather. Expansion towards 4MW would reduce its proportional share unless additional generation were added.
The electrical integration requires inverters, protection settings, metering, controls, and maintenance isolation to coordinate with the site’s main distribution system. Unless paired with storage and controls designed for critical operation, solar generation normally sits outside the uninterruptible power path.
Most savings remain inside the facility
Cooling design and IT utilisation will have a larger influence on total energy performance. Direct liquid cooling can reduce fan energy and support dense racks, but pumps, cooling distribution units, controls, and external heat rejection still consume power.
Part-load behaviour deserves close attention at a new regional site. Data halls can spend long periods below design occupancy, and oversized pumps, fans, or cooling equipment may operate inefficiently unless variable-speed systems and controls follow the actual load.
Higher coolant temperatures can improve the quality of waste heat available outside the facility. A working heat-reuse system would still need a nearby customer or network, suitable temperature levels, pumping arrangements, commercial contracts, and year-round demand.
The environmental contribution of onsite solar should remain separate from the electricity mix serving the rest of the data centre. Almost all facility power will continue to arrive through the grid or contracted energy products, particularly outside daylight hours.
Ground-mounted generation also occupies land that could otherwise support later buildings, cooling plant, electrical infrastructure, access, drainage, or ecological mitigation. The chosen location therefore has to remain compatible with the site’s eventual 4MW buildout.
As the facility expands, its higher base load should absorb all solar production onsite, although the array’s percentage contribution will decline. Storage could shift some output into later hours, but batteries would add capital cost, fire controls, degradation, and another layer of electrical integration.
Heiligenhaus now has a specific, verifiable onsite generation figure. It will trim imports rather than transform the facility’s power balance, leaving grid supply, cooling efficiency, utilisation, and future expansion as the dominant factors in its operating footprint.
