A step towards zero emissions – the Alma House solar power plant cut carbon dioxide emissions

The solar power plant installed on the roof of the Alma house in central Helsinki was commissioned on September 3, 2024, and has proven to be a successful investment. During its first year of operation, the plant produced a total of 120,231 kWh of electricity, covering 27% of the building’s electricity consumption (lighting, elevators, ventilation, and other technical systems).

Production varies by weather and season – efficiency exceeded expectations

Risto Jauhiainen, Alma Media’s Head of Procurement, explains that the solar plant’s output varied significantly throughout the year, as expected. For example, in June, Helsinki had approximately 560 hours of daylight, enabling efficient production.

“In December 2024 and January 2025, the solar plant was able to cover only about 1% of the building’s electricity consumption. In contrast, during the hot July of 2025, production peaked, covering 54% of the consumption,” Jauhiainen notes.

The plant’s best day occurred in early summer: on Sunday, June 1, production reached 993.2 kWh, equivalent to 9.93 full load hours (FLH)*. The lowest output was recorded on December 14, 2024, with only 0.4 kWh produced.

“In winter, with limited daylight, production nearly halts,” Jauhiainen adds.

In the Nordics, typical annual production for a solar power plant corresponds to 800–1000 FLH, but the Alma building exceeded 1200 FLH. Expectations were surpassed, indicating not only favorable conditions but also successful design.

A productive first year

The solar plant generated about 10% of all electricity used in the Alma building, including tenants’ own consumption beyond the building’s technical systems. With the total electricity cost around €0.10/kWh including grid fees, the plant achieved approximately €12,000 in savings over the year.

The remotely monitored plant has operated without disruptions. Panels are positioned on the roof facing two directions to ensure consistent electricity generation as the sun moves from east to west during daylight hours.

Toward a low-carbon future

Jauhiainen emphasizes that in responsible business, the transition to a low-carbon society is accelerating, and energy solutions play a key role.

“We produce electricity solely for the building’s consumption – not for the national grid. Although the panels cover only part of Alma’s total energy needs, every step toward zero emissions is valuable. The remaining energy we purchase is also renewable, generated by wind power. In its first year, the plant contributed to a reduction of 34 tons of CO₂ emissions, based on the emissions that would have been generated by purchasing the equivalent amount of energy.”

*The term “Full Load Hours” (FLH) in solar power refers to the estimated number of hours during which the plant would produce energy at full nominal capacity over the course of a year, assuming continuous full-power operation.

Related reading: The Alma House entered the era of solar power

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