Hallanvahti Solar Park.

The site

Hallanvahti runs across 200+ hectares of old peatland in Joroinen. 129 MW target. Peat thickness varies within metres, and capacity readings between adjacent piles can differ by 30 % or more.

Concrete needs curing time, which is a logistics problem on peat. Driven piles can hit refusal in the underlying till without warning. Manageable on a small site, expensive across 71,000 of them.

How we did it

Test piling first: compression, tension and lateral, across enough zones to map capacity. Every pile in the final design sized to that measured data, not to a spec sheet.

Piles and brackets manufactured at Paalupiste's EN 1090 line in Porvoo, scheduled to run a week ahead of the install front. Zones needing longer sleeves or a different helix size flagged in time for the next batch.

On the install front

Seven machines on tracks at peak. Wheeled rigs stop moving once the autumn rain comes, so the whole fleet was tracked. Crews and pile loads kept moving without temporary access roads.

Every pile GPS-positioned, torque-verified, logged. The torque curve is the capacity reading; a pile that finishes short shows up at install, not weeks later in a desk review.

What got done

71,000 piles installed in 10 months. Each pile has a GPS coordinate and a torque curve in the as-built record. Bank and investor due diligence can read capacity pile by pile.