Pertti Kauranen

In regional freight operation, route, payload, and charging plans for battery electric trucks depend on trip energy. In Nordic winters this demand varies with temperature and road-surface state, which vehicle energy models omit by treating auxiliary demand as constant and rolling resistance as independent of weather. This study predicts the trip-level energy consumption of a battery electric truck in commercial service in Finland and Sweden from 18 months of telematics, matched along the route to road-weather analyses of temperature, water film, and surface snow. A calibrated longitudinal-dynamics model is combined with a gradient-boosting correction and evaluated on held-out trips, months, and an unseen winter. The physics residual rises from slightly below zero above 15◦C to 50 kWh/100km below -15◦C, each 1◦C drop adding 1.17 kWh/100km, and neither a constant-power auxiliary load nor a load-proportional rolling loss reproduces it alone. A 0.15 mm water film adds 8.4 kWh/100km and snow cover 6.8 kWh/100km plus 7.8 kWh/100km per centimeter, independently of temperature, so consumption peaks near 0◦C. On unseen trips thecorrection raises the R2 of total consumption from 0.40 to 0.87 and recovers 53% of the residual variance, 41% for an unseen winter, twice what a temperature-dependent auxiliary load achieves. A wet, snowy day at -20◦C shortens the range of a fully loaded truck from about 260 km to 185–195 km. A diesel truck analyzed as a reference shows that fleet fuel-level signals are too coarse for such prediction.

Reducing the atmospheric CO2 concentration to a sustainable level requires large-scale carbon dioxide removal through direct air capture (DAC). DAC is a heat-intensive process, and waste heat recovery to supply its heat demand has substantial potential to reduce the levelized cost of DAC (LCODAC). This study determines the techno-economic potential of recovering low-temperature waste heat (70◦C) from an off-grid electrolyzer plant for use in a solid-sorbent DAC plant requiring heat at 80◦C–120◦C for desorption. The waste heat recovery system, comprising heat pumps and a heat storage, and the DAC plant are dimensioned to minimize the LCODAC based on optimization at an hourly level, and a comparison with an electric-boiler-based heat supply is performed.It was found that the electrolyzer plant producing 6.3 kt/a of H2 can provide heat for a DAC plant capturing up to 27 kt/a of CO2 under Nordic conditions, where low ambient temperatures are beneficial for the solid DAC process, except for subzero temperatures. The LCODAC can be reduced by 24%–39% when a waste-heat-based heat supply is used instead of an electric boiler. Increasing the desorption temperature significantly reduces the LCODAC, even though the cost of heat supply increases due to the decreasing coefficient of performance of the heat pumps.From an electricity system perspective, the use of waste heat sources to supply heat to DAC plants is highly beneficial, as the primary energy demand and the peak electrical power of the DAC process can be reduced by 60% and 55%, respectively, compared with an electric boiler.

Reducing the atmospheric CO2 concentration to a sustainable level requires large-scale carbon dioxide removal (CDR) through direct air capture (DAC). DAC is a heat-intensive process, and waste heat recovery to supply its heat demand has substantial potential to reduce the levelized cost of DAC (LCODAC). This study determines the techno-economic potential of recovering low-temperature waste heat (70◦C) from an off-grid alkaline water electrolyzer (AWE) plant for use in a solid-sorbent-based DAC plant requiring heat at 80◦C–120◦C for desorption. The waste heat recovery system, comprising heat pumps and a heat storage, and the DAC plant are dimensioned to minimize the LCODAC based on optimization at an hourly level, and a comparison with an electric-boiler-based heat supply is performed. It was found that the AWE plant producing 6.3 kt/a of H2 can provide thermal energy for a DAC plant capturing up to 27 kt/a of CO2 under Nordic conditions, where low ambient temperatures are beneficial for the solid DAC process, except for subzero temperatures. The LCODAC can be reduced by 24%–39% when a waste-heat-based heat supply is used instead of an electric boiler. Increasing the desorption temperature from 80◦C to 100◦C or 120◦C significantly reduces the LCODAC, even though the cost of heat supply increases due to the decreasing coefficient of performance of the heat pumps. From an electricity system perspective, the use of waste heat sources to supply thermal energy to DAC plants is highly beneficial, as the primary energy demand and the peak electrical power of the DAC process can be reduced by 60% and 55%, respectively, compared with an electric boiler.