Biomass: Fluctuation in time
Seasons, regrowth and why biomass can be stored
What this tab covers How availability changes over seconds, days, seasons, years and longer, how predictable it is, and what that means for the plants that use it.The flow follows the growing season and is remarkably stable from year to year globally; the stock can be stored for months, so bioenergy is dispatchable.
Variation by time scale
| Time scale | What happens | How large |
|---|---|---|
| Seasonal | Global land NPP peaks in the northern summer, when the large northern land masses are green.1 | 18.0 Pg C in Jul-Sep vs 11.2 Pg C in Jan-Mar |
| Year-to-year | Satellite data show global terrestrial NPP close to constant; local harvests swing with drought.4 | about 53.6 Pg C/yr with very little inter-annual variation (MODIS) |
| Decades | Forest stocks regrow over decades after harvest; potentials for 2050 depend on land freed from food production.4 | Reaching 250 EJ would need roughly double today's global biomass harvest |
How predictable it is
High for the fuel itself (it can be stockpiled for months); crop and residue yields vary with weather and are known only after harvest.
Capacity factors and utilisation
| Plant or measure | Value |
|---|---|
| Bioenergy power plants, global weighted average (2025) | 78%8 |
| Bioenergy power plants, global weighted average (2010) | 72% (2024, IRENA)14 |
Global land net primary production by quarter (Field et al. 1998)1
Chart: Global land net primary production by quarter (Field et al. 1998)
Pg of carbon per quarterPlant growth follows the seasons, and because the Northern Hemisphere has most of the land, global land NPP in July-September is about 60% higher than in January-March. Ocean production is flatter through the year.
Unlike sunlight or wind, the energy is stored in the plant, so harvested biomass can be dried, piled and burned when needed. That is why bioenergy power plants run at global average capacity factors of about 72-78% (IRENA), similar to fossil plants.
Sources
- Primary Production of the Biosphere: Integrating Terrestrial and Oceanic Components (Field, Behrenfeld, Randerson and Falkowski, Science 281) AAAS, 1998
- Bioenergy: how much can we expect for 2050? (Haberl et al., Environmental Research Letters 8, 031004) IOP Publishing, 2013
- Renewable Power Generation Costs in 2025 (Executive summary, Figure S1) IRENA, 2026
- Renewable Power Generation Costs in 2024: Summary IRENA, 2025