Oil palm empty fruit bunch (OPEFB) is an abundant waste that is commonly incinerated, causing environmental pollution. In this study, an alternative waste management approach was investigated to produce value-added syngas from OPEFB using solar steam gasification. The three operating variables were temperature (1100–1300 °C), H₂O/OPEFB molar ratio (1.7–2.9), and OPEFB flowrate (0.8–1.8 g/min). Central composite design (CCD) was conducted to investigate and optimise the effects of these operating variables on H₂/CO molar ratio and solar to fuel energy conversion efficiency (η_{solar to fuel}). The findings revealed that all investigated operating variables were significant. Experimentally, the highest H₂/CO molar ratio (1.6) was obtained at 1300 °C, H₂O/OPEFB molar ratio of 2.9, and OPEFB flowrate of 1.8 g/min, with a high carbon conversion reaching 95.1%. Results from CCD analysis showed that a higher H₂/CO molar ratio (above 1.8) could be reached at 1200 °C, H₂O/OPEFB molar ratio of ≥3.0, and OPEFB flowrate of ≥2.0 g/min. The maximum η_{solar to fuel} of 19.6% was achieved at 1200 °C, H₂O/OPEFB molar ratio of 1.3, and OPEFB flowrate of 1.3 g/min, whereby a favourable energy upgrade factor (1.2) was achieved. The statistical model showed adequacy to predict H₂/CO molar ratio.