A site-specific study has been carried out on the economics of commercial, hybrid solar and solar coal-gasification plants of 10 7 GJ/yr capacity located at a coal field near Edmonton, Alberta. It has been found that the gasification efficiencies have been improved by approx. 10% in hybrid solar gasification plants and by 25% in solar coal-gasification plants. As a result, the coal economy is from 12 to 30% for hybrid solar and solar plants. For typical values of $5/t coal price and 15% capital charge rates, the levelized † costs of synthesis gas are estimated to be $6.76/GJ from the commercial Koppers-Totzek (K-T) process, $5.62/GJ from the commercial Lurgi process, $7.63/GJ from the hybrid solar K-T process, $10.75/GJ from the solar K-T process, $6.49/GJ from the hybrid solar Lurgi process and $10.15/GJ from the solar Lurgi process. For the same conditions, the estimated costs of H 2 are $7.89/GJ from the commercial K-T process, $8.77/GJ from the hybrid solar K-T process and $12.85/GJ from the solar K-T process.