In this work, 3 MW solid oxide fuel cell (SOFC) system fuelled by seaweed biogas was integrated into polygeneration process: combined heat, hydrogen, and power (CHHP) and its feasibility was evaluated. The integrated process was rigorously simulated using Aspen Plus and techno-economic analysis was performed to evaluate the feasibility of the proposed processes using the target cost of $225/kW as the initial SOFC stack price and the current and projected lifetimes of SOFC. Comprehensive sensitivity analyses were also performed on economic parameters to assess uncertainties in the process. Results show that the integrated CHHP process can generate 2.3 MW of net power and 50 kg/hr of hydrogen from 2,000 kg/hr of seaweed biogas with efficiency of 47%. The calculated levelized electricity cost was 10.45 ¢/kWh, which is comparable to existing fixed power generation.