The universal need for sustainable and renewable energy sources has accelerated the shift towards bioenergy as a valuable option to fossil fuels. However, a significant challenge remains in the underutilisation of biomass resources and the environmental pollution caused by improper biomass disposal methods. Biochar, a by-product of biomass pyrolysis rich with carbon, serves as a means to convert underused biomass into valuable energy and a tool for environmental remediation. Biochar can be integrated into a biorefinery for improved bioelectricity and biogas production, but there are challenges with regard to its production scalability, quality control, and standardisation. This article provides a comprehensive review of the prospective processes useful in the valorisation of biomass into biochar for bioenergy, co-firing potential with fossil fuels, and in waste biomass transformation. This article also provides insight into business development and policy-making by bioentrepreneurs, bioengineers, and the government, as it identifies grey opportunities for bioenergy production and improvement. The prospect of AI technology in improving the production, quality, and yield of biochar, by identifying the most efficient parameters and conditions, as well as optimising the application of biochar in various industries, is also highlighted. The transition to biofuels in aviation, a step towards a future in the industry that is more sustainable, is also suggested in this review.