<p>Plant biomass is an attractive raw material for energy purposes because it is easy to grow, widely available, and relatively inexpensive. One of the crops with great and versatile potential is maize. Therefore, a study was conducted to determine the effects of biochar on maize biomass production, calorific value, and other energetic parameters as well as the chemical composition of the biomass. The study was conducted with soils contaminated with zinc and copper at concentrations of 0, 105, 210, and 420&#xa0;mg&#xa0;kg⁻¹. Biochar was added to the soil as a remediation agent at levels of 0 and 15&#xa0;g&#xa0;kg⁻¹ soil. The heavy metal contamination of the soil had a relatively little effect on the heat of combustion and the calorific value of the biomass as well as on the C, H, S, N, O, and ash contents of the maize biomass. In contrast, the heavy metals tested both biomass and energy production. Translocation factors (TFs) were determined from the HM content of maize aerial parts and roots. The series without biochar had 15.29% higher TF values for plants from Zn²⁺ sites and 12.00% higher TF values for plants from Cu²⁺ sites compared to the series with biochar. Higher accumulation factor (AF) values for the tested heavy metals were also recorded in maize grown on Zn²⁺ and Cu²⁺-contaminated soils where no biochar was applied. Nevertheless, the values of the TF and AF coefficients were &gt; 1. The use of biochar had a positive effect on the heat of combustion, the calorific value of the biomass, and its chemical composition. The use of biochar can, thus, be an effective means for the phytostabilization of soils contaminated with heavy metals.</p>