Abstrak - Gasifikasi biomassa merupakan proses pengubahan bahan bakar padat menjadi gas mempan bakar (gas produser). Gas mempan bakar tersebut selanjutnya dapat digunakan untuk menggantikan sebagian kebutuhan bahan bakar genset dengan sistem dual-fuel. Penelitian ini bertujuan untuk menghitung penghematan konsumsi spesifik bahan bakar dan kesetaraan energi biomassa dengan bahan bakar konvensional. Alat pengkonversi biomassa menjadi gas produser menggunakan jenis downdraftgasifier with throat dengan kapasitas 5 kg/jam. Mesin genset yang digunakan adalah genset berbahanbakar bensin dan LPG dengan kapasitas output daya listrik maksimum sebesar 5 kWe. Jenis biomassa yang digunakan adalah kayu Kaliandra (Calliandra calothyrsus) dan kayu Gamal (Gliricidia sepium). Pengamatan operasi genset dual-fuel dilakukan terhadap getaran mesin, konsumsi bensin dan LPG, konsumsi biomassa pada berbagai variasi beban listrik. Penambahan gas produser ke dalam mesin genset dibatasi melalui pengamatan getaran mesin secara visual. Berdasarkan hasil penelitian diperoleh penghematan bahan bakar bensin sebesar 68,55% dan 44,29% (basis L/kVAh) berturut-turut untuk Kaliandra dan Gamal. Sementara itu, untuk genset LPG diperoleh penghematan sebesar 50,70% dan 47,94% (basis kg/kVAh) berturut-turut untuk Kaliandra dan Gamal. Nilai kesetaraan kayu Kaliandra terhadap bahan bakar konvensional adalah 0,89 kg/L bensin dan 2,44 kg/kg LPG. Sedangkan, nilai kesetaraan kayu Gamal terhadap bahan bakar konvensional adalah 3,08 kg/L bensin dan 3,64 kg/kg LPG. Kata kunci: gasifikasi, Kaliandra, Gamal, mesin generator, produksi listrik Abctract - Biomass gasification is a process that converts solid biomass into burnable gas. This gas could then be used as fuel in internal combustion engine generator by dual-fuel system. Aims of this study were to calculate specific fuel consumption savings and biomass energy equivalence to conventional fuels. In this study, a downdraft gasifier with throat with capacity of 5 kg/h was used to convert biomass into gas. Gasoline and LPG engine generator with each 5 kWe maximum power output were used to produce electricity. Chipped Calliandra calothyrsus wood and Gliricidia sepium wood were used as feed of gasifier. Observations of dual-fuel genset operation carried out on the engine vibration, gasoline and LPG consumption, and biomass consumption at certain electricity loads. The injection of burnable gas into the generator engine was restricted through visual observation of engine vibration. At highest electricity load, gasoline savings (by L/kVAh) were 68.55% and 44.29% for Calliandra and Gliricidia, respectively. Meanwhile, LPG savings were 50.70% and 47.94% respectively for Calliandra and Gliricidia, respectively. The energy equivalence of Calliandra wood to conventional fuels were 0.89 kg/L gasoline and 2.44 kg/kg LPG. Meanwhile, energy equivalence of Gliricidia wood to conventional fuels were 3.08 kg/L gasoline and 3.64 kg/kg LPG. Keywords: gasification, Calliandra, Gliricidia, engine generator, electricity production