Bulk Density 2 topics · 2 sources ScienceEnergyThe weight of a material per unit of volume compared to the weight of the same volume of water.US DOE Office of Energy Efficiency & Renewable Energy — Glossary of Energy-Related Terms retrieved 2014-05-26 Cite Science› EnergyRenewable EnergyWeight per unit of volume, usually specified in pounds per cubic foot.Oregon Dept of Energy — ODOE Glossary of Energy Terms retrieved 2014-06-15 Cite