A new class of other promising petrochemical polymers have recently emerged as alternatives, referred to as dipolar glass polymers. They combine highly polar side groups such as hydroxyl or sulfonyl groups with a high-temperature glass transition (Tg), which increases their operating temperature and decreases the dielectric losses near RT. Thus, they display high discharge energy density values, Ue = 4-10 J•cm -3 , and can reach efficiencies over 80%. Due to their high concentration of hydroxyl groups and highly tuneable Tg, poly(hydroxy urethane)s (PHUs) could meet these criteria, with the added benefits of being isocyanatefree and potentially bio-based. Recently, PHUs have even been considered for energy-related applications, including energy harvesting. Bio-based polymers synthesised from erythritol dicarbonate (EDC) look especially promising as EDC is low-cost, highly reactive and can be produced on large scale, with high conversion yields and in soft conditions from a natural sugar alcohol (i.e. erythritol). In this paper, we demonstrate the potential of bio-based PHUs for energy storage. A series of 100% biobased PHUs is synthesised from reacting EDC with bio-based diamines (H2N-(CH2)n-NH2) by polyaddition in DMSO at 80 °C. Their dielectric and energy storage performance are then evaluated and compared with "state of the art" intrinsic polymers for dielectric energy storage. 6,7