Thermal phase diagrams are computed for binary mixtures of different fatty acids with 1-dodecanol to design new eutectic phase change materials with melting temperatures and latent heatof fusion ranging from 15.5 to 19 °C and 183 to 188 kJ kg−1, respectively. The lauric (LA), myristic (MA) and palmitic (PA) fatty acids with 1-dodecanol eutectic compositions are identified and experimentally validated using differential scanning calorimetric measurements. The measured eutectic compositions are 29:71, 17:83, and 10:90 wt% for LA-DE, MA-DE, and PA-DE binary systems respectively. The melting temperatures and latent heat of fusion for these eutectic compositions are 17, 18.43, 20.08 °C and 175.3, 180.8, 191 kJ kg−1 respectively. The computed and measured composition weight fractions, melting temperature and latent heat of fusion values are in good agreement. The suitable melting temperature and considerably large latent heat of fusion for these designed and developed new eutectic phase change materials make them suitable for latent heat thermal energy storage systems for low temperature solar thermal applications such as building heating/cooling and body cooling clothing applications. © 2017 Elsevier Ltd