Energy-saving retrofit of industrial plants is one of the vehicles of decarbonisation and the goal of modern society. The retrofit of the heat exchanger network allows saving a large amount of primary energy across units and industrial clusters. Usually, selecting suitable retrofit options is a big challenge for decision-makers that impacts future plant profit and environmental issues. This research proposes assessing different retrofit options of crude oil distillation unit based on historical data of energy prices. Periods with different energy price trends were analysed, accounting for the retrofitted unit start-up after the first and third year. The impact of energy price dynamics on economic and environmental benefits of different retrofit option was analysed. The sustainability of the most economically beneficial option was assessed across different energy price trends. The overdetermined/lost benefits of all options were calculated, allowing the decision-maker to proceed with the most appropriate one.