<h4>One year in passenger service&nbsp;</h4>
<p>February 2023 marked the one-year anniversary of HybridFLEX entering passenger service with Chiltern Railways. The two-carriage train travelled over 15,000 miles in its first year&nbsp;and carried thousands of passengers on the 40-mile route between Aylesbury in Buckinghamshire and London Marylebone.</p>
<p>Porterbrook has invested over £7m in the development of HybridFLEX, which&nbsp;involved retrofitting a 20-year-old diesel train with a powerful low emission engine and battery pack. The hybrid powerpack combines both the engine and battery to an electric motor. which can operate in both hybrid and battery only mode and can also recover braking energy into the battery.<br></p>