This paper introduces a novel concept of flap-type wave energy device named the Hull Reservoir Wave Energy Converter (HRWEC). The device is a hybrid of the Pendulum type wave energy converter (PeWEC) and the Pendulor wave energy converter. The device mainly consists of a floating reservoir and a top hinged flap that hangs inside the reservoir. The flap motion is triggered by both the float motion and the fluid motion inside the reservoir and the energy take-off happens through the relative motion between the flap and the float. Because this concept closely resembles the PeWEC, a similar float design is used in the HRWEC to facilitate comparison with available data. The dynamics and power capture are obtained using a frequency domain model, and the power capture is maximized for damping-only control for regular waves. It is shown that this new concept exhibits a broadband response compared to the PeWEC concept, which is linked to an additional mode created by the internal water body motion. As a result, this new concept expected to be suitable candidate for applications in broadband wave climatic conditions. (c) 2021 Elsevier Ltd. All rights reserved.