The present work deals with the techno-economic analysis of a novel combined power cycle consisting of a molten-salt solar tower power plant with storage supported by additional heat provided from the exhaust of a topping gas-turbine unit. A detailed model has been elaborated using in house simulation tools that simultaneously encompass meteorological, demand and required dispatch data. A range of possible designs are evaluated for a suitable location with both good solar resource and vast natural gas resources in order to show the trade-offs between the objectives of achieving low carbon-intensive and economically competitive designs. These were compared against more conventional integrated solar combined cycles of equivalent capacity factors. It is shown that the novel concept is worth further investigating as it is able to outperform the more conventional cycle while simultaneously offering additional flexibility to grid-operators.