These conventional plants run less frequently and produce less energy, which changes their economics and therefore tend to favour less capital-intensive technologies, such as open-cycle gas turbines, instead of combined-cycle gas turbines. These situations of minimum residual load do not necessarily occur during periods of low demand and they have implications for all markets, including the day-ahead market, intra-day or balancing and ancillary services markets. Little consideration has been given to these situations of low load, as it is usually sufficient to shut down plants during a few days or at night time when they are not needed.