This is a typical report by the media whereby environmental statements are untrue, with the lies possibly originating from the hotel. Of course, the reporter probably does not have the technical background necessary to question the statements.
Theoretically, a lithium ion battery can have a coulombic efficiency of 99 percent but, in practice, it is much less. For example, Tesla claim that their batteries can perform with a performance of 86 percent in their cars. For brand-new static batteries, such as is described in their article, a practical efficiency of 90 percent should be attainable. This means that 10 percent of the electricity used to charge the battery is dissipated, mostly in the form of heat. For every 100 kWh that the hotel uses from the batteries, they will require about 110 kWh to charge the batteries. This will of course be derived from the conventional mains power supply. It is therefore false to state that the use of the batteries will reduce their carbon footprint, quite the opposite. To compound the lie, the batteries are charged when the electricity is cheapest and the power stations are at their least efficient. I'm assuming here that the electricity supply is generated from a hydrocarbon source."Premier Inn is showing how hotel chains and large power users can further save money, reduce their carbon footprint and support the development of a lower-carbon, smarter energy grid in the UK."
