Lots of acronyms and unfamiliar stuff: here's a quick (although incomplete) guide to help you!

Battery Energy Storage Systems usually refers to groups of electrochemical batteries, most commonly of the Lithium Ion family and iterations derived from it, although other technologies such as Vanadium Flow Redox Batteries are becoming more popular 

Round trip Efficiency is the ratio of the energy output from the storage device to the energy input to the device during one charge/discharge cycle. In other words, if I feed my storage with 100 units of energy, knowing that there will be, inevitably, some energy losses, what percentage of those units can I get as output? 

To give an example, electrochemical batteries can achieve RTE of 90%, whereas a standalone LAES (i.e. with no heat recovery) is limited to 50%

Needless to say, RTE is a key metric to evaluate the effectiveness of a storage system, but it is in no way the only factor to consider:  in some scenarios an energy storage system with an RTE of 99.999999% but prohibitive costs would probably be less useful than a system with a lower RTE but significantly cheaper

Levelized Cost Of Storage is an average of all the metrics of a given storage system (RTE, lifetime, CAPEX and OPEX) used to objectively compare different technologies from an economic standpoint. While it is true that there are several different methods to calculate the LCOS, it remains a powerful tool to evaluate the performance of a storage system

Capital Expenditure and Operational Expenditure which basically means "how much to buy the car" and "how much to run the car". Some will tell you that it is more complex than that, but at the end of the day that's the gist of it.

Carbon Dioxide behaves differently from Nitrogen, Oxigen and Argon, as it changes phase at a much higher temperature, turning to solid at the extremely low temperatures involved in the process of liquefaction of air. Despite the fact that CO2 in the air amounts to a mere 0,04% of the total, over time it would risk clogging the system, hence the necessity of removing it from the mix of gasses before the liquefaction process is started 

A Nuraghe (pl. Nuraghi) is a bronze age megalithical structure, found in Sardinia and main architechture expression of the Nuragic civilisation. It is shaped like a tower in its simplest configuration, although several examples of complex Nuraghi, with clusters of several towers exist throughout the island. Dimensions may vary from monument to monument, with most of the surviving structures in rather poor conditions, however in their heyday they must have spanned as far high as a four storey tall building. It has been suggested that more than 8000 Nuraghi might have been built, although many have been destroyed over the centuries. 

To this day there is no agreement between scholars about what might have been the purpose for which Nuraghi were built

We are multidisciplinary nerds