Styles I Editing B Oicsiion s (a) The UK National Grid's power generation mix has average CO2 emissions of 193 g/kWh. The average electricity transmission efficiency is 90%. Certain battery electric vehicle (BEV) has a charging efficiency of 92 %. What is the Well-to- Wheel CO2 emissions (in g/km) for the BEV if that has an average energy consumption of 20 kWh per 100 km? (b) Two applications for consent are submitted for tidal energy extraction in an area with a mean spring tidal range of 10m and a mean spring tidal velocity of 2.8nv/s. The first application is for an array of 80 16m diameter twin rotor tidal turbines with a Cp of 0.42. The second is for a lagoon with an area of 6km2 and turbines which are 80% efficient. Which scheme will produce the greatest power during a spring cycle? () A pumped storage scheme has an upper basin which is 250m above the lower basin. The volume of water pumped between basins is 1 x 106 m3 and it takes 4.5 hours to pump the water to the upper basin. If the power output during generation is 135 MW, how many hours can the scheme produce power for