Design Blueprint: A Sodium-Sulphur Molten-Electrode Store at a Distribution Substation: Ceramic Electrolyte Area, Operating Heat and Thermal Standby Loss for Four Hundred Usable Kilowatt-Hours

Design blueprint derived from the source paper (DOI 10.5281/zenodo.24174103): This paper sizes a sodium-sulphur storage system for a distribution substation requiring load levelling through the evening peak. The duty calls for 400 usable electrical kilowatt-hours delivered at a rated power of 100 kilowatts. Working from a stated specific energy of 110 watt-hours per kilogram, an energy density of 180 watt-hours per litre, a usable depth-of-discharge fraction of 0.9, and a round-trip efficiency of 85 percent, the calculation gives a gross stored energy of 444 kilowatt-hours, an active-store mass of 4.04e+03 kilograms, a complete system mass of 5.86e+03 kilograms, and a complete system volume of 3.58e+03 litres (3.58 cubic metres). Full discharge at rated power lasts 4 hours, and a full recharge takes 4.82 hours at the stated charge power. Losses amount to 72.3 kilowatt-hours per complete cycle, appearing as heat at average rates of 7.5 kilowatts during charging and 9.04 kilowatts during discharge. Standing loss is 0.05 percent of the stored energy per day. Life is limited by the cycle limit, giving 4.5e+03 effective full cycles, about 15 years at the assumed cycling rate, and a lifetime delivered throughput of 1.8e+03 megawatt-hours. All values are computed from the stated assumptions; the system is a design study and has not been built or measured. Status: SIMULATED, NOT MEASURED. Status: DESIGN BLUEPRINT — SIMULATED, NOT MEASURED — NOT BUILT. All numbers are simulated values from the source paper's computation, deposited with this blueprint as compute.py and results.json. AI-use disclosure: Dave, an AI research system, assisted with the computation and drafting under the author's direction; author of record William Alexander Aldred.