TEC 262 Dr. Jin Jo ICA 8 1. A large household is signed up for the E-7 rate schedule shown in the following table. The household uses 750 KWh/mo during the summer months. Assume the utility's baseline consumption for their region is 250kWh/mo. Table 10.1 Example Residential Tiered Time-of-Use (TOU) Rate Schedule Tier 1 Baseline Tier 2 101%-200% Tier 3 >200% Season Time (+/ k Wb) (+/ k Wb) (+/k Wb) Summer (May-Oct) Off peak 13.0 18.9 34.8 a. Peak (Noon-6 pm, Mon-Fri) 37.8 43.7 59.6 Winter (Nov-Apr) Off peak 13.3 19.3 35.2 Peak (Noon-6 pm, Mon-Fri) 16.3 22.3 38.2 Source: PG&E E-7 Rate Schedule, 2016. Assuming 450 kWh/mo are used during off-peak times and the remaining 300 KWh/mo are used during peak times, find the monthly utility bill of the household. b. Suppose pre-cooling shifts 125 kWh into off peak time so now only 175 kWh is used during peak times. What are the dollar savings of this pre-cooling? 2. Consider the following circumstance: A battery costs $270/kWh of storage The battery round-trip efficiency is 82.5% The lifetime of the battery is 2300 cycles before it needs to be replaced Off-peak electricity costs $0.09/kWh On-peak electricity costs $0.30/kWh Evaluate and describe the financial implications that are apparent when you buy off-peak electricity, store it in a battery, and discharge the battery to meet your load during an on-peak period. Imagine you've purchased one battery. 3. A 10-KW CHP system has an electrical efficiency of 35% and a thermal efficiency of 35%. It's $24,000 cost is paid for with a 7% 25-year loan having annual payments of $2,400/year. Its heat output displaces $11.00 per million Btu that would have been burned in an existing 80% efficient boiler. If the CHP system has a capacity factor (CF) of .85, find its cost of electricity