System Sizing

1. Sizing methodologies • Sizing calculations System Sizing

2. Sizing Strategy Sizing strategy starts at the load side and proceeds backward to the array.

3. Interactive System Sizing Interactive system sizing is very flexible because the utility can supply extra energy to the system loads and receive excess energy from the utility system.

4. Stand-Alone Systems Stand-alone systems must be carefully matched to load requirements to avoid reducing load availability or wasting excess energy.

5. Load Analysis A load analysis tabulates the various kinds of loads and their power and electrical energy requirements.

6. Kill A Watt Meter Load power and energy requirements can be easily measured with meters.

7. Load Requirements Load requirements include the power demand and electrical energy consumption for all the expected loads in the system.

8. Total DC Energy Requirements The total DC energy requirement is determined from the requirements for the DC loads (if any) plus the requirements for the AC loads, taking inverter efficiency into account.

9. Critical Design Analysis A critical design analysis compares the load requirements and isolation for each month to determine the critical design month.

10. DC-System Voltage DC-system voltage is chosen in proportion with the array size and to keep the operating current below 100 A.

11. Array Sizing Worksheet The array sizing worksheet uses isolation data and load requirements to size the array.

12. Actual Array Output Actual array output is often less than rated output due to soiling and high temperatures.

13. Array Configurations Modules are configured in series and in parallel to match the array rated capacity need to produce the required output.