D—4

At 31st March, 1949, 120,000,000 units were held in storage in Lakes Coleridge,. Pukaki, Mahineranai, and Monowai, as compared with 96,000,000 units at 31st March,. 1948.

Generation details of the interconnected system (compared with 1947-48) are as follows :

Dunedin City (all stations) .. 69,782,514 54,605,191 Invercargill City .. ' .. 1,755,480f . 1,567,590 Kanieri Electric Co. ... .. 3,679,000t 2,691,625 Westland Power .. .. 1,181,496| 742,688 Others .. .. .. 6,960,910f 5,273,536 Grand total .. .. 819,339,590 741,513,770 * Waitaki maximum demand, 08,300 kW., and units, 354,810,740, to 20th March, 1949. No. 5 unit in 21st March, 1949. f Provisional. 2. Reliability of Supply Although 222 faults were experienced, there were no general system outages.

The following analysis does not include prearranged shutdowns. The duration given refers generally to the period of outage of the line or equipment concerned, the periods of interruption to consumers were usually shorter.

18

Year Ended 31st March, 1949. Year Ended 31st March, 1948. Station. Maximum Kilowatts. Units Generated. Annual Load Factor. Maximum Kilowatts. Units Generated. Annual Load Factor. Arnold Coleridge Dobson (oil) Highbank Monowai Waitaki 3,300 42,440 28^000 6,500 82,920* 24,913,600 126,723,510 443,370 178,561,650 34,894,650 370,443,410 Per Cent. 86-2 34 1 72-8 61-3 61-4* 3,500 39,840 28,000 6,700 68,580 23,995,900 109,909,170 3,083,550 184,797,390 28,323,700 326,523,430 Per Cent. 78-0 31-4 75-1 48-2 54-2 Departmental totals 735,980,190 676,633,140

r ± Year Year Ended 31st March, 1949. Ended Description. 31st Distributing March, Number. Duration. Authorities 1948. Affected. h. m. 1. 110 kV. lines: Defects 8 2 15 58 13 2. 110 kV. lines : External causes 7 5 0 51 3 3. 66 kV. and 33 kV. lines : Defect 27 12 10 49 3 4. 66 kV. and 33 kV. lines : External causes 8 8 15 34 13 5. 11 kV. lines: Defects 74 79 81 20 1 6. 11 kV. lines : External causes 38 42 50 19 7 7. Lightning 9 7 25 20 8 8. Storms: Nature of trouble not found .. 18 22 10 33 1 9. 110 kV. equipment .. 5 1 7 41 10. 66 kV. and 33 kV. equipment 7 8 0 43 1 11. 33 kV., 11 kV., or 6-6 kV. equipment .. 9 20 11 24 5 12. Generators 1 0 07 7 13. Turbines 14. Diesel-oil engines 15. Relays 16. Control circuits and batteries 17. Operation : Mistakes '3 5 1 56 4 18. Operation: Accidents 1 19. Faults and overloads on consumers' system ! 2 . 2 0 07 o 20. Other causes 21. Causes unknown , 17 8 4 28 • 1 Totals 232 222 1 237 10