By Lucille Davie
CITY Power's switches are old enough to go to a museum - the originals were installed in 1937, which makes them grandfathers of 68.
However, this is to change over the next five years. City Power, the City's electricity provider, has come under intense pressure recently as the city has experienced a number of power outages over the past 18 months, resulting in businesses losing millions of rands.
The electricity utility, with a R675-million capital budget for 2005/06 (and a R3,6-billion operating budget), buys 85 percent of its electricity from Eskom and the balance from the Kelvin Power Station.
Silas Zimu, the head of operations at City Power, says 70 percent of outages are caused by the condition of the network, which is characterised by "aged, under-designed and technically obsolete infrastructure".
If the network were at an "acceptable level", outages would have been contained at around 8 percent.
In addition, different systems have been installed over the years. Up until recently some of those companies, like Siemens, were no longer represented in the country. Zimu says every company supplied its own unique design.
Outages, however, "will never go away", Zimu says, as there will always be unpredictable factors like fire or lightning.
City Power has undertaken a number of initiatives to reduce outages. It has developed a network master plan; undertaken Eskom pre-engineering studies; commissioned detailed audits from a number of manufacturers; and compiled an internal audit.
The master plan involves appointing:
- PSW Consulting Engineers to assist in the preparation of short, medium and long-term transmission and distribution plans for the Midrand area;
- NET Group Consulting Engineers to assist in the preparation of plans for the remainder of the metropolitan area, in particular loading and network problems in the Siemert Road, Randburg and Roodepoort areas; and
- Eskom to do pre-engineering studies at Fordsburg, Prospect, Delta, Kelvin and Orlando substations.
Each year 10 transformers are being refurbished and 25 new transformers have been ordered. The city has a total of 250 transformers.
Another big problem is that the cable is aluminium, which is very attractive to metal thieves. Zimu says that recently five scrap dealers have been closed down, but have probably moved to Meyerton and re-opened their operations.
City Power spends millions on security at its plants.
Overriding all of this is a system in which Eskom supplies electricity to just under half of the city (Soweto and Alex and north as far as Diepsloot and Lanseria). City Power supplies the rest of the city, right down south to Ennerdale.
The system was run by seven electricity distributors until 2000, when City Power consolidated the disparate systems into one.
An audit of the substation transformers has identified 52 high-risk transformers. Their age indicates an "urgent need" for them either to be replaced or refurbished, a programme that is designed to eliminate the backlog by 2010 or sooner.
The refurbishment programme will drop the length of time the transformers are in service to acceptable levels.
Medium-voltage transformers require R532-million for refurbishment and upgrading, with an additional R70-million required for load growth, totalling R602-million.
The refurbishment and upgrading of low-voltage transformers should cost R100-million, with R32-million for load growth, totalling R132-million. The grand total required for the five-year period is about R2,245-billion.
The ageing switchgear pose far more serious problems than the transformers. The back-up protection is out of specification in most cases; 70 percent of protection relays are older than 20 years, with no spares available; and, to cater for the complete set of protection requirements, the suite of electro-mechanical relays per line should be replaced with new electronic relays.
This has to be done because repairing and refurbishing electro-mechanical relays is not cost effective.
Furthermore, protection schemes and 40 percent of the over-current and earth fault relays had an error margin of about 60 percent.
The allocation for switchgear is R45-million for each year until 2008; thereafter R30-million will be needed for 2008/09 and R12-million for 2009/10.
The allocation of protection equipment in 2005/06 stands at R19-million, with R15-million for 2006/07, R9-million for 2007/08, R7-million for 2008/09, and R2-million for 2009/10.
This produces a total cost for refurbishment and maintenance of R116-million for 2005/06, R85-million for 2006/07, R79-million for 2007/08, R59-million for 2008/09, and R36-million for 2009/10.
Besides plant and operating problems, some of the key challenges facing City Power are low payment levels, coupled with a poor billing system, illegal connections, meter tampering, theft and vandalism, and capital funding requirements.
Zimu says that the Soccer World Cup in 2010 is a risk if things are left as they are. This looks unlikely, however. Eskom is re-employing 30 000 former staff members to take old plants out of mothballing.
He says that City Power should be ready by 2007 with the refurbishment and replacement of plant.
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