25 June 2004
Load limit increased for upper South Island region
National grid owner and operator Transpower says the commissioning of four inter-trip schemes over the next few days
will allow the peak demand load limit for the upper South Island to be increased by 25 MW to 1055 MW.
This will significantly reduce the risk of forced power outages this winter.
The inter-trip schemes are being commissioned with the support and co-operation of lines companies in the region. The
first was commissioned this morning (Friday) and raised the load limit by 10 MW.
The schemes provide identified blocks of load, which could be switched off automatically if a voltage stability problem
occurred on the electricity grid.
This back-up protection allows more electricity to be sent through the grid, increasing the load limit for the upper
South Island to 1055 MW, from the previous maximum of 1030 MW.
The peak demand so far this winter has been 968 MW, recorded on the 9th June.
Transpower’s General Manager System Operations Kieran Devine says electricity supply into the upper South Island
continues to be actively managed.
“Since early April when we first called the industry together, it has been our firm belief that security of supply into
the region could be maintained with the active co-operation of all parties.
“These new schemes, which provide automatic under voltage load shedding, are an innovative solution, and are attracting
interest from our counterparts overseas.
“Added to the other measures already taken, the risk of power shortages in the upper South Island this winter has been
greatly reduced,” Kieran Devine said.
ENDS