The Australian Renewable Energy Agency (ARENA) partly funded the Alice Springs study. The central Australian town has a population of around 29,000 and will have a utility scale PV capacity of 4.1 MW when a power plant expansion project is completed later this year. An additional 10 MW, as recommended by the report, would see solar supply 25.6% of the towns peak load of 55 MW in summer in utility scale PV alone.
The report was carried out by engineering firm CAT projects and it found that while the assumption often is that electricity grids are inherently stable, that in fact small grids such as Alice Springs already encounter a significant level of load variance as part of normal operation. As a result of this, the modeling carried out by CAT shows that large amounts of PV can be added to the grid, in a distributed fashion, and the resulting variation on the grid, can end up being very similar to the step change noise variance which currently occurs in the network.
Alice Springs is currently the location of the Uterne Solar Power Plant, which is currently undergoing an expansion from 1 MW to 4.1 MW. The project is being developed by Epuron and supplied by SunPower.
The CAT study released today, suggests than by installing PV systems at geographically disperse points along the grid that the variation of electricity production a result of local cloud cover. The study advised locating the 1.1 MW arrays at 3 5 kilometers apart.
The findings of this study are timely and show how more solar PV could be reliably introduced into Australian electricity networks, said Ivor Frischknecht, CEO of ARENA. CAT Projects used a network of solar monitoring stations to estimate the maximum number of solar power generators that can be connected to the Alice Springs electricity grid without energy storage.
ARENA says the CAT report also provides data to allow for performance based Power Purchase Agreements (PPAs) to be formulated, which could bring down the cost of financing the PV arrays.
Solar is already cost competitive with electricity generation in remote settlements and towns in Australia, which largely rely of diesel-fired generators. The CAT team believes the grid affects it observed in this recent study are analogous to many other remote Australian communities.