Massive incentives offered to WA householders to install solar panels on their roofs could push up the need for expensive and polluting power generation at times of peak demand.
A landmark energy efficiency trial has also found that photovoltaic systems might be pumping so much power into the grid they are causing localised spikes in electricity, which could damage household appliances.
Energy Minister Peter Collier acknowledged the findings raised serious questions but said one of the points of the trial was to identify such issues and offer possible solutions.
In its report into the $73.5 million Perth Solar City project, Western Power said the runaway take-up of supposedly green solar panels was leading to perverse environmental outcomes.
The State-owned electricity distributor discovered that households with solar panels were often deferring their consumption of electricity to later in the day to take advantage of incentives.
Western Power said this was increasing consumption during periods of peak demand, which typically occurred for a few days a year but required expensive and polluting generation to meet.
It called for a rethink of the design of incentives for solar panels including the net feed-in-tariff, which pays customers between 20¢ and 40¢ for every unit of electricity they “export” into the grid.
The tariff has been troublesome for the State Government after it was introduced in 2010, having been slashed to 20¢ last July and then scrapped because of rising costs. Synergy still pays 7¢ a unit.
However, several thousands customers whose applications were approved before the scheme was axed are still receiving the generous subsidies.
Western Power also found potentially serious problems associated with too many solar panels feeding electricity back into the network.
The utility said in areas where about 30 per cent of homes on a power line had rooftop solar cells, the electricity produced by them was sometimes flowing in the wrong direction. This caused issues, which the Energy Networks Association confirmed could lead to surges.
