Evoenergy is shaking up its pricing to push people with solar panels to use electricity-hungry devices like washing machines during the day instead of in the evening when many others are doing the same.
From July 1, the company will introduce a "solar soak charge" in the ACT to make it unattractive to use power-hungry machines during peak demand. Exporting solar power would be more attractive.
In large parts of New South Wales, Ausgrid has introduced a similar scheme. Under it, solar panel owners would be paid more to send the electricity their panels generate to the grid in the evening, between 4pm and 9pm, when demand is high.
Conversely, there would be a relative penalty if they export their electricity during the day.
Evoenergy said its "solar soak charge" was "not intended to penalize those residents who have solar, but to incentivise the use of solar power during peak production hours".
It said its scheme "rewards customers for using surplus electricity, produced by residential solar generation, during the hours of 11am-3pm. This offers a lower rate to encourage customers to use more electricity during the middle of the day, when solar energy production is at its peak."
Solar panel owners get paid when they give their excess electricity to the grid. It is not clear whether their income from selling it would be cut.
The difficulty for some solar users may be that they are unable to use, say, washing machines during the day because they are out at work. Other items are tied to the evening, like heating in winter.
Some solar enthusiasts said the answer to the new tariff system was batteries to store electricity generated by the panels on the roof during daylight, and then push it out onto the grid when the price is best.
But batteries in Canberra are currently quoted at between $8750 and $15,500 depending on size. The cost can outweigh the price gains from installing solar in the first place.
But solar panel installer Benn Masters of SolarHub said the cost of batteries was coming down. He was optimistic that the new tariff system would boost demand for them.
He thought the change in the tariff "just means that we are going to need to be smarter. Heat your hot water during the day".
The Solar Citizens group wants governments to give more financial support to households so they can get batteries.
"Households with existing rooftop solar are doing the energy grid a favour by exporting cheap, clean solar that their neighbours can use. We should be removing barriers for more households to go solar, not introducing penalties," Solar Citizens' Heidi Lee Douglas said.
