Queenslanders with rooftop solar panels are effectively subsidising power companies, according to a Queensland Conservation Council (QCC) energy engineer.
Feed-in tariffs paid to households exporting electricity are well below wholesale prices, meaning retailers are saving millions of dollars a month, QCC energy strategist Clare Silcock said.
"Because the prices have been so high, we see a massive subsidy," Ms Silcock said.
"It's a bit of a turnaround from what we hear historically — that the feed-in tariff has been middle-class welfare and funnelling subsidies to people who can afford to put solar panels on the roof."
In Loganholme, south of Brisbane, David Baggs earns 7 cents per kilowatt hour for the electricity he feeds to the grid.
Last month, the average spot price for electricity in Queensland was 40 cents per kilowatt hour, according to Australian Energy Market Operator (AEMO) data.
"It's pretty lousy," Mr Baggs said.
He plans to cover his home with more panels and install a battery so his household can run off the grid.
"Renewables should be able to just get recognition for what they can generate and be properly renumerated for that," Mr Baggs said.
'They are paid a fair price'
But Australian Energy Council chief executive Sarah McNamara said tariffs were high enough.
"They are paid a fair price based on the actual value of that electricity at that time of day. And each retailer makes a judgement on what that electricity is worth," Ms McNamara said.
"Naturally, if you are generating excess electricity in the middle of the day, you will be competing with a lot of other solar PV units, so the price will likely be less than at other times in the day."
"There is a lot of solar and wind that's going to be generated at times when it's sunny and windy, and that tends to ensure that the value of it is somewhat reduced because we have plenty of supply."
Queenslanders who applied for rooftop solar from 2008 to 2012 receive a feed-in tariff of 44 cents a kilowatt hour, under a Bligh-government incentive to encourage the take-up of solar panels.
That rate remains locked in until 2028 for people who remain at their property. It cannot be passed on to new owners.
For everyone else, the return is much lower.
In regional Queensland, the feed-in tariff is regulated.
On July 1, the Queensland Competition Authority (QCA) raised it from 6.6 cents to 9.3 cents per kilowatt hour.
QCA chair Flavio Menezes said this was 41 per cent higher than last year's feed-in tariff.
Professor Menezes said the rise largely reflected the increase in wholesale energy costs.
"However, retailers still incur most of their normal business costs, including retail operating costs and network charges," he said.
"That is why the solar feed-in tariff rate is less than the electricity prices you pay."
In south-east Queensland, the market determines tariffs and people with solar panels are advised to shop around for the best return.
Ms McNamara said feed-in tariffs had historically been inflated, and raising them would increase the bills of customers without solar.
"In years gone by, governments had excessively high feed-in tariff rates that were way above the actual value of the electricity that was being fed back to the grid," she said.
"State governments were particularly keen to encourage the take-up of solar.
"Unfortunately that created heightened expectations from householders about what the value of that electricity they were pushing back into the grid was worth.
"If they are not set fairly, then all customers have to pay that price and carry that extra cost."
A joint QCC and Solar Citizens report found that if rooftop solar was absent from the energy mix, demand on fossil fuel generators would be greater, driving up prices further.
Ms Silcock said even in September, when solar generation was high, rooftop solar provided $2.5 million worth of "free" electricity in Queensland.
"That's because the energy that [rooftop solar] did provide would have to come from gas, if it wasn't being met by solar," she said.
"When we need extra electricity, it's primarily extra gas that we're relying on and that has a higher cost.
"In the 2021-22 financial year, we calculated an average of $30 million of free electricity from Queensland rooftop solar per month."
However, Ms McNamara disagreed with that analysis.
"The idea of feed-in tariffs is to replicate the actual value of that electricity were retailers otherwise to purchase it on the wholesale market," she said.
Ms McNamara said people with rooftop solar should use as much electricity as possible when the Sun shone by running "washing machines, clothes dryers and the like in the middle of the day".
She also recommended buying a battery to maximise the value of domestic solar power systems.
