Australian networks are also penalising solar households, now it looks like they will do the same with those that add battery storage.
The trend among some electricity networks to penalise or discourage the uptake of rooftop solar by imposing fixed tariffs or additional fees is now extending to battery storage, with one network accused of trying to lift charges to households with storage even though they are reducing peak demand.
In an analysis of recent tariff proposals by South Australia Power Networks, which included a since-rejected attempt to apply a surcharge to solar households, the Australian PV Institute says SAPN now seems intent on penalising households that install battery storage, despite their obvious network benefits.
The issue is important in Australia, which leads the world in the adoption of household rooftop solar. South Australia has the highest rate of adoption in Australia, with 28 per cent of available homes adding rooftop solar, which now contributes more than 6 per cent of the state’s electricity demand over a year.
Official forecasts suggest this will increase at least four-fold in the next decade, to the point where rooftop solar will provide 100 per cent of the state’s electricity demand at certain times.
Hence the importance of battery storage to balance the output, and to ensure some of it used to reduce peak demand. The state government has announced a tender to install battery storage on its buildings, including Parliament House and the key arts precinct, and the City of Adelaide is also providing incentives.
The APVI says its issues with SAPN are applicable to other networks, because they face similar issues in dealing with solar and storage, and their response with tariff design.
The APVI says that SAPN recognises that the next big development is battery storage, and perhaps electric vehicles. SAPN says the “battery storage has the potential to soak up a lot of the excess energy being generated during sunshine and shift that to later in the day when the network peaks”.
The APVI criticism extends to SAPN’s proposed “cost reflective” tariffs for rooftop solar, which the APVI argues is not cost reflective at all. That’s because the the proposed demand tariff on household loads shows very little correlation between the costs charged to the customer and the customer’s demand at the time of the network peak.
The APVI notes that in SAPN’s own pricing proposal, it acknowledges the ability of solar PV – even without battery storage – to delay and reduce peak demand.
Two things can be taken from this, the APVI says. One, that PV delays and reduces demand peaks; and two, that because demand peaks have reduced, there is no need to augment the network and so (from an augmentation cost point of view) whether PV customers increase or decrease their demand peaks is irrelevant, until such time as demand exceeds previously installed grid capacity.
The APVI makes a damning critique of the assumptions used by SAPN, including its claims that solar households have dramatically different load profiles. It says this is not true, and any changes that are evident are probably caused by metering methods than consumption patterns.