Neighbour to neighbour photo voltaic buying and selling lifts returns and eases pressure on the grid
by Simon Mansfield
Sydney, Australia (SPX) Aug 15, 2025
Australian researchers report that households can earn extra by promoting extra rooftop PV on to close by consumers via peer to see vitality sharing, putting costs between feed in tariffs and retail charges whereas easing native grid stress.
Worldwide, about 25 million households use photo voltaic at present, with 100 million forecast by 2030. In 2024, an estimated 597 GW of photo voltaic capability was put in globally, up 33 p.c on 2023.
Australia leads on adoption, with panels on practically 40 p.c of houses, or about 4.1 million rooftops. Heavy noon surplus has depressed feed in tariffs, prompting questions on worth. A current federal program put aside 2.3 billion AUD for residence batteries, however new modeling finds storage alone doesn’t at all times pay.
Researchers from the College of South Australia and Deakin College analyzed 4 setups utilizing 12 months of actual knowledge from a ten kW photo voltaic residence in Geelong and three neighboring shoppers: peer to grid export, peer to grid with batteries, peer to see sharing, and peer to see with batteries.
“Beneath present situations in Victoria, the feed in tariff is lower than 5 cents per kilowatt hour, whereas the retail value is round 28 cents. Promoting surplus PV vitality on to neighbours at a mutually agreed value in between will be extra worthwhile for photo voltaic house owners and nonetheless cheaper for consumers,” Dr Wang says.
Native P2P sharing additionally stabilizes provide and demand by lowering exports to a community designed primarily to distribute energy a method relatively than obtain it.
Outcomes confirmed that including a 5 kW battery raised self consumption to 22 p.c and reduce imports, however generated no revenue for the host and supplied no profit to the neighbour given the upfront value. With out batteries or P2P, the host exported nearly 12,800 kWh a yr and self consumed simply 14.6 p.c.
Beneath P2P with a 5 kWh battery, self consumption rose to just about 38 p.c, although much less surplus remained for neighbours as a result of charging took precedence. Neighbours collaborating in P2P reduce grid electrical energy use by greater than 30 p.c.
Payback relied on proper sizing. The shortest payback, 12 years, got here with a 7.5 kWh battery within the P2P mannequin.
“Our modelling revealed that beneath present situations, P2P vitality sharing coupled with a 10kWh battery might ship the best return – $4929 – for photo voltaic homeowners over 20 years,” Dr Wang says.
“In distinction, all peer to grid situations resulted in adverse returns over the identical interval on account of low feed in tariffs and excessive battery prices.
“Battery dimension proved crucial. Programs with outsized batteries noticed returns diminish on account of increased capital and upkeep prices and lowered surplus vitality.”
Co creator Professor Chunlu Liu says there’s a commerce off between personal storage and group profit: “When batteries are used, they profit the photo voltaic proprietor by lowering their grid reliance, however this may restrict the quantity of vitality shared with neighbours as a result of they’re absolutely charged earlier than any surplus vitality is shared. The problem is to discover a stability that works for everybody,” Prof Liu says.
The group provides that warmth pumps and thermal storage might absorb extra PV to additional elevate self use. With Australia’s world main rooftop penetration, scaled P2P fashions might relieve grid stress and enhance residence photo voltaic economics.
“Our evaluation exhibits that if P2P vitality sharing costs are set between the feed in tariff and retail charges, each sellers and consumers can come out forward,” in response to co creator Professor Mark Luther. “However market guidelines and technical techniques must assist these transactions at scale.”
Analysis Report:Technical and economic analyses of grid-connected residential PV considering batteries and peer-to-peer energy sharing
Associated Hyperlinks
University of South Australia
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