driving up prices in the WA market in recent months<\/a>.<\/p>\nIn one episode, coordinated charging by all of Synergy’s batteries shortly after midnight propelled spot prices from $120 to more than $350 per megawatt-hour.<\/p>\n
One market player, not authorised to speak publicly, said the incident was one of many in which Synergy’s batteries in particular seemed to be driving prices materially higher.<\/p>\n
While prices in WA’s short-term market account for only about 10 per cent of the electricity that is bought and sold \u2014 most is traded via direct contracts \u2014 experts say they are a vital indicator.<\/p>\n
High prices in the short-term market reflect an underlying tightness in supply and demand.<\/p>\n
Observers also note that prices are highest in winter, when supply and demand is tightest because wind and solar output are at seasonal lows.<\/p>\n
Prices flatter, not always lower<\/p>\n
Ralph Sarich, a senior vice-president of global energy consultancy Rystad, previously explained that batteries were helping to flatten prices across the day.<\/p>\n
But he also noted that they would not necessarily drive down prices if there was insufficient energy being generated in the first place.<\/p>\n
“The role the batteries have done really well is meet that evening demand, which is why you’re seeing the price curve is a lot flatter across the day,” Mr Sarich said.<\/p>\n
“But the other thing you need to remember is batteries are not really generators. They’re really just moving demand around throughout the day.”<\/p>\n
Regulators such as the ERA have been trying to come to grips with batteries and their effects on the wholesale market.<\/p>\n
The authority has set out some of its concerns in a white paper on the topic.<\/p>\n
In that paper the ERA noted batteries were increasingly dominating the market, but behaved differently to conventional generators such as coal and gas plants and wind farms.<\/p>\n
Traditional generators offered \u2014 or “bid” \u2014 their output into the market based on fuel and maintenance costs, but batteries behaved differently, the paper said.<\/p>\n
For batteries, the regulator noted, the biggest cost was not necessarily physical \u2014 it was the so-called missed opportunity cost of not making more money later.<\/p>\n
In practical terms, this means that a battery could discharge at 4pm for $100\/MWh, but at 6pm the price may have risen to $350\/MWh.<\/p>\n
Few ‘good’ explanations<\/p>\n
The ERA said it would look at how much lead-time batteries should be allowed in setting their prices, how they should account for the costs of charging as well as discharging, and how \u2014 and how often \u2014 they should be allowed to change their bids, known as rebidding.<\/p>\n
Also in the ERA’s sights was the question of “portfolio” bidding, or the use of batteries to push up wholesale prices to benefit a company’s other generating assets.<\/p>\n
“As with rebidding, portfolio-based behaviour may also raise concerns under the [market rules],” the ERA said in the white paper.<\/p>\n
The concerns of authorities have been echoed by market experts and observers who say Synergy in particular has been managing its battery fleet in questionable ways.<\/p>\n
Peter Tickler, co-founder of energy analysis and modelling firm Gridcog, said the topic had set tongues wagging in Australia’s rapidly growing battery industry.<\/p>\n
![\"Man](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/09\/6e3a76776af87c00258410cbcaf48b82.jpeg\")
<\/p>\n
Gridcog co-founder Pete Tickler says Australia has an overabundance of green energy at times. (ABC News: Aran Hart)<\/p>\n
Mr Tickler said there appeared to be only two options to explain the way Synergy had been managing its batteries.<\/p>\n
“They’re very ordinary at optimising their assets,” Mr Tickler wrote on social media.<\/p>\n
“[Or] they’re deliberately exerting market power to drive up prices for their other assets to sell into.<\/p>\n
“Choose your poison.”<\/p>\n
Synergy has been contacted for comment.<\/p>\n","protected":false},"excerpt":{"rendered":"Western Australia’s economic watchdog has put the owners of the state’s big batteries on notice amid “unusual” behaviour…\n","protected":false},"author":2,"featured_media":876793,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[32474,64,63,446603,99,17084,446604,216826,446605,84218,446602],"class_list":["post-876792","post","type-post","status-publish","format-standard","has-post-thumbnail","category-business","tag-aemo","tag-au","tag-australia","tag-battery-power-prices-wa","tag-business","tag-era","tag-green-energy-wa","tag-neoen","tag-renewable-energy-in-wa","tag-synergy","tag-wa-big-batteries"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/876792","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=876792"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/876792\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/876793"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=876792"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=876792"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=876792"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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<\/p>\n