Snowy Hydro 2.0 is costing $25bn – 12 times more than its initial estimate. How did we get here?

Key points

• The publicly owned Snowy 2.0 hydroelectricity project now carries an estimated cost of up to $25bn, far above its original figure of about $2bn. Announced in 2017 by then prime minister Malcolm Turnbull, it would link two Snowy reservoirs through lengthy tunnels to store power for periods of high demand.
• Early feasibility work put the cost between $5.4bn and $6.9bn, and a final investment decision followed before geological studies were complete.
• Tunnelling has been slowed by stuck machines and a worker strike, pushing completion to late 2029 with more than a third of tunnelling still ahead.