The Tasmanian government has recommitted to plans to add up to 1000GWh of new renewable generation to the state’s power mix, making it “energy self-sufficient” by 2022, in response to the final report from the state’s Energy Security Taskforce.
The taskforce was set up in the wake of the island’s 2015-16 six-month energy supply crisis, which arose from a combination of severely restricted hydro resources and the failure of the Basslink cable, linking Tasmania to the mainland grid.
The sudden strain on supply resulted in the state recommissioning the mothballed 388MW Tamar Valley (combined cycle gas) Power Station, as well employing a host of diesel gen-sets that cost the government-owned HydroTasmania a whopping $1,163 per megawatt-hour.
The final report from the Tasmania Energy Security Taskforce, released to the public on Wednesday this week, has delivered a suite of recommendations to the Liberal Hodgman government to help avoid such a scenario happening again. The government has since pledged to implement the recommended energy security measures within months.
The recommendations are divided into five key areas, including strengthening independent energy security monitoring and assessment; improved framework for water storage management; keeping the government-owned Tamar Valley gas plant handy for backup; and support for new on island generation and customer innovation.
But apart from noting the future role household solar and batteries could play in managing demand response at a grid level, the report has little to say about the potential role of energy storage in boosting security of supply, ruling most battery applications as too expensive and too limited in their current technology.
“The Taskforce concludes that until there are significant decreases in battery costs and technology, or significant changes to current electricity pricing, adding a battery system represents a significant additional cost to the household that is not offset by reducing the cost of peak electricity,” the report says.
“This partly reflects the unique aspects of Tasmania’s electricity situation, in that Tasmania is generally not capacity constrained (except for some remote locations),” it adds.
On large-scale battery storage, the report says very little, except to acknowledge the support the technology is getting on the mainland.
It does better on renewables, however, noting that the “current on-island energy deficit” can be helped by building additional projects, “which will also serve to diversify the State’s generation mix and reduce its dependence on energy imports.
“Tasmania has a world class wind resource, but the cost competitiveness of wind could be challenged over time as the cost of other technologies decline. Large-scale solar development should not be
dismissed, despite Tasmania’s resource being relatively more limited than mainland Australia.”
On behind the meter solar and storage, the report says small-scale renewables, such as household solar and storage, “has the potential to make a small contribution to reducing Tasmania’s on-island energy deficit, but provides ‘consumer-level energy security’, whereby consumers perceive they have greater energy security when they are able to control some of their supply and demand.”
It also notes that a more technologically advanced network could also improve the grid reliability “(particularly in the face of future challenges) and minimise the impact of emergency power
restrictions if they were ever needed.”
The renewables section ends, however, on a bit of a dull note, saying that “the progression of solar PV, battery storage and EVs depends on a range of factors that are largely beyond the control of the Tasmanian government.
“The ability for Tasmania to significantly influence or control these factors creates uncertainty over their value to, and impact on, the energy security of the stationary energy sector.”
On gas, meanwhile, it is much clearer. The report recommends the government holds onto the Tamar Valley gas plant, as a back-up power station for the island’s grid, and “to provide clarity” to its gas market.
That’s because, before the energy crisis, HydroTas had planned to offload Tamar Valley – which it had mothballed in June 2014 – after declaring in August 2015 it was no longer required for energy security. Of course, not long after that declaration, things went pear-shaped, and gas came right back into the spotlight.
“Natural gas is an important energy diversification today that holds important optionality for the future,” the report says.
But a note elsewhere in the report suggests that the plant, which has again been switched off, would take up to two weeks to get up and running.
“A component of the Energy Supply Plan was returning the CCGT to service. The unit had been in dry lay-up since June 2014. … (It) was successfully returned to service on 20 January 2016 and operated until 19 May 2016 when it was no longer required as there was ample hydro and wind generation available to meet Tasmanian demand. It remains in standby mode and can be brought online within two weeks,” the report said.
It also notes that gas current gas supply contracts to the island end in December 2017, a situation it says must be remedied quickly.
The report has also recommended that the state’s hydro storage settings remain set at a minimum level of 30 percent, having more recently been switched to a lower preferred minimum level of 25 per cent at 1 July each year.
According to the report, that change was based on Hydro Tasmania’s assessment that the combination of Basslink and gas power from Tamar Valley Power Station (TVPS), together with increased wind generation capacity and changed demand projections would result in the ability to operate storages at the lower levels.
“The reduction in preferred minimum operating level saw the storage buffer to the medium risk line reduced by approximately 700GWh,” it said.