Many key solar farms and wind projects have been hit by yet more transmission downgrades, although some have won a reprieve – according to the latest draft inter-regional marginal loss factor calculations published by the Australian Energy Market Operator.
The draft MLFs for 2020-21 – published just days after the market rule-maker, the Australian Energy Market Commission, rejected investor and developer pleas to change the MLF to a more predictable “average loss factor” – features heavy penalties for some of the solar farms already badly hit by grid constraints and “system strength” issues in north-west Victoria and south-west NSW.
These include the five solar farms which have had their output cut in half by AEMO for fear of uncontrollable “oscillations” should a major link fail. The worst hit is the the 52MW Broken Hill solar farm in New South Wales, which has gone from a rating of 97.89 back in 2018, to 0.75 in 2019, and down again to a recommended 0.70 this year.
This means that just 70 per cent of its output will be credited for revenue.
Other Victoria wind farms to be hit by the 50% curtailment have also been hit by further MLF downgrades, including the Bannerton solar farm, which can expect to get a downrgade from 0.82 in 2019/20 to 0.77, the Wemen solar farm, also from 0.82 to 0.77, the Karadoc solar farm, and the Gannawarra solar farm, which is in line for a downgrade to 0.86 from 0.89.
MLFs have become a major issue for wind and solar developers, and prompted UK infrastructure giant John Laing to announce it was pulling out of the wind and solar project sector in Australia after taking a £66 million write down on its Australian projects as a result of MLF changes.
Its interests include Finley, which suffered another 5 per cent downgrade, and the delayed Sunraysia solar farm in NSW, and the Cherry Tree wind farm which did not get MLFs because they are yet to be registered.
Elsewhere in NSW, the massive nearly 350MW Limondale solar farm is in line to get a significant de-rating from 0.78 last year to 0.70 this year, the Griffith solar farm looks likely to be cut from 0.90 to 0.86, and the 66MW Parkes solar farm faces a de-rating to 0.91, down from 0.98 last year.
Manildra, Narromine and Nevertire solar farms all also face slight cut backs, while Moree gets a slight reprieve, lifting from 0.86 to a proposed 0.89.
The Gunning wind farm in NSW is in line to get cut from 0.97 to 0.93, while the Cullerin Range wind farm, also in that state, will see a similar de-rating, from 0.97 last year to a possible 0.93 in 2020/21. The Sapphire and Silverton wind farms in that state, however, get a slight lift in their output. The White Rock solar and wind farms both get a decent boost to their ratings, from 0.83 last year to 0.87 this year.
In Victoria, the Salt Creek wind farm also faces a trim to its output. Challicum Hills wind farm meanwhile looks like getting an upgrade from 0.91 to 0.96 this financial year.
In South Australia, the ratings look likely to remain pretty steady across the board, with the exception of the Lake Bonney wind farms, which face a proposed downgrade to 0.95 from 0.97. Willogoleche wind farm also faces a small cut, from 0.98 to 0.96.
A Queensland project likely to take a hit is Impact Investment Group’s Baking Board solar farm in Chinchilla, which is just under 20MW, and which AEMO proposes de-rating from 0.98 to 0.95, while the Daydream solar farm is on track to get a small boost, from 0.84 to 0.86.
In its notes on the draft ratings, AEMO said changes between the 2019-20 MLFs and the 2020-21 MLFs were mainly due to changes in projected power flow over the transmission network — the key driver of which being increases in generation connections to the NEM in particular in Victoria, New South Wales and Queensland.
“For the 2020-21 MLF study, increases in excess generation have been observed in both Victoria and New South Wales. This increase in generation has largely consisted of semi-scheduled generation, which is projected to offset thermal generation levels in Queensland resulting in decreased flows from Queensland to New South Wales,” the notes said.
“As more generation is connected to electrically weak areas of the network that are remote from the regional reference node, then the MLFs in these areas will continue to decline.”
In north-western Victoria, for example, AEMO says MLFs are lower, largely due to a projected ramp up in large scale solar projects and the impact of increasing diurnal profile of both loads and generation. In the state’s north, meanwhile, MLFs are higher, driven by projected increased exports to New South Wales.
In northern New South Wales, MLFs are higher based on a projected reduction in imports from Queensland, while in the state’s south-west MLFs are lower, due to a projected increase in imports from Victoria and an increase in transfer limits.
AEMO has stressed, however, that these are draft MLFs for 2020-21, and remain subject to changes following modelling of outstanding intra-regional limits, completion of all quality control processes (including consultant review), and any material issues identified in consultation with market participants.
A final decision on MLFs will be published by AEMO on April 01, 2020.