The solar farm and battery on former coal mine land 2.5 km east of Muswellbrook was launched publicly on 21 August, when EnergyCo’s media release called it the first major solar and battery project to connect to the Hunter-Central Coast Renewable Energy Zone and said Construction commenced today. The release describes one project: a 135 MW solar farm and a 100 MW battery, expected to connect to the upgraded grid in late 2027 and be operational by 2028.

The approved paperwork describes something built in pieces. The developer’s construction page says The first stage will involve works within the southern section of the project area only, and that the access point on Sandy Creek Road will not be used until a later stage, after the Southern section has been completed. The order, and what each piece has to clear first, is set out in a letter of 27 November 2025 from the Department of Planning, Housing and Infrastructure, which agreed to the staging as the Planning Secretary’s nominee. The Department says it is satisfied it is necessary to ensure the timely delivery of the project.

The order it is being built in

The project’s consent, granted by the Independent Planning Commission on 27 May 2025, lets the developer stage the work with the Planning Secretary’s approval (condition C3). The staging letter’s table runs from stage 1A to stage 6, and the approved traffic management plan of March 2026 puts an approximate length on each (p. 2).

The approved stages, and the two gates in the way

Bar length is to scale of each stage’s stated length in months (the full width is 20 months). The bars are not a timetable: the plan says Some stages may occur concurrently.

  1. 1ASouthern solar farm, switchyard, substation and 132 kV line, built and commissioned. No escorted loads.About 18 months
  2. 1BSouthern solar farm continues, now with heavy vehicles that need an escort.About 12 months
  3. GateFire safety study approved by the Planning Secretary, with Fire and Rescue NSW’s written confirmation, before any batteries are delivered, stored or installed.
  4. 2Battery built and commissioned.About 20 months
  5. 3Southern solar farm and battery operate. About 35 years
  6. GateSandy Creek Road and northern site access upgraded. No work to be undertaken in the northern area until road upgrades and site access complete.
  7. 4AThe Sandy Creek Road upgrade itself.About 1 month
  8. 4BNorthern solar farm built and commissioned, with the connection to the south.About 12 months
  9. 5Northern solar farm operates. About 35 years
  10. 6Decommissioning.About 12 months
Stages and gates: Department of Planning, Housing and Infrastructure staging letter, 27 November 2025, Table 1 (pp. 1 to 2) and p. 3. Lengths: traffic management plan, version 5, March 2026, p. 2. Stages 4A onward are greyed because none of the documents we read dates them. Bars 18, 12, 20, 1, 12 and 12 months against a 20-month width.

Two things in that table matter most to people nearby. The first is the battery, which the Department places after the southern solar farm and which cannot start until a fire study is signed off. The second is the northern section, which has a road upgrade in front of it and, in the documents we read, no date.

When the southern section and battery will run is given in round terms. OX2’s August 2026 newsletter gives construction as May 2026 to early 2028, commissioning mid 2027 to 2028 and operation in 2028. Neither it nor EnergyCo’s release says whether operational by 2028 includes the northern section.

Which road the trucks use

For stage 1A, all construction access is from Muscle Creek Road. The traffic plan is explicit that the Project would not utilise Sandy Creek Road in any capacity during the construction of Stage 1A (except in an emergency or as directed by an authority) (p. 3). The Department’s approval of that plan, dated 10 March 2026, covers stage 1A only, and requires it updated for stage 1B and for all later stages of the project including Stage 4a which involves the road upgrades and site access on Sandy Creek Road.

The two gates onto the site, and the limits on each

Limits from the development consent; what applies now from the traffic management plan for stage 1A.

  • In use now Muscle Creek RoadYes. The only construction access in stage 1A. Sandy Creek RoadNo. Not used in stage 1A; opens after the stage 4A upgrade.
  • Heavy vehicles Muscle Creek RoadThe whole project is capped at 90 heavy vehicle movements a day, at most 13 an hour (B1(a)(i)). Sandy Creek RoadPer hour, at most 10 light vehicle, 2 shuttle bus and 2 heavy vehicle movements (B1(a)(ii)).
  • Escorted loads Muscle Creek RoadAll of them: a maximum of four movements (B1(a)(iii); plan p. 28). Sandy Creek RoadNone (B3, B4).
  • School terms Muscle Creek RoadNo school-term limit in the consent. Sandy Creek RoadNo construction traffic 7.30 to 8.30 am or 3.45 to 4.45 pm (B1(b)).
  • Vehicle length Muscle Creek RoadUp to 26 metres (B1(c)). Sandy Creek RoadUp to 19 metres (B1(c)).
Sources: Muswellbrook Solar Farm development consent SSD 46543209, conditions B1, B3 and B4 (p. 7), each unless the Planning Secretary agrees otherwise where the condition says so; traffic management plan, version 5, March 2026, pp. 3, 23 and 28; OX2’s construction page. Escorted loads are vehicles that need a pilot or escort vehicle, as the consent defines them.

The plan has the site gatekeeper record every heavy vehicle and warn the construction manager when 80 have come through in a day, ahead of the 90 limit (p. 24). The four escorted loads wait on the stage 1B update. Transport for NSW, as the plan quotes it, asked for that update and its consultation preferably 4 to 6 months before commencing high-risk OSOM movements on the network from the Port to the site (p. 3). As at 8 October, the Major Projects register listed the stage 1A traffic plan and no stage 1B version.

OX2’s construction page, as at 8 October, says that from 7 September 2026 the civil works subcontractor will begin mobilising personnel, site offices and plant to the project site, with works starting in the site compound and substation hardstand areas and using excavators, water carts, dozers and graders. Approved hours are 7 am to 6 pm weekdays and 8 am to 1 pm Saturdays.

What the battery waits on

The consent requires a fire safety study prepared to the satisfaction of Fire and Rescue NSW and the Planning Secretary before the battery’s construction and footings start (condition B29, p. 13). The staging letter goes further, to what can arrive at the gate.

the FSS must be approved by the Planning Secretary, including written confirmation from FRNSW that it meets the requirements, prior to the commencement of Stage 2 including the delivery, storage and/or installation of any batteries on site
Department of Planning, Housing and Infrastructure, staging letter to OX2, 27 November 2025, p. 3. FSS is the fire safety study; FRNSW is Fire and Rescue NSW.

A second letter, of 10 March 2026, explains why: Fire and Rescue NSW indicated they are unable to comment or review interim phase construction phase Emergency Plans, so OX2 will prepare the study once the final battery design is confirmed, and a final emergency plan after it. As at 8 October, the register’s approved management plans were the environmental management strategy, the traffic plan, the Aboriginal cultural heritage plan and the biodiversity plan; no fire safety study was among them.

How big the battery will be is also less settled than the release suggests. The consent caps it: storage must not exceed a total delivery capacity and storage capacity of 135 MW / 270 MWh (condition A5, p. 5). OX2’s May 2026 information sheet gives it as approximately 100 MW for approximately two hours, and its 18 May construction announcement as 100 MW.

The numbers, by whose count

The project’s own publications give several of its basic figures in more than one version.

One project, several versions of its figures

Each figure as the named publication gives it.

  • Homes powered
    • about 52,000OX2 announcement, 18 May 2026, from about 347 GWh of clean electricity annually; EnergyCo release, 21 Aug 2026
    • up to 52,310OX2 information sheet, May 2026, and newsletter, Aug 2026
    • up to 79,000OX2 community benefits page, read 8 Oct 2026
  • Battery
    • about 100 MW, 2 hoursOX2 information sheet, May 2026; EnergyCo gives 100 MW
    • up to 135 MWOX2 community benefits page; the traffic plan
    • cap 135 MW / 270 MWhConsent condition A5
  • Construction began
    • May 2026OX2 construction page, Construction began in May 2026; announcement of 18 May
    • 21 Aug 2026EnergyCo release, Construction commenced today; OX2 calls the day a sod-turning ceremony
  • 7.6 Mt of emissions
    • yearlyOX2 information sheet and benefits page, avoided yearly
    • over its lifeOX2 newsletter, Aug 2026, over its operational life
  • Approved
    • March 2025OX2 planning page and information sheet, by the Minister for Planning
    • 27 May 2025The consent itself, granted by the Independent Planning Commission
Sources as named in each row; all are listed below. The consent is the document that governs. Where a row gives two dates for construction, both come from the publishers’ own words; the consent’s definition of construction excludes some early works such as fencing and surveys.

Some of these are rounding. Two cannot both be right: a figure is either per year or over the project’s life, and the consent itself was granted by the Commission on 27 May 2025. On the benefit payment the documents agree: the consent sets a contribution of the greater of $850 per MW of installed capacity a year or any finalised state guideline, adjusted for CPI (Appendix 3), and OX2’s benefits page works that out at $114,750 a year for 135 MW (135 × $850). The traffic plan adds that the planning agreement with the council will initially be executed for stages 1A to 3, and updated for stages 4 and 5 before stage 4A (p. 3).

The workforce

The traffic plan says During the peak construction period, a workforce of approximately 200 personnel will be required on site, mostly housed in Muswellbrook, and that An accommodation solution is proposed within Muswellbrook, with details in an accommodation and employment strategy the consent requires before construction (p. 22; condition B36). Muswellbrook Shire Council’s April letter on the transmission line, which we reported on 7 October, describes the solar farm’s developer looking for housing for a peak construction workforce period of Dec 2026 to June 2027 (p. 8). That is the council’s description, not OX2’s.

How we read the documents

The two staging letters, the traffic plan and its approval are under “Approved Documents” on the project’s Major Projects register page, which we read in a browser on 8 October 2026; the document lists load only when each tab is opened. The consent is the copy OX2 publishes on its project website. Traffic plan page numbers are its printed numbers, which run seven behind the PDF page index. Stage lengths are the plan’s approximations and the bar arithmetic is 18, 12, 20, 1 and 12 over 20. The staging letter does not state how much of the 135 MW sits in the southern or northern section, and we have not estimated it from the layout plans. We did not contact OX2, EnergyCo or the Department.

Our read

This section is opinion, based on the facts and documents above.

Staging is sensible, and the plan should be easier to find. Building the section served by the existing access first should get power flowing sooner, and holding the battery behind a fire study is the order you would want. But the staging decision lives on the state register, not on the project’s website, and the Department’s March letter asked OX2 to put the traffic plan on its project website at the earliest convenience. As at 8 October, the website’s planning page did not list it and its search returned nothing for “traffic”. A Sandy Creek Road household should not need the register to learn that its road is next.

The figures need one owner. Three counts of homes and two readings of the same 7.6 million tonnes undercut a project that is otherwise unusually well documented. The consent and the staging letter are the numbers to trust.

What to watch next

Three documents would move this story: the stage 1B traffic plan with its escorted-load plan, the battery’s fire safety study, and the first notice of a date for stage 4A on Sandy Creek Road. Each lands on the project’s register page.