Catholic schools go big in rooftop solar and battery storage

A massive rollout of solar PV with storage has begun for schools in Central Queensland. Schools in the Rockhampton Catholic Diocese, which stretches from Bundaberg to Mackay, and west to Longreach, have contracted for rooftop solar totalling more than 4MW with battery storage of 3MWh.
GEM Energy, the Brisbane-based firm who last year completed Queensland’s first large solar/battery storage school installation at Bundaberg Christian College (200kW solar PV with 250 kW usable storage) started the project roll out in December 2015 in Emerald, Central QLD.
The deal features energy efficiency initiatives across 52 sites ranging from LED lighting upgrades to solar and storage, with systems varying in size depending of the respective school or college requirements.
Although some system designs are still being finalised, and pending council approvals, Jack Hooper, GEM Energy CEO, says that the largest installation could end up being more than 1MW solar PV and over 1.2MWh battery storage. GEM Energy has opted for Q CELLS solar panels, SolarEdge inverters and power optimizers, and Tesla batteries for the roll out.
Over 20 installations have already been completed, including St Patricks Catholic Primary School in Emerald (pictured below).

Pay-back periods for the project costs are expected to be as short as two years for the smaller solar PV-only projects, and up to eight years for the larger projects which have the additional cost of battery-storage.
Jack Hooper says that one of the keys to generating the cost savings is tariff optimisation.
“We look to minimise demand peaks and maximise on-site usage of the “free” power.”
“Schools are a natural fit for solar PV, as the bulk of the metered usage (air-conditioning and lighting) occurs while the sun is shining.
The dispatchable energy from battery storage is important when cloud cover moves in during peak load periods, and for meeting the more modest night-time loads.”
All of the schools remain grid-connected, but as Ergon Energy’s network regulations currently prohibit export-to-grid from installations over 30 kW, generating cost savings while meeting the network operator’s requirements has been a challenge for GEM’s principal electrical engineer, Dimitar Iliev.
“Limiting excess solar production, which is common in schools on weekends and during holidays, to ensure zero grid export, while maintaining smooth battery charging and discharging on projects of this scale is technically very demanding.
Storage batteries add to costs, but assist by soaking up excess solar energy generation”
Hooper adds, “Meeting the design challenges means we can now give school CFO’s the accurate financial and system performance modelling they want before they’ll commit to major spending. Otherwise it’s just a guessing game.”
Acting Director Catholic Education – Diocese of Rockhampton, Ross Jones, is enthusiastic about the rollout.
“The project aligns well with our ongoing endeavours to be proactive in the area of sustainability and care for the environment across our kindergartens, primary schools and colleges.”
The rollout will occur in three phases and is expected to be completed in 2019.
John Elliott is a Science and Maths teacher at a Brisbane public school, and has been active in lobbying the Qld state government to make the (obvious and profitable) step of rolling out large solar PV on government schools, of which there are nearly 1300.