Batteries arrive for Horizon’s grid-scale “spinning reserve” trial

One Step Off The Grid

WA utility Horizon Power is set to trial the use of large-scale battery storage to meet peak power demand – acting as an alternative to fossil fuel-generated “spinning reserve” – after two batteries capable of delivering up to 2MWh of power arrived in the coastal town of Carnarvon.

In a first-of-its-kind trial for the state, the two 1000kW batteries housed in two 40 foot containers will be connected to the 170MW Mungullah Power Station and used to store energy produced by that station with the primary function of providing back-up power for the islanded power station.

Mungullah-Photos-11

The batteries – provided by Chinese company, Tianjin Lishen Battery – will be tested to see if they can rapidly provide energy in the event of a spike in demand or if an existing back-up generator stops running, potentially saving hundreds of thousands of dollars a year in fuel and maintenance costs.

It’s a function that would have been useful two years ago, when a category three cyclone tore through Exmouth, Coral Bay and Carnarvon leaving blackouts in its wake – a situation Carnarvon Shire president Karl Brandenburg described as “critical” for the town’s 9,000-odd people.

By comparison, the nearby Thevenard Island was kept in power, thanks to its then relatively new solar-hybrid mini grid that not only survived the storm, but continued running throughout, on stored battery power.

“We have a clear aim to embrace new technology and drive the increased uptake of distributed energy and the capability of microgrid technology,” said Horizon Power managing director Frank Tudor on Wednesday.

“The use of (the Carnarvon) battery storage unit means that the cost of providing spinning reserve to supply electrical power for Carnarvon will be significantly reduced as we will be using stored battery energy rather than gas or diesel to provide reserve power,”

Project director Brett Whisson said the trial also aims to investigate how battery storage might be able to support the installation of more distributed renewable energy in the region, which already has one of the highest penetration levels of all of Horizon’s islanded networks, with 121 individual PV installations totalling 1.3MW in capacity.

More specifically, says Horizon, the is a first step towards meeting its commitment to incorporating renewable energy into the 17MW Mungullah Power Station.

This article was originally published on RE sister site, One Step Off The Grid. To sign up for the weekly newsletter, click here.

Comments

7 responses to “Batteries arrive for Horizon’s grid-scale “spinning reserve” trial”

  1. Chris Drongers Avatar
    Chris Drongers

    1.7 MW of distributed PV connected to the 17 MW Mungullah power station doesn’t sound like enough to justify the severe curtailments on new PV connections that I understand are in operation in Carnarvon.
    Is the power grid in the area that sensitive to distributed power?

    1. Open Air Avatar

      As this is a spinning reserve system, its primary purpose is not related to solar PV installations.

      In any power grid, islanded or not, there is the danger of a generating unit suddenly failing. To maintain system voltage when that happens, the grid keeps “spinning reserve”, which means keeping enough spare generation running to cover the loss of the largest unit that could fail.

      In this context, the Mungullah station is 10 x 1.7MW marine engines, 5 gas and 5 diesel. What that means is if 3 engines are required to cover a demand of 5.1MW, a fourth will be on and running to cover the loss of one of those engines. It doesn’t do anything other than provide a safety net, but it uses fuel which is particularly expensive if the spinning reserve engine is a diesel one.

      This battery system provides the same purpose, meaning that you can turn that fourth engine off, and save the fuel. If one of the others fails suddenly, the battery system (2MW, the same size as 1 unit) will pick up the slack until another engine can be started up (which might take 5-15 minutes). Most of the time, though, it will be idle.

      The way PV interacts is secondary. The main power station provides the balance of power after PV input into the grid is accounted for. This battery system could theoretically serve that purpose to an extent, which is why Brett Whisson says they’re just “investigating” how battery support might work. There’s no real need for it with the power station there.

      1. Chris Drongers Avatar
        Chris Drongers

        Thanks for the explanation re spinning reserve. Re the PV though, if the battery provides spinning reserve covering short falls due to engine failure or, equivalently, clouds over the sun, I see little difference. If anything clouds are more predictable than engines.

      2. wideEyedPupil Avatar
        wideEyedPupil

        Does the spinning reserve run at full capacity (top rated speed) to cover the outage of another turbine within a millisecond or is it running at an idle speed so it can be powered up within seconds/minutes?

        1. Open Air Avatar

          There are various operating strategies. Generally though, the engines tend to be most efficient at around 80% load, so the perfect case is to have is where you have, say 4MW load with 5x1MW engines running. You can run all 5 at 80%, or if one fails ramp up the remaining 4 to 100% while another starts. Demand rarely gives you the perfect scenario, though, so it’s a matter of balancing the instantaneous load with the number of engines online and their ouput levels to get the best efficiency out of the combined system.

  2. FeFiFoFum Avatar
    FeFiFoFum

    The article refers to a “170 MW’ Power Station which is a typo.
    Its a “17 MW” station 🙂

  3. stephan011 Avatar
    stephan011

    Great job, congratulations.

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