Resi-BESS

Testing and Trials

Michelle Taylor

Ergon Energy May 2016

Residential Battery Energy Storage Systems

• Industry survey – March 2014 and again May 2016

• Product selection

• Lab testing

• Field deployment

• Results

Funding for this work has been provided by The Department of Energy and Water

Supply, Queensland Government

Industry survey

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• 2014 - About 40 manufacturers bringing or intending to

bring in specific resi-BESS product to Australia

• 2016 – Over 70 manufacturers bringing or intending to

bring in specific resi-BESS product to Australia

• Includes Multiple Mode Inverters, packaged batteries,

packaged systems but not build compilations in general

• Understanding of products operation has increased

• Local support has increased

• Lots of changes in the market and in the product over

the time frame

• Lots of planned evolution of product

Product Selection

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• Up to 10kVA/30kWh single phase or 30kVA/50kWh

three phase

• High level of control enablement

• Some form of remote access

• Back-up function

• At first we only looked for fully packaged systems

• As the systems needed to respond to a series of tariff

scenarios, higher levels of control were sought.

• None appeared to have all aspects covered

• Started with 3 products – now this has increased

considerably

Lab Testing

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• Installation assessment

• Review of safety in relation to device/s – general

aspects and where available standards conformance

• General functional tests

• Operation under tariff scenarios

• Operation in end states – ie states where BESS could

not complete assigned task due to lack of battery

capacity (either as a load or a source) within command

Field Deployment

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• 11 units installed in a residential location in 10 houses

with 4 blocks of testing over a period of 1 year

• Each homeowner was also given an Energy Monitoring

Device which provided very rich level of information

• Solar shifting, time of use, time of use demand and

capacity tariff concepts were trialled

• Customers were heavily engaged for feedback

Results – Lab Testing

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Compliance issues – earthing, labelling, insulation, trip times

Installation assessment – some very straightforward to install, some needed a lot of extras (this is before you get to considering the state of the customer’s switchboard)

Operational assessment – the manuals left wanting for providing a good understanding of what the systems were able to do, and likely to do

- the systems generally performed consistently but in some cases this was even in contravention to what the manufacturers had noted in their manuals

- all systems were controlled via time clock and some had the additive of state of charge controls – at the time of lab testing, none actually enabled operational controls based on the energy monitoring of the installation (which was provided in various forms across the products)

- there was no consistency in terminology of operation

- the way in which systems were programmed was diverse

- the connectivity for monitoring and in some cases control was also diverse

- accuracy of system data was poor on some systems

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Testing in the Lab

Operational Development

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Results – Field Trials

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• Only 3 of the 11 systems did not have issues that resulted in failure or

inconvenience to the customer over the period of 12 months

• System failures included inverter, BMS, battery management module,

communications, on board circuit breakers

• Support for repair of systems took up to 8 weeks (system offline) and local

industry personnel were only able to provide very limited support, support

came from Brisbane, Perth, Adelaide, Melbourne and China

• There were some upgrades in operational firmware whilst in the field

• There were some in correct programming errors we made whilst the units

were in the field

• Correct installation with essential circuits separated and with the

installation of circuit monitoring required substantial work for brownfield

installations

• The cost of the system did not correlate at all to the reliability or to the

manufacturer’s desire/ability to resolve failures, or to the level of control-

ability of the systems.

Results – Field Trial – from the customer’s perspective

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• Due to some power cycling caused by interaction between the HEMS and

the BESS, and possibly other reasons, there were 4 appliance failures on

the trial that could have been attributed to the project

• All systems were installed outside on verandahs or carports, or in garages

and utility rooms (not habitable rooms)

• Customers lost interest in most cases in how the systems operated and did

not want to understand the details

• Customers wanted set and forget functions

• Having a user interface that is understand-able at a glance but does not

require a manual to interpret is important (apps are useful but not when

things go wrong)

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Outage Management

Figure 11: BESS and PV performance during outage

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Wiring challenges

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Some installed systems

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System installation

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System installation