Electrical Connection Autumn 2016

www. e l e c t r i c a l c o n n e c t i o n . c om . a u

GC PV is now on a clearer growth path.

The technical and compliance implications

are more manageable, as experience,

training regimes and trained personnel

permeate all levels of the industry.

GROWTH

The industry consensus is that the

energy storage market will match, if not

exceed, the historical growth of the GC

PV market.

It is important to note is that storage

growth cannot necessarily be viewed as

an extension of the GC PV market.

Industry, households and

governments will investigate installing

energy storage, and this will involve

product and service providers with little

or no experience in GC PV.

Such service providers must develop

an underpinning knowledge of the

technology and the market to service

these enquiries.

TRAINING

The knowledge and experience

requirement for the design and

installation of energy storage in the

current market consists of:

Electrical work.

GC PV theory, product and installation

knowledge.

GC PV energy storage theory, product

and installation.

Network connection.

Financial assessments, etc.

Without an adequate understanding of

the above topics and issues, systems will

be installed that are not appropriate and

are potentially unsafe.

Currently, it is only possible to complete

the required units of competency that deal

with battery installation if the student has

first completed the units for GC PV.

Given that battery systems do not

necessarily need to be installed alongside

a PV system, howwill these installers gain

the required information and training?

In addition, the performance and

product data quoted for equipment and

storage units currently on the market are

often inadequate and misleading. Training

is therefore required to ensure that

installers have a thorough understanding

of the technologies they are installing, what

the limitations are and how to properly

assess the information in a datasheet.

CONFIGURATION

An energy storage system can be

configured in several ways.

Is the energy storage system in addition

to a new or existing GC PV system? Is the

intended storage system stand-alone or

GC? The system’s designer, installer and

equipment supplier all have to understand,

quote and install the correct solution.

GSES has identified the following

possible system configurations:

Single hybrid inverter – provides

functionality of GC PV and regulates the

battery charge and discharge. Capable

of providing some back-up for selected

AC loads.

Single inverter with separate solar

controller – provides functionality of GC

PV as well as some back-up for selected

AC loads.

Two inverters with connecting switching

device – this configuration has both

inverters, the specified loads and the grid

all connected.

Multi-mode and GC PV inverter – this is a

simple configuration with a conventional

GC PV system operating as normal, and

a battery system essentially operating

independently supplying specified loads.

Multi-mode and GC PV inverter – both

inverters are able to supply the specified

loads independently of the grid.

In addition to any of these

configurations, systems can be set up

to optimise self-consumption of solar

generation.

An external current sensor monitors the

customer’s mains to detect when power is

being exported to the grid. This allows the

multi-mode inverter to seamlessly switch

between import/export to the batteries in

order to minimise exporting PV to the grid.

ECONOMICASSESSMENT

The economic rationales and

assessments that surround energy

storage systems are varied and in many

cases not defined by current practices,

regulations and Standards.

There is much uncertainty about the

technology’s performance, capabilities

and longevity.

The pricing of electricity and its supply

is also subject to continual variations

and performance stipulations. Therefore

any proposed business models of energy

storage companies could be inaccurate

over time.

STANDARDSANDGUIDELINES

There are no Australian Standards or

guidelines applying to energy storage as

currently promoted in the market.

Standards exist for stand-alone

systems, power systems and stationary

batteries, but they deal only with lead/

acid technology, not lithium ion (most GC

battery products).

Revisions are under way, but energy

storage systems are being sold and

installed according to current Standards

and laws. In many cases these are

imprecise and not technology specific.

So, howwill the industry monitor the

state of health, performance and financial

viability of energy storage systems? PV

can be very forgiving, but energy storage

does not provide the same comfort.

CONCLUSION

Regulations must catch up with energy

storage, and products need to stabilise in

the market.

Until then, there should be continuous

professional development for all levels

of the industry. Participants must be

equipped to quote, supply and install

acceptable and safe storage systems in

the absence of specific Standards and

guidelines.

> GSES