With the increasing use of stationary batteries in residential, small commercial and light industrial situations, Peter Vandenheuvel believes now is the right time for the more entrepreneurial to take off the blinkers.

All successful entrepreneurs know; to be successful an enterprise must have a point of difference. Something that stands out clearly above the pack. Being the same ol’ doesn’t cut it. And the early electric vehicle (EV) adopters will love it.

This article started life looking at the safety of stationary batteries. However, experience so far shows while there may be different hazards, their overall risk profile is sufficiently similar to not press alarm buttons.

The focus then shifted to the inevitable increase in complexity of battery inclusive installations. Was that a good thing or a bad thing?

Well for those just wanting to plod on as of now, the demand for basic installs will still be there for some time. By doing it right they will still get some part of the action – business as usual. However, for those in our industry looking for an edge, it could be a bonanza.

Looking at the current market, it was realised this ‘batteryfication’ – installing batteries everywhere – was all customer driven, the main aim being to begrudgingly make some savings on their out-of-control electricity bills.

Then the light went on; it could be much more than that.

With the right smart initiatives, existing solar systems can be expanded and new systems designed from scratch, to take full advantage of both these ‘maxed’ outputs can be reached by:

• maxing out solar panel area and so the power generated by it; and
• boosting system efficiency through better power management.

And because the installers’ ‘smarts’ will add complexity, and be an integral part, it will be very difficult for the same ol’ brigade to compete.

So, designing and delivering an end-to-end ‘maxed output’ system will be the smart installer’s point of difference.

What’s in it for the customers?

A one-stop solution to max-free power.

Packaged by the installer to be end-to-end and comprising the entire design, installation, testing and setting work – including arranging approvals from authorities – the owners have a one-stop shop and a single point of contact.

They will have a high level of confidence and peace of mind knowing they need do nothing themselves and a knowledge every solar watt reaching the panels will be put to the owners use before need to top up with any electricity from the grid.

And the customer’s top benefits?

A much greater supply of free electricity to use as they wish to:

• Fast track the change to EVs – no more servo fuel to pay for
• Live in much greater comfort – not worrying about the cost of heating or cooling
• Add more heating and cooling – including split systems, heat banks etc.
• Get a pool or spa – with the pool pump and spa heater running at no cost

And what’s in it for the switched-on installers?

By taking their customer offerings that one step further, beyond just saving on the power bills, electricians could change the business from one where they wait ‘in the pack’ for customers to find them, to being in the box seat: deciding who their customers will be and picking those they want.

Do it right and the result will be more prospects, more customers, better margins and then some, including the follow-up service and system tweaking. Yes, it will mean that the dreaded identifying and selling to customers, but that is what being an entrepreneur is all about.

By having such a unique selling proposition and the right presentation, aimed at both extending existing systems and installing new ones, the installer is in full control.

And where to find them – everywhere, every home or business is a potential customer – then just look on the roof, no solar; offer new installs, solar; offer upgrades.

So, for those entrepreneurial installers, the time for packaging and proactively selling ‘maxed’ solar packages is now.

Here’s the challenge

To all electricians and contractors now chasing – or entrepreneurially minded – to expand in solar:

• Do your homework and become the expert
• Develop options for different installations
• Build an end-to-end package
• Develop own smart ‘maxing’ initiatives
• Build close alliances with top-notch suppliers
• Develop and implement the marketing strategy
• Deliver the installs timely and professionally
• Follow up with service

Listed below are the key issues installers must be across to gain customer confidence and get the order. It also includes the issues to be agreed upon and signed off by the customer to eliminate misunderstandings.

It is the installer ‘what to do’ list. The ‘how to do it’ – the smart initiatives – are up to the installer’s ingenuity, originality, imagination and resourcefulness, and it is what will give their unique edge.

And don’t forget compliance. This includes the following important Standards:

• AS/NZS 3000 – The Wiring Rules
• AS/NZS 3011 – Secondary batteries in buildings (parts 1 and 2)
• AS/NZS 4777 – Grid connection of energy systems
• AS/NZS 5033 – Installation of PV arrays
• AS/NZS 61439 – Low voltage switchgear and controlgear
• AS/NZS 61851 – Electric vehicle charging system

Why batteries?

Because we are already being warned of a 35% power cost increase by mid-2023 and all politician’s promises for many years now – that we would have cheaper power – have come to two-tenths of three-fifths of zilch.

So, people with access to sunlight and the money to install their own solar are seeing the light.

For those with solar already, a battery will give them cheap or free power around the clock and stop owners from being forced to sell their surplus power to the network at insultingly low feed-in tariffs – only to have to buy that power back at an exorbitant cost later.

By maxing the storage of their solar generation, they can live much more comfortably and with no stress about power bills. They are perfect candidates for upgrades with an opportunity to optimise their return on investment.

And this is where the astute installer’s inventiveness, resourcefulness and end-to-end and one-stop-shop approach to maxing their free power take customers from being undecided to full-on converts.

Given there may be compatibility or ratings upgrades for panels or devices, installers must liaise closely with their suppliers to overcome any potential limits to what can be economically upgraded, added to, or changed.

Then, if customers are made aware the new technology and equipment will essentially give an existing system a 15-year life extension with upsized capacity that can be the tipping point to get the sale over the line.

For the solar newbies, now is their time to invest – because the earlier they start the earlier they’ll benefit.

Paint them a picture of the potential: what extra appliances they can power up from a ‘maxed’ system over the next 15 to 20 years. For them, a battery presents the opportunity to get ahead of the game and fast-track their change to EVs right here and right now.

So, those potential customers become immediate red-hot prospects, especially as energy prices keep skyrocketing and batteries are now very affordable.

And the potential for them to install more heating and cooling and run it without worrying about the cost will be a luxury in itself.

The opportunity to heat the spa, run the pool pump and warm the whole home, as well charging two or more EVs – so no more fuel cost – will also appeal.

In fact, in the long term, the charging of EVs will be one of the major benefits of both upsizing existing and installing new systems.

How big?

Sizing the battery, or batteries, needs customer involvement. What is their ‘magic wand’ objective – is it to:

• Just ride out power failures?
• Cover-off only the main appliances?
• Optimise return on investment?
• Generate all ‘captureable’ energy?
• Have independence from the grid?
• Or somewhere in between?

The optimum: target all that’s ‘captureable’ for the greatest flexibility and maxed savings.

Whatever the objective, all short-term loads and peak demands as well as future loads and hoped for little luxuries must be factored in, with staged charging for two or three EVs also high on that list.

As the uncoordinated use of two or more large power users will considerably affect battery size, with their ‘smart initiatives’, the installer must include smarts to prevent their simultaneous operation (as with the EVs above) where possible.

The higher the expectations, the bigger the battery, in size, capacity and cost. Cost is typically a big factor, so there’s even more of a reason for the installer to propose an all-captureable option and optimise their ‘smarts’ to match.

As factoring in extended power outages could also impact battery capacity this may be better dealt with by generator-driven UPS systems – the supply and interface of which can also be included in the ‘smart initiative’ package.

In sizing battery capacity there are a number of elements to consider and a factor of +25% is generally recommended, in addition, the losses detailed below also need factoring in.

System losses

The losses when charging and discharging batteries are a minimum of 5% in each direction, with similar losses for other devices, including inverters, EV chargers and more. So, a minimum for the battery and inverter of at least 15% (total) capacity should be included.

Battery life and performance optimisation are at least partly impacted by excessive charging and discharging and so there are recommendations battery life be extended by limiting charging to around 90% or 95% capacity and not discharging below some 20% to 30%, creating a 60% to 75% ‘capacity window’.

If adopted this could effectively reduce the usable capacity to between 60% and 75%, so require further upsizing, and by averaging those (by my reckoning to 100/67.5 = 148), to about an extra 50%.

Upgrading or new?

For current solar users, the smarts for the installer should also include a cost-effective way to add panels and upsize converter capacity. This may mean creatively finding space (or more structures) for more panels and uprating of the inverter.

Due to the possibly being some additional work in uprating, this could create some owner reluctance.

However, as all new equipment will be good for around 15 years, the opportunity to have the extra capacity now (perhaps for EVs or lifestyle) can appeal to customers and should at least be suggested.

For solar ‘newbies’, the ideal opportunity is to maximise the system rating and battery capacity and enjoy all the benefits from day one.

Battery voltage

The most common battery voltage ratings are incremental in the 6V DC to 48V DC range.

The voltage decided on will be influenced by the input capacity of the solar cells, the output from the battery, the DC to AC inverters and directly connected DC loads, if any. As efficiency rises with higher voltage increases, care selecting the optimum voltage is important.

Battery type?

Subject to suitable space, access and compatibility with system devices, there is no technical limit on battery type. Typical battery types include:

• Lead acid: tested technology but with corrosive liquid electrolyte that can spill and cause injury hazards.
• Nickel-cadmium (Ni-Cad): reduced maintenance needs compared with lead-acid types but not widely used.
• Lithium-ion (L-I): the most recent battery development, can overheat, catch fire or explode if charged in an unsafe manner.

As larger batteries can instantly release much arcing or explosive energy from internal failure or external short circuit all terminals and other live parts must be protected, and suitable fire extinguishers should be made available within safe reach (class D for L-I type).

Selecting the optimal battery will have a major impact on the economic performance of the entire system lifespan, so an overall lifetime cost-benefit study may be required with deep cycle batteries also considered.

Charging the battery

To charge the battery, a solar charge controller must be installed to help manage power into the battery and save batteries from overcharging during the day as well as preventing the battery from draining from reverse flow overnight.

There are two main types:

• On-off – switching power from the panels off and on at pre-set voltage levels; and
• pulse width control – allowing voltage to continually rise and maintain it at a high but steady level.

The charge controller’s primary function is to manage power, but some also offer load control or other features like the ability for configuration to coordinate other components, so devices of this type should be explored as part of the ‘smart’ initiative.

Similarly, battery monitoring, control of charging and discharging to prevent over and undercharging and extending battery life, as well as preventing the installation from using grid power unless absolutely necessary should be considered as part of the smart initiative package.

Inverter size?

There are different types of inverters including:

• Micro inverters – one for each single solar panel, maximise power generation but can’t be linked directly to batteries.
• String inverters – most common and long-standing, all panels connecting in a string, but these export all unused power to the grid and reduced sunlight on one panel affects the entire output.
• Battery inverters – convert stored DC into AC, but still require a string converter and solar charge controller to charge the battery.
• Hybrid inverters – combining solar and battery converters into one unit so the panels and battery are powered and managed by one technology.

Once the inverter type is decided, its rating must be at least equal to the maximum power the battery is able to supply to the converter-connected loads at any one time.

From the above, it appears the hybrid type would be best suited to a smart system.

Single or three-phase?

Obviously, a single-phase installation will include a single-phase inverter.

For three-phase installation, depending on the purpose of the battery, the output can be connected to one of the phases with a single-phase inverter or across all three phases using a three-phase inverter.

When a three-phase solar PV inverter is installed, it assists in balancing the power load.

How many components?

A solar generation system requires one or more suitably rated DC cut-off switches for the panel output as in AS/NZS 5033:2021.

Apart from solar panels, their isolators and the wiring, a battery inclusive installation also requires a combination of three components: a solar charge controller, the battery and an outgoing DC to AC converter for connection to the ‘normal’ installation supply.

The battery can comprise separate cells or sections with series, parallel or combination connections, and there may also be more than one, depending on any other outgoing loads.

For safety and maintenance reasons, if not already mandated, additional suitably rated cut-off switches should also be considered on both sides of the solar charge controller.

Additionally, circuit protection devices (fuses or DC-rated circuit breakers) should also be installed upstream of the inverter (in place of the isolator in that position suggested above), and other outgoing circuits.

However, the typically ‘series’ connection arrangement described above may be complicated if other DC or AC loads are supplied directly from the array or battery output.

This includes where other batteries, loads EV chargers etc are connected directly bypassing the inverter.

Location

Ideally, to minimise ‘voltage drop’ losses, all the input and output devices should be the minimum distance from their input sources and output ‘consumers’ with all interconnecting cabling generously sized to suit.

Not only that, to optimise the battery and other components’ lifespans, they should be in a cool, dry, weather protected, ventilated, shaded, sun-protected, safely accessible and egressable, adequately sized and a suitable manufacturer instruction specified environment.

Also, all system components must be securely protected from unauthorised access, foreseeable mechanical damage, vandalism and EV or other vehicle impacts.

They should also be located away from ignitable materials, fire hazards and situations where component, internal battery failure or external short circuit fault could spread a fire to ignitable materials or structures, especially above or adjacent the equipment.

Ready to take on the challenge?

This can be your ‘batteryfication’ maxing eureka opportunity – the market is ready and willing to pay for astute installers to help reduce or eliminate customer’s electrical bills, add extra luxury and comfort to their life style and fast track EV ownership.