Well-integrated renewable energy systems that include solar PV, battery storage and energy management systems have proved themselves for simplicity and efficiency, writes Nathan Dunn.

The desire for greater energy independence, rising electricity prices and changes to feed in tariffs are driving more consumers to adopt energy storage to optimise their investment in their residential rooftop solar systems. Coupled with the high adoption rate of rooftop solar across the country, the Climate Council predicts Australia would emerge as one of the largest markets for battery storage globally.

Storage is increasingly seen as a vital companion to a rooftop solar system. According to the SunWiz 2017 Battery Market Report, the battery market is set to treble in the next 12 months. SunWiz predicts that 70% of households in Australia with rooftop solar will add batteries to complement their rooftop solar systems this year.

A survey by Energy Consumers Australia survey has also revealed that close to a quarter of its survey respondents were motivated to consider investing in batteries to reduce their energy bills and their dependence on energy from the grid.

How technology is changing

The anticipated demand for batteries has driven an influx of storage brands being offered at a range of price points, storage capacities, battery chemistries and technical specifications. While each battery could stand on its own merit, installers can often be overwhelmed when they are trying to identify a suitable solution to recommend to their customers.

Traditionally, storage has been associated with two distinct use cases: for backup or off-grid use. In large countries like Australia, off-grid batteries are generally associated with communities that may not be part of the electricity grid. However, off-grid storage would still need to be backed up with generators and require oversized solar photovoltaic systems to run effectively.

Backup storage stores power for use during an outage of the electricity grid. Grid outages rarely occur; in fact, on average only 60 blackouts occur across Australia every year. These blackouts usually affect small regions and for up to an hour at a time so it is a challenge to justify the cost of an over-engineered backup storage solution. Such an investment would generally take years more to pay off over a regular battery solution due to the need of an oversized system to handle a homeowner’s load when a grid connection is cut off.

Recipe for savings

The applications associated with backup and off-grid use have evolved over time with solar technologies. New use cases have emerged with improvements to battery chemistries that are safer and easier to install in homes.

The development of home energy management systems (EMS) has enabled a new thinking as it relates to energy storage in the home. Energy management systems are designed to help manage the energy generated and stored, allowing homeowners to choose how they would like to consume excess solar and storing it for use at a later time. This effectively gives homeowners greater autonomy over how and when they would like to use grid electricity or solar power.

Self-consumption is a core benefit for homeowners who want to get better value from energy generated instead of drawing energy from the grid during peak hours in the evening. Batteries that are designed for self-consumption tend to allow homeowners to right-size their batteries to maximise on storage capabilities. By pairing storage with an EMS, homeowners can determine when they would like to use solar, energy storage or grid electricity.

These technological enhancements make storage a more attractive value proposition since it allows homeowners to align the way they use and consume energy. With grid electricity prices on the increase across all states, combining the right amount of storage with an EMS can result in significant cost savings on energy bills.

Key considerations for storage

One of the key points is not all batteries are created equal. The largest storage capacities or the least expensive options may not always be the most viable solutions. While there are many considerations for installers and homeowners who are thinking about storage, Enphase believes these are the top three considerations for recommending and selling storage to their customers:

Going modular instead of going big

Modular batteries which have smaller storage capacities will allow homeowners to increase their capacity by purchasing more batteries in the future instead of making a single, upfront investment for a battery that may be much larger than their day-to-day requirements. A modular battery allows installers to build storage into solar systems of any size and gives homeowners the flexibility of purchasing more batteries if needed in the future.

Australian energy analyst firm Energeia has cited that the optimal storage system is around 1-2kWh. By starting with a modular design, homeowners do not have to end up paying for any unused storage capacity. If a solar system produces only an excess of 4kWh a day, it is hard to justify the cost of investing in a 10kWh battery even if the cost/kWh is much lower.

Safety and reliability is crucial

Installers need to be confident they are recommending a battery chemistry that is safe and reliable for homeowners.

Zinc bromide, lead acid or lithium iron phosphate are some of the most commonly found battery chemistries in Australia. Lithium iron phosphate has been widely touted in the industry as a safe and reliable chemistry that is safe for any home environment. Installers should consult with the Clean Energy Council certification standards to ensure batteries they are recommending meet industry safety standards.

Smart and integrated

With batteries fast becoming a mainstream feature in households with rooftop solar, installers are best positioned to work with an integrated solar and storage solution instead of trying to integrate different components from various software and hardware providers.

By combining smart hardware technology with a sophisticated software system, installers have all the tools they need to install and commission a system much faster. Instead of having to call different providers to get a storage system online, they can rely on a web or mobile app to provision a storage system, setup and update software and system profiles from a single interface for the battery and EMS.

The Enphase Home Energy Solution combines solar, storage and software to provide an integrated system that delivers savings to homeowners by allowing them to make the most out of their solar production. It is powered with software technology that offers flexibility to installers to handle growing energy requirements to smart home and smart grid integration.

Storage is a significant and long-term investment for many homeowners. During our conversations with installers, all evidence points towards how homeowners are increasingly reliant on installers to guide them through a complex decision-making process.

Installers can take this opportunity to reach new customers by helping them achieve their energy goals with a smart storage system – a system that brings together smart technology, great software and batteries that evolve and expand with their lifestyle needs.


Nathan Dunn is managing director Asia-Pacific of Enphase Energy.