We are pleased to share our Energy Storage interview with DONALD MCPHAIL, Senior Network Strategy and Policy Engineer, Ergon Energy / Energex, Australia. He was a speaker at the 10th Energy Storage World Forum in May 2017 in Berlin. Learn more about the 11th Energy Storage World Forum and the 5th Residential Energy Storage Forum 2018 in Berlin by downloading the program
What is Australia current outlook for Residential Energy Storage and where things are headed?
Australia is very much at the forefront of the Residential energy storage evolution and this is being driven by a combination of items. Australia – in particular states like Queensland – have some of the highest uptake of solar PV, with 1 in 4 households owning a system, typically 4kW in size. Australian energy prices also doubled over the 10-year period, and subsequently energy is now a common talking point of the general public, with advertisements for solar and energy storage now as common fixture. While there is now over 100 integrated battery energy storage products on the market in Australia, uptake still remains quite low in comparison to Germany, largely due to the payback being greater than >10 years for all but a very minute portion of the population (including with recent price drops due to introduction of Tesla Powerwall. However, Bloomberg expects the average payback period for residential consumers to fall below 10 years in the early 2020s, with around 100,000 battery storage systems to support rooftop solar photovoltaic generation predicted to be installed by 2020. Subsequently there is a significant amount of activity across the supply chain for energy storage, including regarding improving regulations, connection processes, and related standards.
In your opinion, can voltage regulation with customer storage sufficiently mitigate extreme undervoltage and overvoltage events that trip off customer solar and storage?
Ergon Energy / Energex has really focused on over the past 7 years this area. Voltage management in the low voltage and medium voltage networks are some of our biggest challenges, in part due to the fact we operate long radial networks, but also because we have significant peak demand, as well as large reverse flow due to PV export during the middle of the day in residential areas. This stretched us to our limits of our statutory voltage limits (note 240V +/- 6% in Queensland, however we’ve successfully lobbied to move to the Australian/International standard of 230V +10%/-6% which has a larger range), and therefore have been focused for some time on lower cost non-traditional solutions, including on the customer side of the installation. In 2013 we undertook an extensive modelling exercise of our portfolio of network types to look at the effects of leveraging reactive power control capability in inverters (which were not common place at the time) and found we could increase the network’s ability to facilitate DER connections by 50% without noticeably impacting on customer kwh generated. As a result, we lab tested a number of inverters on the market at the time, and ran a field trial involving high-penetration of solar PV with the capability. These results confirmed our modelling and as a result we introduced the need for basic reactive power support in 2014 as part of our connection standard, and made it mandatory for all installations >2kVA from 2015, when AS4777.2-2015 was introduced. Expanding off this we now call for Volt-Var (or Q(V)) functionality to allow for support in battery systems that can act as both a load and a generator – hence during times of both high and low volts.
Accompanying this we’ve also invested in supporting the development of LV STATCOM and similar devices, having modelled, lab tested and trialed a number of devices to dynamically manage voltage in LV networks, namely where we have high Solar PV penetration. These again provide us with a low cost solution that is readily deployable. Unfortunately, the maturity of the technology and hence the range of products has been low, however we have just run a tender over the past year to bulk purchase these devices to use as a standard piece of gear in the field. We’ve also been expanding our modelling work to see how these units will interact in open and closed loop control arrangements of LV networks when you have mass uptake of inverters with dynamic voltage management capabilities, along with STATCOMS, and traditional voltage management devices like line and transformer regulators. The majority of this work has now been published and available via IEEE Xplore in order to support other utilities.
The next phase for us is tying in voltage management along with capacity management with other DER and smart load devices, both through direct utility control, onsite smarts, or market based aggregated control.
As Ergon Energy / Energex is Australia’s largest electricity distribution business, what role do you play in the future home battery storage development? How do you respond to the ever changing growing energy industry?
The merger of Ergon Energy and Energex has established the largest network business in Australia. One unique opportunity we have is that we now have a common leadership across the state of Queensland, which is a really great strength to have leading into the level of transformation the industry will undergo over the next decade, particularly at the edges of the grid. Since 2013 the two businesses had been working together on establishing common connection standards for distributed energy resources, and sharing knowledge around trials and technology developments in this space. This is really starting to pay a dividend to the organization and to our customers as Queensland is now being held up as the benchmark for other networks to strive for by industry bodies like the Clean Energy Council. A key area of focus going forward however is going to be how we transition our existing load management capability (which makes use of hot water systems, pool pumps and air-conditioning units under control to address network capacity constraints) to include DER, but also be effective in a shift to a market based approach due to the introduction of Power of Choice legislation, and the work underway currently by the AEMC on the future Distribution Market Model. To support this we’ve been leading the development on the use of the open access standard for Demand Response Enabling Devices(AS4755), and the use of incentive programs that use a risk based approach to value demand management for constraints that are expected to emerge beyond the current regulatory period 3-10 years – we call this optimal incremental pricing.
What are the global technological market innovations that drive the next generation solutions?
Integration and control capabilities are probably the largest shortcoming of the technology currently. We see a massive gap between what the glossy brochures say they can do, and what the can actually do. This is critical to not only properly take advantage of the use cases and business models that exist now in the residential space – such as tariff arbitrage or improving solar utilization – but even more so when you factor in things like peer-to-peer trading, network support, and wholesale market participation via aggregation. Currently the capability, generally speaking, isn’t that much different to a hot water storage with a time clock. However, there are some bright sparks starting to emerge.
Donald McPhail (BE, CPEng, RPEQ), is the Senior Network Strategy and Policy Engineer with Ergon Energy. Donald has been responsible for the development and implementation of Ergon Energy’s connection standards, strategies and policies for distributed energy resources – including Solar PV, Battery Energy Storage, Electric Vehicles and microgrids. The focus of this work has been to facilitate Ergon Energy’s vision to become a market enabler, in an increasingly dynamic industry. From 2011 to 2013 Donald was an E.S. Cornwall Scholar, working in the UK, Netherlands and US and gaining exposure to international developments in the integration of DER. Donald is a steering committee member of the Australian Energy Storage Alliance.
If you want to know more about this and other topics directly from end users of energy storage technologies join us at one of these annual events: The Energy Storage World Forum (Grid Scale Applications), or The Residential Energy Storage Forum, or one of our Training Courses.