New directions in community solar

With momentum building towards net zero in Australia — most recently boosted by the passing of the federal government’s Climate Change Bill 2022 and its emissions reduction target of 43% below 2005 levels by 2030 — an increasing amount of research is being undertaken into energy diversification and the deployment of small to midscale community-driven solar initiatives. Several trial projects discussed by speakers at Australian renewable energy expo Energy Next provided inspiration, cautionary advice and a glimpse at possible solutions to the energy transition.

Community batteries

Louise Bardwell, from the Battery Storage and Grid Integration Program at the School of Engineering, ANU, spoke about community batteries, which are a form of medium-scale energy storage, normally in the range of a couple of 100 kWh — though they can go up to 1 MWh. (For reference, household batteries might be 40–50 kWh.)

Bardwell pointed out that while there are many large grid-scale batteries in Australia, there is a need for smaller-scale storage, including household batteries, electric vehicles and most recently: community batteries. All of these could have a role to play in Australia’s increasing need for storage to accommodate its particularly high penetration of household solar.

A community battery is located in the distribution network, in the low-voltage area around the houses it serves, close to where it’s being generated from solar. A defined set of households makes up the community of customers — this community is as much a part of the process as the technology.

In addition to its financial and environmental benefits, a community battery eases pressure on the grid by storing excess energy, increases hosting capacity (ie, increases the number of distributed energy resources [DERs] like EVs and solar panels that can be integrated into the grid) and is more efficient than household batteries. However, implementing these projects is complicated; community battery models are difficult to structure, especially with regard to tariffs.

A case in point is the Alkimos Beach trial, WA, 2016, run by state utilities Synergy and Western Power. While significant benefits included peak consumption being offset by 85%, and 83% of customers benefiting financially, the $11/month subscription fee wasn’t sustainable for Synergy. Additionally, the community were confused by the fee structure and didn’t feel engaged in the trial.

In contrast, the ongoing Solar Sponge project in North Fitzroy, Melbourne, owned by non-profit org Yarra Energy Foundation (YEF) and run in partnership with retailer Acacia Energy, has no direct customer involvement. This was a community choice; consultations found that reducing the cost of electricity bills was not the primary concern of people in the area. Instead, they wanted assurance that their solar was not being wasted and that it was being retained and used locally. They were willing to pay more for efficient, local energy.

Community battery ownership models vary and include:

• Third party (eg, YEF’s Solar Sponge).
• Third-party owner with community co-investment.
• Distributed network service provider (DNSP), eg, Ausgrid in Sydney.
• DNSP plus market participant, eg, Western Power and Synergy at Alkimos Beach.
• Community co-op model, in which participants buy and sell their energy to the battery, reducing their energy costs.
   

Operational models include: virtual storage (eg, Alkimos Beach trial), where there is no physical battery connected to the premises and individual customers are allocated virtual storage capacity in the battery; passive (eg, YEF Solar Sponge), with non-financial benefits but reduction of customer energy costs long term; billing; or peer-to-peer trading, in which participants buy and sell their energy to the battery.

There will need to be transparency about where the profit from community batteries is going, especially since many of them are government-funded. Bardwell recommended ownership by a not-for-profit organisation such as YEF.

There is significant support on the horizon for community batteries, including the Victorian Government’s Neighbourhood Battery Initiative and the federal government’s funding of 400 community batteries to the tune of $200m. While community batteries have exciting potential, Bardwell stressed that they are only one part of the energy transition.

Solar gardens

Kim Mallee from the Community Power Agency, a not-for-profit that works with industry, government and community towards making the transition to renewable energy, presented the solar garden model. This model is designed for people who are ‘locked out’ of solar, due, for example, to being a tenant, or living in a house that doesn’t get any sun or is heritage-listed. It’s a relatively new model for Australia that has not been attempted before on a large scale in this country.

Solar gardens provide the opportunity to purchase a solar garden ‘plot’ in a large solar array. An electricity retailer is then used to distribute the benefits from the solar garden generation back to the purchaser’s electricity bill. This differs from other arrangements in that customers are buying the solar in order to offset the brown power on their bill, rather than using the solar energy directly.

A major benefit is flexibility, with solar gardens allowing families to move house while still retaining their solar garden plot. Solar gardens enable investment in mid-scale solar, there is no maintenance involved for owners of solar plots and solar developers large and small can rent a portion of their panels as solar gardens. The federal government clearly believes in the potential of solar gardens, or “solar banks”, as it terms them, as seen in its new Solar Banks Initiative, which is investing $100m into 85 solar banks.

Haystacks Solar Garden pilot

Run by Community Power Agency and supported by the NSW Government Regional Community Energy Fund, the Haystacks Solar Garden pilot is Australia’s first large-scale solar garden, drawing on models popular in Germany and the US, and building on ARENA-funded research. Its aim is to find out how this model will work within Australian energy and legal systems.

A 1.5 MW solar farm near Grong Grong in the Riverina region in NSW, Haystacks will have capacity for 333 plots, enabling buyers to obtain credits on their electricity bill via a retailer for 10 years. It aims to be operational by March 2023.

Standalone power systems (SAPS)

Jonathan Knott, from the Institute for Superconducting and Electronic Materials at the University of Wollongong (UoW), gave an overview of standalone power systems — power systems not connected to the main electricity grid that can supply either a single customer (individual power system) or multiple customers (microgrid).

To create a SAPS, the following are needed:

• One or more sources of generation — a way of getting energy to your system.
• A load, or sink for the energy — something that’s using up energy, like a house or business.
• Control — a method of controlling the flow of that energy around the system.
• Storage — a buffer to help with control, like a battery or diesel.
   

SAPS can range from a simple Endeavour Energy SAPS in Kangaroo Valley serving a single-family residence (solar, Tesla battery, back-up diesel generator) to a microgrid serving an entire island.

Customer-led SAPS have been around for a long time, Knott said, with 2% of small-scale solar PV installed in Australia already being off-grid. A big factor in the future success of SAPS will be understanding customers’ level of energy literacy, because there is a cost in educating them.

Why should SAPS be used now?

Knott cited the significant reduction in battery cost, which has come down approximately six times from 2013–2021; while still expensive, batteries are becoming increasingly cost-competitive.

SAPS provide an opportunity for DNSPs to mitigate various issues arising from traditional power systems, like the cost of maintaining traditional electricity infrastructure, which can amount to a startling $25,000/customer/year to clear vegetation in some areas. Also, the 10% of Australians who live outside of urban areas, leaving them particularly vulnerable to floods, bushfires and other natural disasters, may be best served by SAPS.

Further expanding the potential use of SAPS, in 2018 an AEMC market review of regulatory frameworks for SAPS was instigated by the COAG energy council. The review has set out two priority areas of work:

• Priority 1 was to develop a national framework for transition of grid-connected customers to SAPS supply provided by the current DNSP (ie, companies that would otherwise be providing electricity to sites by poles and wires) as well as a mechanism for transition of grid-connected customers to third-party SAPS.
• Priority 2 was to develop a national framework for the ongoing regulation of third-party SAPS.
   

UoW’s work has primarily been concerned with Priority 1.

How is a SAPS site identified?

The UoW research earmarked four key areas:

1. Technical requirements, eg, energy consumption, location, whether the site gets a lot of sun/rain.
2. System requirements, eg, generation, storage, maintenance. What will the customer actually be using?
3. Customer profile, including energy literacy and engagement with the process.
4. Latent value, eg, in natural disasters.

Knott stressed that the way the above data is taken and interpreted has a huge impact on the way a SAPS is designed, its utility and whether it actually serves its purpose.

MyTown Microgrid

Continuing the SAPS theme, Dr Scott Dwyer from the University of Technology Sydney’s Institute of Sustainable Futures spoke about the institute’s “community-led, data-driven” microgrid project, MyTown Microgrid, which began in 2020. An ARENA initiative, this feasibility study aimed to discover how to make it easier, cheaper and faster for communities to understand whether a microgrid was suitable for them; and to develop toolkits and guides for this purpose.

The rural Victorian town of Heyfield (population about 2000) was chosen for the trial due partly to its community’s high level of energy literacy and commitment to sustainability.

UTS, Federation University and RMIT partnered with Heyfield Community Resource Centre on the project, along with Public Interest Advocacy Centre Ltd. (PIAC); Community Power Agency; Wattwatchers Digital Energy; Ausnet; and LaTrobe Valley Authority (LVA).

The project moved through several stages, beginning with community vision and goal-setting. Real-world data was then collected through Wattwatchers’ IoT platform, involving energy monitoring devices (96 devices, 76 sites, 98 audits) and community engagement through an app and dashboards installed around Heyfield. Step 3 involved technical and economic analysis of the data, leading to step 4, where a business model was co-designed with the community.

Dwyer emphasised the importance of having a community liaison officer to facilitate constant dialogue, answer questions and help with installations and energy audits.

What’s next?

A key finding from all the solar initiatives discussed at Energy Next was the need for community engagement. Small-scale solar initiatives might have a role to play in the energy transition, but only if the groundwork is laid for strategic implementation — via collection and interpretation of data, and prior consultation — in communities that are receptive, engaged and informed.

Image credit: iStock.com/Lacheev