Australia does not have a problem with too much renewable energy. It has a flexibility problem. Rooftop solar has grown so quickly, and so unevenly, that parts of the electricity system now need more storage, smarter exports and demand-shifting to make better use of solar power when it is abundant.
Annual small-scale solar installations show how quickly rooftop solar has spread across Australia.
Source: Clean Energy Regulator, SRES postcode data — SGU-Solar installations.
Australia’s rooftop solar story starts as a success story. Millions of small systems have turned homes into distributed power generators. But this growth also changes how the electricity grid behaves during sunny low-demand periods.
Some states and territories have far more small-scale solar installations, creating different levels of local grid pressure
Source: Clean Energy Regulator, SRES postcode data — SGU-Solar installations
The grid challenge does not arrive evenly. States and territories with more rooftop solar have more distributed generation entering local networks at the same time, especially during sunny middle-of-the-day periods. This helps explain why the rooftop solar boom creates different grid-pressure problems in different parts of Australia.
Annual installations show that the rooftop solar boom has not followed the same path everywhere
Source: Clean Energy Regulator, SRES postcode data — SGU-Solar installations
The rooftop solar boom is not just large; it is uneven over time and place. Some states have seen sharper installation waves, which means the timing and scale of local grid pressure varies across the country.
The top postcodes show where rooftop solar has clustered most heavily, creating localised network pressure
Source: Clean Energy Regulator, SRES postcode data — SGU-Solar installations
The rooftop solar challenge is not only national or state-wide. It is also local. Some postcodes have far more rooftop solar installations than others, meaning grid pressure can concentrate in particular distribution networks.
The share of installations added since 2020 shows where rooftop solar has grown fastest in recent years
Source: Clean Energy Regulator, SRES postcode data — SGU-Solar installations
The solution is not to slow rooftop solar. The solution is to add the missing shock absorbers: batteries, flexible demand, electric vehicle charging, smarter exports and market settings that reward using power when the sun is abundant.
Rooftop solar is not the villain in this story. It is a clean-energy success that has grown faster than the grid’s flexibility.
The five charts show the scale, geography and timing of Australia’s rooftop solar boom. First, rooftop solar installations have grown into a major part of the electricity system. Second, that growth is uneven across states and territories. Third, different states have experienced different waves of installation growth. Fourth, rooftop solar is concentrated in local postcode hotspots. Finally, a large share of installations has arrived since 2020, increasing the need for storage, flexible demand and smarter export management.
This is why the story is a “blindsided” issue. Australia has focused heavily on adding clean generation, but the next challenge is making the electricity system flexible enough to absorb that clean power when it arrives.
This visual story uses public small-scale solar installation data from the Clean Energy Regulator. The dataset used is the SRES postcode data — SGU-Solar installations, 2011 to present and totals, which records small-scale solar installations by postcode and reporting period. This dataset was selected because the story focuses on the scale, geography and timing of Australia’s rooftop solar growth.
The data was imported and analysed in R. Column names were cleaned
using janitor, and the original wide-format dataset was
reshaped into a long format using pivot_longer, so that
each row represented a postcode-period observation. Installation counts
were converted to numeric values, year values were extracted from the
reporting-period labels, and postcodes were grouped into states and
territories using standard Australian postcode ranges.
The five charts analyse the same official dataset at different levels of detail. Chart 1 aggregates rooftop solar installations nationally by year. Chart 2 compares total installations across states and territories. Chart 3 compares annual installation trends by state and territory. Chart 4 identifies postcode-level solar hotspots. Chart 5 compares the share of installations before 2020 and from 2020 onward to show where recent growth has been strongest.
All visualisations were created in R using ggplot2 and
converted into interactive charts using plotly. Users can
hover over the charts to see values such as year, state or territory,
postcode, installation count, percentage share and total
installations.
No artificial, simulated or representative data was used in the final visualisations. All five submitted charts are based on public Clean Energy Regulator data. AEMO is used only as contextual background for the electricity-system concept discussed in the story. AEMO defines underlying demand as operational demand plus rooftop PV generation, which helps explain why rooftop solar can reduce the electricity demand visible to the grid during sunny periods.
The main limitation is that the charts measure installations, not real-time solar generation, exports or operational demand. Installation data shows where and when rooftop solar systems have spread, but it does not directly show half-hourly electricity demand. For that reason, the charts should be read as evidence of the rooftop solar growth pattern behind the grid-flexibility challenge, rather than as direct measurements of the midday demand dip.
Australian Energy Market Operator. (n.d.). Operational demand data. https://www.aemo.com.au/energy-systems/electricity/national-electricity-market-nem/data-nem/operational-demand-data
Clean Energy Regulator. (n.d.). Small-scale installation postcode data. https://cer.gov.au/markets/reports-and-data/small-scale-installation-postcode-data
Clean Energy Regulator. (n.d.). SRES postcode data — installations — 2011 to present and totals. https://cer.gov.au/document_page/sres-postcode-data-installations-2011-to-present-and-totals
Generative AI was used only for limited support with troubleshooting, checking R Markdown structure, and suggesting ways to improve chart clarity. The topic selection, data decisions, coding work, interpretation, visual checking, written analysis, and final submission were completed by me.
All final charts use real public data from the Clean Energy Regulator. No artificial, simulated or fake data was used in the submitted visualisations.