Music from the Sun

Off the Grid 100% Renewable Music Festival, Melbourne, Australia

Off the Grid was a 100% renewable music festival held right in the heart of Melbourne in December 2015. Festival organizer Finding Infinity was the first client to use an innovative mobile renewable power plant developed by Australian on-site renewable power specialist Green Power Solutions (GPS). The plant was designed to be easily transported to off-grid or weak-grid sites, and it uses an UltraFlex storage system supplied by Ecoult.


Off the Grid, Australia’s first fully solar-powered music festival, was held in central Melbourne in December 2015. Its only energy source was a 7 kW photovoltaic (PV) array, which powered the festival during daylight hours while also charging Ecoult’s UltraFlex, which in turn powered the festival through cloud cover and long after sundown. The festival’s back-up biodiesel generator was never switched on.

Off the Grid Renewable Music Festival Melbourne

No grid, no diesel – just reliable solar power, day and night.

Client challenge

Generally, a PV-only system requires generator back-up for peak loads, periods of cloud or night-time use. But Off the Grid festival organizer Finding Infinity was committed to producing a music festival with Australia’s lowest-ever rate of carbon emissions. With the festival running until late into the evening, that meant finding an energy storage solution that could allow the available solar power to be used well beyond daylight hours. It would need to be able to handle the site’s night-time electrical load, as well as smoothing the day’s solar and charging at very fast rates, so that if the back-up generator ever had to run (which it didn’t), it could do so at its highest efficiency-rated output for the shortest possible period of time, just to recharge the batteries. Finding Infinity sought help from Australian on-site renewable power specialist Green Power Solutions.

Off the Grid Renewable Music Festival Melbourne

Solution Provided

To meet the challenge, Green Power Solutions (GPS) developed a solution based on its innovative new-generation mobile renewable power plant, which is designed to be easily transported to off-grid or weak-grid sites. GPS chose Ecoult’s UltraFlex for its power plant, because UltraFlex uses Ecoult’s renowned high-powered UltraBattery technology, includes advanced remote monitoring, and comes with Ecoult’s commitment to on-the-ground customer service.

The solution developed by GPS for the music festival comprised:

  • 7 kW solar panels
  • 50 kVa rated biodiesel generator (as a back-up power source)
  • 48 V, 20+ kW UltraFlex energy storage system from Ecoult
  • Selectronic SP Pro inverter.

The load in this case included the entire site – from sound equipment and lighting to food stalls and more. The peak load used on site was under 20 kVa.

UltraFlex and the solar array managed the load throughout the entire festival, with the back-up biodiesel generator never once needing to come on.

The renewable power solution used was designed for medium-load temporary applications such as festivals and construction sites. It has since been containerized and its storage expanded for fast, fully installed delivery. The containerized version includes PV panels, two UltraFlex units, a biodiesel generator and power control systems.

The system delivers significant fuel reductions. In the case of the Off the Grid music festival, fuel reduction was 100%.

UltraFlex at the Off the Grid Music Festival Melbourne


The storage chemistry in the UltraFlex is based on the extraordinary CSIRO-developed UltraBattery, a hybrid device containing a lead-acid battery and a carbon ultracapacitor, both sealed in a single unit sharing a common electrolyte. This technology combines trusted, world-class lead-acid batteries with an ultracapacitor for fast cycling capabilities and partial state of charge operation to meet modern energy storage needs.

Ecoult has developed this high-power, fast-cycling invention into fully monitored kW- and MW-level energy storage systems to suit any storage application.

UltraBattery chemistry – lead oxide (PbO2) and lead/carbon electrodes  in a common electrolyte
UltraBattery chemistry – lead oxide (PbO2) and lead/carbon electrodes in a common electrolyte