A renewable home supplied with a with innovative renewable energy systems.

Australian First Utility Room

Worlds 2nd Largest Battery Array

Geothermal Heating and Cooling

Bespoke Toorak Home

NGroup were asked to equip a new home beng built in Melbourne with innovative renewable energy systems – geothermal heating and cooling, solar power, batteries and hydronic (hot water) heating. The four story home was constructed by Bespoke builders, hence NGroup’s name for the project.

The house has 15km of pipes, in-slab hydronic heating on its four levels. There is ducted heating and cooling, a heated swimming pool and two spas and a chilled-water wine cellar kept at 15 degrees celsius. The in-ground pool has hydronic popes embedded in the pool walls to speed up heating of the water and the pool walls and floor are insulated to retain the heat.

There are 100 solar panels on the roof supplying 250 volts of direct current (DC), which goes through the AERL voltage regulator and is stepped down to 150 volts DC to charge the batters of 160 kWh capacity. The panels were manufactured by Risen Energy, a tier one manufacturer in China.

The Catepillar generator in a large ground floor utility room utilises a Ford V10 that runs on natural gas. Heat is recovered from an exhaust heat exchanger that captures the 600-degree Celsius exhaust gases. There is a second heat exchanger in place of the standard Ford radiator. Each recovers about 80 kilowatts (kW) of rejected heat for a total of 160kW of free energy.

A key part of the Bespoke system is the aqueous hybrid ion (AHI) batteries, made by Aquion Energy of Pittsburgh in the United States.

NGroup installed 66 of the 2.5-kWh batteries. The batters will last for more than 8 years at 80% charge capacity and longer still, as much as 15 years, if a lower capacity is acceptable. The batters are bhind a Perspex window so visitors can easily see the world’s largest battery technology. The homeowner did the initial research before he and Mark agreed to install the AHI batteries.

A key element of the air-conditioning system is a 330,000 litre rainwater tank, which functions in the same way as a condensing unit on a normal reverse-cycle air-conditioner place on the roof or walls of a house. Ingeniously, the tank is under the tennis court and assists heating and cooling through the 22 separate ducted systems run by 6 Mitsubishi Electric water-cooled condensers. The tank also supplies water for the garden and for the swimming pool.

The hierarchy of systems work like this:

  1. Rooftop solar panels and batteries.
  2. Catepillar generator.
  3. Mains electricity from the grid.

Hot water sources:

  1. Rooftop solar panels and batteries driving the heat pump
  2. Recovered heat from the Catepillar generator.
  3. Baxi condensing boilers, which are connected to mains gas.


View some of our projects