CHARGE AROUND AUSTRALIA

Printed OPVs and electric vehicles

Q: How many printed solar sheets are you using for Charge Around Australia (CAA), how big are they, and how much do they weigh?

A: We are using 18 printed solar sheets, each of which is 18 metres long. They are rolled up and stored in the boot of the car when not in use. Each sheet weighs about 12 kg.

Q: How many miles (range) can be achieved from each charging session?

A:  We estimate that each six-hour charging session can provide sufficient charge to power around 100 miles of driving. This is one of the parameters we are measuring on our journey. 

Q: How is the solar energy be stored?

A: The harvested solar energy is immediately converted into a form suitable for charging the Tesla, which is connected to the charging system. The car charges in exactly the same way as it would if it was plugged into a standard wall socket. 

The charging system uses a maximum power point tracker to ensure the most energy is captured from the solar sheets. This energy is then converted to AC, suitable for charging the car using an inverter.

Q: Are you be using conventional charging points too?

A: In populated areas, we are using conventional charging points, but in remote stretches of the journey where no established charging stations are available, we are using the solar sheets. 

Q: How much does it cost to charge an electric vehicle using these printed OPV solar sheets?

A: Excluding the price of the solar sheets themselves, it should be virtually free to charge the electric vehicle from the sun using the OPV solar sheets.  

We are monitoring charge usage over the course of the journey. We estimate that total charge costs for a 15,000km journey is less than A$80.  This would save more than A$1500 on energy costs for the CAA trip, compared to the cost of a petrol vehicle. 

Q: How much CO2 can be saved using a solar-powered electric vehicle?

A: It’s currently difficult to estimate. We are working on this question and hope to be able to answer as the project progresses. 

Energy production

Q: How much energy can these printed solar cell panels harvest from the Sun?

A: The pilot scale printed solar cells can produce around 20W/m2 whilst they’re in full sun conditions.

Production modules would likely produce up to 50W/m2, which with a 200 m2 installation would produce around 60 kWh of energy. This energy would charge the Tesla for about two days of the CAA journey, or more than a week of typical commuting in a Tesla.

Q: What is the efficiency of the printed solar cells compared to silicon-based panels?

A: The projected efficiency of the initial pilot scale installation is around 1%-2% but we are working hard to improve efficiency all the time. We are trialling new materials and architecture that should deliver higher efficiencies and lifetimes. For manufacture at scale, this would equate to a cost of electricity as low as A$0.33 per kWh. 

Q: Can the printed solar cell sheets only work efficiently in strong sunlight (like in Australia), or do they work if there is a cloud cover, or the temperatures are not hot?

A: Climate change is affecting weather patterns across the globe and temperatures in Australia can fluctuate greatly, as they do all around the world. The good news is that the solar sheets aren’t temperature dependent and work even in moderate light. However, for them to work most efficiently we believe that they need a specific degree of sunshine or light. These are some of the things that we are monitoring on the CAA trip.