The joint use of solar panels and electric vehicles offers a sustainable option for decarbonisation, say University of Auckland researchers.

A study explored the connection between solar potential and electric vehicle uptake, and was published in the international journal Energy Policy.

It used Auckland-centric data to determine whether the existence of solar panels is positively associated with electric vehicle (EV) uptake.

Energy Centre research fellow Dr Le Wen says the researchers found that households that had installed residential solar were more likely to purchase EVs.

"As researchers, we wanted to see whether there is a link or potential correlation between solar and EV uptake, and we found that there is. 

"Our study shows that solar panel uptake has the potential to encourage the adoption of EVs by providing sustainable charging solutions."

Government and transport agencies have implemented strategies such as the Clean Car Discount to promote EV uptake, resulting in significant EV sales growth. However, solar capacity is still low, says Dr Wen.

"This is an area that policymakers should pay attention to. Because solar panels are positively associated with EV uptake, developing policy packages that can promote the uptake of both would benefit emission reduction and help achieve the net-zero carbon target by 2050."

Electric vehicles and solar installations are mutually beneficial when it comes to helping Aotearoa New Zealand transition to a low-carbon economy, says Dr Selena Sheng, co-author and a senior research fellow at the Business School's Energy Centre.

"EVs can provide storage to take care of any surplus energy produced by solar panels. They can use this stored energy for driving or household use.

"If you don't use the energy generated by your solar panels, you can sell it back to the grid, or it goes to waste. But if you have an EV, it will increase usability because you can charge your battery and store energy there. Households investing in solar have the potential to accelerate EV uptake."

The researchers also note that power collected from solar can be stored in the EV and used as an emergency backup in a power outage, with the help of a bidirectional charger.

Basil Sharp, an emeritus professor in energy economics, says the study further shows that, unsurprisingly, the availability of public chargers bolsters EV uptake. The early-adopters phase of solar also positively impacts subsequent EV uptake, he says.

"We also found that males are more likely to install solar. Larger households are more likely to use solar because of their greater electricity needs. And, not surprisingly, higher unemployment rates mean people are less likely to adopt solar."