Electric vehicle study suggests plug-in batteries better than hydrogen fuel cells
Image credit: Julia Herzog
Plug-in electric vehicles with batteries present a better option for eliminating fossil fuel consumption than hydrogen fuel cell-powered cars, a study has revealed.
The study by researchers from Stanford University, USA, and the Technical University of Munich, Germany, was the first to compare the two types of electric vehicles including analysis of required infrastructure as well hydrogen and electricity generation.
The study envisioned a situation 20 or 30 years from now when the technology is widespread and more affordable than it is today.
“We looked at how large-scale adoption of electric vehicles would affect total energy use in a community, for buildings as well as transportation,” said Markus Felgenhauer, a doctoral candidate at TUM and former visiting scholar at the Stanford Global Climate and Energy Project (GCEP), who led the study published in the journal Energy.
“We found that investing in all-electric battery vehicles is a more economical choice for reducing carbon dioxide emissions, primarily due to their lower cost and significantly higher energy efficiency.”
While both plug-in electric and hydrogen fuel cell cars directly emit zero greenhouse gas emissions, the overall carbon footprint of their operations depends on the way the fuel, hydrogen or electricity, has been obtained.
Currently, plug-in vehicles are frequently charged using electricity coming from fossil-fuels. Similarly, the most common way to obtain hydrogen is currently through processing natural gas.
In future, however, as the cost of renewable power drops to the level of fossil-fuel based electricity, electric vehicles would become almost perfectly clean. The same goes for hydrogen fuel cell cars if the hydrogen is produced through the process of electrolysis using spare renewable electricity.
The major factor differentiating between the two technologies will thus be the cost of the technology itself together with the cost of the required infrastructure.
In the study, the researchers envisioned the town of Los Altos Hills in 2035. The affluent Californian community of 8,000 is already known for the popularity of solar power generation among local residents.
The researchers envisioned that in 20 years, the community could be producing all its hydrogen through electrolysis using spare solar power. This hydrogen could then be used to warm up houses or produce electricity in return when the sun doesn’t shine.
“We provided data on the amount of energy Los Altos Hills needs throughout the day, as well as financial data on the cost of building new energy infrastructures,” said study co-author Matthew Pellow, a former GCEP postdoctoral scholar now with the Electric Power Research Institute.
“We included the cost of making solar panels, electrolysers, batteries and everything else. Then we told the model, given our scenario for 2035, tell us the most economical way to meet the total energy demand of the community.”
To compare each scenario’s costs to its climate benefits, the researchers also calculated the carbon dioxide emissions produced in each case.
The calculation revealed that betting on plug-in electric vehicles would be the most cost-effective way to achieve the required emission elimination.
“The analysis showed that to be cost competitive, fuel cell vehicles would have to be priced much lower than battery vehicles,” said Felgenhauer. “However, fuel cell vehicles are likely to be significantly more expensive than battery vehicles for the foreseeable future. Another supposed benefit of hydrogen – storing surplus solar energy – didn’t pan out in our analysis either. We found that in 2035, only a small amount of solar hydrogen storage would be used for heating and lighting buildings.”
They researchers hope to analyse larger networks of communities in future studies and examine other factors that could influence consumers’ choices when deciding whether to buy a battery or fuel cell car.