Costs And Demand Charges Of DC Fast Charging

Jan. 10, 2016

 

The EV Project was a major infrastructure study focused on examining various situations of EV drivers and charging infrastructure, spearheaded by ECOtality. Using data collected from the EV Project, Idaho National Laboratory on the overall costs of installing a direct current electric vehicle charger, from the installation costs to the accrued demand charges from the operations. For the study, 111 fixed DC Fast Chargers were installed by the end of 2013 in workplaces and publicly accessible locations near traffic hubs, retail centers, parking lots, restaurants, etc. The results were published in separate papers, focusing on the cost drivers of DC Fast Chargers and the effects of the demand charges on the DC Fast Charger site hosts.

Number of EV Project DC Fast Charger sites by installation cost, shown in thousands of dollars.

Number of EV Project DC Fast Charger sites by installation cost, shown in thousands of dollars.

Key findings on the cost for setting up fixed fast chargers resulted from the highly variable cost of installation. The actual hardware of the charging station was hardly variable but the installation costs ranged from $8,500 to $50,000 depending on materials needed, administration, existing ground surface conditions, and necessary electrical service upgrades. INL dives into the details of the factors that influence the costs in each of these categories in their published paper on cost drivers of DC Fast Chargers.

Electrical profile of a small office after an installed fixed DC Fast Charger

Electrical profile of a small office after an installed fixed DC Fast Charger

Three months of charging data were analyzed for the study. It was found that demand charges were significant for DC Fast Chargers that delivered high power - 50 to 60kW. Since demand charges are based on the single highest power requirement for the month, the more vehicles served by one fast charger results in a lower cost per vehicle charged. During the setup, site hosts have to decide whether the fixed fast charger would be powered through the facility or provided by a separate meter. The decision of the two is more complicated than simply deciding to relay the fees onto the EV driver. Selection required consideration of the proximity to the site's electrical service to the location of the fixed DC Fast Charger, existing facility power demands, and capability to add new loads. INL's published paper on the effects of demand charges on the DC Fast Charger site hosts gives a very thorough breakdown of the key findings.  

 

 

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