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Apr 29, 2014

Pulling Back the Veil on EV Charging Station Costs

 

Electric vehicles seem to have finally gained a solid foothold. With continued adoption, there will be an increasing need for access to charging locations. We recognize that many drivers today do most of their charging at home, but many others still require access to a robust nationwide charging station network before even considering the purchase of an electric vehicle. But high costs of equipment and installation are currently impeding the build-out of such a network. Therefore, cost-effective solutions are needed to ensure future investment in charging stations.

We recently interviewed over a dozen companies involved with charging station infrastructure—including utilities, automakers, cities, research institutions, and charging station companies—to pull back the veil on current EV charging station infrastructure costs. From there, the next post in this series can then explore charging station business models and strategies to reduce those per-station costs.

We’ve broken down the cost into several categories: 1) the actual charging station hardware, 2) other hardware and materials, 3) electrician and other labor, 4) mobilization, which we define as time for the electrician and others to prep and get to the worksite (often including an initial on-site consultation), and 5) permitting.

This is a look at raw infrastructure costs. We did not include: a) general and administrative overhead, which can easily contribute 20 percent or more to costs but which also reduce rapidly with experience, b) other miscellaneous costs, such as wage requirements for federally funded projects, which can add 15–25 percent to costs, and c) financing (and other costs of capital/debt) for charging station owners.

Similarly, we don’t include federal, state, and local EV charging station incentives that could reduce per-charging-station infrastructure costs, such as the federal EV charging station infrastructure tax credit that expired at the end of 2013, Connecticut’s EV charging station grant program, and the plug-in EV charger rebate program with the city of Anaheim, CA.

At-Home chargers

When charging at home, many EV owners are content to charge overnight plugging into their regular home 120V outlet using level 1 equipment that is included with the vehicle. However, for those who desire level 2 speed or other features, a typical installation will cost a little over $1,000 (Figure 1). Over half of that cost is the charge station itself. Manufacturers are now offering level 2 home chargers for as low as $450, down from well over $1,000 in the early days. More expensive stations offer additional features like charge management, smartphone compatibility, or even grid integration.

Installation by an electrician—installing a 240V circuit from an existing breaker panel and making the connection to the station—accounts for most of the remaining cost, including materials, labor, and mobilization. A new breaker panel isn’t usually required, but in some older homes or if the existing panel is full will add approximately $500.

Public AC chargers

Public stations are more expensive than home chargers and costs vary over a larger range depending on the type of installation, number of stations, and site specifics.

Single-port charging station hardware usually costs about $2,300, but can be as high as $6,000 for some features and brands. Public stations are heftier and often pedestal mounted. Extra features include LCD screens, advanced payment and data tracking communication, and dual-port power routing capabilities.

Unlike home stations, where hardware is the dominant cost, installation is the major contributor to public station cost (60–80 percent of total). Distance to the breaker box is usually the most important factor for determining installation cost, typically ranging from 50 to 100 feet. Runs longer than 150 feet are usually too expensive to justify station installation.

Parking garage installations are the easiest and most economical public charging stations and typically cost about $6,000 (Figure 2). Conduit and wiring can be wall mounted. Curbside and surface lot stations tend to be much more expensive than parking garage installations (Figure 3) because they frequently require costly ($25–$100/ft) trenching or directional boring to run conduit and wire to the station.

Installing a multi-port station, or multiple stations at once, reduces the cost per charger (second column of Figures 2 and 3), but demand must exist to justify the extra capacity. Cost is reduced mainly because a single trench/bore, conduit, and wire can be used to service the adjacent stations. Multiple stations are more likely to require a breaker box upgrade, and the feeder wire that is run from the box to the stations will be slightly more expensive, but the added cost can be divided across the extra stations. There are other efficiencies in mobilization, repetition, permitting, etc.

Public DC fast chargers

Level 3 stations allow much faster charging and many in the industry suspect they will eventually overtake Level 2 as the predominant method. However, their current cost is an order of magnitude higher than a Level 2 charger (Figure 4), costing $50,000–100,000 per station.

There are two main contributors to their high cost: 1) expensive equipment and 2) frequently the need to install a 480V transformer. Level 3 station hardware can be an order of magnitude higher than Level 2, although Nissan has recently designed a station with slightly lower capacity for about $13,000. Transformer cost adds $10,000–20,000, but with some searching locations that don’t require a transformer can sometimes be found. Electrician and other labor and material costs for level 3 chargers are only slightly higher relative to other increases.

Permitting, mobilization, and project overhead can also be much higher for a level 3 station—40 hours of time or an additional $10,000 would not be unusual. In one case, getting approval required attendance to a city planning commission meeting plus additional conversations with the city fire chief.

Network and Operating Costs

Data and payment communications and capabilities can also have a significant impact on cost. Some packages are subscription-based and cost about $250 a year. For instance, ChargePoint offers a service plan that allows station hosts to set pricing, monitor usage, and enable drivers to locate and reserve stations online or through a mobile app. These costs vary depending on the intelligence of the station and the desired business model of the host or operator. There are valid arguments for and against installing stations with networking intelligence, which we’ll explore in future posts.

We didn’t include maintenance costs in our analysis, but studies suggest about $300 for a public Level 2 station and $1,000–2,000 for a Level 3 station.

In the next installment of this series, we’ll take a look at strategies and business models that can help to reduce these per-station infrastructure costs, thus making it more economically viable to realize a nationwide network of public EV charging stations.
 

Join the Discussion


Showing 1-7 of 7 comments

April 30, 2014

Good article, Ben and Josh. As you mention, a major cost over time is the cellular data feed for billing, and if there is a business case, DR. This is the case at Austin Energy.

As part of your business model article, you may want to look into shared services to bundle the cost into other services that a building owner typically funds or passes on to tenants. Since Chargepoint is the de facto largest network provider, their market position will likely drive service innovation.


May 1, 2014

Cost per KW would say something of interest, especially for rapid charge sites.


May 1, 2014

I think charging stations would help for sure but I wish we would think bigger sometimes. What we really need to do is treat the battery as a resource and not tie it down to the vehicle. That way you just swap out your depleted battery for a new one, much like you swap out your empty propane tank for a full one.

http://www.ted.com/talks/shai_agassi_on_electric_cars


May 1, 2014

Interesting article, but I installed my plug in for about $100 and use it daily. New 50amp breaker, 14-50 plug and#6 wire. The car is fancy (Tesla) but the plug in is plain. Then PGE installed a smart meter, I charge after 10 PM for 4 cents/KW and there you have it. Thus I average around 300-400 mpg equiv. cost wise


May 1, 2014

Here's something very interesting related to charging infrastructure cost.

What's an EV driver's biggest fear when planning a trip around existing charging infrastructure? That a station will be both operable and available once they get there.

There is a very interesting topic on the Tesla Motors Club forum where someone applied the Erlang-B capacity model to charging stations. What one finds is that adding additional stations multiplies the overall efficiency of each station while maintaining the same level of service - the same odds that one will show up and find all stations busy.

http://goo.gl/eiOcvN

In the post, going from 2 stations to 4 increases throughput by a factor of 5! Doubling again to 8 stations gets another 3.5x improvement in throughput.

So not only do you get economies of scale with regards to install costs when installing multiple charging stations at a single location, you also can sustain significantly higher utilization rates without people finding that all stations are busy.

In my calculations, let's say you want to keep the risk of someone finding all stations busy to under 10% (what good is a charging station if you can't count on it being available?). For a single station, you can only handle about 0.1 charges/hour - or it being busy 6 minutes out of the hour on average. That's abysmal! But if you install 5 stations, you can handle 2.85 charges/hour maintaining the same risk of one finding all stations busy.

That's a 28x improvement! If you are installing these curbside (using the numbers above), you have also cut the cost per station by about 40%. Now you're looking at a 40x improvement in costs/efficiency while maintaining the same level of service. Maintenance costs should also shrink as well (fewer locations to visit when repairs are needed). If you have the demand to keep these stations busy, it's very clear that installing more stations at fewer locations is by far the way to go.

At a minimum, one should strongly consider prepping the site for multiple charging stations ahead of time so that adding more stations to a location can be done for little more than the hardware cost instead of having to re-trench to pull more conduit all over again.


May 2, 2014

While interesting, these are hardly the only or even the most important economic barriers to installing publicly available charging stations. Changes in the demand charge for the hosting organization (a particular issue for parking garages, which have low and very even electricity demand), liability concerns of property owners, loss of parking spaces when they are not occupied, an ability to recover costs given the low cost of at-home charging, the negative image of the EV world to those using public money to pay for rarely used infrastructure, the challenge of perception as being primarily for the rich. It would be helpful for RMI to address these issues realistically.


May 2, 2014

Josh & Ben, great article!

Simplicity and real need is often the key here. On 28 design build schools for Alberta Infrastructure we installed over 75 EV points at minimal cost.

How? We simply added key controlled access to 120 (and some 220V) outlets on the already required block heater pedestals. By adding this at design stage the upgrades were minimal. We based the capability on the fact that school visitors are mostly local, and use would be top-up rather than a full charge. We had hoped to use a low speed, low cost utility EV for the maintenance contract, but Alberta laws don't allow for that as yet.

it would have cost more to meter and charge for the power than to provide it for free to staff and visitors, a case that I would expect to be true in many, many situations. In reality, all we need is to get electrons from the grid to the vehicle: it's control, speed and charging that make it expensive.

In Northern climates block heater outlets are already standard in most lots, and available for free. In reality they could already be used as a top-up option, though i wouldn't want to rely on them!

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