Part two of a multi-part series discussing the shortcomings of the recent NEVI final rule and what that may mean for EV charging in coming years.
In my last article I discussed how the NEVI final rule, the most important set of government standards for determining how EV infrastructure is deployed along the nation’s corridors, missed the opportunity to set a baseline for what actually constitutes ‘fast’ charging. Here I begin delving into why the charging sites built to meet NEVI standards will not be sufficient to meet EV owners’ needs today, let alone those of the near future.
Determining the appropriate number of charging posts to satisfy demand is admittedly a difficult problem. From my time at Tesla, where I ran the charging infrastructure team for the Northeast US, I know only too well that many factors play into the calculation. How many vehicles do you expect to service during peak times? How much energy will they require on average? How quickly will they be able to charge? How reliable are the chargers you are installing and what degree of redundancy are you aiming for? How much do your chargers cost and how many charge sessions per month will be required to pay them off in a reasonable amount of time? How do you expect all of these factors to change over the lifetime of the site, which is likely decades?
These are still the early days of EV infrastructure, and so these questions can’t be definitively answered but nevertheless should be considered when designing a site. At Tesla, I was equipped with very detailed information about the cars, chargers and usage patterns and was able to reasonably assess how many chargers would be needed to serve demand for the next few years. Though I had this information at hand to ‘right size’ any given location, when a site host would ask how many spaces for charging I wanted, my answer was always ‘as many as you will give me’. And even at this stage, we insisted on building sites with no fewer than eight stalls.
This was our approach even though when I joined in 2016, the EV market was a fraction of what it is today–then Tesla’s global fleet was just over 100,000 cars, whereas nearly a million EVs were sold in the US in 2022 alone. Despite not even earning direct revenue from the chargers until 2017, Tesla was willing to invest in large sites because it was building for the long term, the agreements it signed with site hosts spanned decades, and crucially, because it understood three fundamental rules of EV charging.
The first rule is that for a given location, every additional charger you install reduces the average cost per charger of the site as a whole. This is mainly due to the fact that for most charging stations, it is the infrastructure on and under ground rather than the chargers themselves that drive much of the cost. Significant drivers of cost include laying conduit; pulling conductors; pouring pads for transformers, switchgear and charging posts; landscaping; paving; and line painting, and these are costs that don’t change much whether you are building a 4-stall or 10-stall site. By spreading this infrastructure cost over a larger number of chargers, you get more chargers per dollar spent. Tesla knows this and builds sites with at least eight and as many as one hundred chargers. This is one reason why Tesla’s cost per charger is so much lower than that of other charging providers.
The second rule is that even if you don’t need the additional chargers now, they will almost certainly be useful within the design life of the site. It doesn’t take much imagination to picture more than a dozen cars an hour needing to charge at a given site along the Interstate within the next few years, which is roughly the best-case scenario for a four-post, 150kW site that meets the NEVI standard, even accounting for the fact that future vehicles should be able to charge faster than today’s cars (on this, see my last post). Critically, more stalls also means more redundancy. That’s important because as any EV driver can tell you, chargers don’t always work. According to a recent study, as many as a quarter of them are nonfunctional at any given time. While EV supply equipment manufacturers and operators certainly need to improve that statistic, the consumer pain of a nonfunctional charger can be mitigated in the meantime by building larger sites that provide more redundancy.
The third rule is that it is essentially just as difficult to add more chargers to an operational site as it is to build a new one from scratch. For starters, you often have to go through permitting, planning and zoning again, a process that can take years. Even assuming that process can be simplified for public corridor chargers, a site undergoing expansion would need to be closed down for at least a few days or weeks, and in most cases the transformer and switchgear would need replacement. The site would also need to be excavated again to lay new conduit and pour new concrete pads and relandscaped when the work is done.
The upshot of these rules is that, when viewed in the long term, it always makes sense to build larger sites. What’s more, they should be built to support future capacity.
Let me explain. It is understandable that EV charging operators would have a different approach to charging than Tesla. Tesla sells cars, not energy, and so is not as focused as a charging operator might need to be on shortening ROI timelines for each site. For much of its history, Tesla was losing money on every use of its public chargers but invested in quality chargers anyway because it recognized that a fast, reliable charging experience helped sell cars. For most charging operators, the incentives are reversed. A busy site is a profitable one. Keeping drivers waiting to charge does not affect their bottom line, while building chargers that sit underutilized does. For this and other reasons, it might not be reasonable for the government to mandate that charging operators install excess charging stations that may not be fully utilized for years in all cases. There is, however, a middle ground that NEVI could have utilized to prepare the country for the inevitable expansion of EVs and their increasing demands for public chargers: incentivizing and subsidizing make-ready.
Simply put, make-ready means making the site ready for future installations, and includes building infrastructure to support more chargers to make future expansion of the site quick, cost effective and easy. In practice this means when the initial four chargers are installed, they would be fed by a slightly larger piece of switchgear containing spare breakers to support another four or more chargers. While the sitework is done, empty conduit would be run to additional spaces in the parking lot. All this conduit would be a little larger than is strictly necessary so that larger conductors could later be installed to support even faster chargers in the future, should that become the new standard. These steps represent minimal increases to construction costs when the site is initially being built, but would be far more expensive to go back and do later. This small amount of additional investment would future-proof each charging site, not only facilitating its ability to deploy more chargers quickly and easily, but simplifying upgrades to existing chargers.
During the notice and comment period, FHWA fielded submissions underscoring the importance of encouraging or even requiring make-readies from environmental and industry groups alike (for example, see comments from RMI, Plug in America, Oncor, and Clean Fuels Michigan). By instead making the minimum site size four chargers and not providing any incentive or guidance on how to design sites to be cost effectively expanded in the future, the NEVI final rule has locked us into small sites that will be congested almost immediately, and will require costly, time consuming upgrades well inside their design life.
