By Tom McCalmont, CEO and cofounder of Paired Power
With a sharp increase in electric vehicles (EVs) on American roads, the nation’s charging infrastructure is struggling to keep pace. While the EVs of today have rapidly caught up to their internal combustion engine (ICE) counterparts in performance, reliability, and ease of use, the infrastructures supporting the two resemble a night and day difference. ICE vehicles have had the benefit of a century of innovation, iteration, and refinement, while the EV charging network is still in its infancy. Some of the biggest obstacles to growing EV charging are external factors, and out of the operators’ control, but there are options.
Growing EV charging is not just a matter of installing more chargers, but also creating the grid capacity needed to power these chargers and doing so in concert with the myriad of other electricity-consuming activities. The wait for grid upgrades for charging hubs can take years and can be prohibitively costly. A closely related issue to grid capacity is that of demand charges that result from charging vehicles during peak demand times, that can easily triple energy costs and wipe out any profits operators might earn.
Integrating solar panels and battery energy storage systems (BESS) has been increasingly recognized as a method to resolve grid bottlenecks and eliminate demand charges. Rather than waiting for the grid to increase capacity, operators can create their own, utilizing grid power in periods of low demand, storing energy for peak use, and generating electricity throughout the day. These solutions have shown themselves to be effective both for individual chargers, as well as fleet charging systems.
While installing charging systems with integrated solar panels may seem like a straightforward proposition, developers should consider a few factors when looking to integrate solar power into their EV charging networks:
Integration
Developers should ensure that all elements of their charging network are properly integrated. An EV charging microgrid needs to ensure that grid power, the network’s BESS, and the solar array harmoniously work together to efficiently charge vehicles, avoid demand charges, and maximize the system’s uptime.
Increasing interest in solar-integrated EV charging systems has led to some providers integrating parts from various manufacturers into one system. This has resulted in poor performance, spotty compatibility, and increased downtime. Occasionally, OEMs of each of the individual components have pointed fingers at each other, blaming the faults found in these systems on each other. Ensuring that solar arrays, battery systems, and power conversion equipment are designed and programmed to work together seamlessly and are operated with a well-integrated and proven software stack vastly reduces risk for the operator and end user.
Ease of Deployment
Solar canopy deployment can be a complicated process that creates parking lot disruptions for customers and employees and impacts operations. Prior to erecting a solar canopy, a site needs to be prepared for the canopy’s foundation. This involves casting concrete footings to securely anchor the posts, which often requires tearing up a parking lot. Large solar canopy installations also require trenches for electrical cables that disrupt access to parking lots. Erecting the canopy itself usually requires heavy machinery and scaffolding, after which, solar panels are individually secured and wired into place.
Operators can keep disruption to a minimum by using canopies that do not require specialized lift machinery, in which the canopy structure itself can lift the solar panels into position. These types of pop-up canopies rely only on ground screws to provide stability in severe weather, expediting installation.
Level 2 vs. Level 3
Operators looking to use solar-integrated charging systems will need to think about the charging speeds that they will be able to offer. Level 2 (L2) charging can add 10-50 miles of range per hour and full charging can take anywhere between 2 and 10 hours. A Level 3 (L3) charger allows for significantly faster charging speeds, with some chargers needing only 20-30 minutes for an 80% charge.
Integrating solar with L2 charging can dramatically reduce the system’s load on the grid.
For example, twenty 6 kW L2 chargers will create 120 kW of new load. On the 208 volt, 3-phase power that is typically available at most commercial buildings, that would require a new 500A circuit. Many existing facilities simply do not have that much spare capacity available in their transformer. However, the same charger infrastructure if combined with a solar array and battery storage to time-shift power availability, could reduce the required circuit size to 100A or even less. This makes possible many EV charging projects that would otherwise not be practical without expanding the existing electrical service, a lengthy and expensive proposition.
Solar integration for L3 chargers is more complex and makes a significantly smaller impact on the total power needed to operate effectively. L3 chargers require immense amounts of power, ranging from 50 kW to 350 kW or more. An L3 charging station would require a much larger commercial solar array to generate sufficient power, and would be a supplemental, rather than a primary power source.
Ultimately, the decision to integrate solar and battery storage into EV charging networks solves grid bottlenecks and eliminates the threat and high cost of demand charges. Most importantly, this technology paves the way for the rapid growth of EV infrastructure. By carefully considering factors such as system integration, streamlined deployment, and the right charging speeds to meet vehicle needs, developers can unlock a new era of sustainable and profitable charging, transforming a potential obstacle into a powerful catalyst for a clean energy future.
Bio:
Tom McCalmont is CEO and cofounder of Paired Power, specializing in resilient solar microgrid charging solutions for EVs and EV fleets. He has over 25 years of solar, storage, and EV charging experience. Prior to Paired Power, he co-founded the respected solar engineering firm, McCalmont Engineering, which has designed over 15 gigawatts (GW) of solar projects in 40 U.S. states (and today designs over 10% of the country’s total solar project capacity each year). Prior to that Tom was CEO and cofounder of Regrid Power, one of California’s earliest and most successful solar installation companies.
Tom has a demonstrated track record of creatively applying new technology to solving real world customer problems. He earned his MS degree in electrical engineering from Stanford University and both Sc.D. and BS degrees from Muskingum University. Tom holds 18 U.S. patents and is a licensed Professional Engineer, a charter NABCEP-certified Solar PV Installer, and an EVITP-certified licensed electrical/solar contractor in California.
