HPC- High Power Charging
HPC enables significantly higher power outputs, reducing charging times and future-proofing for fast-charging EVs.
A key challenge facing drivers as they transition to electric vehicles is that charging an EV has always taken much longer than refilling a petrol tank. Because of that, the onus is on those working behind the scenes in eMobility infrastructure to do whatever they can to speed this process up. The faster vehicles can charge, the quicker they can get back on the road, and the more customers charge point operators (CPOs) can handle at any given time.
What is High Power Charging (HPC)?
High Power Charging is an evolution of DC fast charging that allows EVs to be charged much more quickly. HPC uses DC charging technology, new connector types and specialised cable-cooling systems to be able to deliver energy at capacities exceeding 100kW, but as high as 350kW – or even 500kW with newer cables. For drivers, that means potentially adding 100 kilometres of range in just 3–5 minutes, or 600 kilometres (approx. 80% charge) in around 20 minutes.
How does HPC work?
Before we dive into the specifics around HPC, we need to understand the difference between AC and DC charging – otherwise known as Level 2 and Level 3 charging.
Electricity flows from the energy grid to car chargers in an alternating current (AC). This means the electricity flips back and forth between positive and negative currents in a wave-like motion, which helps it travel huge distances. The thing is, battery-powered devices – including car batteries but also your phone and laptop – use electricity in the direct current (DC) format.
That means these devices need to convert the electricity before sending it to the battery – using inbuilt power transformers. DC fast chargers for EVs are so named because they have this mechanism built into them, which means they can pre-convert the energy into DC and send it straight to the car battery. This cuts out the ‘middleman’ process and speeds up charging.
HPC takes this one step further by layering in extra technology – in the shape of dedicated connector types and cooling efforts – that greatly increases energy transfer speeds.
Alongside using higher-capacity Combined Charging System (CCS) cables and CHAdeMO connectors, HPC DC charging often uses liquid cooling in the cables. Transferring electricity naturally generates heat, and heat is detrimental to the efficiency of the energy transfer – not to mention that too much of it is fundamentally dangerous over longer periods of time.
DC connector types explained
Combined Charging System (CCS1 in the US, CCS2 in Europe)
If you buy an EV today in either the US or Europe, it’s likely to have one of the two standardised CCS connector types. This combined design allows for AC or DC charging – it’s effectively the traditional Level 2 (AC) J1772 with a couple of DC pins underneath.
Tesla Supercharger
In the US, Teslas have traditionally worked with a proprietary Supercharger connector, but since the EU can be tighter on limiting proprietary formats, European Teslas ship with CCS2 connectors. US Tesla owners, meanwhile, can buy a cable adapter for CCS1 compatibility.
CHAdeMO
The CHAdeMO standard is big in Japan, but it’s not that common outside of the Asian market – aside from use in the Nissan Leaf. It enables DC fast charging, but this requires a separate J1772 cable to be plugged in at the same time.
By proactively cooling the cables during a session, High Power Charging stations can deliver much higher kW capacities safely and efficiently. And that’s what takes normal charging times for a standard EV down to under 30 minutes.
Why ‘80%’?
You’ll often hear or see people talking about ‘charging to 80%’ when it comes to EVs, but why is this? Well, it’s all down to managing the longevity of lithium batteries.
All rechargeable batteries have a shelf-life; over time they will degrade and become unable to retain as much of a charge as they once did. You’ve probably experienced this before if you’ve ever hung onto a smartphone for more than a couple of years.
It’s generally considered that battery health is best protected by keeping its charge between 20 and 80%. That’s because batteries are actually under the most strain when at extremes – when they’re nearly empty or full. Smart charging, including DC and HPC technology, works with this in mind.
When drivers first connect to a charger, it will use algorithms to detect the optimum speed, peaking as it nears 80%. After the EV battery has reached the 80% mark, it will still continue to charge, but the charger will gradually reduce the rate of charge in order to protect the battery.
High Power Charging: Advantages and challenges
High Power Charging has a tonne of upsides, but it also comes at a cost – and requires that both drivers and CPOs have compatible components.
Here’s a quick rundown of the pros and cons of HPC technology:
HPC benefits
Reduced charging times
The higher a charger’s capacity, the more kW it can send and the faster drivers can charge. This speed has obvious benefits for drivers, but for CPOs, it means higher turnover and increased profits.
Improved user experience
Faster charging means less waiting around, and less time having to strategise when it comes to charging. When charge times are just a few minutes, EV owners have less to worry about when it comes to keeping on top of their car’s range.
Strategic applications
In fleets and heavy transport, faster charging carries innate benefits that can be transformative when it comes to logistics. Buses, for example, can use HPC technology to quickly top up at dedicated charging bus stops – instead of needing to charge overnight or be otherwise out of commission for hours on end.
Future-proofing for fast-charging EVs
Charging technology is only set to improve, becoming more and more efficient over time. Deploying the fastest possible chargers now will help future-proof CPOs for tomorrow’s EVs, which could be equipped to handle charging at upwards of 500 kW.
HPC challenges
Infrastructure investment
HPC stations are faster and more technologically advanced than their AC counterparts, so they require significant upfront investment compared to standard charging options. For some CPOs this higher investment can seem like a barrier to entry.
Battery compatibility
Not all EVs on the market are fully compatible with the highest HPC power outputs. While most manufacturers are now working with HPC in mind, users will need a compatible vehicle with the right kind of connector.
Grid integration
Widespread HPC adoption necessitates grid upgrades to ensure sufficient power capacity. Higher charging speeds – and the higher turnover they allow – will naturally result in higher energy demands. To that end, High Power Charging needs to be able to effectively manage and mitigate grid strain.
That last point is a key one, here. As more drivers switch to electric, and as charging technology evolves to deliver higher energy transfer rates, the strain on energy grids will grow in turn.
The solution here is to ensure that chargers don’t just get faster, but smarter too. Smart charging, as enabled by the ever-evolving OCPI (Open Charging Point Interface) standard, offers eMobilty Service Providers and CPOs the ability to enable intelligent charging measures designed to work in harmony with local energy supplies.
Emergent technologies like peak shaving, demand response and vehicle-to-grid (V2C) all work to do just that. These smart features dynamically adjust energy usage – and in the case of V2G actually giving energy back to the grid – to ensure against surges and electricity shortfalls.
The future of HPC
So what does the future of High Power Charing look like? We can probably boil it down into two key areas:
Proliferation
eMobility infrastructure is booming, but we still need more charging points – and more grid connections – if EVs are going to supplant fossil-fuel cars without a hitch. Deploying more HPC connections can help here, because it will mean each driver can charge faster, freeing up connections for the next much sooner.
The challenge here is in making grid connections. It’s a known issue in many markets that it can take a while for CPOs to gain access to the robust grid connections needed to offer high-speed charging. The onus is on governments and bodies like the EU to make this process improve, to supplement the energy grid with new, clean energy supplies, and to ready local energy grids for this new need.
Technology advancements
As EVs proliferate, charging technology will only improve. There are already charging cables capable of hitting 500kW speeds, for example, while more and more HPC-compatible vehicles are hitting the roads from major manufacturers.
It’s likely that as things progress, charging times will come down in relation to continued increases in energy transfer rates. But what’s important here is that smart, sustainable and grid-friendly features continue to complement this raw power.
At Spirii, we understand that the future of charging is platform-based, where new features like V2G and demand response can be retroactively deployed to existing chargers in much the same way that new features and apps come to the OS found on your smartphone. And that’s why we continue to work tirelessly behind the scenes to unlock the next generation of grid-friendly charging tech.
In other words? The raw speed offered by HPC charging is only one side of the story; smart, interconnected software is what will really drive tomorrow’s EV infrastructure. And you can learn more about what that will look like here.