Still charging your EV like it’s 2018?

That’s the power equivalent of sipping a milkshake through a cocktail straw. Grids are tight, demand charges bite, and yet we keep dropping ever-bigger DC fast chargers onto feeders not built for them. The smarter play is hiding in plain sight: battery-buffered fast charging that turns EV stations from grid stressors into grid assets.

The problem

Direct-to-grid DC fast charging can spike hundreds of kilowatts in minutes. Those peaks trigger punishing demand charges, slow or costly interconnections, and fragility when feeders are constrained. As EV adoption accelerates, this model struggles to scale economically or reliably, as documented in this NREL assessment of DC fast charging viability.

The breakthrough

ADS-TEC Energy just took battery-buffered DC fast chargers from smart idea to grid asset. In Austria, its ChargePost system was technically prequalified to provide ancillary services in APG’s balancing markets, via Salzburg AG’s virtual power plant. In short, a fast charger with integrated storage can now earn money stabilizing the grid while serving EV drivers, as reported in Energy Storage News.

Austria’s balancing markets span FCR, aFRR, and mFRR. The rules and roles are clear on APG’s site, including technical requirements for response times and accuracy, as noted here: APG ancillary services overview.

How battery-buffered fast charging works

Think of these stations as grid-sipping chargers with a high-power supercharger under the hood. A local battery charges steadily from a modest grid connection, then discharges at high power to the vehicle. That same battery can respond to grid frequency signals and participate in reserves. ADS-TEC’s ChargePost delivers up to 300 kW per dispenser and integrates roughly 200 kWh of storage, designed to operate on standard low-voltage infrastructure, per ADS-TEC product specs. For tighter sites, ChargeBox is engineered to slash grid draw while delivering ultra-fast sessions, a fit illustrated in convenience store deployments.

Why this model matters now

• Ease interconnection: Lower peak draw avoids transformer upgrades and messy feeder studies.
• Improve reliability: Local storage buffers grid disturbances and keeps sessions running during short events.
• Cut operating cost: Smoothing peaks materially reduces demand charges, a dominant cost driver for DCFC, as shown in NREL’s DCFC economics work.
• Stack revenue: Ancillary services add a new income stream on top of charging fees. Austria’s prequalification proves the concept.

Evidence you can bank on

• Austria’s market: ChargePost passed technical checks to join Salzburg AG’s VPP and bid into reserves, per this report, with the market structure detailed by APG.
• Demand charges are the hurdle: They can make or break station profitability. NREL calls them a critical factor in DCFC viability.
• Scaling imperative: The U.S. may need about 28 million EV charging ports by 2030, per DOE’s analysis in this update. Grid-friendly deployment is not optional.

How it compares to grid-forming BESS rollouts

Grid-forming BESS are the heavy artillery for system strength and inertia. They create voltage and hold frequency in weak grids, enabling high renewable penetration. Battery-buffered fast chargers, by contrast, are surgical assets at the edge: smaller capacity, distribution-level interconnections, targeted local services, and fast-charge delivery.

• System role: Grid-forming BESS deliver system strength and inertia services at transmission or large distribution nodes. See National Grid ESO’s Stability Pathfinder and their grid-forming inverter guidance.
• Field proof: Australia’s Hornsdale Power Reserve demonstrated grid-forming performance and system strength contributions after its inverter upgrade. Read more via Neoen and AEMO’s case study.
• Right-sizing: Where a feeder is constrained and charging demand is spiky, buffer the station. Where a region needs inertia and voltage support, deploy grid-forming BESS. They are complementary tools.

What PJM’s interconnection reforms signal

Interconnection delays are the silent killer of promising DER and storage projects. PJM has moved from first-come to first-ready cluster studies and expanded Surplus Interconnection Service for storage resources, steps intended to unlock near-term capacity and speed queue processing. See the PJM reform overview here, PJM’s reform page here, and FERC’s July 2025 compliance actions here. For surplus service expansion details, see this summary.

The takeaway: faster, clearer cluster studies and surplus service pathways favor assets that can do more with less grid capacity. Battery-buffered fast charging fits that bill and can be paired with DER aggregation for market participation.

Operator playbook

• Start with the feeder: If peak capacity is tight, buffer the station and right-size your interconnection.
• Model the tariff: Quantify demand charges and peak mitigation. Use storage to keep the grid draw flat.
• Join a VPP: Aggregate stations to bid into ancillary services. Austria offers a working blueprint via Salzburg AG’s integration, per this coverage.
• Engineer for both worlds: Optimize for EV throughput and grid signals. Spec storage, power electronics, and controls accordingly, leveraging vendor platforms like ChargePost and ChargeBox.
• Future-proof with standards: Watch grid-forming guidance from ESO and AEMO as these capabilities move into mainstream specs.

The bottom line

Battery-buffered EV fast chargers are no longer just a clever workaround for weak feeders. They are bona fide grid assets that can earn ancillary services revenue, cut demand charges, and accelerate interconnection. Pair them with evolving interconnection reforms like PJM’s cluster studies and surplus service, and you have a scalable template for profitable, grid-friendly fast charging.