Can V2G really make money? Unveiling the bidirectional inverter on the 22KW AC charging pile's mainboard!

Can V2G make money? The answer is yes, but currently, it mainly relies on subsidies and the price difference between peak and off-peak periods. Pure market-based profitability is still far away. Using a 22kW AC charging station for V2G is technically feasible, but commercially, it's a bit like "shooting a cannon at mosquitoes".

How to calculate the revenue account:

• Based on actual measurements in Guangzhou, car owners charge their vehicles at 0.3 yuan/kWh during the off-peak nighttime, and discharge at 1.0 yuan/kWh during the peak daytime. The price difference per kWh is approximately 0.5-0.7 yuan. Coupled with the government's subsidy of 2-3 yuan/kWh for discharging, the daily income ranges from 80 to 200 yuan.

• However, please note that this is a pilot subsidy price, and the net price difference income will significantly shrink after the subsidy reduction.

• According to calculations in Hefei, the net price difference for a single charge and discharge of a 50-degree battery is only 40 yuan. If we assume 20 charges and discharges per month, the total cost would be 800 yuan, which amounts to less than 10,000 yuan per year - and this doesn't even take into account the cost of battery degradation.

The V2G of a 22kW AC charging station is "pseudo-bidirectional".

• Genuine V2G requires a bidirectional inverter on the side of the pile or the vehicle.

• The 22kW AC charging station itself is merely an "intelligent socket". For bidirectional inverting, either the on-board converter (OBC) of the vehicle should be bidirectional (at the vehicle end), or a bidirectional AC/DC module should be added inside the charging station.

• If modules are added inside the pile, the efficiency of the 22kW bidirectional AFE+CLLC scheme can reach 97%, but the cost is more than double that of a regular pile, with a BOM increase of 1500-3000 yuan.

• If this price is applied to an operational scenario, the payback period will be very long.

Core changes in motherboard design:

• The unidirectional mainboard only manages relay on/off and CP signals, while the V2G mainboard requires the addition of four-quadrant electric energy metering (charging and discharging are billed separately), ISO 15118-20 protocol stack (to negotiate power direction with vehicles), and OCPP 2.0.1 extension (to report discharge data to the virtual power plant).

• The most crucial point is that the relay must be equipped with a mechanical lock to prevent arcing when the gun is pulled with a load during discharge. This is 30-50% more expensive than ordinary relays.

Virtual power plant is an amplifier, not a money tree

• After the pile is connected to the virtual power plant, the grid dispatching center will instruct you to discharge electricity, and the payment will be for auxiliary service fees (such as peak shaving subsidies of 0.1-0.18 yuan/kWh), not the difference in electricity prices.

• The Teclast VPP platform generated over 300 million yuan in revenue through demand response in 2024, but this was achieved by aggregating a total capacity of 1045MW, and the amount allocated to a single 22kW pile was merely a drop in the bucket.

The real constraint is battery anxiety.

• Users are concerned about the battery degradation caused by frequent charging and discharging, leading to low willingness to participate.

• Guangzhou Automobile Group and other automakers have eliminated concerns by introducing "lifelong warranty for three electric components + conversion of endurance into discharge capacity".

• Without the endorsement of car companies, individual car owners will basically not engage in V2G.

Conclusion:

• The 22kW AC charging pile's mainboard can be used for V2G, technically achievable with an AFE bidirectional module, four-quadrant metering, and grid-synchronous phase lock. However, commercially, it is only suitable for policy pilots and operational scenarios (parks, logistics fleets) at this stage. For personal household piles equipped with V2G, they can break even during the subsidy period, but after the subsidy phase-out, there is a high probability of battery life loss. If you want to make money from this, it's better to directly buy an energy storage cabinet - with dedicated batteries, independent metering, and no car companies to wrangle, the returns are more stable.

The AC charging pile mainboard produced by XinCheng Technology is of high quality and competitive price. Welcome to inquire and purchase!