Who uses the energy, and who pays for it?
The evening peak. The house draws 3 kW, all of it from the car. The grid meter barely moves.
After midnight, the car recharges from the grid at a lower price.
The questionWho gains from this, and how?
A composed evening of about 13 kWh. The car covers the house's load in the expensive hours and recharges after midnight.
| Who gains | How | |
|---|---|---|
| V2Hbehind the meter | the household | cheap energy used at expensive hours |
| V2Ginto the grid | owner and aggregator | payments for energy or flexibility |
In V2H the value is a lower electricity bill; in V2G it depends on market access and the contract with an aggregator.
The spread is the value
earns from the difference between when energy goes in and when it comes out. With prices that move every quarter hour, the spread between night and evening can be large on some days and small on others. The same logic drives flexible charging, see Energy and grid integration, stop 05.
With , a car can also offer flexibility to the market through an , as RED III intends.
Check your understanding
3 questions. Answer all of them to complete this stop. Each answer explains itself.
Where does the value of V2H come from?
V2H shifts the household's consumption from expensive to cheap hours, using the car as storage.
Who usually brings a single car into the electricity market for V2G?
One car is too small for the market; aggregators pool many devices.
On a day with flat electricity prices, what should a good controller do?
Without a price difference, losses outweigh the gain; the car simply stays charged.
- Aggregator A company that pools many small devices, such as cars and home batteries, so they can take part in electricity markets. Energy and grid integration, stop 02 Glossary
- Bidirectional charging Smart charging in which the electricity can also flow from the car's battery back to the charging point. Stop 01 Glossary
- V2G Vehicle to grid: the car feeds energy into the public grid, usually through an aggregator or supplier. Stop 02 Glossary
- EUR-Lex: Directive (EU) 2023/2413 (RED III), Article 20a inserted into Directive (EU) 2018/2001. https://eur-lex.europa.eu/eli/dir/2023/2413/oj. Checked 09 Oct 2026. © European Union, reused under Commission Decision 2011/833/EU.