2025/2026 Hybrid Powerunit speculation

[Ferry]

Than use a capacitor as a buffer

Capacitors are way too small for this use. It must be a EDLC, aka supercapacitor, ultracapacitor. They are bridging the gap between batteries and capacitors. Roughly, capacitors covers from 1 second and down, SC 1-10 seconds, batteries 10 seconds and up. Supercapacitors are bulky, with low energy density. But they can handle a lot of power

[Big Tea]

Than use a capacitor as a buffer

Capacitors are way too small for this use. It must be a EDLC, aka supercapacitor, ultracapacitor. They are bridging the gap between batteries and capacitors. Roughly, capacitors covers from 1 second and down, SC 1-10 seconds, batteries 10 seconds and up. Supercapacitors are bulky, with low energy density. But they can handle a lot of power

What about a 'hot swap' box? It would be limited by weight and size, but this is the area EV's need to be developed.
They manage OK swapping 4 wheels in 2 seconds.

[gruntguru]

Than use a capacitor as a buffer

Capacitors are way too small for this use. It must be a EDLC, aka supercapacitor, ultracapacitor. They are bridging the gap between batteries and capacitors. Roughly, capacitors covers from 1 second and down, SC 1-10 seconds, batteries 10 seconds and up. Supercapacitors are bulky, with low energy density. But they can handle a lot of power

Supercapcitors and ultracapacitors are capacitors.

[mzso]

Supercapcitors and ultracapacitors are capacitors.

But still inadequate.

What about a 'hot swap' box? It would be limited by weight and size, but this is the area EV's need to be developed.

It's more like an idea that everyone abandoned, for being troublesome, and having a lot of overhead.

[Rodak]

For a 'technical' website it's sort of amazing to see the lack of actual calculation that goes on. Run some numbers before commenting instead of just making science fiction wish guesses.....

[wuzak]

I'm sure the current battery size is sufficient to store the energy that can be recovered under braking with a 350kW battery.

The current ES has a maximum to minimum charge per lap of 4MJ, but their total capacity is certainly higher. How high is anybody's guess, but I recall a few years ago one of the teams mentioning that the energy storage density in the ES is not as high as EV batteries, due to the minimum weight requirements and capacity constraints.

A 100kWh Tesla battery is 625kg, or 25 times the weight of the F1 ES (direct comparison can't be made since 25kg maximum ES weight does not include some components).

1/25 * 100kWh = 27.8MJ, which is somewhat more than the ES in F1 could carry.

Likely the most an F1 car could recover would be in Singapore, where the braking time is the highest on the calendar. Assuming 20s of braking, that would recover 350kW * 20s = 7MJ.

They should be able to make a battery of 25kg that can store that 7MJ+.

It is probably also possible to get a battery to store 3 laps of recovered energy, or 21MJ, for tactical use during the race or qualifying. That would amount to 1 minute of deployment at 350kW. That should be more than sufficient.

Of course at most tracks it will take longer to get that amount of storage.

The idea that the MGUK could be used for push to pass has been used before - when they introduced KERS. The result was that the drivers used the energy at strategic points around the track for maximum continuing benefit, rather than storing it for attack laps a few laps later. The reason seems evident - not deploying the energy each lap increases lap times so that when the driver does his attack lap he is too far behind to get ahead anyway.

[Tommy Cookers]

... Likely the most an F1 car could recover would be in Singapore, where the braking time is the highest on the calendar. Assuming 20s of braking, that would recover 350kW * 20s = 7MJ......

well ....
a single axle 350kW MGU-K will plummet below 350 kW whenever speed falls below 170 kph (iirc Henry's figures)
presumably quite a lot of that eg 20 sec Singapore braking is below 170 kph

as present GU-K action plummets below 120 kW whenever speed falls below 120 kph iirc

there may be some question of what action (if any) can or does occur below those speeds

[Stu]

With 1000kw charging, 1s charges as much as 3s of 350kw brake recovery.
4s of charge could be as much as a full lap of brake recovery.

If this powerunit is introduced in 2026, features like quick or inductive charging can be added in 2027 or 2028. In 6 years allot can be improved in power and efficiency.

No battery would take that even if it was possible to deliver 1000kW.

Than use a capacitor as a buffer

Exactly what I was thinking, the perfect charge/discharge cycle requires a mix of battery architectures AND capacitors.

[mzso]

Exactly what I was thinking, the perfect charge/discharge cycle requires a mix of battery architectures AND capacitors.

Put the kitchen sink in there as well, that should help with packaging...

[Ferry]

Supercapcitors and ultracapacitors are capacitors.

Well yea, but so are tantalums, ceramics and plastic film capacitors too. If you mean supercapacitor you should use that term. They are quite different from regular capacitors. High capacitance, but low voltage. So you need a lot of them in series to handle the voltage in a F1 car.

For a 'technical' website it's sort of amazing to see the lack of actual calculation that goes on. Run some numbers before commenting instead of just making science fiction wish guesses.....

I would like to see some numbers too. What would the size and weight be on a (super)capacitor to give any meaningful addition to the battery?

[Dr. Acula]

A 100kWh Tesla battery is 625kg, or 25 times the weight of the F1 ES (direct comparison can't be made since 25kg maximum ES weight does not include some components).

1/25 * 100kWh = 27.8MJ, which is somewhat more than the ES in F1 could carry.

Likely the most an F1 car could recover would be in Singapore, where the braking time is the highest on the calendar. Assuming 20s of braking, that would recover 350kW * 20s = 7MJ.

They should be able to make a battery of 25kg that can store that 7MJ+.

They already have that. There was a picture of the, i think 2018, Mecedes ES with a sticker on it which revealed some of the technical data. It was actually discussed here in the forum, i don't know in which feed it was though. Anyway the actual capacity of the energystore was about 8MJ.

[FW17]

Can the engine charge the MGU K when off throttle?

[wuzak]

Can the engine charge the MGU K when off throttle?

Yes, but how much? And will the FIA want to allow that?

I guess it could be that the MGUK could recover energy during the acceleration phase too - the driver wants Z amount of power, so the engine delivers X hp, which is more than Z, while the MGUK recovers Y hp so that Z = X-Y.

That would work in the traction limited phase of acceleration, before the driver can get to full throttle.

But that is burning fuel to convert to electrical energy. Not sure if that is desirable either.

[henry]

A 100kWh Tesla battery is 625kg, or 25 times the weight of the F1 ES (direct comparison can't be made since 25kg maximum ES weight does not include some components).

1/25 * 100kWh = 27.8MJ, which is somewhat more than the ES in F1 could carry.

Likely the most an F1 car could recover would be in Singapore, where the braking time is the highest on the calendar. Assuming 20s of braking, that would recover 350kW * 20s = 7MJ.

They should be able to make a battery of 25kg that can store that 7MJ+.

They already have that. There was a picture of the, i think 2018, Mecedes ES with a sticker on it which revealed some of the technical data. It was actually discussed here in the forum, i don't know in which feed it was though. Anyway the actual capacity of the energystore was about 8MJ.

I think the label was something like 2.4 kWh l8.6 MJ) but we don’t know if that was the physical capacity or the working capacity. I tend to the latter. I guess one of the advantages of solid state batteries is that the working capacity can be a higher proportion of the physical capacity.

[henry]

Can the engine charge the MGU K when off throttle?

Yes, but how much? And will the FIA want to allow that?

I guess it could be that the MGUK could recover energy during the acceleration phase too - the driver wants Z amount of power, so the engine delivers X hp, which is more than Z, while the MGUK recovers Y hp so that Z = X-Y.

That would work in the traction limited phase of acceleration, before the driver can get to full throttle.

But that is burning fuel to convert to electrical energy. Not sure if that is desirable either.

The regs pretty much ban the part throttle use of this technique. It is still possible to do this at full throttle, say at the end of straight, but I don’t know if anyone does so. I think Ferrari used to do this in the period when they seemed to have a straight line power advantage. AMUS published end of straight speed traces for Mercedes and Ferrari at Hochenheim which only made sense by simulating full throttle K harvesting.

5.1.5 Below 10500rpm the fuel mass flow must not exceed Q (kg/h) = 0.009 N(rpm)+ 5.5.
5.1.6 At partial load, the fuel mass flow must not exceed the limit curve defined below:
- Q (kg/h) = 10 when the engine power is below -50kW
- Q (kg/h) = 0.257 x engine power (kW) + 22.85 when the engine power is above -50kW