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Nissan ePower - Good or Evil?

38981 Views 139 Replies 25 Participants Last post by  McPhee
I guess it is inevitable that Nissan will introduce their "ePower" serial-hybrid tech into Europe, to compete with Toyota hybrids. They can even do the same "No need to plug in" advertising :rolleyes:

Is more hybrid choice (non plug in) good or evil? Or something in the middle?

Incidentally, I get annoyed when the press use REX to describe a car powered 100% by petrol. Talk about confusing the public - "Ooh the Nissan REX is much cheaper than the BMW i3"

Nissan to END Diesel car sales in UK and Europe | Cars UK
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In terms of sharing the world's resources just as there is something crazy about having a 200 bhp ICE and popping down the road to the supermarket in it. There is a madness in having a heavy 70+ kWh BEV to do the same.

I think the E-Power but only as a duel fuel vehicle is a very good thing and not evil at all because while it is not the ideal solution for emissions, it does mean a plug-in E-Power with a sensible sized battery and an ICE powering a generator would be buildable in greater numbers sooner, given the known battery cell production bottlenecks. Thus reducing emissions sooner and by more overall than a smaller number of pure BEVs.

It would even with a 20 kWh battery be cheaper than a 60 kWh BEV. The ICE and generator should be about half the cost of a 40 kWh of battery.

In use: range issues are gone, battery decay has almost no impact on practicality in terms of range achievable (the ICE kicks in a bit sooner instead), less noise in urban use on an all electric trip. Long range use is possible without rapid charging fade since rapid charging is not necessary. So the CCS v Chademo choice is avoided. Plenty of heat available on long winter trips from engine and instant start-up heat and pre-heating available from battery. No gears, no clutch, sensible regen, so less brake dust.

Two car BEV and ICE families can consider one E-Power that can cover all the bases unless two cars at the same time are required in which case you would have two E-Powers and always be travelling electric for short trips.

Bonus too instead of spending a pile of cash on a few rapid charges, install lots of three phase 22 kW fast chargers so more folk can top up at an MSA at the same moment for a few more miles without the ICE turning on. No hanging about for a charge to complete just go when you want to after a stop over for a break. E-Power vehicle suitable for business use to make a meeting appointment with a predictable journey time.

UK would still have reasonable mobility if fossil fuel was rationed due to war blocking supplies.

Bottom line:

Right now: Lots of vehicles doing mainly electric miles is better for the planet than a few doing all their miles electric.

Until BEVs have solid state batteries, the E-Power (series hybrid) has a key role in electrification of transport. Current BEVs point the way but are not of themselves going to fully replace the ICE functionality. They are only an alternative that has some major limitations around capital cost and utility.
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It is not dual fuel - ePower uses one fuel which is PETROL. Just like a Prius.
I am well aware E-Power in its current form is a vehicle fuelled by petrol. That is why I would rate it only good but the next generation of plug-in dual power as very good. I hope Nissan will not mess about but go for an affordable dual fuel E-Power using the Micra and the Qashqai. It would tick so many boxes for the majority apart from the BEV purist. A little taste of electric driving and Joe and Jo public will want to ditch the ICE bit as soon as it is feasible.
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REX is a terrible idea. The fossil engine doesn't get used often enough and breaks down.
Strange, I use a 15 year old 1.3 petrol ICE to do the trips the LEAF cannot do. It now only does about 600 miles a year and has done for the last three years. The old car sits in the garage for weeks between outings. It has been out today for a 110 mile return run to a rural area lacking in reliable public charging. Just because one design (a de-rated scooter engine) of REx had initially condensation problems due to lack of use, don't mean they all have to be like that. Confident Nissan could come up a robust three pot ICE electricity generator and keep condensation out of ICE/generator.
The problem with e-Power is, that it's a really interesting design that would have been great as a transition mechanism a decade ago, but it is fundamentally flawed by not doing anything to prevent pollution at the point of use.

But it does reduce pollution a little as the engine is smaller than normal and more efficient so the mpg will be improved. Every little helps. The converse is that a big BEV is a resource (thus carbon from manufacture) hog. 60 kWh battery in just one car when it could be 6x 10 kWh E-Power.

A transition mechanism is needed when the transition takes place which is in the future since BEV are still at (2% of new car sales) at the early adopter stage and for the affluent only on the current deals.

You have only to look at public charging to accept that we are still at early adopter. I have stopped called it a charging network since it is not actually joined up yet. If public charging was to be improved then BEVs would come sooner, but given the way the UK is run that is unlikely so it has to be E-Power for some time to come to get a reduction in emissions now.

Once folk experience electric drive with no gears, instant response and strong torque that will create the demand for BEVs at the mass adoption stage. I believe a car like E-Power will speed up the transition not slow it down. Because the drive experience is compelling. You only sell a few BEVs on the virtue of them being 'green'. Instead you sell them because they are better and for most it will be the driving experience that does it.
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We can all dream up ideas of what OEMs should do, but I really don't want to see future BEV designs being compromised so people can choose to have a tiny battery and ICE in it. Personally, I don't want a Volvo Q40 BEV that looks the same as a mild hybrid version and has associated compromised packaging.

I dream of more, new, inspiring "BEV only" designs and give Jaguar full praise for designing the iPace to be bigger on inside than a comparable size ICE. Same goes for Model 3 which also has more interior and boot space than similar sized ICE.
Yes, lovely cars but look at the price. They are of no relevance to Joe and Jo Average Driver. Compromise is necessary to get affordable electric driving experience within the reach of the majority soon. Sometimes an indirect route to the top of the mountain is better than the direct route.

Think how many LEAFs and Zoes would be out there now if Nissan & Renault had not done give away PCP deals. Now the deals have gone and PCP is realistic year on year sales of BEVs are flat. Coincidence? I think not.

Now with the 'Road to Zero' report published today there is the prospect of the £4500 grant being reduced as soon as Oct 2018. Would makers drop their prices? I doubt it.

Affordability not purity is the key to adoption in my view.

To replace my LEAF with a 40 kWh LEAF or a one year old i3 94 Ahr REx will cost me £10k more than replacing my 2004 ICE with a new ICE equivalent to the LEAF. Am I going to drop an extra £10K just to be 'green' or run the 24 kWh LEAF on and keep another ICE as well for the bits the LEAF cannot do? No prizes for guessing correctly.

£10k invested in a renewable energy company instead will more than compensate for the CO2e emissions from having another ICE and help fund an affordable BEV or a plug-in E-Power when they finally turn up.
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No, this is ICE thinking.

The larger the engine the more efficient it is.

Show me a counter example.

If you need an explanation then let me know.
Thank you @donald. I don't an explanation because you assumed wrongly that I wrote that the engine is more efficient because it is smaller than normal when in fact I wrote 'smaller than normal AND is more efficient'. It is more efficient for reasons other than its size. I am well versed in the efficiency of large marine engines so your patronising reply and false assertion attempt at 'flame bait' will be discarded.
AutoExpress 16th June 2018

New high-tech 2020 Nissan Qashqai set to go hybrid

Worth reading the rest of the article, if you are interested in filling in the blanks,.
@TVEV Thanks for that. That's really interesting article since it is the clearest indication yet for some delay in bringing E-Power to Europe in something heavier than a Note i.e a Qashqai. Because the higher speeds of European driving compared with Japanese driving requires an ICE with more output at one of its efficient operating point(s). The E-Power Note in Japan runs a 1.2l 3 cylinder at 2500 rpm when charging. For better fuel efficiency it looks like they are turning to the more advanced Mitsubishi engine which I assume could perhaps run on two or three pots as required in order to keep up when needed and may be direct injection for greater power out at the same sort of rpm.

Wonder if a performance E-Power could have super capacitors in addition to the battery? This would allow powerful regen and a boost for acceleration to take some of the hammering on charge/discharge cycles that the very small battery in an E-Power would be subjected to.
Some digging unearthed this:


(Nissan Motor Sustainability Report 2017)

On marked page 136 (page 21 of 26 according to the pdf reader) there is an assessment of the lifetime CO2e reduction (18%) of an E-Note over the same generation Note. There is also an assessment of the LEAF compared with an equivalent sized ICE. A 40% reduction for the BEV. These are assessments carried out by Nissan but independently verified.

The figures are there. You decide from the numbers if the E-Power is a good or evil relative to a pure BEV in respect of CO2e. For NOx and PM there is no contest and seems to me to be the strongest reason to be getting rid of ICEs as soon as it is achievable.

The comparison for the LEAF because of the date of the report (2017) will be for the 30 kWh LEAF. With a bigger battery in the 40 kWh LEAF the CO2e associated with manufacture will rise and the lifetime reduction compared with an equivalent ICE will be less.

The critical factors look to be the renewable mix in electricity generation and the size of battery in the BEV or E-Power cars. Good public charging would tend to counter the drift to very large battery BEVs.

@NissanGB Thanks to Nissan for publishing their 2017 sustainability report.
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May I take the risk of reviewing what has been written at #57 and #58 because I think the same words but in different contexts are causing disagreement when in fact in the same context there is agreement?

Cars are often about image and 'big' as in more powerful has always sold cars. For example my uncle 'progressed' from restoring a classic 3.5l Bentley to one of the few straight 8 6l cars left in the world. As W.O Bentley described it 'a bigger thump'. We have today ICEs that are far more powerful than is practically needed on UK roads.

In the BEV world 'big' links to more energy capacity in a battery than is usually needed. The heart of the matter is not about the physical size of the battery or the physical size of the engine. It is about over powering the vehicle and in the case of the BEV additionally adding more range insurance.

Part of having a battery of greater energy capacity is that it allows you to extract more power at a given moment and thus we have like the ICE the same 'walk-up' of electric motor size towards more peak power than is really necessary. The LEAF motor is walking up as the battery capacity increases and is already far more than is really necessary for a practical car.

In the ICE the question is: Does the ICE consume more resources in the engine compartment than it need do and thus have an excessive CO2e footprint for manufacture? For the BEV does the battery have more capacity than is practically needed yielding an excessive CO2e footprint since the CO2e battery footprint increase is roughly linear with the capacity of the battery and the battery CO2e manufacture footprint is the cause of BEV footprints being larger than for equivalent ICEs.

Nobody is saying we should be forced to buy spartan vehicles and the market will always tend to provide choice but rather the question is: Should government policy (i.e. tax I suspect) encourage sizing of both ICEs and BEVs to constrain better and sooner the lifetime CO2e footprint?

I wonder if anybody has done a study to show the reduction in lifetime CO2e that might be achieved if a good public charging network powered by renewables reduced the car buyers tendency to oversize their battery capacity as a costly individual safety net against running out when we could do that as a joined-up society with reliable and frequent public charges at a potentially lower cost.

The corresponding study is what can a public charging network do to reduce the demand for a REx in each car as an alternative approach to handling range anxiety.

ICE peak power output and BEV battery capacity and when is enough enough put into some context the discussion about the E-Power being a good or evil thing in terms of CO2e reduction.
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The problem is, you and me and probably most of the people reading this forum, might be willing to make some compromises in order improve our local air quality, but is the mass market. That said, the least amount of times I have to stop and charge the better.

If there were huge tax or other financial advantages to having a smaller battery and having to charge more frequently, then maybe I would be willing to compromise. It's a big maybe, as having the convenience of not having to charge as often is huge as well.
@TVEV Well said. Personally just two more rapids in the right places and my old old ICE car can go and my 24 kWh LEAF does not need to be replaced with a longer range BEV. Yes, a few times a year an extra stop and delay but the alternative would cost me thousands more a year in fresh deprecation on top of a low annual mileage. Most of the time for me a 40 kWh would not be doing anything that the 24 kWh cannot do.

Sure I would like a 40 kWh or even 60 kWh LEAF but if only the public charging was that little bit better it would be a want not a need. The 24 kWh LEAF could but currently cannot do all trips. BEV heaven for me is more public charging and a battery replacement option when the battery is degraded. So close to not having to think about an E-Power or an i3 ReX as a single car replacement for the current two. Can I hold on until public charging comes good? - I don't know.

PS Just discovered this inside the 'Road to Zero' report so if the A303 in Somerset gets covered that is one of my dead spots for rapid charging sorted out just four years later than I had hoped. Hopes this helps others suffering charging dead zones.

'Highways England (HE) have completed a gap analysis to identify locations required to
fulfil their target. Under the grants process, HE have already issued grants to two local
authorities, Mid Suffolk and Shropshire (A49) with a further four applications received:
South Somerset (A303); Ryedale District Council (A64 York – Scarborough);
Herefordshire (A49); Chichester (A27). Chargepoints will be installed this year.'
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The technology of e-power has worked well in Japan in the Note. But the driving speeds in Japan are slower than in the UK. The efficiency (i.e. mpg) at UK motorway speeds will be poor. Like most things it is a compromise in design and had strong and weak points. It is an alternative rather than out and out good or bad. Personally rather than consider the potentially marginal CO2 case, the fact e-power produces PM is the reason I would try to avoid it.
The i3 is very similar to the Nissan e-Power apart from the battery size (22-44kWh Vs 2kWh), the fact that the battery could be externally charged, and that the ICE power was much lower meaning that performance was limited when the battery was depleted.

According to @Miles Roberts it can manage up to 4 miles in urban traffic which fits with the heavily buffered 2kWh battery.

I look forward to @Hitstirrer 's review but still question how many buyers of large crossovers really need more daily range than the Ariya offers, a point that we disagree on.
No the i3 and e-power are very very different. The 650 cc engine that can generate 28 kW is a range extender in the i3. I have never had to use it in anger in 4 years of driving an i3 but it does allow me to use the battery to the very edge and get home safely. The e-power is almost the reverse you will not go very far without the engine having to recharge the tiny battery. The i3 is carbon fibre to make the car light and efficient. E-power is not about efficiency but the electric driving experience with added noise, smells, pollution and vibration less range anxiety and home charging. An i3 is a dual fuel car but e-power can only be fueled with petrol.
Pity it doesn't have a lock-up clutch for higher speeds, like the Outlander.
In e-power the ICE does not mechanically drive the road wheels. It is a series hybrid.
To me it's not the 140kW that the ICE produces, but the 178kW that the electrical motor can put out from the battery. Admittedly after a few minutes at maximum power the battery will deplete despite the efforts of the ICE to top it up, but the chances are that the car will have hit its limited maximum speed even up a very steep hill.
So with the same power as an Ariya and less weight it should be fast enough.
Worth noting that the Ariya can also tow twice the amount, and that if you include "fuel" in the monthly costs the Ariya may well cost less.
Given that an i3 with 28 kW electrical output from the 650cc REx can hold the battery charge level in all but the most extreme circumstances, the e-power should have no problem holding its own with 140 kW mechanical output. That 140 kW mechanical might translate (guessing 90% efficient) into 125 kW electrical. The tiny battery will drop charge very quickly as a percentage compared with the i3 battery so the engine must be able to keep up within tighter limits. In an i3 the REx steps up to max output (two settings) if the battery percentage is starting to sag. It in the i3 tends to battery hold to about +/- 1 %. Given the e-power has only 2 kWh then the battery holding is going to have to be much faster acting. Be interesting to see how many steps the engine has for charging rates. It might even be linear rather than stepped. Feedback from test drivers please.

I bet the car would limit rather than let the battery run out but most drivers will never experience that situation. In the UK you would just run out of road and we don't have mountains like the Andes to climb. It will be essential to protect the battery if the car ran out of petrol.

Given that the old Qashqai had one of the dirtiest diesels still on the market Nissan were going to get hammered with fines on fleet Euro emissions if they did not do something.

It is a pragmatic solution for them given battery building capacity, common components, and shipping costs. A 'bridge' car which is ideal for an ICE driver wanting some electric drive experience but a backward step for anybody who has make the switch to a BEV and has home charging available.

It might even have quite a long run if future versions have bigger batteries and smaller engines along with a charging port.
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