Fisker . . . a poor shadow of a Volt?

off-topic warning ... I have sent in a suggestion to fuelly to add "garage stats" that would reflect the balanced usage of multiple vehicles in a garage, like your 25% mini-van and 75% prius scenario. If you want to second my suggestion, maybe send them an email.

From a recent response from fuelly, they are trying to figure out how to better support PHEVs on thier site, with some way to import or add and track "electric fueling".

 

I thought that plugging in and, more importantly, remembering to plug in would be a PITA as I still forget with my phone and other things but so far it hasn't been an issue. I have the charger cord conveniently set up on the wall parallel to the charge door when I park and I have to walk right by it to enter the house. Having it on the rear right fender like the PIP would be a major inconvenience for me.

 

I have to concur that filling up in my own garage or at the Whole Foods parking lot is a lot more pleasant than the gasoline station.

I wonder if I can get the Hybrid Electric UPS delivery truck to deliver me a gallon of gasoline once a month to my front porch. If I don't need it I could give it to the neighbor with the Prius

 

Bob, an advanced lead acid battery is likely needed to run electric air conditioning and power steering efficiently. This adds efficiency to non hybrids from reducing parasitic losses. This can also be used to do auto stop. This in conjunction with a turbo charged engine (gasoline or diesel) gives most of the highway benefits of a hybrid if it is designed for efficiency.

A hybrid battery is needed for improved city mileage. This is needed to store significant energy from regen brakes and aid initial acceleration. Whether it is assist like in the new gm's, or ima, or a full hybrid like the prius. The key here is a battery large enough to be able to handle the power from the re gen brakes. This is like a minimum of 0.9 kwh in lithium or 1.3 kwh in nimh for a prius sized car. Heavier cars need more power and thus higher capacity batteries.

I must be missing something here. Range should not decrease with larger batteries it should increase. Cost increases with larger batteries, but government tax credits make this cost not high for consumers.

If you mean trips, the government has compiled statistics, but YMMV. IIRC for the average american the percentage is fairly linear to 20 miles a day, hitting 45% of miles (2.25%/day-mile). After that it drops off as long trips have more of an impact with around 75% at 80 miles. As you add more miles there are shimming returns.

There is a problem with how you set this up. The battery needs to provide enough power for your trip during warm up. I have a big hill and a short on ramp to a 65 mph highway, so even the 4.4kwh pack in the prius phv would turn on since its only 38 kw. The 7.5 kw pack in the energis provides 68 kw (90hp) which would be fine. There is also cost. 4 mile range would not be a good goal.

Right, you need that SOC for hybrid mode, then additional. I would think 4 kwh would be the absolute minimum you would want. Future batteries may have higher usable SOC and/or max power draw.

Very bad idea. You are paying for a large amount of solar cells that most days won't do a thing. This adds much more cost than the battery capacity. Many people can get away with charging the pack with 120 VAC.

The reason SOC is not kept high is to leave room for regen braking. You are charging with gasoline, and will not get the power back

 

With a high efficiency engine that may not be enough distance while its just idling. High thermal efficiency, low fuel requirement to keep the engine spinning at min level, and thus less excess heat to warm things up. The Prius makes heavy use of the ICE at the start because that's the quickest way to heat it up.

If you want to just reduce or eliminate that warm up period, a block heater and a high heating pad for the catalytic convertor is the simplist way to go. Maybe even heating pads for the battery.

 

But is it worth the cost, and not just the monetary one? There is weight and being able to mount them in a way not to hinder aerodynamics. The hit to fuel economy for warm up only has a major impact on short trips. This is not the norm for most drivers. For the manufacturer, should feature needs to add little cost to be considered. Adding a plug and charger to a normal Prius to top off the battery is probably too much.

 

I wonder if an engineer has considered a solar heat pipe to pre-heat the ICE and catalytic converter during the day.

 

Both Nissan and GM advise to park in the shade if possible to help keep the batteries cool; not sure about the PIP.

 

Bob its a gimmick, like tailfins on those old cars. They didn't really make the aerodynamics much better.
Say you have decided to add a plug, and set the software to retain an extra 1 kwh for the next restart. Today's pricing that extra battry costs about $600, maybe charging it every day for 10 years is another $500. It takes up volume, but today's solar panels also add weight. Now if you park in a garage when you get home that solar panel will only work on days when its sunny enough and it has enough time. Its not going to put much energy back in on a trip to the store. My guess is about $2K to manufacture those panels into the roof and add inverters to charge the battery. Much more cost effective to put the solar panels on your roof and the bigger battery in the car.

Toyota was having trouble even doing it when parked. You likely need to add an expensive power management module to work while the battery is being used. The current phv allows you to save charge for the next start up or for later use at the end of your drive.

Now I suppose you are thinking of not adding the charger and plug just the solar panel. The current batter has a 40% SOC and 1.3kwh giving about 0.5kwh usable. But you would not want to run it all down to 0. Say we are at 0.25kwh usable and the solar panel charged it 0.25 kwh. That is good, but an unwarm system limits ev speed to 10 mph, not vary usefull. What you want is at least 1 kwh usable in the system. In nimh that is 2.5 kwh and will take up as much volume as the phv battery. In Lithium we may be able to have a SOC of 60% meaning a 1.7 kwh battery. I doubt that plus the solar panel saves much manufacturing cost compared to the phv. The prius phv pack must add 2.7 kwh plus charging system which likely cost toyota about $2500 not much more than adding those solar panels. You as the customer can offset 10 miles of gasoline with electricity for every charge. It seems like an easier sell. Costs of both batteries and solar pannels are going down.

 

Also keep in mind that solar panels mounted on a car aren't in the ideal position for generating power. So you'll need to add excess capacity in order to get enough charge when the sunlight is available.

 

Be sure to show us photos. How much are you going to hurt aerodynamics by putting the panels on the roof? I'm curious how much power a day you are able to charge.

How are you going to take out the lead acid battery. Don't you need it as a buffer? How will you start the car in the dark?

 

I just remembered this.
Solar-Powered Toyota Prius Project : TreeHugger

Unfortunately, his site seems to have gone out.

 

I'm sure once he built his system and tested it, the gains were nowhere close to what he expected. No reason to keep a website up for a failed project. The article said he did not charge the car with the engine off, which is a strange engineering choice.

On topic

The fisker solar roof provides 120W to power accessories while driving, or charge the battery when stopped and in the light. Justin Bieber has one with a solar roof.

Or specs of an old prius solar roof
APRS Solar PHEV
prices have gone down but -

 

+1

Steve Lapp was the guy that seemed to have the bad idea of installing the panels. Bob B in the APRS piece above seemed to have the right idea but tried to do it too cheaply, although $3300 isn't exactly cheap. He may have some good ideas on how to do it right and what it should cost today. I'm sure you need an additional battery, and some management electronics along with the solar panels.