don novicki wrote:Why don't car manufacturers make the hood, roof and trunk decks out of solar panels?
Solar panels are a very expensive way to produce electricity and as you note, they are not cheap to start. They only work when the government subsidizes heavily beyond certain niche applications and this is not one of those niches.
My guess is that the solar panels could only provide a small fraction of the total energy the car would need on an average day.
The average household uses about 30 kW-hr per day. The Tesla battery I believe is 100 kW-hr of capacity for the long ranges advertised.
If you cover your entire roof top in Arizona, I believe you are looking at an average of around 20 to 30 kW-hr per day. So jut covering the car, would be just a few per day and you need probably 10 times that or more.
don novicki wrote:Where in the hell do you charge these things other than at home?
It's not just where, but also how quickly.
https://www.cars.com/articles/2013/11/how-quickly-does-the-tesla-model-s-battery-charge/Stop at a Tesla Supercharger station and you can top off the tank with 300 miles of range in just an hour,
Even with the best of the best, a refueling stop every 300 miles is a minimum of 1 hour.
This is a few years old article, but it has not and will not fundamentally change.
don novicki wrote: the minimum starting price for one, not an S3, is 80K+, the S3 starts for 140K.
Electric engines are great. Batteries suck. The engineering problem is that it takes a lot of energy to push a car around and it is very difficult (there are real physical limits on density of chemical energy) to store a large amount of it in a small volume with a small mass.
All trains use electric engines. However, they either have a diesel electric generator so they store the energy as diesel fuel and convert it to electrical energy as needed. It's easy to store a lot of energy with gasoline or diesel. That's what batteries have to compete with and the competition is really quite amazing. If they don't store the energy as diesel, they are attached to the grid and the vast majority of the energy is stored elsewhere as coal, nuclear, natural gas, or water at an elevated height provided on demand.
Since gasoline is so efficient at storing energy, we can live with a lot of inefficiency. We can use heavier cheaper (and normally safer) steels, cheaper power trains that are less efficient, less aerodynamic designs, less efficient heaters, less efficient air conditioners, etc. We can get by with a lot simpler and cheaper designs because the trade off is low cost gasoline that you can easily store all your practical requirements. My grandfather had a truck with 2 20 gallon tanks. You could do that easily on any car if you needed it, but given how quickly and easy it is to fill up, no reason to any more for most.
A gallon of gasoline has about 33 kw-hr of energy per gallon. Now you have to convert that to useful energy, so you lose a large fraction, probably around half. 20 gallons x 30 kw-hr per gallon x 50% efficiency = 300 kw-hr equivalent. That is 3 times the energy of the biggest tesla battery.
So they need to cut the energy required dramatically. That gets expensive. Higher cost, lower density materials. Everything has to be more efficient and use more expensive materials. Tons of engineering to get everything better and you have to pay for that.
And then there is the cost of storing the energy. Your typical lead-acid battery like you use to run the electric trolling motor is likely around 100 amp-hrs of capacity. For a 12 V battery, that is about 1 kW-hr of energy and weighs about 40 lbs. To store 100 kW-hr of energy, you would need 2 tons worth of batteries. And 100 batteries would cost thousands of dollars for the "cheap" batteries and still have 1/3rd the energy that you have in your gas tank.
It really truly may be a bridge too far.
Unless of course the government simply orders you to do it and eat the huge cost or hides all the cost by taking it from you in taxes so you don't see the huge cost like they currently do with the wind and solar power plants being built today.
