Remember zapping ants with a magnifying glass?

[RVUSA]

Breakthrough clean technology

SunPower, which has been Ford's solar technology partner since 2011, is providing high-efficiency solar cells for the roof of Ford C-MAX Solar Energi Concept. Because of the extended time it takes to absorb enough energy to fully charge the vehicle, Ford turned to Georgia Institute of Technology for a way to amplify the sunlight in order to make a solar-powered hybrid feasible for daily use.

Researchers developed an off-vehicle solar concentrator that uses a special Fresnel lens to direct sunlight to the solar cells while boosting the impact of the sunlight by a factor of eight. Fresnel is a compact lens originally developed for use in lighthouses. Similar in concept to a magnifying glass, the patent-pending system tracks the sun as it moves from east to west, drawing enough power from the sun through the concentrator each day to equal a four-hour battery charge (8 kilowatts).

clicky

[atreis]

Sometimes these are called "range extenders" (optional on the BMW i3, included on the Chevy Volt) - the car is a true electric, but if the batteries run low the car will automatically start up an on-board gas generator. The generator is only used to generate electricity, not directly move the car (like in a hybrid).

[mena661]

mlts22 wrote:
then just plop in an Onan generator with a battery charger and a fuel tank.

They do, it's called a hybrid. EV by definition does not have a onboard generator. That's the whole point of an EV.

[mlts22]

I've wondered why someone doesn't design a true EV, then just plop in an Onan generator with a battery charger and a fuel tank. This would solve the problem, as the genset could run on gasoline, diesel, or even LP gas, and it wouldn't require that much extreme automotive engineering. Best of all worlds, EV range, and if one needs to go on a longer trip, the genset fires up and keeps the batteries topped off.

[mena661]

pianotuna wrote:
Hi mena,

Populate the roof of the RV with solar panels. Use that to power the BEV or Phev.

I have enough room for one 300W panel and maybe a couple more very small panels. Not near enough to compensate for an EV. I DO have enough roof space on my house for at least 30 panels, likely more.

BTW, regular hybrids all have regenerative braking.

[atreis]

Francesca Knowles wrote:
I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims. When folks say "I get > 50mpg", is that after they've bought whatever electricity the car needs for recharge?

MPG is really an economic factor, and it seems to me that "fuel use" ought to somehow account for whatever electricity is being consumed by the car.

Are there "energy use per mile" figures, expressed as a total of energy units(?) combining both gas and electric?

Depends on the car.

For hybrids that are not plug-in hybrids (the VAST majority fall into this category), all energy used is generated (one way or another) via the gas engine. For mine, MOST of the electricity needed to run the electric motor is captured through regenerative braking (recovering energy that, in other cars, is wasted to heat). The rest is generated by the engine while cruising.

Since all of the energy comes from gas, how can my car average > 50 mpg? It's efficient. The engine is just big enough to propel the car at speed with a little extra for acceleration (but not much). The energy needed to accelerate quickly is provided by the electric motor - these have the advantage of providing very high torque through a wide range of RPMs (from zero), allowing a relatively small electric motor to provide quite a lot of umph for acceleration. (A few stats for my car: The engine is an 80 HP 3 cylinder. The electric motor is 18 horsepower.)

In addition, the car is very lightweight and aerodynamically shaped. Operating just on gas (which I did for about 2 weeks when the hybrid battery needed replaced) it still averages around 42-43 mpg.

For my car, a "energy use per mile" value isn't needed. mpg works fine, as all of the energy comes from the gas engine. It really gets > 50 mpg.

Plug-in hybrids (Chevy Volt, Prius PlugIn Hybrid, etc...) and electric cars (Tesla, Nissan Leaf, Chevy Spark electric, etc...) get some, or all, of their energy from the grid. The EPA has a formula that they use for calculating mpg for plug-in hybrids and electric cars that yields mpge (miles-per-gallon equivalent). I believe that this is the "energy use per mile" value that you're looking for. It's really only useful for comparing one such vehicle with another. (e.g. one electric car might get 118 mpge, while another gets 106 mpge... The former will use less electricity per mile.)

[pianotuna]

Hi mena,

Populate the roof of the RV with solar panels. Use that to power the BEV or Phev.

[mena661]

Francesca Knowles wrote:
I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims.

I don't think that's factored in. I DO know that without a second meter, a PHEV or EV would put me in the next higher tier for electricity in CA.

[Francesca_Knowl]

I always wonder about how the electricity used to charge hybrids is factored in to the "MPG" claims. When folks say "I get > 50mpg", is that after they've bought whatever electricity the car needs for recharge?

MPG is really an economic factor, and it seems to me that "fuel use" ought to somehow account for whatever electricity is being consumed by the car.

Are there "energy use per mile" figures, expressed as a total of energy units(?) combining both gas and electric?

[atreis]

Eh? What kind of Honda could I have gotten in 2004 as a 1 year old used car for $16K that would have gotten > 50 mpg? (The Honda Fit wasn't introduced in the US until 2006.) For that matter, what kind of non-hybrid car of any make or model could I have gotten in 2004 for that amount of money that would have gotten > 50 mpg?

Most of my drive to work is highway (at 70-75 mph). The Honda Insight (first generation) has better mileage on the highway than on surface streets (official EPA estimate was 48/59 - I've averaged 51.8 mpg over the life of the car so far). The hybrid system works differently than the one in the Prius, which does better on surface streets.

[pianotuna]

Hi atries,

You have to compare apples to apples, not apples to oranges.

A plain jane non hybrid of the same make and model is significantly cheaper, and mileage is often nearly identical, particularly at highway speeds. It takes a lot of miles before the fuel savings add up to the difference in price--and the math may show it never breaks even. A Phev may or may not be better.

[atreis]

pianotuna wrote:
Hi westend,

If you run the numbers you will find a hybrid is a bad investment possibly even if it is a Phev.

Not necessarily. I bought my Honda Insight used for 16K in 2004. I've since put 120,000 miles on it, and it has a present value of about 5K. During this time it has averaged a bit over 50 mpg. If I didn't have it, I would have driven the minivan to work every day (same number of miles) at about half the gas mileage.

So, I saved ~60,000 miles worth of gas at 25 mpg (plus lots of wear and tear on the much more expensive minivan, but let's just look at the gas), or at $3 a gallon on average, $7,200 worth of gas. That's $12,200 (leaving less than $4K to go, or about another 60K miles before the car has literally paid for itself). Now consider that it kept me from needing to replace a $35K vehicle (which has 65K miles on it, but would have had 185K miles on it if I had needed to drive it to work every day), and the savings is considerable.

This is harder to calculate, but maintenance on the Honda Insight has also been A LOT less than maintenance on the minivan. The tires are less expensive, the service intervals are less expensive (by about $100 for the 30K ones). It still has its original brakes (regenerative braking will do that). It's needed one new battery pack, but that was free (covered under warranty). If this one fails before 142K miles, the next will be free also (there's a fair chance of this, they last about 7 years in this car) - Honda is warranting the electric half of the hybrid system for that many miles on this particular car.

Thus far, the car has been completely reliable with no repairs needed. I've no reason to believe that I won't be able to drive it (at least) for another 60K miles.

[JiminDenver]

Maybe if you could use a mirrored tube skylight so you could park the Ford in a garage and still use the solar it would be nice.

I bought and set up a Tesla for a customer so he could reduce his carbon footprint. For what he spent I could have covered his houses in panels. The car was one of the original little sports cars that went 0 to 60 in OMG was that my kidney I left back there. ($160,000) Add then the charger and the electrician to install it and a new sub panel, convert the two electric water heaters to gas so that there was enough power available and then he had a car he could drive around town. He was going to have a charger put in the Aspen cabin but the car didn't have the range to get there.
The car is neat and very fast but to hit its range you had to drive like a little old lady and hope for a tail wind. Normal driving cut it a lot and showing the 0-60 abilities to a few friends really cut the range. About the time I left the household Tesla was having issues and was telling people that there were cars built and took money when they didn't have the parts to complete them. I hope they are doing better now.

[RVUSA]

mena661 wrote:

RVUSA wrote:
hopefully tesla produces that <$50K sedan next year.

That one is supposed to be a SUV.

Even better, hopefully he can pull it off.

[pianotuna]

Hi westend,

If you run the numbers you will find a hybrid is a bad investment possibly even if it is a Phev.