Fuel is Fuel.... An alternative view to economy

[roosterk0031]

Not familiar with the salts, the one linked is for cold storage Freeze/thaw temp of 47 dF wouldn't work well for heat storage, but the latent heat of fusion of 50 btu/lb if that is the same or close for a mixture the that has a freeze/thaw of 180 would work well and obviously give 50 more btu per lbs vs the normal 1 or less btu/lb/dF. I've seen the plastic balls filled with water used inside tanks for chilled storage, I think it would have to be similar here with solid salt inside plastic balls inside a tank circulating anti-freeze to get the heat from exhaust to heat then melt the salt.

So energy wise, to get the same 1 gallon worth of LP (ignoring the antifreeze) assuming the same 140 dF delta + 50 btus latent heat of fusion we get 190 btus/lb, so it would take 481 lbs of brine balls.

Obviously we cold heat it up to 220-240 dF and store a little more heat.

Actually thinking about it now, it would probably work better to us a small liquid to liquid heat exchanger and use the engine coolant on one side and the heat storage anti-freeze on the other side. That would automatically limit max temperature to engine temperature to make controlling it easier. Not sure how to limit max temperature using the exhaust.

I wonder if those plastic bags for water storage have large enough openings to get the balls in. It would form fit to the trunk when filled up and wouldn't need an expansion tank since it's flexible.

[Ecky]

Originally Posted by oil pan 4

I bought a Nissan leaf.
If happen to charge it with mostly natural gas then the power likely came from a natural gas combined cycle plant which can easily be 50% efficient.
If it's from a coal plant, less than 38%.
For wind power I'm just going to say it's about 100% efficient.

In Europe they seem to have figured out how to use waste heat for home heating, but in the US no one really seems interested.

This is a very pertinent point. An EV may be 80-90% efficient from outlet to road miles, but there's also the efficiency of power plants to account for, and transmission of that power.

Honda and Toyota both have engines which can make 40% of energy in gasoline usable.

How does one compare the fuel "efficiency" of a solar panel or hydro?

Cost per mile is one way of looking at things, but over what period do you calculate it? A projected lifespan of the vehicle? Do you calculate only cost you have to pay, or should overall cost of production and disposal (and even pollution) be accounted for?

[teoman]

If you have natural gas or lpg or diesel home heating,

Get an EV and a generator. Use the generator to charge the car and use the waste heat from the generator to heat the house.

On the plus side you only have heating when you are in the house.

[aardvarcus]

Why not just design the house to use such little energy that supplemental heating is very minimal?

I utilize what you are suggesting when I need to work on my car in the winter, make sure it is nice and warm before pulling into the garage for the free heating.

What we really need is an exhaust heated oven to cook our dinner on our drive home. Simple heat exchanger... Or how about a engine coolant heated crock pot.

My issue with the phase change material is that they tend to loose their effectiveness over time.

Toyota had the vacuum insulated canister to store heated coolant to preheat the engine for the next trip, it would be cool to see that idea on steroids.

It frustrates me in the winter to see industrial cooling towers running expelling waste heat from industrial process water, and then to see the same plants burning natural gas to heat water for building heat. Not even trying...

[freebeard]

Why not just design the house to use such little energy that supplemental heating is very minimal?

Excellent question. That would be a hemisphere with an oculus.

[teoman]

Do you have designs for such a house?

Preferrably one in a very hot climate.

[teoman]

Wonder how much work it is to convert a gasoline generator to natural gas.

[freebeard]

Do you have designs for such a house?

This is the only one in my albums.

This one is suspended on an Eiffel-tower post with decks that shutter the fenestration. I've got everything from McMansions to tiny houses, but not in shape to show. The example is unviewable, isn't it?

[teoman]

Unviewable?
I can see the picture and understand the concept. Is that a vertical wind turbine on top?

[teoman]

Back to the orginal question. Storing heat will be a bit of a problem. (transporting such a mass may be a big problem). There are things like this:

https://www.amazon.com/HotSnapZ-Reus...8243843&sr=8-8

they do a phase change. I am not sure of the thermal capacity of these at the moment.



Another aspect of climate control is humidity. Humidity has a strong effect on how you
perceive temperature. A dehumidifier can be recharged using excess exhaust heat. That would be a worthy use of exhaust heat...

I personally was thinking of using the exhaust to distill water.