[acsinuk (OP)]

The best fuel is a renewable fuel, like solar heat fuel; commonly called sunshine. 
As the sun does not shine at night or much in winter we need a fuel that converts sunshine into a liquid that is store-able like oil.
As crude oil is running out we need other oils to burn. Does anyone know which oils will give the best return on investment?
CliveS
 

[CliffordK]

The number of 100% synthetic organic fuels are low...  perhaps Hydrogen, Methane, and Methanol. 

With plants and microbes, one can produce vegetable oils (can be used as fuel straight, or converted to biodiesel), as well as producing alcohols (Ethanol, and perhaps butanol), and, of course, methane.

Organic material can also be decomposed with heat to produce methane and methanol.

Perhaps one is looking at the wrong type of fuels for synthetics.  If one isn't using plants to produce the fuels, then one might be able to consider inorganic fuels.  For example many metals could potentially be used as fuels.  Sodium Metal for example would produce a vigorous reaction in certain conditions.  Even Aluminum metal can be reacted to produce an intense burn.

[yor_on]

You have water too, you can use micro, as in small, turbines producing electricity, built in, in the water pipes of a town. They do it in Japan. Over 800 times as much energy than the same amount of wind power, if I remember right.

[acsinuk (OP)]

Yes, Clifford I like the sound of vegetable oil.  But can we develop one that is highly efficient as a fuel oil? 
What about a cross between a palm tree and rubber tree?  Just walk outside and bleed the tree put the sap in the fuel tank and off we go.
CliveS

[CZARCAR]

You have water too, you can use micro, as in small, turbines producing electricity, built in, in the water pipes of a town. They do it in Japan. Over 800 times as much energy than the same amount of wind power, if I remember right.

water really sux when i'm trying 2burn WVO+sawdust

[Don_1]

Palm oil is already being used extensively.

It is so good for the environment, that its production has decimated 1000's of square kilometers of forest in countries such as Borneo, resulting in the very serious threat to many species which depend on the diversity of natural forests. The Orangutan is one very good example. See this.

Vegetable oils are not the answer.

[peppercorn]

Palm oil is already being used extensively.

It is so good for the environment, that its production has decimated 1000's of square kilometers of forest in countries such as Borneo, resulting in the very serious threat to many species which depend on the diversity of natural forests. The Orangutan is one very good example. See this.

Vegetable oils are not the answer.

Palm oil plantations can also lead to large releases of methane from the surrounding peaty soil if poorly managed - doing many times the damage that burning the equivalent requirement of crude oil would do in terms of climate change.