Instead of having of using lava for fuel what about like superheated rocks to provide fuel like in Greenland 
(Warning this is a block of text and may contain lots of typos!!! I would also love other ideas added to this concept :D)
Well this is how it works, any rocks directly over lava become superheated rocks which will provide steam if you put a constant supply of water over it(it has to be a water block the rushing water), but you need to build pressure so you can use it like fuel, for that you have to build a sphere around the superheated rocks so the steam will not escape and build up pressure around 300 PSI(well it depends where the superheated rocks are, the deeper it the more pressure it will need to reach the generators at the surface in the small sphere you should a have a pressure valve to release the pressure at the breaking point into a small hole or pipe when it reaches the ground you can distribute them to 1 or many generators(1 generator can hold up to 100 psi). 1 psi = to 1 second of fuel and 2 eu. The generator also need 5 PSI or up to work and if has to much steam(over 100 psi) it will explode in 10 seconds and have a pressure cooker sound :D, the generator will also have a pressure dial on the side of it or top or better yet in a GUI, RED = gona explode Yellow = gona explode = Green = Ok White = needs more steam. To be more accurate it will have a GUI of how much PSI or steam is in it :D. You can also add a pressure valve to the generator to automatically release pressure but will damage any person standing 3 blocks away from the generator when discharging steam.
Now let’s talk about pipes and pressure valve, steam will lose PSI when traveling through the pipes but it depends on which kind pipes the steam is traveling in, if it traveling in a small pipes they can hold there PSI for most of the trip but small pipes can only handle 100 Psi and less. Medium pipes are pretty much the basic one they are balanced can hold around 250 psi used for distrusting high pressure steam along you generator plant. Large pipes, these pipes are special because they are mainly used to transfer the steam from the super-heated rocks to your power plant they can hold 2000 PSI the steam will lose barley any steam because of the high pressure just like 5 to 15 percent. Now pressure valves are very handy first things they have a GUI so you can track the amount of PSI inside them and change the setting when they will discharge the steam into a pipe. Keep in mind that valves can only keep 5000 psi inside them or else they will explode like the generator and that you can only hook up 1 in put like a pipe or above superheated rocks which generate steam and 1 output. But what if you have too much steam?? Well you can make steam banks (Suggestions for a better name :D???) that can store up to 6000 psi but beware they will explode in 10 seconds like everything else if they have to much steam and they have gui so you can track how steam is going in and going out to other pipes and you can also control that
I also like more suggestion
Recpies
Well i cant really now because i dont know the blocks yet so i can make it balanced so give your ideas about the recpies guys 
Well i guess here my try :D?
Iron I
Machine( if you still have in the mod ;D) M
Redstone R
Valve V
Space "
Small pipe
I I I
" " "
I I I
Normal pipes is just 2 small pipes stacked together
Big pipes is just 1 Normal Pipe Stacked together
Valve
I I I
RMR
I I I
Steam Bank
I I I
I V I
I I I
And for the Geothermal generator i bet you already added them -.-
Well I tried my best