What he is saying is that lava is early game. Once you start scaling up it is a good idea to use a different method to generate power. Believe it or not you can basically drain the nether. Outside of some weird/laggy lava bees setup, lava quickly becomes unsustainable as your power needs grow. Lava is a legitimate choice, especially in single-player, but if you want MOAR POWER™, then you're gonna want something else. Heck, even charcoal/biomass ends up beating out lava fairly soon in progression.
There are a variety of other choices for generating RF. I will list some below with the major resources they use, starting with those listed already in this thread . Some other choices are obviously left out because I either don't use those mods or I don't care to write them out unless someone actually wants them mentioned.
Big Reactors. Consumes Yellorium.
Major Hurdle: Loads of iron, loads of options/choices in how to build them as they are custom multiblock structures.
Output Potential = Very High/Extreme+
Reactorcraft: Basically uranium.
Major hurdle: Willingness to learn and apply physics concepts to the infrastructure you build to make the materials as well as the energy processing and material handling aspects of nuclear fission based power.
Output Potential= Extreme
Railcraft:
Steam boilers. Burn either liquid fuels or solids depending on which version you make
Major Hurdle: Steel, warmup time, Explosions
Output Potential= Medium
Forestry:
Biomass/Charcoal and/or Bees
Major Hurdle: time and desire to breed endlessly to get desired traits on bees and trees. Easier with Gendustry if you have it.
Output potential=Low/Medium depending on what you do with the fuels once you make them
Other options are mostly in the genre of grow plants to make different varieties of resources and/or use the wind/sun magic box sort of things.
However, if you are dead set on lava then using an ender-thermic pump instead of the bc pump would be advised.
Remember, it isn't actually lava. It is just really hot jam.