Using BC, RP2 and an automatic crafting table and those wonderful power converters you can set up an automatic lava cell refiller in the nether. Obviously, find a lava source. There might be a couple there. Geothermal generator to converter running a BC pump, attached directly to the pump. This will feed it lava directly without needing those messy pipes.
Run a pipe to a stack of 2-3 tanks or attach those directly to the pump as well. Redstone deployer takes buckets of lava from the tank, restone filter pipes it to a chest filled with empty cells. Yay tin!
Automatic crafting table (fed with the recipe and powered by a redstone engine) will fill the lava cell as soon as the ingredients are available. Redstone engines pump the cells out of the crafting table into a receiving chest, a filter sends the empty bucket back to the deployer.
Wire all of this together with a redstone sequencer (I prefer to use 2 engines for the removal of the filled cells so I can run it twice as fast and keep the engines and the filters/deployer on separate circuits) and it's fully automatic. Edited to add this: Running the engines on a sequencer, staggered so they don't cycle at the same time, will double output and the engines will never overheat. They won't even turn green.
You have to attend it for a bit since it won't run on a chunkloader thanks to the nether being a separate world but it fills the cells pretty fast and it can be nearly risk free if you enclose the entire mess in a cobblestone housing.
I know it sounds a bit complicated but producing a lava cell every second or so while you refill your charging station or whatever you have set up there to keep you occupied for 5 minutes can save you a lot of cave crawling searching for new sources of lava.
If I hadn't lost my savegame in a corruption I'd take a screenie of my setup. It was pretty sweet and extremely useful since I lived underground. Solar falls apart when your floor is at 15.
That seems amazing. Maybe you could've remade your system by memory? Either that or look up tutorials, I'm sure a lot of people got inspiration from your system. For me, I prefer a solar flower made from 25 solar panels, preferably in the wiki's design, which looks amazing btw and generates quite a bit of EU, enough to quickly fill a CSU. Great for early-to-mid-game power, then I double it to get enough for late-game energy, plus it's renewable. If only I had the Sun Torch mod, if it recognized the Sun Torch as actual sunlight, I could exploit that as infinite power day and night.