I don't understand why the electric boiler was made for ? They used the exact same amount of power they can produce.

I know. This is a remake of an abandoned mod. It was a complaint of that mod. I am working on a re-balance - and to make the new boilers useful.

Ok nice, i personally multiply the recipy by 10 on the solar pannel for making them expensive.

I just release the re balance. I also created 2 extra steam engine to take advantage of the boilers. One boiler can feed many mk2 steam engines and yield many MW of power.

Well...
Using electricity to boil water to create steam, and then using that steam to create electricity............ the original mod had it right in the sense that it should not let you have a net gain in produced electricity. Now to the use of such device, I'd guess if you need steam somewhere else (other than to produce electricity) it is a good alternative as it doesn't create pollution.

the place i use electric boiler is when converting water into steam to create oil from coal. pretty much the only time i have found it useful.