Years ago in the DOS world we used to create a RAMDRIVE, and accomplish much the same thing. RAM takes a fraction of the power of a hard drive, and is faster by orders of magnitude.

Another strategy: while attached to AC power open the files and programs you intend to work on. Then put the latop in SUSPEND mode. When it wakes up, you won't need to wait as long or waste as much power bring up all the programs and files from scratch.