Components in a data storage subsystem are tracked, and their status monitored, with the use of memory devices such as RFID tags. The high shear mixing conditions produce a poly dispersion in which the poly solid contains reduced amounts of undesirably fine particles. The fine semiconductor particles contained in a layer of the layers located closest to the counter electrode, the layers constituting the porous semiconductor layer, have an average particle size of 380 nm or less. At the unfolded position, the sliding joint is upwardly slid to an upper end of the transmission link to move the side frames away from each other. Energy amounts having a higher likelihood of availability in the future are sold at higher prices than other energy amounts.