Photovoltaic system in northern climes to 5.61 kWh/m²/day in the sunniest regions. For large systems, the energy gained by using tracking systems can outweigh the added complexity (trackers can increase efficiency by 30% or more). For very large systems, the added maintenance of tracking is a substantial detriment. Tracking is not required for flat panel and low-concentration photovoltaic systems. For high-concentration photovoltaic systems, dual axis tracking is a necessity. Pricing trends affect the balance between adding more stationary solar panels versus having fewer panels that track. When solar panel prices drop, trackers become a less attractive option. Systems designed to deliver alternating
Mir Docking Module experiments were installed on the docking module during STS-76, and retrieved during STS-86. Mir Docking Module The Stykovochnyy Otsek (, ), GRAU index 316GK, otherwise known as the "Mir" docking module or SO, was the sixth module of the Russian space station "Mir", launched in November 1995 aboard the . The module, built by RKK Energia, was designed to help simplify space shuttle dockings to "Mir" during the Shuttle-"Mir" programme, preventing the need for the periodic relocation of the "Kristall" module necessary for dockings prior to the compartment's arrival. The module was also used to transport two new photovoltaic arrays