Electric lighting systems are superior to fuel-based lighting systems because of convenience, cost, safety and overall quality of light output. Small, 12 or 24V DC lighting systems are appropriate for systems of between 1 and 20 lights. They can cost-effectively be powered by lead-acid or nicad batteries recharged by PV, wind, and, in some cases, generator sets or central recharging stations. It is often economical to have a number of dispersed lighting systems rather than a central interconnected system. In general, DC lighting systems should use fluorescent-type light fixtures, as they are much more efficient than incandescent or halogen alternatives. Low-power incandescent lights (3-10 W) can be used for ambient lighting needs. Halogen lamps with reflectors are ideal task lights. Note that PV lighting systems must be properly sized, using the daily energy requirement. Wind turbines can also be used to power lighting systems.