Solar Powered House Numbers. High Visibility Maintenance Free Weatherproof Solar Powered House Numbers. Solar powered house numbers light up at night, charge during the day. Do-it-yourself installation - no electrician required. You will receive 120 hours of usage from just 1 day of charge Even the Pizza Man and taxis will thank you! 2 Yr extended guarantee. The Unit is 20.5 cm long 15 cm high and 3.5 cm width. This provides a viewing window of 17.5cm long and 7.5cm high.