During the day, the solar panels provide electricity and keep the batteries charged. Knowing the total wattage also determines the number of PV solar cell panels needed. This varies depending on the solar cell technology you choose, your budget and the amount of sun energy available in your area of the country. The two basic types of PV solar cells are crystalline and thin film. Crystalline has proven reliability and some kits have a 20-year warranty.
Thin film is newer and less expensive, but requires larger panels and more area.
Update Bulletin No. We use our central air conditioner most of the summer. Although the condition of the weatherstripping on a storm door is not as important as on your primary door, it helps lower your utility bills if it seals well. The crack around the glass panels is often the most leaky area. First adjust the storm door latch so that it closes as tightly as possible without hanging open.