Sri Saravanas Agencies The most common way to compare solar panel costs is by Price Per Watt ($/W), which is the total system cost divided by the system's power capacity. The type of panel cell technology is a major factor in the per-panel cost. For a homeowner on a budget, Polycrystalline panels are often the direct 'low price' choice, though monocrystalline can sometimes be more cost-effective overall if roof space is limited.