The price of solar panels has declined substantially over the last decade as the industry has matured and reached production at the largest global scale. Since 2010, the cost to install solar panels on a home has fall. Today's premium monocrystalline solar panels typically cost between $1 and $1.50 per Watt, putting the price of a single 400-watt solar panel between $400 and $600, depending on ho. There are two main ways to calculate the cost of putting solar panels on your home: 1. Price per. There are a few ways to get a rough estimate of how much solar panels will cost without sitting through a sales pitch. These include: 1. Online calculators 2. Hand calculations base. The third – and least accurate – way to get an idea of how much solar panels will cost for your home is to see how much solar panels cost for homes similar to yours. Now, we absolut.