The Energy Saving Trust estimates a typical 4kWp system can knock ￡125 off a family's bills each year. Electricity prices are predicted to rise massively over the next 20 years, which means the amount you'd save would as well.

Depends on how much power you want to produce from one panel. more expensively panels can either produce more power or be stronger against the elements. I would estimate 10,000+ for a 1-2 story house. To get solar you must weather proof all the doors, and make sure your home is efficient as possible. How much sun you get will also affect how much energy you make. If you get intense sun you will get good amounts of electricity but if there are a lot of clouds they won't produce nearly as much. You will get multiple panels for the 10,000+ budget

please avoid it. because it's a loss project business. because there are more and more popular company cover the market. so nobody buy from you. i have more experience about it. so i advised you don't invest in solar business.