Before you finally decide on a particular system or size, you have to consider your local weather conditions and other factors too. If you live in an area that experience regular to constant rainfall, a solar system may not be feasible. However, if you have lengthy periods of sunlight then a larger system may work efficiently and serve your purpose.
Typically, the higher the need for constant power or larger the number of appliances in your house, the bigger should be the power tolerance and size of the panels. Furthermore, a professional installer will also measure your actual voltage use and accordingly suggest panels with similar amounts of power tolerance.
Your budget limits
It goes without saying that the bigger the system, the higher the cost of maintaining, installing and investing in it. When you consider your budget constraints you have to keep future upkeep costs in mind too.
Although solar power panels and the entire system in general are expensive to install, in the long run it can help you recover costs because of reduced overhead bills. Before you plan on investing in a system, it helps to make the adequate financial provisions for it. It is always better to invest more money in a state of the art, reliable, high quality system that has lower chances of failing in the future. That is because maintenance and repair costs are relatively higher when it comes to solar power systems.
Make sure your solar power panel is compatible with the type of roof you have.