You should never feel pressured to buy something, especially an expensive solar energy system. These types of salespeople are pretty common in this industry. You can tell them you'll be back later, and they should be fine with it. If they are persistent about making a deal now, tell them that the deal should be just as good in the future. Making decisions under pressure can be more costly later on.
Once your solar panels are installed, you need to keep track of how much power you are producing and using on a daily basis. Invest in a quality monitoring system and look at the data as often as possible. If you notice your panels are not producing as much energy as usual, it might be time to clean them.
A video presentation on Solar Energy, strictly on Photovoltaics (PV). These presentation is specifically based on a college project for an Engineering course.
Solar water heaters have been around for hundreds of years. For over 50 years people have been using them to heat everything inside and outside the home. Over the years, these solar water heating systems have become much more efficient. If you are located in sunny areas of the country, you should look into buying a solar water system.
Before installing solar panels on your roof, check with your home owners association. Some associations have restrictions on what you are allowed to do to the outside of the property, and this might mean solar panels are not an option for you. It is better to have this information up front than to purchase the panels and be forced to remove them at a later time.