Home Solar Systems 101
As you know, solar power is a clean, renewable source of energy that is especially well suited to home-scale installations. Homeowners interested in reducing their carbon footprint, lowering their utility bills, or even going “off grid” completely can benefit from a home solar system. I've been researching different kinds of home solar systems, and whether it makes sense to invest in residential solar or not.
Home solar systems are best suited to homes in relatively sunny regions. Though solar systems do work on cloudy or overcast days, they are not as efficient. Solar systems are most commonly placed on the roof – a great way to use otherwise unused space – and work most efficiently on flat or sloped roofs with good southern exposure. If the roof is shaded or otherwise unsuitable for solar installations, ground mounted systems are available. Using an online solar calculator can help homeowners accurately assess the relative costs and benefits of a solar power installation for their region.
Types of Home Solar Systems
Home solar systems can be divided into two main categories: passive and active.
Passive solar systems use thoughtful design and built in features of the home to passively heat or cool the interior. Some examples of common passive solar features include south-facing windows, thermal walls, and solar chimneys.
Active solar systems, on the other hand, include mechanical parts and can be divided into two main categories of their own: solar photovoltaic (PV) systems and solar thermal systems.
Solar photovoltaic systems, which convert the sun's energy directly into electricity, are the most common type of home solar system. They can be off-grid, which typically requires a battery bank to store power for use at night, or grid-tied. Grid-tied systems are most popular, because they allow homeowners to use conventional power sources when the sun is not shining and to offset this energy use during periods of peak home solar electricity generation. Some utilities even allow home owners with home solar power systems to sell surplus electricity generated by grid-tied photovoltaics to the utility and make money!
Silicon panels are the most common type of solar photovoltaic system in use today, but thin film photovoltaics are growing in popularity as well. Though less efficient than silicon panels, thin film photovoltaics are smaller and can be more easily integrated into a building's design. For example, one popular application for thin film photovoltaics is solar shingles designed to look like ordinary roof shingles!
Solar thermal systems use solar radiation to heat water, heat and cool the interior of the home, or both. They are less expensive than solar photovoltaics and can also create significant savings for homeowners, since heating, cooling, and water heating are typically among the most energy intensive processes in the home.
Solar hot water systems absorb solar radiation and use it to heat the home's hot water supply. For homeowners with swimming pools, solar pool heaters are another energy saving type of home solar system that uses solar radiation to heat water.
Solar thermal space heaters work on a similar principle to solar hot water systems (and are often combined with them), but solar thermal cooling systems, which are either absorption or desiccant systems, are more complicated.
Whether passive or active, solar photovoltaic or solar thermal, home solar systems are a great way to save money and go green!