Solar Power for Houses: Your Residential Solar Power System

Have you always dreamed of having a house powered by the sun? Perhaps you are seriously thinking about it, but want to know more about your options. When most people think about solar power, they think of the classic solar panels that produce electricity. These are solar photovoltaic panels. But solar photovoltaics are not the only way to use solar energy.

Solar hot water: uses the sun to heat your water instead of fossil fuels. There are several different types of solar hot water systems available. They are usually lower tech and cheaper to install than household solar photovoltaic systems, although pricing varies widely with the type of system chosen.
Pro: cheaper to buy than photovoltaic
easier to DIY than photovoltaic
Con: will only give you hot water
too heavy for some roofs
cheapest varieties don’t work in freezing temperatures

Solar swimming pool: this is actually a very inexpensive way to heat your swimming pool. It pays for itself within a few years.
Pro: short payoff time
Con: only heats your pool water

Solar thermal: technically this includes both solar hot water and solar swimming pool systems, as well as solar cookers. It also refers to heating air by the heat of the sun.
Pro: cheaper than solar photovoltaic for the amount of energy produced
Con: heat only, won’t give you electricity

Passive solar/solar architecture: designing or renovating a house so that it gains the maximum benefit from the sun’s heat, while not getting overheated during the summer.
Pro: adds very little to cost of a new house for major reductions in heating needs
Con: hard to retrofit

Solar cooker: uses the sun to cook food. It tends to cook food more slowly – can be compared to a slow cooker. Very easy to DIY compared to other solar options. They are also inexpensive to buy.
Pro: easy to DIY
cheap to buy or make
Con: needs sun to cook food
won’t do anything other than cook food
cooks food slower than most cooking methods

Solar photovoltaic: solar electricity created using the classic solar panels. A full system for your house is expensive compared to other solar power options, but it’s more versatile. It is also possible to buy very small systems intended for charging cell phones for laptops. These are very much cheaper.
Pro: extremely versatile as electricity can be used for almost anything
Con: more technically complex than other solar methods
more expensive than other solar methods for the amount of energy acquired
high-voltage electricity produced makes DIY photoelectric more hazardous than other solar power projects.

Passive solar heating is a great way to provide much of your home’s heating for free. Almost every home gets some solar energy coming through the windows, but there is a vast difference between the average house and a home heated with passive solar energy.

Building a new house that is passively solar heated is not significantly more expensive than building a normal house. This makes passive solar the most cost-effective form of solar power for the new home. Every new home should be built using passive solar techniques because home heating and cooling needs can be reduced greatly – potentially to zero in certain circumstances.

All this sounds wonderful, but there is one caveat: you must find a good architect who understands passive solar design. Some architects do not understand how to do it properly and mistakes made during the building process may prove costly later.

Passive solar heating covers a wide range of strategies, including passive solar thermal hot water heaters such as the batch and thermosyphon, but it’s usually used to describe heating the house air and structure.

Direct Passive Solar Heating

The simplest form is direct passive solar heating. This involves big windows on the south side of the house. The sunlight falls onto a dark surface with a high heat storage capacity such as a masonry floor or wall painted a dark color. Water is sometimes used instead – this involves water contained in glass or transparent plastic. It has slightly different properties than solid walls, but the basic idea is the same. The wall or floor absorbs energy on sunny days, and releases it at night or on cloudy days when things get cooler.

Of course, you don’t want the house to overheat in the summer. This is generally avoided by building overhangs over the windows. In the winter the sun is at a low angle and comes in the window. In the summer, especially near midday, the sun strikes the overhang and doesn’t come into the room. This leaves the room much cooler.

Trombe Walls (Indirect Gain) and Solar Spaces (Isolated Gain)

There are two other major passive solar heating strategies, Indirect Gain and Isolated Gain. The most common Indirect Gain method is the Trombe Wall, and the most common Isolated Gain method is the solar space.

Trombe walls involve a thick wall painted a dark colour. An inch or so in front of it is glass. Sunlight enters through the glass and is absorbed as heat by the wall. The glass helps prevent heat loss, and wall slowly releases the heat into the rest of the house. Again, a Trombe wall is placed on the south side of the house.

A solar space is basically a glassed-in space on the south side of the house. They are also sometimes known as solar rooms or solaria. Solar spaces can act as greenhouses, and they are sometimes referred to as greenhouses. However, they are not the same as greenhouses designed to grow plants.

The glass is vertical, and there usually isn’t glass overhead. This is so that the glass can be shaded in the summer to avoid overheating. It also means the plants that grow there have less light than they would in a true greenhouse, although more than they would in your house. Since they are attached to the house, you may not want to grow large numbers of plants in it if you’re allergic to mildew. However, if you’ve always wanted a greenhouse,why not use it to grow plants?

These three types of passive solar heating are the most commonly used. While the systems describes here are simple and this overview is simple, there’s a lot more to passive solar design when you really start looking deeply into the subject.

Sources:

Arizona Solar Center

US department of energy: energy efficiency and renewable energy. Passive solar home design.