Because your solar power system depends on absorbing sunlight, the placement of your panels is of utmost importance. Ideally, in the northern hemisphere, panels should be affixed to the south face of your house, the direction from which the sun will shine most of the day. If they are slightly to the east or west of true south, they will retain about 90% of their absorptive capability, but if the configuration of your house prevents you from orienting them more or less to the south, you should consider remodeling or choosing another energy source.

Building a solar system is a substantial financial commitment. It has both fixed and variable costs. That’s why many people choose to start out with a small system and build on as they can afford to do so. The federal government offers modest tax credits for energy-efficient home improvements, including solar power, and many states also offer tax credits or other incentives, which can reduce your costs significantly. Even so, payback periods on solar power systems are long and extremely variable.Before you install a photovoltaic system, or any alternative energy system, make your home as energy-efficient as you can (link). Every dollar you spend on increasing your home’s energy efficiency will save you between three and five dollars on the cost of your solar power system.

On-Grid: The energy produced via a residential renewable energy system both feeds off of and into the outside utility’s system.

A PV inverter is the part of your solar power system that converts the DC power from the photovoltaic panels into AC voltage for use in your home.The size of an inverter is measured in its maximum continuous output in watts, from less than one hundred to several thousand. Its physical size will also vary based on its power - currently the smallest inverters can be smaller than laptops.

In some cases battery banks are an optional component of your residential solar or wind power system, while in others they are necessary. In either case, the bank’s function is to store energy for later use. In an off-grid system, the battery is necessary because solar power is your only source of energy, and you don’t stop needing power when the sun goes down. Your system will collect excess solar energy while the sun shines and store it in a battery bank until you need to use it.
In an on-grid system battery banks may still be useful, because they will allow you to store solar energy for use when neither the sun, wind or your traditional power source is available -for instance, if there were a power outage at night.

One of the most immediately appealing ways to conserve energy in your home is through passive solar heating. It is a method completely distinct from the use of solar cells; passive solar designs don’t convert energy - they just make better use of the stuff that’s already there! To take full advantage of the ways you can use the sun to heat your home, it’s best if you can design it from the ground up, so passive solar heating is most useful for buildings in the planning stages. But through moderate re-modeling you can help your existing home make much better use of natural light and heat.

Because your solar power system depends on absorbing sunlight, the placement of your panels is of utmost importance. Ideally, in the northern hemisphere, panels should be affixed to the south face of your house, the direction from which the sun will shine most of the day. If they are slightly to the east or west of true south, they will retain about 90% of their absorptive capability, but if the configuration of your house prevents you from orienting them more or less to the south, you should consider remodeling or choosing another energy source.It is also crucial that your panels receive full sunlight as often as possible, so you must ensure that nothing shades the panels or blocks sunlight from reaching them. Even something as thin as an electrical or telephone wire can interfere with optimum exposure. Keeping trees trimmed so they don’t shade your panels is important.

In buildings that use the sun as a heating source, the most important element of design is a southerly exposure, and windows are the most common form.

The following forms of insulation are less commonly used than fiberglass and cellulose, but this doesn’t mean they’re less desirable. Most offer unique advantages over more traditional insulation, although they may have higher initial costs or other drawbacks as well. We urge you to consider them and make the decision that works best for your home, your finances and your environmental commitment.

Foamed insulation is a bit expensive initially, but lasts longer and insulates better than others. It is made of various materials in their liquid states, and can be sprayed, injected or poured into the building envelope. Because foamed insulation can be made of many different materials, its R-values vary widely, from around 3 to at least 8.