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.

Some panels, known as tracking panels, come with a device that allows them to sense the angle at which the sun is shining and to adjust to that angle. Others can be manually adjusted from one tilt to another, while still others are fixed at a certain tilt. Tracking panels are the best because the sun shines at different angles both throughout a given day and throughout the year, as the seasons change. The optimal tilt will also vary based on your latitude. If your panels are adjustable, it is worth knowing the best angle from which to absorb the sun’s rays.

For information on calculating optimal panel tilt, please visit: http://www.macslab.com/optsolar.html    Personal page of Charles Landau

http://niwascience.co.nz/ncces/csu/2004-07/    National Centre for Climate-Energy Solutions

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.

A solar power system requires the following expenses:

• PV Modules (solar panels)

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

Off-Grid: No connection exists between a residential renewable energy system and the outside utility’s system. All necessary electricity must be produced via the residential system.

While being off-grid is a great way to declare your energy independence, in most cases an on-grid system is more advantageous. It is cheaper and, even in cases where residents choose to obtain all of their energy from the solar power system, most like to know they have a back-up source readily available. Those who go off-grid have additional costs, because their systems must be big enough to supply all their power, and they must store the energy in batteries that on-grid users don’t need. Off-gridders also cannot take advantage of potential net-metering savings.

When residents choose to go off-grid, it’s usually because they live in a remote area where access to a power grid is not available. In this case, solar power becomes not only an environmental decision but a pragmatic one as well. Others choose independence from utilities for political reasons or so they can retain normal energy access if their utility suffers a blackout.

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.

For More Information:

Unfortunately most of the online information available concerning inverters is provided by companies selling the product. Conservation Consultants, Inc does not favor one producer over another and is not eager to advertise for any in particular. We advise you to do an Internet search on your own to find inverter manufacturers near you that provide what you’re looking for. To learn more about inverters, the following sites are helpful even though they are selling a product.

http://www.solarexpert.com/PVinvtinfo.html – Go Solar Company

http://www.solar-electric.com/solar_inverters/inverters_for_solar_electric.htm – Northern Arizona Wind and Sun

http://focus.ti.com/docs/solution/folders/print/349.html – Texas Instruments

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.

Picture from backwoodshome.com
For more information on battery banks, please visit:

http://www.backwoodshome.com/articles2/yago88.html Solar Power 101 with Backwoods Magazine – an excellent in-depth look at the specifics of solar power battery banks

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.

When you have a great deal of sunlight entering your home through windows, you have provided yourself with a sufficient amount of heat when the sun is shining. But on cloudy days and at night, you will still need to rely completely on your traditional heating system – unless your home has a built-in way to store the sun’s heat. There are several home designs that can achieve this.

Passive heat storage systems absorb and store the excess thermal energy that enters a well-designed passive solar home during the day. In most cases the heat is stored in the masonry of a house, or its walls, floors and ceilings, which can be made of a number of heat-conducting materials.

For more thorough information on passive heat storage systems, please visit:

Arizona Solar Center – a very thorough list and description of several heat storage systems

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.

Some panels, known as tracking panels, come with a device that allows them to sense the angle at which the sun is shining and to adjust to that angle. Others can be manually adjusted from one tilt to another, while still others are fixed at a certain tilt. Tracking panels are the best because the sun shines at different angles both throughout a given day and throughout the year, as the seasons change. The optimal tilt will also vary based on your latitude. If your panels are adjustable, it is worth knowing the best angle from which to absorb the sun’s rays.

For more information on calculating panel tilt, please visit:

Personal page of Charles Landau

Or

National Centre for Climate-Energy Solutions

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.

Window Position

Your windows must face south so the sun has maximum exposure into the house, although you will lose only about 10% of the potential solar radiation by placing solar windows up to 25 degrees to the east or west of true south.

Window Size

The size of your windows is very important: if they are too small your home will miss out on the full benefit of the sun, but windows can also be too big, leading to overheating, even in winter. The recommended size ranges for windows in passive solar homes vary according to climate and latitude. For Pittsburgh, whose average temperature in January is 27 degrees and whose latitude is 40.440 N, the recommended ratio is .25 square feet of window for every 1 square foot of space floor area. Therefore a 200-square-foot space will need 50 square feet of south-facing windows. This ratio will keep your space at an average temperature of 65-70 degrees during the day.

Window Alternatives

If your wall space is otherwise occupied, or if you’d like to mix things up a bit, try using skylights, Sola Tubes or clerestories throughout your home as well. The passive-solar-heating principles are similar. In fact, clerestories offer some benefits over windows in that, if they’re designed correctly, they can accept “low angle” winter sun while preventing “high angle” summer sun from entering and overheating your home.