Renewable Energy

Photovoltaics (PV) - Solar Energy - Click Here For Full Information


To improve PV building technology and to educate consumers and the building industry about PV to overcome technical and commercial barriers to market acceptance of the technology.

PV for Homes
The best way to add photovoltaics (PV) to your home is from a "whole-building" perspective. It can make a big difference in energy and PV cost savings. Whole-building design combines energy efficiency with passive solar to boost your energy savings and make the most of your PV system. It reduces the amount of energy required to operate your solar home compared to conventional houses. It uses pleasing architectural designs to brighten up living areas using sunlight rather than electricity, which also makes the home a quieter place to live. Most importantly, whole-building design can significantly reduce your home's energy consumption, allowing you to purchase a smaller PV system or get more value from a "package" system provided by a vendor.

The following illustrations highlight some whole-building design features used for a home in Florida: External Whole-building Features Internal Whole-building Features

 

External Whole-building Features

External whole-building features that complement PV systems include features such as light-colored roofs in hot climates that reflect heat away from the house, solar controlled windows, proper insulation, and landscaping. For more information on whole-building features, see "Making the Most of Residential Photovoltaic Systems" (PDF 915 KB) or "How to Build A Better Home" (PDF 590 KB).



Internal Whole-building Features

Internal whole-building features that complement PV systems include energy-efficient appliances and lights.



PV for Commercial Buildings  


An important first step when considering the purchase of a photovoltaic system for a commercial building is whole-building design because it can save building owners time and money. Whole-building design takes into consideration the building structure and systems as a whole and examines how these systems work best together to save energy and reduce environmental impact. Besides allowing building owners to get more value from their solar electric system, whole-building design can also benefit building owners by improving comfort for building occupants, which can lead to such things as improved employee productivity or less tenant turnover.

A good place to start reducing energy consumption for an existing building is through energy efficiency measures. For new construction, passive solar features incorporated into the building design can have a significant impact on a building's energy consumption. For example, a building that uses lots of natural light will not only reduce electrical consumption for lighting, but will also reduce the amount of heat given off by lighting fixtures, thus, allowing for a smaller air conditioning system. A smaller air-conditioning system needs less electrical power to operate, and therefore, less solar panels will be required for cooling the building, allowing building owners to get more value from their solar-electric panels. Other technologies that can reduce electrical demand are solar thermal technologies for space and water heating.

On a broader scale, whole-building design can help reduce the enormous amount of energy consumed in the United States by commercial buildings. By creating buildings that use less energy and have lower power demands, greater robustness of the buildings as well as the power grid is achieved. This reduces the need for fossil fuels and consequential environmental impact. Other benefits of whole-building design include:

Reduce energy use by 50% or more
Reduce maintenance and capital costs
Reduce environmental impact
If done correctly, whole-building design need not cost more. In some cases, it can even eliminate or reduce unnecessary building space and reduce construction costs. However, because all the pieces must fit together, it is essential that the design team be fully integrated from the beginning of the design process. The building design team can include architects, engineers, building occupants and owners, and specialists in areas such as indoor air quality, materials, and energy use. For commercial buildings, it is essential to bring energy consultants into the design process from the beginning and keep them involved throughout the process so they can advise owners of how changes to design will affect a building's energy performance.


Oberlin college used a whole-building approach to
reduce electrical demand and save money on a
roof-integrated photovoltaic system when it built its
Center for Environmental Studies.


View Illustration
Learn About Photovoltaics  (Click Here to Download in PDF Version )     
Two of the most common questions about photovoltaic technology are "what is it?" and "why should I use it?" Photovoltaic (PV) technology is basically "solar electricity" that results from converting sunlight into electricity. The sun provides enough clean energy in one day to provide a year's supply of FREE FUEL for powering buildings. The only thing homeowners pay for is the system. Why homeowners should consider using PV is simple: it helps preserve the Earth's finite fossil-fuel resources such as coal, oil, and natural gas. It also helps reduce air and water pollution associated with these energy sources. When faced with power outages and future electricity price increases, homeowners can also benefit from the purchase of a PV system.

How a solar cell works

We have prepared a 72-second animated video showing the function of a solar cell. To play the animation, you'll need a movie player like QuickTime. A free QuickTime plug-in available for both Windows 95 and Mac OS.

This animation is provided courtesy of NCPV and is available in small or large format. The smaller format will download more quickly, but the large format will fill more of your screen.

Right Lick on the Mouse and Save Target As to Download and play the small animation.
(180X135, 7.9 MB)

Right Lick on the Mouse and Save Target As to Download and play the large animation.
(240X180, 11.4 MB)

Basics of a Solar Electric System

Today's solar technologies are more efficient and versatile than ever before, adding to the appeal of an already desirable energy source. Solar electric systems, which use a natural source of power-sunlight-produce less pollution than traditional forms of electrical production. And they can offer homeowners the security of producing their own power.

Components of a System

Interconnected solar cells, which convert sunlight directly into electricity, form a solar panel or "module," and several modules connected together electrically form an array. Most people picture a solar electric system as simply the solar array, but a complete system consists of several other components.

  • An inverter converts the direct current (DC) electricity produced by the modules into alternating current (AC) electricity for powering lights, appliances, and other needs.
  • Wiring connects the various components of a solar electric system. In some cases, the system is also interconnected to the utility power grid. If the system produces more power than is required for the house, the utility may offer the home-owner credit for the excess power produced through a program called "net metering" or "net billing." Your state energy office or local utility can provide more information.
  • Batteries are used to store solar-produced electricity for nighttime or emergency backup power. Batteries may be required in locations that have limited access to power lines, as in some remote or rural areas.


If batteries are part of the system, a charge controller is included to protect them from being overcharged or drawn down too low.

Finally, disconnect switches allow the power from a solar electric system to be turned off to provide safety during maintenance or emergencies.
Most providers of solar electric technologies can supply you with all the components you will need for a fully functional system.