Outdoor Photovoltaic Solar Lighting

Most homeowners put a lot of effort into landscaping.  For many of us our yards and gardens are a continuing source of recreation and pride.  Solar energy systems can further enhance the  experience by providing lighting and other features which highlight our landscaping efforts while saving us money at the same time:

Advantages of Solar Outdoor Lighting

Photovoltaic outdoor lighting systems have grown rapidly in popularity.  They can be used to mark pathways, highlight gardens and yards, and  illuminate shadows around your home to improve security.  Photovoltaic outdoor lighting provides a number of benefits compared to standard landscape lighting:

1. Photovoltaic lighting systems are much faster to install then conventional lighting because it is not necessary to run any wiring.  You just put them where you want them and away you go!
2. Solar lighting systems are safer since there is no wiring to trip over or get shocked by. 
3. Photovoltaic lighting provides far greater freedom as to where you place your lighting since no electric wires need to be run from your house to the point where you want to have the light.  Have a large yard, PV lighting is the perfect solution.  Lights can be placed anywhere you want.
4. For existing gardens and landscaping PV lighting is less environmentally disruptive.  There is no need to dig up your plants or your yard in order to run the wiring.
5. Solar lighting saves money!  Solar lighting will not add to your electric bill and there is no need to pay for wiring or installation.
6. Solar lighting is more uniform.  With many low voltage lighting systems the lights will show a drop in power after the first few lights, meaning that the ones placed further away from the transformer will be dimmer than the ones closest to the house. With solar landscape lighting all of the lights will be of uniform brightness as they draw their power from the sun and not the transformer.

All of these benefits have led to a tremendous growth in the implementation of solar lighting.  Nonetheless there are a few downsides to using solar lighting that you should be aware of. Solar lights do require sunlight to recharge the small batteries that are in each light.  If your garden or yard has a lot of shade, or if you live in a very cloudy part of the country the batteries may not receive a very strong charge and may be a bit dim.  You can help circumvent this problem by avoiding putting the lights in direct shade wherever possible.

Most solar landscaping lights are not as bright as incandescent lights of the same size.  In the last few years almost all solar lights have gone over to using LED's rather than incandescent bulbs which has improved brightness considerably. The LED lights also last a lot longer on a day's charge because they use so little electricity. The more LED's you use the more illumination you will get. In general most solar outdoor lights will illuminate for 8-10 hours based on the previous day's charge. One way around the brightness issue is to use a small solar panel in conjunction with the LED lights.  Because the solar panel can absorb much more light energy than a single standalone solar cell on an individual light much more energy is stored and the lights can be brighter.

Types of Outdoor Solar Lighting

There are several types of solar photovoltaic lighting packages.  Let's review these:

• Standalone LED Landscape Lights - Solar landscape lights look like conventional landscape lights but require no wiring.  Most are between 6 to 16 inches tall and are built around a center stake which can be simply pushed into the soil.  Almost all solar outdoor lights made today use light emitting diodes (LED's) for illumination.  They combine one or more LED's with a single solar cell on the top of the light, a small battery, and a sensor which turns the light on at night and off at sunrise.  Because LED's use very little electricity these types of lights can provide much brighter and longer lasting illumination on a single day's charge. Most will last provide light for 8-10 hours on a single day's charge.



• Solar Lamp Posts  - Another type of solar lighting that can be used are standing lamp posts.  These lamp posts come in a variety of styles, many of which are based on old English or French lamp designs. Except for their height they are built the same as other landscape lights with one or more solar cells mounted on top to collect energy, usually two or more LED lights, a small battery and a sensor which automatically turns the lamp on and off.



• Solar Flood Lights -  Another approach is to combine a small solar panel with LED lights to create more powerful flood lights.  With these types of lights a separate solar panel is used to generate electricity. Most panels are designed to hold 2-4 solar cells.  The panel can then be connected directly to a single flood light with multiple LED's or to multiple flood lights. If multiple lights are used with one panel then there is usually wiring that runs from the solar panel to each light in the group. The longer the wiring the more flexibility you will have on where to place the lights.



• Solar Home Security Lights -  Another common use of solar lights is home security.  These type of lights are similar to solar flood lights but usually include a motion sensor so that they only come on when the sensors detect motion.  Because no wiring is required solar security lights can be put in places that otherwise might be difficult to run wiring to. This makes them useful for both residential and commercial security lighting. Like flood lights, security lights are usually connected to a separate solar panel which generates energy to recharge the batteries for the light. Since these type of lights are usually only meant to run for a short time once triggered they can make use of multiple LED's to ensure strong illumination.
  
  
• Specialty Solar Lighting -  There are an amazing number of different kinds of solar lights and you can find one for just about any lighting scenario.  Because solar LED lights are compact and require no wiring then can be used in a wide variety of landscaping scenarios.  One type of solar light are Floating Lights which can be placed into a garden pond or pool.  Many of these are shaped to look like lilly pads or other aquatic plants.  There are solar lights that are designed to look like rocks or stepping stones so they look natural in a garden setting.  There are solar lights that have been built into bricks so they can be embedded into brick pathways.  There are solar lights which are designed to be used as driveway markers. Our favorites are solar lights which have been built into garden statuaries like frogs or garden fairies. If you can think of it there is probably a solar light for it.
• Decorative Light Strands -  For holidays like Christmas or Halloween it is sometimes fun to put up outdoor light strands.  The nice thing about solar light strands is that you can put them wherever you want without the need for long extension cords.  We have seen some homeowners create some impressive displays using decorative solar lighting around trees in their yard at Christmas time using solar lighting.  Strand type solar light use a separate solar panel and then have one LED for each light.  Some systems use different colored LED's while use a white LED with a colored fixture.  One thing about these types of lights is that they tend to run out a little faster than solar landscape lighting because there are so many LED's on each strand (25-50 lights per strand depending upon the manufacturer).  But all the ones we have tested will go at least 4 hours and many will go 6 hours. 

Getting the Most Out of Solar Lighting

As with any lighting, how you use the lighting can make a big difference in its impact.  Here are a few tips for getting the most out of your solar lighting:

• Select a focal point or main element around which to build your lighting plan
• Consider the impact of tree and roof shading upon the placement of the solar cells.  Consider how much shading each light might get during different parts of the day and adjust their placement accordingly.
• Experiment with both down-lighting and up-lighting to get the maximum effect.
• Make sure the solar cells or solar panels face to the south to take  full advantage of the sunlight if possible.
• Consider how regular yard and garden maintenance will impact the placement of lights.  Don't place lights so close to the edge of your yard that they might be hit during routine lawn mowing or trimming.
• Match the color of your lights to your landscaping. Choose verdigris and black for fixtures that you want to blend in with surrounding foliage. For fixtures that will be close to your home's exterior use colors that match the house's color scheme.
• When using lights for path lighting aim the lights so as to minimize glare on someone walking down the path.  Its a good idea to test this at night just to be sure.

Don't be afraid to experiment. One of the great things about solar lights is that you can keep trying them in different locations until you find the placement that perfectly matches the look you are going for. The sky (or the sun) is the limit!