Solar lighting is not made equal and this is particularly true for solar lamps.
Rule Number 1: Never buy "discount solar lamps." Good lighting stores, however, don't usually carry the "cheapest solar lamps" because they know that with solar lighting, you generally get what you pay for. More importantly, stores should provide customers with a solar lamp designed and constructed to meet the needs of a particular site and how the area is used.
Even among quality solar lamps, there is a vast difference in the strength and duration of light that produced each night by lamps. And, different solar lamps can produce reliable light for more days without sunshine than others. Without getting really technical, we'll try to outline some of the things to think about when buying solar lamp posts.
Knowing some basic terms is really the only way to get what you need and make sure that your salesperson is directing you to a product that meets your lighting requirements.
For Solar Lamps, Batteries DO Matter
For many smaller solar lights, particularly accent lights, the type of battery for which the product was designed is the best battery for that product. But there is a huge difference between the amount of light expected from garden accent or pathway lights and solar lamps.
And, the best choice for solar lamps is lithium ion (Li-Ion) batteries. Not only do Li-Ion batteries match up particularly well for the way that solar lamps work, a design that uses Li-Ion batteries is far more likely to incorporate other "state-of-the-art" solar lighting technology.
Bulbs
Most solar lamps use LED bulbs and you really shouldn't buy a lamp with another type of bulb, even if you can find them these days. LEDs are the most efficient light bulbs available and therefore the right configuration of LEDs with other solar technology provides a far more efficient overall light than other types of bulbs. Some solar lighting manufacturers also incorporate specialized reflectors into lamp design to intensifies light.
Before going shopping for a solar lamp, think about the area to be illuminated. Who uses? How many people use it? Are there any potentially dangerous areas nearby, such as downward stairs, steep hills, or waterways?
Even if you don't understand about voltage, charging capacity and other jargon and you want information about the best solar lamp for the area you want to illuminate, contact a couple of different stores. If you are specific about the purposes and users of the property, a savvy and honest retailer should be able to recommend what is best.
A store that does solar lights that are inadequate for the intended function, even if it does save the customer a bundle, is NOT doing the customer a favor. If a solar lamp is not strong enough or reliable enough for the layout and users of the property, the property owner that installs the light could be opening themselves up for liability.
Before going shopping, customers should think seriously about what their lighting needs are. Here's a checklist of what to think about.
Who will use the property? Customers, the general public, elderly or disabled people, family, friends?
What is the area like? Open to the street or the general public or part of a private area? Are there any hazards such as downward stairs, bodies of water, steep hills?
How close are other lighting sources or doorways in the event of an emergency? Is this near a doorway to a building? Is there another light source in the event of an emergency? Or, is this a remote area, such as a secluded public or semi-public parking area, a recreational facility, or a marina?
The answers to the above will help you determine what needs are best for you. If a salesperson tries to sell you a more expensive model than what you were looking for, he/she should be able to explain why they recommend the different model, and not only because of a more costly "aesthetic quality."
If a store, online or brick and mortar suggests a model different than what you have in mind, ask them why one lamp is more appropriate than another. A knowledgeable retailer should be able to explain this to you in language you understand.
What You Should Be Familiar With When Buying Solar Lamps
Other than having a lithium battery and quality LED bulbs, we're going to put broadly define two basic terms: voltage and charging capacity.
Note: The term "watts" is used a bit more loosely now that incandescent bulbs are fading away. Some manufacturers still use the term 150 Watts, for example, for an LED bulb when what they really mean is what the strength would be if the bulb was incandescent. Regardless of how the manufacturer describes the light, a good retailer, however, should be able to give you a rough idea of what any LED (standard for most solar lights) is equal to in terms of "incandescent watts." It will take quite a while before people stop thinking about lights in terms of 30, 60 or 100 watt incandescent bulbs.
When picking a solar lamp, "voltage" generally refers to the strength of power the battery will produce. "Charging capacity" generally refers to how much power the battery can store. Different manufacturers use different terminology, so you often will have to rely on the store to help you compare items.
The biggest thing to look at is "voltage." Below are three typical scenarios in which solar lamps are used and which provide baseline technical specifications best for each situation.
Example 1:
Let's say you want to light a small entrance way, or maybe a patio or deck. This is a private area and access to other light sources is nearby. In this case, a small solar lamp would suffice.
Typical specifications for such a solar lamp acceptable for this area could be as low as a 3.2 volt battery with a charging capacity of 1500mA (mA means milli-amperes). 1500 will provide a good, but not extremely strong or long-lasting light.
Most lights with these specifications are designed for small areas and the lamp typically will stay lit for 10 to 12 hours with a full day (5 to 6 hours) of sunlight.
Example 2:
In this scenario, the area to be lit is a common walkway for a residential complex or a large driveway for a private residence.
For the private residence, one high intensity lamp designed for residential purposes would be better than the smaller lamp used in Example 1. For the residential complex, several lamps will be used each about 15 feet away from each other.
Let's say that both areas are away from the street, doorways are nearby and there are no dangerous obstacles such as bodies of water or downward staircases.
In both cases, a stronger residential solar lamp would be ideal, with specifications such as 3.2 volts and 3000 mA.
A lamp with these specifications would illuminate larger areas, and could provide about 15 hours of reliable light after 4-6 hours of sunlight, enough most times of the years to provide light for 2 days with minimal sunshine.
The light is about 40 percent stronger than the lamp discussed in example 1.
Example 3:
In this case, the focus area is a small public parking lot where there are no other lights. (For example, a small office building that accommodates 15 cars or a recreational area gathering point.)
Let's assume for size that 10 to 12 cars can easily be parked and that three solar lamps will be used, installed equally around the parking lot's perimeter.
If this is the only light source and the property owner is concerned about liability, a stronger lamp capable of staying bright for more nights without sunny days is necessary.
Certainly, the type of light should be stronger than required under Example 1 or Example 2. In this case, we would recommend "commercial grade solar lamps."
Typical specifications would be a 12 Volts, with 3000 mA. Even though the charging capacity is the same, the voltage is 2.5 times that of the lamp in Example 2. The light would not only be significantly brighter, the battery would be able to store enough power so that the lamp could longer without sunny days.
For many businesses, commercial, institutional and industrial applications the scenario shown in is common.
While it's true that a solar street light could provide stronger light for up to 5 or 6 days with minimal sunshine, the upfront costs would be, on average 8 times greater than a commercial grade solar lamp. Commercial grade solar lamps are a great way for people to go green with solar lighting with the smallest upfront cost.
While the cost of commercial grade solar lamps and lamp posts are higher than light fixtures that are great for residential applications, commercial solar lamps are a great bridge for those who want the economical and environmental benefits of solar without the upfront cost of solar street lights.