Solar lights are great for saving on electricity bills, but they have one critical weakness: They need the sun to keep them on. If you need light on a cloudy or rainy day, can you use a light bulb to power a solar light instead?
You can power a solar light with a light bulb, but more efficient options exist. A light bulb’s ability to power a solar light varies depending on the bulb’s brightness (lumen output), color temperature, and distance relative to the solar light.
Keep reading to learn more about powering a solar light with a light bulb. I’ll discuss — among other things — the steps you need to take, the pros and cons, and whether you’ll harm your solar light in any way if you regularly power it with a light bulb.
How To Power a Solar Light With a Light Bulb
As their name suggests, sunlight is the best power source for solar lights. However, you can use other means to power your solar light — such as a light bulb.
Here are the steps to power a solar light with a light bulb:
- Place the solar light panel directly beneath the light. Since solar lights absorb energy via built-in solar panels, you’ll want to place the light bulb directly above the panel for maximum energy absorption.
- Ensure the bulbs you’re using have a high lumen rating. Natural sunlight has a lumen rating between 1,000 and 6,000, depending on whether the light is direct or indirect. Consequently, you’ll want to use a bulb with a high lumen rating (1,000 lumens or more) when powering a solar light with a light bulb.
- Charge the solar light for at least 12 hours. Most solar lights only activate when nearby light sources are removed. To ensure your light bulb-powered solar light activates in the dark, you must expose it to at least 12 hours of artificial light.
Powering a Solar Light With a Light Bulb: Helpful Tips
No matter your reason for wanting to power a solar light with a light bulb, you can implement some helpful tips to increase the likelihood of effectively charging a solar-powered light with artificial light sources.
Without further ado, let’s delve into some of the most helpful techniques that can help power a solar light with a light bulb.
Invest in Incandescent Lights
Even though incandescent light bulbs are more affordable than LED bulbs, they’re less energy-efficient and have shorter lifespans. That said, incandescent bulbs are often the better choice when powering a solar light using artificial light.
That’s because incandescent lights emit a low level of UV radiation. This quality makes them better stand-ins for sunlight than LED lights, which don’t emit any UV light.
And although incandescent lights don’t come in as many color temperatures as LED bulbs, white and bright-white options are available. This distinction is essential, as most solar light panels respond best to white or full-spectrum light.
Use Full-Spectrum or White-Light Bulbs
When you think of sunlight, do you picture a butter-yellow glow? While the sun appears yellow to the naked eye, the sunlight that reaches Earth is closer to white than yellow.
Because solar light panels are designed to react to this type of light, using a bright white or full-spectrum light bulb to power a solar light can yield better results than using standard “warm color” bulbs.
KOR 40-Watt A15 Incandescent Bulbs (available on Amazon.com) are an excellent choice for those using incandescent light to power a solar light. They emit light similar to sunlight and are designed to fit snugly into most light fixtures. However, their comparatively low lumen rating (approximately 560 lumens) means you must place them close to your solar light’s panel.
If you’d prefer to use a higher-intensity LED bulb to power a solar light, you might want to invest in a Philips LED High Lumen A19 Bulb. This light bulb produces a far more powerful 1,500 lumens and is more energy efficient than incandescent bulbs.
Consequently, this LED bulb could charge a solar light more quickly (and use less electricity to do so). Still, the final choice between LED and incandescent is up to you. Just be sure you’re choosing a bulb that imitates the bright white color of natural sunlight.
Don’t Skimp on the Lumens
In addition to light color, you’ll want to pay attention to your chosen bulb’s lumen output. A “lumen” is essentially a unit of measurement. It describes a light’s brightness.
The lower a bulb’s lumens, the softer and dimmer it’ll be. The opposite is also true: Bulbs with high-lumen ratings are often quite bright and powerful, capable of lighting much larger spaces than low-lumen bulbs.
Because natural sunlight produces a lumen rating between 1,000 and 6,000, it’s best to select bulbs with a lumen rating within that range. Otherwise, you might find that your solar light fails to charge, even when placed beneath multiple bulbs.
Install Mirrors Around the Solar Light and Light Bulb
Placing a cone of mirrors around your solar light and bulb setup can dramatically increase the rate at which the solar light’s battery charges. That’s because mirrors reflect light, bouncing it back toward its source.
Surrounding your solar light’s panel with mirrors essentially traps light emitted from the light bulb placed above it, forcing it to travel back and forth above and toward the panel’s surface. It focuses the light toward the panel, reducing “lost” light and potentially decreasing the solar light’s charging time.
Of course, creating a box or cone of mirrors can be challenging. Fortunately, you can use virtually any highly reflective surface to increase the effectiveness of your artificial bulb.
For example, you can create a cone of reflective aluminum foil.
Wrap the foil around the solar light’s panel, then roll and wrap upward toward the artificial light source, ensuring the smallest part of the cone is the portion wrapped around the panel. To ensure this cone doesn’t unravel, secure the foil using a few pieces of transparent tape.
Leave Space Between the Bulb and the Solar Panel
When powering a solar light with a light bulb, you might be tempted to situate the bulb as close to the panel as possible. However, the heat emitted from a light bulb, especially incandescent and fluorescent bulbs, can damage solar panel cells.
Consequently, leaving a gap of six to 12 inches (15 to 30 cm) between the bulb and the panel is an excellent idea.
If you’re using a high-lumen bulb, you won’t need to worry about the distance between the panel and the bulb impacting charge efficiency. The light intensity will ensure that light reaches and penetrates the panel’s solar cells.
It’s also worth noting that LED lights emit less heat than incandescent bulbs. So, if avoiding damage to your solar light is a top priority, you might want to trade the UV benefits of incandescent bulbs for the reduced-heat qualities of LED ones.
Pros and Cons of Using a Light Bulb To Power a Solar Light
Aside from the convenience of not needing sunlight, light bulbs are great for powering solar lights because:
- Light bulbs are easy to find. Light bulbs are available at most grocery stores, pharmacies, and hardware stores. And if you can’t find light bulbs in-store, you can always order them online from retailers like Amazon. In fact, many online retailers sell high-lumen bulbs that can effectively power solar lights.
- Light bulbs are inexpensive. Most light bulbs can last up to 20 years. Replacement bulbs are relatively affordable, typically costing between $1 and $3 per bulb. This low cost, combined with the long lifespan of most bulbs, means that powering a solar light with a light bulb isn’t a costly endeavor.
Although light bulbs can be a good choice for powering solar lights, they have a couple of drawbacks.
- Light bulbs require electricity. If you need to power your solar light on a cloudy day, and your area happens to experience a power outage, your light bulb won’t be able to power your solar light. There’s also the added electricity consumption.
- Light bulbs can make the usage of solar lights redundant. Think about it: If you already have light bulbs to light up your home, and they have a more reliable power source, why bother using solar lights?
- Light bulbs can reduce the lifespan of your solar light. An LED light bulb doesn’t emit ultraviolet (U) rays, but sunlight does. A solar light’s sensors are designed to absorb UV light. Solar light sensors cannot store as much energy when exposed to artificial light. Over time, this can reduce a solar light’s lifespan.
How To Keep Solar Lights Charged for a Long Time
Whether you choose sunlight or light bulbs to charge your solar lights, you need to maintain your solar lights to help them enjoy the longest possible lifespan. Below are a few tips for doing so.
Replace Drained Batteries
Most solar lights store solar energy in rechargeable AA or AAA batteries. Over time, these batteries will lose their ability to hold a charge due to normal wear and tear.
If you notice that your solar lights’ batteries keep draining faster than they should, it’s probably time to replace them.
Brightown Rechargeable AA Batteries (available on Amazon.com) are a great choice when replacing worn-out solar light batteries. These batteries have a comparatively long lifespan of 1,200 charge cycles and can retain most of their charging capacity for years after initial use. Besides, you can even charge them using solar energy.
Clean the Panels
Cleaning a solar light’s panels ensures that it absorbs the maximum amount of sunlight possible. A dust or dirt-covered solar panel will absorb less light than a clean, unblocked one.
For this reason, it’s an excellent idea to clean your solar light’s panels every week (or at least every month).
Fortunately, keeping these panels clean is as simple as wetting a soft microfiber cloth (with plain water, don’t use cleaning liquids) and wiping away any grime. You can use a dry cloth to gently buff away any remaining dirt or moisture for a streak-free shine that significantly increases the efficiency of your solar lights.
Place Solar Lights in Sunny Locations
Sunlight is the most effective way to charge solar lights, so it’s an excellent idea to ensure that your solar-powered outdoor lights are placed in locations that receive plenty of sunlight throughout the day.
If your yard doesn’t enjoy a lot of direct sunlight due to tree cover or shading from nearby buildings, consider investing in a wall-mounted solar light. These can transform sunlight that falls on your home’s exteriors into storable, usable light that self-activates at night.
Aootek Solar Lights (available on Amazon.com) are some of the most durable and efficient wall-mounted solar-powered lights. They can withstand high heat conditions and rain and feature three modes (motion-activated, all-night, adjustable brightness) to meet your outdoor lighting needs.
These solar lights also have built-in reflectors that increase lighting intensity without putting more strain on the internal battery. Consequently, you might find that you don’t need to recharge these lights’ batteries quite so often.
Turn Off Solar Lights When the Weather Is Cloudy
When the weather outside is cloudy, foggy, or rainy, the panels on your solar lights aren’t able to absorb much (if any) solar energy. Low-light conditions caused by inclement weather can also trigger your solar lights to turn on during the day.
To reduce the strain on the solar light’s battery and help it enjoy a longer lifespan, you’ll want to switch off your solar lights during cloudy or rainy weather.
A light bulb can power a solar light. While the light bulb may not be as bright as the sun, it can provide enough light for the solar light to charge during the night or when there’s not enough sunlight outside. However, it’s important to note that this method should only be temporary, as it can damage the solar light sensors if used repeatedly.
- United States Department of Energy: Lumens and the Lighting Facts Label
- HowStuffWorks: How Sunglasses Work
- National Library of Medicine: The risk of ultraviolet radiation exposure from indoor lamps in lupus erythematosus
- West Texas A&M University | Science Questions with Surprising Answers: What is the color of the sun?
- Amazon: KOR 40-Watt A15 Incandescent Bulbs
- Amazon: Philips LED High Lumen A19 Bulb
- United States Department of Energy: LED Lighting
- Solight: How Long Do Solar Garden Lights Last?
- Amazon: Brightown Rechargeable AA Batteries
- Amazon: Aootek Solar Lights
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