Solar Panels With UV Lights (Indoor Solar)

The idea of running solar-powered devices with UV lights indoors is not new. But, it is not the UV portion of the light spectrum that produces solar energy.

UV light is good for plants, heat, and sunburn. We need to talk about the visible portion of the light spectrum. It is light you can see that produces solar power.

  • What you can run with a light bulb.
  • How much energy does light provide?
  • How much light is required to power a device?

It is a common misconception that it is the heat from the sun that solar panels use to produce power.

Actually, it is photons in visible light that produces solar power. Since light bulbs produce photons of visible light energy, they too can power solar panels.

Uv Light Ultraviolet
Uv Light Ultraviolet

Indoor Solar Devices

There are several common household devices that are run by indoor solar power. These are mainly small, digital devices.

Solar-powered clocks, timers, calculators, and wristwatches are widely available. Incidental light from natural and man-made sources are all these devices require for operation.

  • Small devices.
  • Digital.
  • No motors or very, very small motors.

Why Only Small Devices Can Be Used For Indoor Solar

The types of devices that can operate indoors with a solar panel require very little power. A digital clock or timer uses between 1 and 3 volts and a few milliamps.

The reason only such small devices use solar applications is a matter of scale. A very small device requires only a small solar panel.

  • Low Voltage.
  • Milliamps.
  • Small solar panel.

The Problem With Larger Devices and Solar

Larger devices could be run with solar using indoor lighting. The problem of scale becomes apparent very quickly. It takes a large panel and a lot of light to produce watts.

The size of tools required is prohibitive. Let’s take a small radio as an example.

  • Small tabletop radio.
  • 9 volt DC Power supply.
  • 1 amp
  • 9 watts

A 10-watt solar panel is about 1 square foot in size. Under ideal circumstances, such a panel could power a small radio.

Inside, with electrical lighting as a power source, the panel would only provide a fraction of the rated power.

In that case, it would take 2 or 3 such panels to power the radio. But, WHY?

The Energy In Light – Lumens Power

Light is measured in several ways. When we discuss man-made light we usually describe it by the energy used to produce it: Watts.

The light produced, the brightness of light, is measured in Lumens. For context, a 100-watt incandescent bulb produces about 1500 lumens of light. In solar applications we are working backward, using light energy to produce watts.

Sunlight UV Power

The sunlight that hits the earth’s surface is full-spectrum light. It includes forms of light from infrared to ultra-violet and all forms of visible light.

Depending on where you are on the planet and the season, the maximum amount of solar energy hitting the ground is between 600 and 1000 watts per square meter.

Light Bulbs Lumens

Light bulbs are rated by the watts of power they consume (watts), not the light they emit (lumens).

Due to inefficiency and losses to heat, a 1000-watt bulb can not emit the equivalent of 1000 watts of light energy.

To further diminish the solar effectiveness of a light bulb, the light is limited to a fraction of the available light spectrum.

Finally, most light bulbs are designed to distribute light. The light produced is spread in a spherical area.

Energy From The Sun

  • 600 – 1000 watts per square meter.
  • Approx. 10,000 lumens per square foot.
  • Full-spectrum light.
  • Variable.
  • Free.

Energy From Light Bulb

  • Wide variety of watt ratings.
  • Light energy is difficult to focus on.
  • Limited light spectrum.
  • Stable.
  • Expensive at higher energy ranges.

Power Collected By Solar Panels

Solar panels only use about half of the light energy that hits them to produce electricity. The other forms of energy in sunlight do nothing or produce heat, which reduces the effectiveness of the panel.

Man-made forms of light produce this heat as well, reducing the efficacy of artificial light in solar applications.

Power to Run A Solar-Powered Device Indoors

Now that we have a better notion of what a solar panel needs to provide power, we can look at the requirements for a light bulb-powered solar device.

We will consider the tabletop radio and 10-watt solar panel discussed earlier.

What We Know;

  • Radio requires 10 watts at 9 volts.
  • 10-watt panel is approx. 1 sq. ft.
  • The panel requires 10,000 lumens over the entire surface to emulate sunshine.

Number of lights to power LED lights;

  • 10,000 lumen light source of the appropriate spectrum.
  • The light source must provide light over the entire panel surface.

There are 10,000 lumens LED lights available that should satisfy the power requirements of the radio.

It may take a little experimentation to determine the light spectrum that best powers the solar panel. LED lights come in a variety of spectrum ranges.

One that closely matches the spectrum of sunlight would be the logical starting place.

PROS – Indoor Solar

  • Solar-powered radio indoors.
  • Can operate regardless of the weather.
  • Can operate at night.

CONS – Indoor Solar

  • Large solar panel for indoors.
  • LED light large enough to power the panel is expensive.
  • The power requirement of such a light source is near 100 watts.

While the technical aspects of driving a solar device with indoor light are fairly simple, the practical aspects are not.

The equipment required to provide adequate power to something as minimal as radio is rather daunting. Most of all, it is not economically sound.

A set of rechargeable batteries and a solar charger would be more practical.

Is Solar Indoors a Good Idea?

Powering solar devices with household lights is a practical and creative idea.

Unfortunately, it is not easy as we would hope. After a little research and calculating it becomes obvious that we take the energy in sunlight for granted.

There is a lot more power in the sunshine than we imagine. Replacing it with artificial light is not practical.


General Solar Panel FAQ

What Problems Do Solar Panels Solve?

In environmental terms, solar panels can potentially solve a handful of problems, including;
1. Air pollution
2. Water pollution
3. Greenhouse gases
4. Reduction in fossil fuel use

For individuals, solar energy allows you to become completely self-sufficient when it comes to your electricity needs and can save you a lot of money in the long run.

What Are 3 Important Uses Of Solar Panels?

The three most important uses of solar panels are;
1. Solar electricity. This can be used to power almost any appliance in your home, including TVs, computers, and fridges.
2. Lighting. In addition to the use of low-power, LED lightbulbs, solar panels can provide an efficient, low-cost, and environmentally friendly way to provide lighting to homes. 
3. Portable solar. In our modern, always-connected lives, our phones, tablets, and computers are almost always with us, and all run on batteries. Portable PV chargers can help keep our batteries topped up no matter where we are, as long as there is some sun to charge them.

Do solar panels give you free electricity?

Once the cost of the array is paid in full, the energy it produces is free. There are ongoing maintenance costs, too, such as annual panel cleaning, etc. 

How much will my electric bill be with solar panels?

Suppose your solar array includes a solar battery backup system, and it is large enough to fully cover your energy usage per day. In that case, your monthly electric bill will be next to zero dollars, even with a grid-tied system. 

If your solar array does not include a solar battery backup system, then at night, your house or business will use grid electricity. That cost will vary but expect to pay from 1/3-2/3 of your average electric bill, and that cost will fluctuate seasonally. 

Do you save money with solar panels?

The simple answer is, Yes, you save money with solar panels. There is an initial upfront cost, but since solar panels are warrantied for 25 years, you will save money over time. You will also begin to see monthly savings in energy bills, but there are other ways that solar panels pay you back. Those include:
1. Adding value to your home or commercial building 
2. Monthly decreases in energy costs
3. The ability to add more energy appliances without increased monthly costs
4. The potential for tax credits for going solar

Can solar panels power a house 24-7?

Most definitely! Solar panels can certainly power a house 24-7, with the addition of a high-quality inverter and a suitable battery bank, of course. To power, a house under normal usage will require a massive solar array, though, and there will be a very expensive initial financial outlay.

Do I need to tell my energy supplier I have solar panels?

This depends on where you live, but in most cases, it’s not necessary to inform your energy supplier that you have solar panels. That said, you may be producing excess power with your solar system, in which case you may be able to sell that excess power back to energy companies.

In this case, you’ll naturally need to be in contact with them. 

What Are Solar Cells Known as and Why?

Solar cells are also called photovoltaic (PV) cells. They are called so because the term ‘photovoltaic’ literally means light i.e. photo and electricity i.e. voltaic.

These cells generate electricity through the photovoltaic effect. This effect basically causes the generation of free electrons from the semiconducting silicon material of the solar panel when sunlight hits its surface.

What Type of Solar Panels Are Most Efficient and Why?

There are currently three types of solar panels available in the market that are:
1. Monocrystalline
2. Polycrystalline
3. Thin-filmed

Among these, monocrystalline solar panels are known to be the most efficient among all others.

Does heat enter your home through the roof?

Absolutely. Heat enters your home through your roof, and on a hot day your attic can get up to 150 degrees Fahrenheit or more. Through conduction, heat from the sun warms your roof which then warms your attic and the rest of your home.

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