It’s our goal at Voltaic Systems to provide the highest quality, small scale solar panels to our customers. Should one of our existing small solar panels not fit your needs, here is our guide to making a custom solar panel.

For more information, contact us at (212) 401-1192 or better yet, schedule a consultation with a Voltaic expert.

What is the solar panel development process?

Voltaic solar panels have a track record of thriving in almost any environment, 24x7, 365 days a year. Our panels have been bobbing in the saltwater of the Indian Ocean, mounted on huts in the deserts of Africa, and braved the snow and altitude in the Himalayan Mountains.

Here's what you get when you choose Voltaic custom solar panels:

  • Panels designed to last 10+ years in production environments
  • Construction using the highest quality materials
  • High-efficiency photovoltaic cells
  • Designers with years of experience meeting demanding solar specifications

What is the solar panel development process?
  1. Exploratory Discussion - Typically a combination of phone and email conversation so we can learn about your project specifications and timeline
  2. Panel Specifications and Design* - You will help us specify voltage, power, dimensions, materials and mounting mechanism and we will provide one or more designs that meet your requirements.
  3. Prototype
  4. Full production

*To determine the panel specifications, we typically need to know:

  • Power consumption per day and peak power requirements of the device to be charged
  • Geographic conditions of field use
  • Any physical constraints
  • Voltage, capacity and chemistry of battery you expect to use and desired charge time

What power and voltage options do I have?

Total power is determined by surface area. We most frequently use 19% efficient monocrystalline cells which provide about 0.019 Watts per square centimeter or 0.12 Watts per square inch. For example, the solar cell sections on this 2.2 Watt panel measures approximately 4in x 4.8in, adding up to 2.2W.

calculate power on solar panel

SunPower cells are more efficient, about 22%. The small silver lines are moved to the back of the cell, earning the description "back contact cells."

SunPower panel with ETFE coating
SunPower panel with PET coating

The advantages of using SunPower cells are:

  • Higher efficiency adds 10-15% additional power per unit area
  • Fewer constraints to cell size and layout
  • Even appearance that can disappear on a matte black background
  • Costs are lower at scale as they can be manufactured using an SMT process

The downside is that our SunPower panels have a laminate construction vs potted urethane which lowers the overall lifetime. Read more on coatings below.

As a general rule of thumb, we typically recommend that the voltage of the solar panel is 1.5 times the voltage of the battery. This ensures efficient charging throughout the charge cycle.

Recommended Panel Voltage

Battery VoltagePanel Voltage
3.7-4.2V 6V
7.2-8.4V 12V
10.9-12.6V 18V

You might deviate from this rule if your charge control chip can efficiently convert from lower voltages to the voltage needed to charge your battery. In that case, having a lower voltage will decrease power attenuation from shading.

We create a specific voltage by stringing individual cell pieces in series. Each cell piece is ~0.55 Volts (0.58 - 0.59 for SunPower), so for the 2.2W panel shown below we used 12 pieces to create a 6 Volt panel.

string cells in series solar panel
 

What chemistry cells do you use?

We use mono-crystalline cells for their high efficiency. Traditional cells are 19 - 19.5% efficient while available SunPower cells are closer to 22%.

What are the coating options?

All solar cells are protected with some sort of coating material. For commercial solar panels, it is often glass. For smaller panels there are a number of different options.

Urethane: Highly UV resistant, but heavier than ETFE. Our standard panels have a urethane coating and last up to 10 years in the sun with minimal power degradation. The urethane coating is poured or "potted" on the solar cells and leads to a highly waterproof panel. Each individual cell is completely encapsulated by the urethane.

ETFE: Slightly less UV resistance than urethane, but lighter weight. ETFE and EVA are attached to the cells via a lamination process. With high quality materials (there is a difference in the production quality of ETFE and EVA), these panels have an expected life of 5 years outside.

Epoxy or PET: Panels made with these coatings will be inexpensive, but we don't recommend this coating as it tends to have a relatively short lifetime. They are the least UV resistant of any of the options.

Glass: Most UV resistant, but also the heaviest and can be challenging to mount in a streamlined manner.

The left images shows a) aluminum-plastic-aluminum substrate with urethane coating b) PCB substrate with ETFE coating and c) aluminum substrate with glass coating. The right image shows ETFE then glass then urethane.

urethane vs ETFE vs glass coated solar panels
solar panel coating options

What are the substrate options?

The solar cells are mounted on a substrate or backing. Again, there are several options.

Aluminum-Plastic-Aluminum: Very high strength to weight ratio material used in commercial building applications. Easy to create waterproof panel. Allows embedding of screw or nut into substrate.

PCB Plastic: Different thicknesses available, from 1mm to 5mm depending on requirements. Allows embedding of knurled nut into substrate. Higher density than Aluminum-Plastic-Aluminum substrate. Not waterproof without additional hardware.

Aluminum: Typically the strongest substrate option, but is also the heaviest. Thin and rigid.

What mechanical mounting features are available?

Depending on the substrate material used, we can embed screws or nuts into the panel, leave empty through-holes or simply flat backs.

mounting options on back of solar panels
 

What type of wire is used?

Our standard wire has strain relief is about 12 inches long and terminates in a 3.5x1.1mm plug. This can be changed to whatever length and terminal you prefer. The wire can be embedded into the substrate to keep it waterproof or soldered on the outside of the panel. Power and ground wires can even be separated as shown below.

wire connection on back of solar panel
solar panel with JST connector

Another option is to place contact pads on the back of the panel. These can be positioned anywhere on the panel.

solar panel on PCB with solder pads
 

Are there any design or tooling fees?

There are no design fees to create a prototype of your custom solar panel. Some, but not all designs may require a fee to prepare the machinery to create your specific panel at volume. This tooling fee begins at around $2,000.

Is there a minimum order quantity or MOQ?

Our MOQ is 1,000 - 2,000 panels. If it is a minor update to an existing panel, this may be lowered.

Any useful tips that you can offer in advance?
  1. Reduce your circuit’s power requirements before discussing the panel’s power requirement. For example, if you can reduce your circuit’s mA requirements by 50% this reduces the size of the solar panel by 50%, saving you money, size, and weight.
  2. Prototype your project with solar panels we already manufacture before moving forward with custom designs. We have circuit boxes that allow you to sum the panel power in parallel or series to increase the current or voltage, so you can approximate how the custom panel will perform.

Can I consult with a Voltaic solar panel expert?

Yes, please fill out this form so that we can help and someone will contact you within one business day.