How to build a portable solar power system

Portable solar power systems are very useful tools -actually much more than you could think. Most of us would think of them for camping and outdoor activities in general, but they are extremely useful also at home when emergencies and power outages surprise us.

Whether small or large, a portable solar power system consists of the same components. If you are interested in building a portable solar power system, this guide can help understand basics and help you decide which portable solar power system is most suitable for your needs.

In order to optimally generate electricity from solar panels wherever you go, and in basic terms, the following is the list of things you will need when building your portable solar power system:

• Solar Panel
• Charge Controller
• Power Storage
• Inverter

How solar panels work

Solar panels are the main component in the solar power system that does all the magic. A solar panel consists of a number of solar cells made of silicon (semiconductor material), composed of two different crystals: P-type and N-type. Positive P-type contains holes and negative N-type contains electrons. When the sunlight hits the surface of the cell, the recombination of electrons and holes begins, creating a negative and positive charge in the cell. These moving electrons will create an electrical circuit, and they cannot be worn out. In order to generate output, solar cells are interconnected into the solar panel.

Nowadays portability plays a key factor as more power in a more convenient (small) way of carrying them is what makes them ideal when looking into building a portable solar power system.

Solar panels are commonly available in three forms; suitcase, flexible, and folding.

A suitcase panel is a suitcase-like panel. You could close the solar panel lids down, lock the latches, and carry conveniently in carrying bags.

Flexible solar panels are usually the type of solar panels that you could curve up to 30 degrees. They offer the advantage of using on uneven surfaces like a boat deck, RV to, etc.

A folding solar panel are regular flexible solar modules sewn into the polymer canvases which come in an array of layers that you can fold them down quickly.

Solar Panels: Monocrystalline or polycrystalline?

The most common types of solar panels are monocrystalline and polycrystalline. How to choose the best type of solar panel?

Monocrystalline solar panels are the first type of photovoltaic modules on the market. This technology has started a revolution in the use of solar energy. Let's look at some facts on monocrystalline solar panels:

• have the highest efficiency rate (16%-20%)
• have the longer lifespan (solar panels manufacturers are offering 25 years guarantee)
• work better in periods of low sunshine radiation

But:

• they are more expensive than polycrystalline solar panels
• dust or snow can reduce the overall output of the solar power system

Polycrystalline solar panels are created as more affordable successors of monocrystalline solar panels. Production technology is cheaper, giving the less cell's efficiency, but other characteristics can give a better impression:

• manufacturing costs are lower, thus the price is more affordable
• higher heat tolerance (yes, on a hot sunny day monocrystalline solar panel can give lower output than polycrystalline)

But:

• lower cells efficiency (13%-16%) mean larger panel surface
• more panels needed for optimal output

When choosing between monocrystalline and polycrystalline solar panel there is no perfect choice. The best choice can be based on budget, surface area and average maximum summer temperatures. But as an overall recommendation, Polycrystalline solar panels will be your best choice.

Charge Controller (The heart of the system)

A solar power system with energy storage requires a charge controller or charge regulator, in order to regulate charging and discharging of solar batteries. This acts as a ‘safety valve’ and prevents overcharging (from unstable current) or draining of batteries and extends battery lifespan. Without the solar controller, the battery will be charged continuously which leads to battery overheating and mechanical damage to the energy storage unit, causing even more damage to electrical appliances connected to the solar power system. During the night, without charge regulator, all the power from battery storage will flow in reverse direction to solar panels, instead of powering appliances as end consumers. A charge controller can be seen as the ‘heart’ of the system which makes direct current from photovoltaics runs safely.

There are commonly two types of solar charge controllers; PWM ('Pulse Width Modulation') and MPPT ('Maximum Power Point Tracking'). They are very different from each other since they are based on different principles of operation. MPPT will be the most recommended option because of its effectiveness in turning extra amp from solar panels into electricity and storing it perfectly in your backup systems.

Batteries

Energy storage provides freedom and reliability in the consumption of electricity produced from renewable energy sources. Energy is stored in solar batteries and can be used at night or in cloudy weather. Proper battery capacity planning is crucial to the functioning of the entire solar system, and it depends on the needs of the consumer. Solar batteries manufacturers are competing to bring more reliable power, improving battery capacity, round-trip efficiency, depth of discharge and battery lifespan, so these are the main characteristic to look on when choosing energy storage for the portable solar power system. When reliable power is absolutely essential, don't make a decision based on price, but on battery performance. 

By the way, the battery is the heaviest part of a solar generator. Make sure you pick lightweight battery units like lithium instead of heavy lead-acid batteries.

Inverter:  effectiveness and innovation

Invertor or converter is the ‘brain’ of a portable solar power system. The job of a power inverter is convert direct energy (DC) from solar panels (or battery storage) into analog current (AC) to run your every day electronics. It can be installed in the solar power system, or as a backup power from battery storage. Inverters should be installed in a dry, clean area free of dust. Too much dust and dirt can make inverter overheat causing them to lower energy output which means that they deliver lower performance. With the development of technology, these electronic devices have also taken on new roles in the overall solar power system, so, today, inverters can be used as solar power monitoring systems. What to look at when choosing an inverter for a portable solar power system? Just efficiency. Inverters are consuming a small percentage of power, so the best inverter has higher efficiency, which means lower energy loss.

In case of an emergencies you’d need to run different appliances with your DIY solar generator. For example, an oven needs 1000-1500 watts to run. A coffee maker, small TV, and other AC appliances also consume as much as power to operate.

What’s more, just to neatly light up your home or camping tent, your inverter should produce 70 to 100 watts. Keeping this in mind, make your DIY portable solar generator with the right inverter. You should pick an inverter with the right power. It is the inverter that offers running watts for the appliances you want to run with the solar generator.

Application of portable solar power system

A portable solar power system will provide you independent and stable off-grid power supply. This is good for outdoor activities in general such as boating, yachting, RVs, camping, or even as back-up energy for security alarm, emergency lighting or electronics at home. With a portable solar power system you can have a stable power supply wherever you are. But size really matters.

50W solar panel can't handle much, but with battery storage, it could handle LED lightbulbs, charging smartphones, iPads, Laptops. Solar panel only, can run one 40W - 50W lightbulb (that you actually don't need during the day), tuner or small solar water pump.

120W solar panel can run lighting, tuner, water pump, laptop, small freezer, and more. For more applications, energy storage is essential, so you can count on small home appliances, fridge and entertainment, too.

Standardization is the magic word that has led to the definition of the common characteristic of solar power components. The more power from solar panels and battery storage - the more independence and autonomy. When it comes to a portable solar power system - there is no room for reduction, exploiting all available potential of free energy sources can never be too much.

A kit for every case

Our portable solar kits are designed to survive in environments that would normally cause another solar power system to fail, without compromising outstanding performance and reliability. No matter where your location, we have a solution for you. Find out why power system owners count on us rather than any other company for their energy independence.

Other Accessories To Consider

Besides your main components, other accessories are also necessary to set up your solar generator in the best way.

• A voltmeter to measure the voltage, although it is not a necessary component to operate the solar generator.
• If your inverter doesn’t have a USB hub and 12V ports you might also need them in separate units.
• All required wires and cables for the system.
• Strong and durable box or case.

Wrap up | Step-by-Step

Step 1: Plan Your Solar Generator

Do your planning. Decide what capacity your DIY portable solar generator should be. Think on your requirements for this part. Are you thinking on camping, RVing, boating, or emergency, or home use? Whatever is the need, make a detailed check on your needs and plan a solar generator in mind at first.

Generally speaking, 120W, 105W, and 100W panels are a very good starting points that enable to capture a good amount of power, faster. And they are foldable, which makes them highly convenient to carry around.  

Step 2: Purchase Parts

It is the second step. Buying the parts for a solar generator is not a difficult thing today. But you also have the option of buying all together as a kit (best choice). Still, you have a wide variety of options to pick from. Under each category, you have dozens of varieties under different price and power ranges.

Step 3: Integrate Parts to a Case

If you wish to build the generator inside a case, it is time to integrate the parts. Commonly, charge controller, battery, inverter, voltmeter, and other things come inside the box. Make sure you have a quality box or case with waterproof and ruggedness. Better place solar panels outside.

Later, you could buy a bag to move the solar panels easily. See the diagram on how to do the wiring of a DIY portable solar generator.

Step 4: Connect with Solar Panels

It is always nice to place the solar panel outside the case. That gives you a chance to place the panel away from the main unit for grabbing as much as sunlight possible.

Step 5: Test the Device

As you can see, there is no complicated task in building a DIY portable solar generator. If you have followed the diagram well, everything would be fine for you. Once you are done with the solar generator, you could test it under sunlight. And enjoy unlimited access to solar power even when you are on the move.

Example of a single panel system (voltmeter included) 

Credit parkedinparadise.com

Our most recommended

Summary

As you can see, after you understand the basic concepts and the framework, it is not as complicated as it seems at the beginning. Everything is quite simple. Having all the parts readily available and knowing what function each of them is for, is what matters. Now, all you have to do is buy them and bring them together into a unit to make solar energy.

A portable solar generator is a good idea while going out on a camping, outing, or emergency. It is definitely the best backup plan you can think of. Good luck and happy DIY.