Campervan solar power: Here’s what you need to go off-grid in your van

Free off-grid electricity is a must for most van lifers but how do you find the right solar power system for your campervan? Here, Van Life Matters has partnered with renewable energy specialist, Renogy UK to compile this beginner’s guide to campervan solar power.

Want to know how to get solar power in a campervan, not sure what size solar panels you need, how many batteries you should get or what the best controller is for you?

It’s easy to get overwhelmed by all of the solar power options, technology, costs and the installation process, but with a basic understanding, you’ll be able to determine how what size solar panel to get, how many batteries and the best solar panel controller for your campervan.

IN A NUTSHELL: Solar panels are made up of many solar cells made of silicon. Panels have both a positive and a negative layer, which creates an electric field. When sunlight hits solar panels, they create an electric current. Panels are then connected to a charge controller, which controls how much current goes through a battery. Batteries store and produce DC power.

How do I get solar power in my campervan?

1. Budget: Consider how much are you willing to spend on a campervan solar system. This will determine how many solar panels and leisure batteries you can install, as well as specific technologies.
2. Space: Next, think about how much square footage you have to work with on your roof. If you’re dealing with a small space on your roof, you’ll either want to install just a few roof-mounted panels or use portable solar panels. Many portable solar panels are available as a folding-suitcase style kit, meaning you can just set them out on the ground and start collecting energy. You also need to think about how much space you have inside your van for batteries as well as all of the other components of a campervan solar system – more on that to come.
3. Climate: If you’ll mostly be travelling somewhere with sunshine for the majority of the year, you’ll be able to collect and store plenty of energy to power your appliances. But if you’ll mostly be travelling in the UK, you’ll need to ensure you’re able to store as much energy as possible when the sun does eventually make an appearance.
4. Usage: Now’s time to consider how much energy you need to harvest and store. Properly sizing your campervan solar system ensures you don’t overspend on a large system that you’re not going to fully utilise, or under-build a system that doesn’t adequately meet your needs. Start by making a list of all the appliances and devices you plan on running. The main appliances to take into consideration when addressing energy needs may include a TV, lighting, water pump, laptop, fans, microwave, and refrigerator.

TOP TIP: Use the Renogy Solar Panel Calculator to help determine your specific energy needs. You’ll just need to know what total watts your electronics will consume, how long you plan on running the devices, your charge controller efficiency, and average sun hours per day. The solar panel calculator will then tell you the minimum and recommended system size, as well as the recommended battery output.

Once you’ve worked out a budget, how much space you have and how much energy you’ll require, you can start to think about the campervan solar power equipment that you’re going to need.

While every set-up is different, most will feature solar panels to harvest energy, a controller to regulate how much current goes through to a battery, and the battery itself.

In order to use household AC appliances, such as blenders, laptops, and phone chargers, an inverter is also needed to convert battery DC power into AC power.

Campervan solar panels

The first step in generating off-grid power is the collection of energy through solar panels.

Campervan solar panels can be monocrystalline or polycrystalline, flexible or rigid and portable or roof-mounted.

Polycrystalline solar panels, while cheaper, are less efficient than monocrystalline solar panels which are also more space-efficient.

THE SCIENCE BEHIND SOLAR PANELS: Solar panels are made using semiconductor layers of either gallium arsenide or crystalline silicon. These semiconductor layers use a combination of both positive and negative layers connected by a junction. When sunlight hits the panels, the semiconductor layers will absorb the rays and send the solar energy to the PV cell. This solar energy bumps electrons loose, which move between the positive and negative layers and produce an electric current – that electric current is DC.

Flexible solar panels weigh less than the rigid solar panels and can be installed directly on your campervan roof. Rigid panels, which are more typically durable, can also be mounted to tilt, which makes their solar energy collection more efficient.

If you can’t/ don’t want to mount solar panels on the roof, portable solar panels are an excellent alternative and are available in a few different forms, from folding suitcase panel kits that can be set up on the ground to flexible panels that can be hung from your vehicle or other vertical surfaces.

Campervan solar panel controller

Solar panel controllers, also known as ‘controllers’, are installed between the solar panels and battery to prevent the overcharging of batteries by limiting the amount and rate of charge.

They also prevent battery drainage by shutting down the system if stored power falls below 50 per cent capacity.

There are two main types of charge controllers to consider: the cheaper, but less efficient Pulse Width Modulation (PWM) charge controllers and the highly efficient Maximum Power Point Tracking (MPPT) charge controllers.

Campervan batteries

To store the power you’re generating from your solar panels, you’ll need at least one battery.

There’s a range of deep cycle battery options, such as lead acid, absorbed glass matt, and lithium ion batteries.

Lead acid batteries are the most inexpensive option and are available at most automotive and leisure shops.

Absorbed glass matt batteries store 10 to 15 per cent more energy than lead acid batteries and charge up to four times faster.

Lithium-ion batteries are the most expensive options, but also last four times longer than lead-acid batteries and weigh much less.

NEED TO KNOW: Batteries operate best in a cool environment. If it’s too hot, they may overheat. Too cold, and your batteries will have to work harder and at a higher voltage to charge. Keep this in mind when sizing your system and selecting batteries.

Campervan inverters

An inverter converts the direct current (DC), created by solar panels and stored in batteries, into alternating current (AC).

An inverter is necessary to power appliances such as laptops, TV’s, microwaves and hair dryers.

NEED TO KNOW: Direct current (DC) is electrical current which flows consistently in one direction. Solar panels generate DC power and batteries store DC power, which can be used to operate 12V lights, 12V power outlets and USBs. Alternating Current (AC) is a type of electrical current, in which the direction of the flow of electrons switches back and forth at regular intervals or cycles and is used to power household appliances.

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