A Guide to Caravan Solar Panels 2022 Tom Gill Last updated on 5 July 2022 10 min read Caravans represent freedom for many people, with the ability to up sticks and live off grid one of their most appealing features.Many caravans still rely on fossil fuels to function however, meaning they’re not reliable enough to truly go off grid.That’s why more people are using solar panels to power their caravans, so they can reduce their reliance on fossil fuels.With solar panels on your caravans, you won’t need to worry about running out of power. So if you’re ready to start looking for solar panels, why not fill in our simple form? Just pop in a few details and our trusted suppliers will get back to you with quotes.What's on this page? 01 How much do caravan solar panels cost? 02 How many solar panels do you need for your caravan? 03 Regulators and charge controllers 04 Top tips for looking after your caravan solar panels How do caravan solar panels work?Solar panels for caravans function exactly like those seen on roofs. They are photovoltaic panels, which means they convert sunlight into electricity.Silicon, the material used to make solar panels, produces an electric current when exposed to sunlight. Panels are typically made from multiple layers of crushed silicon crystals, which makes them polycrystalline.On the other hand you have monocrystalline panels, which are increasing in popularity. The solar cells in these panels are made from a single piece of silicon and are more efficient than polycrystalline, but they are more expensive.They’re more efficient than polycrystalline panels because they allow more space for the electrons to move around. This gives them greater energy potential, because the more room there is for electrons to move around, the more energy they produce.Attaching either polycrystalline or monocrystalline panels to a caravan would allow you to power the leisure battery, without the need to turn on the engine.A leisure battery is exactly what it sounds like — a battery within your caravan that can power all the amenities you'd need. From a TV to the lights, through to more demanding appliances such as a fridge or a kettle, leisure batteries are essential. How much electricity can caravan solar panels generate?The largest widely available solar panel system for a caravan is 250 watts (W), so we’ll use it as a benchmark.Assuming your caravan is exposed to six hours of direct sunlight in a day, we can multiply 250 W by six to get 1,500 watt hours (Wh), or 1.5 kilowatt hours (kWh) of electricity.You should consider accounting for cloudy weather as well, which can reduce solar panel efficiency by as much as 66% during heavy clouds. Can you go fully off-grid with caravan solar panels?Your ability to go fully off grid in your caravan depends on your solar setup. If you’ve got a small system, say one with a 30 W output, you would struggle to go fully off grid.This is because a system of this size would only work to top up your caravan’s leisure battery for limited use at night.To go fully off grid, you would need a solar panel system capable of generating enough power for your needs even when there isn't much sun. Do you need a solar battery for your caravan?Most people use solar panels to fully power their caravan during the day, and charge the leisure battery for use at night.A leisure battery, typically 12 volts, is enough to power basic appliances such as kettles, televisions, or even a fridge for hours at a time.If you plan to go truly off grid, you will need a larger battery, especially if you plan to use more power-consuming appliances.Portable solar batteries exist and typically range in power capacity from 210 Wh to 3.5 kWh. Caravan solar panels start from £70 for a small 30 W system, and go up to £1,000 for panels with 250 W or more.Prices for portable solar batteries start at around £270, up to over £4,000 for high capacity units. How long do caravan solar panels take to install?Installing solar panels on your caravan will take 1–2 days, depending on the size of the system.You can install solar panels on your caravan by yourself, with many DIY kits sold online.It is always better to use a trusted installer however, because of the potential risks.Installing solar panels correctly can be complicated — installing it incorrectly could result in either not enough power being generated, or none at all.Worst still, you might end up damaging your battery, which can lead to a fire or even an explosion. How many solar panels do you need for your caravan?It’s very important to make sure you get enough solar panels to meet your daily needs — too few and you’ll run out of energy to power your appliances. Too many and you’ll feel like you’ve wasted money.Below are three helpful steps you can take to work out how many solar panels you might need for your caravan. 1. Make a list of your appliances’ wattagesTo find out how many solar panels you’ll need for your caravan, you first need to work out how much electricity you use.Start with working out the wattage of the appliances you use in your caravan. You’ll typically find this on the bottom of the appliance, but if not you should be able to find it out online.Here’s a few appliances commonly found in caravans and their typical wattage:ApplianceWattageAlarm clock2Coffee maker300Electric kettle1,000Hairdryer1,000Iron1,000Laptop50Phone charger3Electric fan10Electric heater1,500Microwave600Radio70TV70Toaster800Water pressure pump120Satellite dish20LED light82. Work out your daily appliance usageNext, work out how long you use each appliance for each day. For example, if you use an 8-watt light bulb for 3 hours a day, you will need 8 watts x 3 hours = 24-watt hours per day for that light.Do this for every electrical item, then add all the results together to find out how many watt-hours, in total, you’ll need your solar panels to generate.In the example below, you would need to work out what size solar panels would give you 224-watt hours of electricity each day.ApplianceWattageNumber of hours used each dayEnergy needed each day in watt hoursLiving room light16348Halogen light10220Kitchen fan200.510Water pump400.2814-inch 12-volt TV4529012-volt radio24248Total224All solar panels’ power ratings are measured in watts, but it’s important to remember that they won’t produce this much power all the time.Instead, the rating is the maximum amount of power the solar panel can produce in optimal conditions — that is, when the sun is at its brightest. 3. Work out how much power you’ll need through the seasonsSummer will bring between four and seven hours of bright sunshine per day. To produce 224 W over four hours, you’ll need a 56 W solar panel (224 ÷ 4). The winter is different — you can expect around one hour of peak performance from your panels.So you would need a panel capable of outputting at least 224 W to keep your caravan’s lights and appliances running in winter. Spring and autumn sunshine hours fall somewhere in the middle.Here’s the amount of power you can expect from various sizes of a panel on an average summer and winter day:Solar panel rating in wattsPower generated on a summer’s dayPower generated on a winter’s day424 to 28 watt hours3.2 watt hours1060 to 70 watt hours8 watt hours20120 to 140 watt hours16 watt hours25150 to 175 watt hours20 watt hours50300 to 350 watt hours40 watt hours80480 to 560 watt hours64 watt hours100600 to 700 watt hours80 watt hours150900 to 1,050 watt hours120 watt hoursThe ratings above aren’t a guarantee of how much power you’ll generate — think of them as a guideline for what to expect. You can assume a 50 W panel is going to produce twice as much power as a 25 W panel, for example.Our advice is to add an extra 20% of power onto what you think you’ll need. That way, you can compensate for cloudy days and shade. Considering the above, we suggest:Getting an 80 W panel if you plan to only use your caravan in the summer.Getting a 250 W panel if you plan to use your caravan all year round.If you only want to keep the battery charged when you’re not using the caravan, a 20–30 w solar panel will be enough. Regulators and charge controllersUnless you’re installing a tiny solar panel, you should get a regulator or charge controller. This stops your battery from being overcharged, which damages it, and also regulates its temperature to stop it from overheating.Check the regulator includes a blocking diode, which prevents power from going back into the solar panels from the battery when it’s dark. If your panel is so small that you’re not using a regulator, you’ll need a blocking diode anyway.Prices for regulators start at £15 and go up to £70. Get a good quality regulator; it will help you get the best out of your system. You may also need an inverter, which converts the battery current (DC) to mains electricity (AC).A regulator is essential if you’re installing solar panels over five watts. This is because solar panels can overcharge your battery, which can cause damage to the battery or worse, a fire and/or explosion.Solar panels under five watts don’t need a regulator, because the power output is low enough that they won’t cause damage to the battery. Top tips for looking after your caravan solar panelsSolar panels are well known for requiring little maintenance, but that doesn’t mean you can just leave them alone indefinitely. Here are a few top tips to get the best out of your solar panels: Keep the panels cleanWhen solar panels get dirty, their ability to convert sunlight to electricity is reduced, as less sunlight is able to reach the silicon crystals. This is especially likely to be a problem with solar panels for caravans. For cleaning the solar panels, use a soft cloth, warm water, and gentle soap. Don’t use any abrasive cleaners, as they could damage the panels.Use more efficient appliances By using more efficient appliances, you will use less electricity. This means the energy generated by your solar panels will go further, which can be essential for off-grid living. For example, opting to use LED light bulbs instead of halogen bulbs is a good way to get more from your solar panels.Make good use of your regulator If you can see how fast the battery is discharging, you can identify which of your appliances use the most power, and turn them off when you don’t need them or when the battery charge starts to get low. SummarySolar panels for caravans are a no-brainer if you can afford them. They let you drastically reduce fuel usage, help you reduce your emissions, and with a large enough system, allow you to live off grid for longer or even indefinitely.Ready to get solar panels for your caravan? Get the ball rolling by filling in our simple form. Our trusted suppliers will get back to you with bespoke installation quotes. Tom Gill Writer Tom is a big fan of all things eco and has a passionate interest in how technology and localised projects can work together to make the world greener.