It was clear to me from the start: I needed a solar system for my small mobile home. Firstly, I want to be independent and as self-sufficient as possible. Secondly, it also makes sense from an economic point of view because camping site electricity is expensive. Since I converted my mobile home myself, it was also clear that I would do all the electricity myself–and that included planning and installing the solar powered generator system myself.
It doesn't matter whether you're camping in a mobile home or caravan, on a pitch, or in the outback. Solar makes you independent. It was important to me that I always had enough electricity - regardless of whether I drove on or just stayed for a week in a nice free-standing area. And since, in addition to the typical consumers such as water pumps, lights, or mobile phones, power-hungry devices such as refrigerators or laptops are also in continuous operation, it was important for me to carry out thorough planning. First of all: it has risen. In two years of continuous use, electricity was rarely scarce.
But what components does such a mobile solar system consist of, what should you pay attention to when planning and installing it, and how much power does it actually have to provide to ensure a self-sufficient solar power supply in the mobile home? There are many factors at play here.
DESIGN SOLAR SYSTEMS: PLAN AND CALCULATE
If electricity is only available to a limited extent, consumption behavior looks very different than if energy could flow seemingly forever. Suppose electricity is a scarce resource, the awareness of one's own electricity consumption changes. Before the actual planning of the solar system, the power consumption in the mobile home should first be analyzed. Always with the thought in the back of my mind: do I have to use this electricity or is there a more economical way?
Because, if one thing is a fact: even if the price were not an issue, we have a limited roof space available on which we can install small solar panels. A solar battery also takes up a lot of storage space, and weight also plays a role here. Therefore, it is very clear: the less electricity we consume in the mobile home, the easier it is for us to implement a self-sufficient power supply. And your camping solar system will also be cheaper.
My electricity consumption in the mobile home? Measuring instead of guessing
If you already own a mobile home with a solar panel battery, you can see relatively easily how much electricity is consumed. When you buy a new one or do it yourself, you are probably just as clueless as I am about the question of how high your electricity consumption in the mobile home will actually be.
However, if you want to know more about it, you should get an electricity meter, connect individual consumers to it for at least 24 hours and see what consumes how much electricity and when. This not only leads to the realization of how large a new solar system for the mobile home should be. But also electronic devices unexpectedly eat up a lot of electricity. And which power guzzlers can be dispensed with. In addition, this procedure provides a first indication of how many watts a potential inverter can process.
I myself measured all power-consuming components that (must) be used in my mobile home conversion over a period of several days.
With a power consumption of 1,000 watthours, this would mean that I would have to draw (and recharge) 80Ah (1000Wh: 12.5V = 80Ah) from my solar battery every day. But we'll get to that in a moment.
Solar calculator! Calculate the size of the solar system and RV battery
A calculator that tells you how many watts your solar system should have - and also what battery capacity makes sense. What you also need for this solar power calculators are your power consumption. Based on this, it shows how much power your solar system should have in order to recover the daily power consumption - with graded values for German summers, Andalusian winters, etc.
Optimizing power consumption, the first step towards a cheap solar system
Because I'm planning the cheapest possible solar system for my van, I will, of course, do it without unnecessary consumption. And I can say one thing right away: including a fan heater in the calculation here, you can forget about that again. I also lost various small appliances: a fan, electric toothbrush, hair dryer, etc. I took this as an opportunity to think again about what I REALLY need. And what I would have packed just out of habit.
My most important power guzzler is my laptop, followed by the 230V refrigerator. But I can also simply switch off this and the inverter if the electricity is a little scarcer in winter. So I'm designing an electric refrigerator, so it's easy enough if I turn it off. Everyone has to find their own way here. Is the light generated with LEDs, or are incandescent bulbs still used? Are unused devices perhaps in standby mode unnecessarily?
As a result of this process, you should be able to report your power consumption in watthours because they are the basis for the planning of your solar system that is now starting.
How much electricity should my solar system be able to produce?
Now it would be nice and easy if my mobile solar power system on the mobile home simply had to generate as much electricity as I use over the course of a day when camping, and solar batteries also had to store the corresponding amount of electricity. Of course, it's not that simple. The efficiency of solar modules and solar controllers, power loss through inverters, and maximum discharge of batteries must be taken into account. Keeping one's own consumption levels also plays a role: do we primarily use electricity during the day or in the evening? Early risers need to allow for a little more battery capacity so they can cook eggs and coffee at 6 a.m. without a headlamp. Late risers, on the other hand, can rely on their mobile solar system to supply the mobile home with electricity before they fall out of bed and cook a cup of coffee on the electric stovetop (my variant ;-).
Your travel destinations should also be taken into account. Winter in Scandinavia has damn long nights. Summer camping in Spain, on the other hand, promises a large electricity yield. Thanks to strong sunshine and a few rainy days, solar systems for mobile homes can exploit their full potential.
My own planning tool: calculate power consumption, battery capacity, and module performance
It doesn't look like much, but there's quite a bit of research behind it. What consumes how much electricity? How deep should a battery be discharged anyway? How much power can solar modules, lying flat on the roof, actually produce? This calculation is certainly not 100%. But it worked out well for me, so the calculation can't be that wrong!