Generator or Solar

IMG_7565Do you want to start an online ‘street brawl’…? Go onto a caravanning or camping forum and ask about using a generator, then sit back and enjoy the fireworks.

No other subject (other than kids and dogs) seems to enrage people more than using generators at camp grounds. There’s the brigade that say they should be allowed to use them whenever they want and the others that hate them with a passion and would see them all thrown into a crusher.

The problem is that both have valid reasons and reasonable basis for their arguments. Rarely will you ever get a consensus or compromise from either side. I believe there is a middle ground and I’ll explain why.

First things first, let’s understand and define the problem. If you want to do a lot of free camping or remote outback travel, you’re going to need a good supply of 12v power. That means big batteries and likely 2 or 3 of them in your camper or caravan. Now unless you have deep pockets and can afford lithium batteries, yours are likely to be lead acid batteries of some description (wet cell, gel or AGM). These can hold a large about of reserve power but they also take a long time to recharge, especially if you are on the move and draining power out of them to run a fridge or two at the same time. You can recharge them on the go via your car’s alternator (connected through an Anderson plug) but even with the best DC-DC chargers, you’re alternator will have enough trouble keeping up with your car’s batteries and power demands, let alone a couple more on the van or camper. You will need more charging capacity to keep up with the load.

Many vans and even some higher spec camper trailers come with fixed solar panels on the roof or other solid structure and these can function while you’re on the move, recharging the house batteries. But again, you’re relying on the sun being available and even if it is, you may only be getting 5 amps or so, depending on how much solar capacity you have, which really isn’t a lot.

So if you do the maths, it is quite likely you will not be able to replenish your batteries even after a full day’s driving. So, when you arrive at your next destination, it’s out with the solar panels. But you have arrived late in the day and you may only have 2 or 3 hours of usable sunlight remaining in the day and that will never be enough to recharge those batteries completely. You can see where this is heading. There will come a point, likely after 4 or 5 days when you will need to supplement your solar charging with 240v, and if you’re miles from a power point, a generator may be your only remaining option.

From our perspective, we always travel with a generator but only use it as a backup to our solar panels. We try to ensure we have sufficient solar capacity to keep up with our power usage. For instance our new van will be supplied with 200ah of batteries and 450 watts of solar panels imagemounted on the roof. We have also fitted an additional Anderson plug to connect an external 100 watt solar panel to ensure we can maximise what sun is available. 550 watts of solar panels can reliably generate around 20 amps. That is sufficient to recharge 2 x 100ah batteries in around 5 hours.

To supplement the van’s batteries I made a 5m extension cord to go from the car’s Anderson plug to the van so that the additional 100ah battery in the car can be used to power the van, giving a total of 300ah of batteries. By using 12v power devices sparingly, we should be able to run our setup for 7 to 10 days without needing 240v power to recharge.

Now that’s all good in theory, but in practice, anything can happen. We could get 3 or 4 days of overcast or rain and that could throw our power regime right out the window and we will have no choice but to resort to generator power to keep our batteries going. In this instance, we would attempt to camp at a campsite that allows the use of generators. Even then I would be asking our neighbours if it is OK with them if we use the generator, explaining our situation. We also have a good quality generator that is very quiet and we run a long electrical lead so we can place the generator far into the bush to minimise the noise at the campground. By facing the exhaust away from the camp also minimises the noise. Finally we respect any time restrictions in place. If there is none, we never run before 9am and not after 6pm. By sticking to these rules, we have never had an issue running our generator on the few occasions we’ve needed to.