One alternative power source that many will be familiar with is Liquefied Petroleum Gas (LPG). It’s often used for cooking and heating in caravans but you may well have used it with your common garden barbecue. It comes in two forms; Propane and Butane. These are held in high pressure canisters so a low pressure regulator (28 mbar for Butane and 37 mbar for Propane) must be fitted to the bottle as the pressure would be too much for the pipes inside a caravan to take.
Obviously when dealing with gas you must be careful. Bottles must be stored properly and, when in use, ventilation is paramount, especially at floor level as LPG is heavier than air. If the gas canister has a leak and there isn’t sufficient ventilation it can cause dangerous build ups of explosive gas.
The key differences between Butane and Propane are that Butane is less toxic and contains more energy litre for litre. Butane bottles generally use the more convenient clip-on connections and are therefore often favoured for their ease of use. Propane has one key advantage in that the liquid in the bottle has a much lower boiling point than Butane meaning the supply of gas is much more reliable in colder weather. If you are caravanning in freezing conditions, Propane is a must.
Another alternative energy supply is leisure batteries. These, often used together with solar panels, are designed to provide power steadily over a long time and then recharge. You can buy leisure batteries from reputable caravan dealers.
How long a leisure battery will last depends entirely on how you use it. Again, finding the WH for each of your appliances will let you know how long your battery will last.
To preserve the life of your battery you should turn off equipment when not in use, avoid high energy appliances like televisions and maintain a good charge (above 50%) in the battery, not allowing it to die.
There are a range of different solar panels but choosing one often comes down to budget and available space. A 15W to 30W kit would be about right for a weekend break but for longer holidays, 60W or more may be necessary. Panels are generally roof-mounted, either flat or on tilted brackets. They are a clean energy source and work even in British weather.
When charging a battery using solar panels, it is important to take care not to overcharge or ‘kill’ it. A charge controller will protect the battery and the solar panel. It can be very useful to know how much energy your battery can store, how much energy your appliances use and how much energy your solar panels can generate over a period of time.
The capacity of your battery is measured in Amp Hours (AH). The figure you want to work out is Watt Hours (WH) and you find this by multiplying the AH figure by the battery voltage (V). So, a 12V battery with a capacity of 60AH would supply 720WH. (60 x 12 = 720). This means the battery could supply 720W for one hour. Obviously, the more energy you use, the faster the battery will discharge.
In order to calculate the energy your appliances will use you need to multiply the power consumption (measured in Watts) by the hours of use. For example, a 18W light fitting being used for two hours will use (18 x 2 =) 36WH of the battery’s charge. Repeating this calculation for each appliance and adding the results will give you the total energy consumption in WH.
To measure how much energy your solar panels generate you need to multiply the Watts by the hours exposed to daylight and then multiply this figure by 0.85 in order to factor for natural losses. So, a 30W panel in four hours of daylight would produce (30 x 4 x 0.85 =) 102WH. This is the amount of energy that will be supplied to the battery.
It’s a bit heavy on the maths, but taking the time to work out your battery capacity and energy consumption will give you a good idea of how long you can use different appliances for. This should make your caravan holiday a bit more relaxing.
Another option is to use a generator. There are things you must take into consideration before investing in one, some sites place restrictions on their use because of the noise they create, below 70db is best – ask to hear it running before you buy. Generators have even been banned from some forest sites by the Forestry Commission, so check when you’re planning your holiday.
You must also ensure that the generator you choose is suitable for your needs, this requires you to work out the total energy consumption of your appliances.
When using a generator it’s a good idea to let it warm up before connecting it. You should also try to avoid using high energy appliances such as microwaves as these can cause the output to spike which can blow low voltage equipment.
All care must be taken to ensure generators don’t get wet, investing in a cover would be a good idea. The weight of the generator must be considered as this can affect your road weight limits when towing. As most generators run off petrol or LPG, the usual precautions must be taken when transporting or storing fuel.
Other energy saving ideas
Replacing your halogen lighting with LEDs is a great idea. LEDs consume less energy, making a big difference when you’re not on EHU, and also produce less heat than halogen bulbs. If you shop around for the correct fitting, you’ll find it’ll be an investment well worth making. The environmental benefits are also a plus.
Like in your home, having good insulation is one of the most important energy saving measures you can take. Many modern caravans won’t require much adjustment but fitting acrylic sheets cut to size and edged with rubber insulation strips on windows and lining the underside of your caravan with foam sheeting are good steps to take to reduce condensation, keep heat in and conserve energy.
Gas heaters can be good when camping in cold conditions but they do cause condensation and should never be left on when sleeping. A central heating system with appropriate flues for air intake and gas removal would be more efficient and safer.