Living off the grid: Wind Powered Caravanning

Interest in 'wild camping' is growing and as is learning how to enjoy the benefits of a caravan without being connected to the grid. But, how can you go wild camping in the UK without being less comfortable? One way is to fit a wind generator to your caravan.

Mike Kingdon & Alan Ross fit a Rutland wind-powered electricity generator to a touring caravan for off-grid charging. 

As members of the Home Counties Area of the Camping and Caravanning Clubs’ Folk Dance and Song Group (FDSG), our regular caravanning is conducted without mains electrical hook-ups.

New touring caravans make ever-greater demands on their 12-volt leisure batteries, so, if we wish to enjoy the facilities that modern caravans provide, and camp regularly without electric hook-ups, 12-volt power management becomes a challenge. Fitting a high-capacity solar panel and LED lights helps, but when the sun doesn’t shine and meets extend to five nights, caravanners can experience 12-volt power shortages. After several FDSG Easter Meets when the weather didn’t cooperate, we decided to take a look at wind generation and focused on a company called Marlec with its Rutland range.

Fitting a wind generator to a touring caravan

1: Components to rig the Rutland 504 Wind generator

Marlec provides kits to fit its wind generator to boats, static caravans and motor caravans. However, all are designed to be permanent fixtures. Any solution for a touring caravan had to be easily erected and dismantled, and we set a nominal time of ten minutes for both.

Marlec loaned us a Rutland 504 wind generator , its land tower and rigging kits, and HRDi charge controller. The box for the wind generator measures 54 x 54 x 25cms and weighs just 6Kg. All the rigging attachments – apart from the poles – can be transported in the lid of the box.

2 (left): Close-up of the middle of the improvised connector. Note the channel for the power cable comes well below the shoulder to support the upper set of stays. (See also Fig 11, which shows the cable and lower stays in place.)

The Land Tower Kit contains:

• Two 2m stainless steel poles, which we reduced to 1.6m each;
• Ground plate and spike to support the lower pole, with an exit for the power cable;
• An aluminium connector to join the tubes. The connector has a central hole for the power cable to pass through, and also supports the bracket for the lower set of stays. We decided early on to replace this with a longer connector, which provided greater rigidity and allowed the cable to exit between the poles. Our connector has a groove for the cable and a shoulder to support the lower stay bracket;

The Tower Rigging Kit contains:

• Two sets of three wire stays with ground anchors and adjusters;
• Essential nuts and bolts.

For several reasons, we rejected the idea of a free-standing wind generator anchored to the ground with guy lines only, and using the awning channel to support the pole became over-complicated. Instead, we decided to anchor the land tower poles that would support the turbine using the jockey wheel clamp on Mike’s Sprite Finesse 2 caravan. To facilitate this, we added the following items to the Land Tower and Rigging Kits:

• A nylon brush to hold the lower pole in the jockey wheel clamp (supplied by Marlec);
• Four plastic-coated (Bradcot) awning clamps to attach two pairs of stays to the caravan grab handles;
• Four cable clamps (from a local boat chandlery) to adjust the length of the stays.

3:  Mike prefers to have a charge controller with a digital display mounted inside the caravan so he can monitor the charge rate and battery condition.

Marlec’s HRDi Charge Controller has separate inputs for wind turbine and solar panel plus outlets to a main and secondary battery. When the battery is nearing its maximum charge the HRDi slows the speed of rotation of the turbine to prevent overcharging. An additional safety feature is a temperature probe (black wire on left) to check for battery overheating.

Converting the caravan to take wind generator power

4: The Finesse 2 is fitted with an internal pre-wired connection to the battery so the biggest electrical change we had to make, to install the WG, was to take the wind turbine power cables into the caravan using an additional 12v auto socket located on the side of the battery box.Note: On the left is the pre-existing plug and socket for the solar panel.

5: We installed a switch to disconnect the HRDi from the battery when turbine or solar panel power are not in use.
While the HRDi has a switch to isolate it from the both inputs, we foresee situations when we might want to use one but not the other, which implied the need for separate switches. As the solar panel was likely to remain the primary source of 12v power, we used a double pole switch on the battery line so that users cannot switch on the panel (smaller black switch) before they connect the HRDi and battery.

6: We were able to fit all three switches into the sides of a project box which we mounted on a bracket below the HRDi. As shown in Fig 4, you can't see when the cushions are in place.

7: For added safety, we fitted fuses to the positive lines to the turbine, solar panel and the battery. As we didn’t intend to use the charge controlled on the back of Mike’s 90w panel, Marlec advised us to fit an 8-Amp diode to the panel line. (90watts ÷ 12-volts = 7+amps).The cable blocks, fuses and diode all fitted into a second project box.

Assembling the wind generator on site

We found it best to join the wind generator and its poles on the ground and swing it up into a vertical position.

8: Fit the awning clamps and adjusters on the grab handles ready to take the stays.

9: Fit Nylon bush to base of lower pole

10: Slide the lower set of stays onto the upper pole. Feed the wind generator power cable through the top pole. Join the two poles together using the connector. Position the lower set of stays, taking care not to pinch the turbine power cable.

11: Slide the upper set of stays onto upper pole and secure with a bolt.

12: Insert the turbine power cable into the upper tube. Connect the wind generator to the power cable using the terminal block and check the polarity.

13: Slide to wind generator stalk into the end of the upper pole and secure with bolts.

14: Fit the tail to the turbine

15: Level the caravan and put the steadies down, then remove the jockey wheel and position the ground spike and plate directly below the jockey wheel clamp. Swing the turbine pole with wind generator into a vertical position, and slide it through the jockey wheel clamp and into the ground spike. Adjust the nylon bush and tighten the jockey wheel clamp.
 

16: Fit two upper guy-ropes to grab handles and adjust until the pole is vertical. Fix remaining top stay forward using the ground anchor. Tension using the adjusters. Fix lower stays, if needed.

Plug the turbine flex into the 12-volt auto socket. Inside caravan, turn on the HRDi connection to the leisure battery, scroll through the screens to find the wind generator menu, switch on the power input on the HRDi, and switch on the power from the solar and/or wind generator screen as required.

We encountered several minor issues when using the grab handles to secure the stays. First, using the jockey wheel clamp meant that when we shortened the guy-lines, they all became different lengths. As a result, it was important to have the bracket that held the guy-lines to the poles the right way up and we colour-coded some of the lines.

On some caravans, the lower guy-lines might prevent the opening of the front box. The upper guy-lines provide adequate rigidity on their own for most occasions. However, we reconnect them at night, when the caravan is unattended and when the wind gets up.

First real test

We experienced 36 continuous hours without sufficient sunlight to generate adequate solar power. The wind generator did all we could have expected of it. We had power to spare and could have charged an additional battery. The HRDi showed that it was generating between 0.5 and two amps – depending on the wind speed – and it was structurally stable. We could only just hear it in the caravan at the height of the storm but only when we listened out for it. Otherwise, its noise was obscured by other sounds. The next morning was dark and dismal. When we asked neighbours about the noise levels, none had even been aware of the turbine.

Evaluation

We have tried out the wind generator on several subsequent events, and our assessment is ongoing. Our judgement so far is that, although the Rutland 504 wind generator doesn’t provide significant quantities of power when compared to contemporary solar panels, it will provide a valuable supplement during the autumn and spring. That's when the hours of daylight are limited and on longer meets during the season when the sun can’t be guaranteed to shine every day.

In our view, it provides a more friendly and less polluting alternative to petrol generators.

We are content with our method of mounting the turbine, and the jury is still out on whether the lower set of stays are needed all the time. The one thing we haven’t tried yet is charging a second battery. Overall it has been a positive result.

List of components (all prices correct at time of writing and include VAT):

From Marlec (Tel: (01536 201588)

• Rutland 504 Wind generator £367.95
• HRDi Charge Controller£159.95
• 8amp diode £3.75

Marlec is in the process of revising their tower rigging kits to include the nylon bush and the new connector for joining the poles – price on application.

From any local chandlery

• Four cable clamps (designs vary) to adjust the length of the stay and thimbles £8(ish)

From Bradcot Awnings (Tel: 01274 306811)

• Four plastic coated awning clamps @ £3.75 each £15.00

From CAK Tanks: (Tel: 0844 414 2425)

For the wind generator . (If you decide to connect your solar panel the same way you will need 2 of everything):

• MP12ACS 12v auto socket with splash proof cover £10.77
• MAC1NL/G Module cornice to hold 12v auto socket £1.55
• MAT1NL/G Module frame to clip over cornice (optional) £1.55
• R419F 12v auto and DIN plug £2.99
• MAS50 back box for socket (optional) £1.74

From any branch of Maplins:

• 2-core 12v 15amp flex @ £2.59 per metre
• 15 amp terminal blocks (per 36) £7.99
• 3 blade fuses & blade fuse holders @ (89p + £2.49) £10.14
• A dipole switch £2.69
• 2 monopole switches @ £1.99 each = £3.98
• 2 project boxes @ - say - £4 each = £8.00

Acknowledgements

• Stuart James and colleagues at Marlec
• Keith Jackson and other Home Counties FDSG members
• Mike Smith, for help with the photographs

Mile and Alan