WIND TURBINES / GENERATORS
Wind turbine generators for narrow boats are a great way of extending your charging system. Solar power generation drops off during the winter months as wind speeds tend to increase. Why not harness this typically UK source of renewable energy for your narrowboat!
Wind Turbines / Generators… The Basics!
Wind generators are another method of charging the narrowboat battery banks. A propeller is driven by the power of the wind to spin a generator. This electricity is used to charge the battery bank.
In a typical installation a wind speed of 20 knots will produce around 130 watts from the generator. This equates to a little over 10amps of power flowing into the battery bank in ideal, sustained conditions.
The wind turbine is connected to a charge controller, very similar to the ones used for solar energy management. The controller will progressively brake the blades when the battery bank reaches a full state of charge. Some controllers can also be integrated with solar panels to provide a fully renewable energy based charging system.
Benefits of the systems are that in our climate, if the sun isn’t shining then it’s often blowing a gale. The search for a nice gusty mooring becomes more important than shelter, but it is a great feeling knowing the narrow boat batteries are charging without the need to run the engine.
The obvious disadvantages for narrow boats include noise when running (including shell vibration if roof mounted), storage and installation space. If there is no wind there is no power.
Wind generators are generally mounted on a mast positioned centrally on a narrowboat roof. Extra support is then provided from four wire guide ropes with tension adjustment. These wires terminate to eyelets retro fitted to a canal boat roof or integral handrails.
Wind turbines for narrow boats are relatively expensive per amp when compared to the much more common solar installations but are still used by many live-aboard boaters as supplementary systems.
RenSMART has produced UK wind speed data for those of you considering the fitment of canal boat wind generators.
Wind Turbine… Detailed Charging Analysis
Is it worth investing in a wind turbine for your narrowboat? It is a question we are often asked when people pass our boat and clock our wind generator.
We have collected data over the past year to show how much energy we have harnessed from our wind generator. We have a digital regulator installed which provides an instant reading of charge to batteries and a cumulative amp/hrs charge. It also provides a volt reading of your batteries, which helps you understand the current state of charge. A budget regulator is also available, which will simply serve its purpose to protect your batteries whilst ensuring the turbine is charging efficiently.
September 2015 – 40 amp/hrs
October 2015 – 50 amp/hrs
November 2015 – 210 amp/hrs
December 2015 – 287 amp/hrs
January 2016 – 212 amp/hrs
February 2016 – 236 amp/hrs
March 2016 – 202 amp/hrs
April 2016 – 138 amp/hrs
May 2016 – 103 amp/hrs
June 2016 – 33 amp/hrs
July 2016 – 60 amp/hrs
August 2016 – 58 amp/hrs
Annual total = 1629 amp/hrs
To put it in to perspective a typical 12v fridge uses 4 amp/hrs, which if run for 24 hours of the day = 96 amp/hrs; or 2880 amp/hrs over the course of a month.
Wind Turbine… Considerations
As with most narrow boat related subjects, there are lots of variants which can affect how effective the wind generator will be on your narrowboat.
Firstly the weather, obviously it needs to be windy for the turbine to work! It also needs to be consistently windy to harness energy from your turbine. In the UK, we actually have very few very windy days, where it is blowing a gale for most of the day. We have seen our regulator reach 20 amp/hrs at a given moment in time, but this isn’t maintained for any level of consistency.
Your mooring location will greatly impact the effectiveness of your wind turbine. Any trees or buildings will disrupt the turbines ability and reduce any potential power output. The ideal location needs to be flat, open space. Unfortunately our mooring location does have some trees offering some protection from the wind, thus reducing the effectiveness of the wind turbine.
The secret to maximising efficiency is to position the turbine as high as possible. Low level wind is turbulent. If the wind turbine was mounted to a building, you would be looking to reach a height of 6 metres, this is very difficult to achieve on a narrow boat. Our mast is 3 metres, which given the height of the boat as well, we are looking at a maximum height of 4 – 4.5metres.
If you have low power consumption on your narrow boat, potentially no fridge, minimal, if any, 12v phone charging, low wattage lighting etc you may find the wind generator can provide sufficient charge to your batteries. Likewise if you have a leisure mooring, on a bank side mooring, and are looking for a way to trickle charge your batteries when the boat is not in use, then a wind turbine may be a really good solution.
If you are a continuous cruiser you do need to consider the time and effort required to put up and take down the wind turbine when cruising. The turbines are top heavy so require a mechanism to ensure you can safely lower the turbine down, and then have something available to rest the turbine nose on so as not to damage the blades.
Wind Turbine v’s Solar Panels
Clearly there is a place, given the UK weather, for both systems on a narrowboat. From the data we have collected, wind generation cannot be seen as a reliable source of renewable energy over solar power.
However, solar isn’t so effective in the winter but a wind generator may be. You have to appreciate a narrow boat solar panel set up is generally larger than a wind turbine; you can install multiple solar panels, but would normally only install a single turbine. A single solar panel is likely to be more comparable to a wind turbine in terms of energy output.
If we had a choice we would always opt for solar panels, but do appreciate the power we harness from the wind generator on those windy days in the winter!
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