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Our new friend Ben is not your average run-of-the-mill architect. In 2005 he decided to buy a boat to live in. He tells us that his original plan had been to get a dutch barge - a sensible choice for a houseboat. That was the plan anyway...  Later that year Ben chugged up the London's Thames with, er, a 28-metre, decommissioned Polish icebreaker, with plans to convert it into a mecca of stylish alternative living.
Ben asked us to help him fit a wind turbine to his mast to run his lighting, a water pump, and other 12v devices via a bank of batteries. We thought this was a great opportunity to test out one of the turbines, and monitor it closely over the coming months. Our research tells us that FuturEnergy's 12v turbine is the one for the job, as this DIY turbine will kick out a lot more power for your pound than its rivals. His mast is a large steel C-section, so it'll be strong enough to take the strain. Measuring the wind speed The first task was to measure the wind speed at the top of the mast. Many sites in London are unsuitable for small wind turbines - there are just too many interuptions to the wind flow like other buildings and trees. Luckily, Ben's spot on the Thames is fairly open, and his mast is tall, so it will hopefully be a reasonable site for the turbine. Toby shinned up the mast and fitted one of our anemometers to record the wind speed. We got an average of 4.1 metres per second over the time we recorded. Ideally you'd measure over several months and seasons before buying the turbine, but we're testing it out so we'll leave the anemometer up there alongside it so we can check out the published outputs. Mounting the turbine hub A couple of weeks later, our boxed Futurenergy turbine arrives, in lots of bits. The Futurenergy range is designed to fit neatly onto a standard scaffold pole, so we attach a pretty-much-vertical pole alongside the not-entirely-vertical mast, and paint it white to match. This isn't as easy as it sounds, but by the end of the day 1 we are pleased with our work - and finish by threading the power cable down through the pole, and fitting the heavy generator part of the turbine onto the top (pictured right).
Assembling the turbine blades Our next day starts with putting together the five plastic turbine blades. Each one slots snugly between the two halves of a cast metal hub which then clamps them together.
Each blade is set to an exact angle, and we test the blades are equally balanced by hanging the assembly up on a special string from the roof of one of the boat's cabins. Fitting the blades and hoisting the turbine up  We're happy that the blades seem well balanced and are firmly seated in the metal housing. So Toby climbs the mast again and Seb winches up the blade assembly to him for bolting directly on to the front of the generator hub. It's a bit windier than we'd like during this precarious step, but it all goes smoothly and, with the blades in place, we fit the white enamelled nose cone to finish it off nicely. Although we can hardly wait to see the turbine whizzing around, we have to secure the blades at this point with a bungey cord to stop them turning until we're ready. Next we gradually inch up the completed turbine and its pole high enough alongside the boat's mast so the blades are clear of all obstructions.
Charge controllingSo we've got the turbine itself ready to go, with a positive and a negative cable running down the mast. So far so good. These cables will be connected to batteries in the boat's engine room, but first we need to fit a charge controller. This clever box of tricks monitors the batteries and makes sure they don't get overcharged or damaged. The Xantrex C60 charge controller is designed to do just that, and comes with an optional screen to display the battery voltage, and current (amps) is being generated so you can see it is working. Dump loadIf the batteries get fully charged, the energy that is being generated by our turbine needs somewhere else to go. So the usual thing to do is connect a 'resistive load' (or 'dump load') to the charge controller to act as an overflow to suck up the excess power. We toyed with the idea of using an old kettle heating element, but in the end opted for a specially-made dump load box supplied by FuturEnergy. Connecting the batteriesBen had previously strung together a load of old 12V car batteries in his boat's engine room, but we knew these weren't going to be good enough. To work properly, renewable energy kit needs 'deep cycle' batteries, that hold much more charge and don't gradually go flat like car batteries do. We found some suitable batteries on offer that in a former life had been used as backup power for a mobile phone transmitter. It was a long wait for them to arrive, so in the meantime we had to make do with the old car batteries - which rapidly demonstrated how unsuitable they were for the job, as they hardly held any charge. Finally, the new batteries arrived at the boat and we headed down to hook them up with the help of Dave Letham, a friendly local DC-charging expert who popped down to help the set up. All done! It took a bit longer than we thought, because of the trouble with getting the batteries, but we now have a FuturEnergy turbine up and running on Ben's boat, which so far has admirably supplied the crew of 5 with enough power to run their lights, 12V water pump, and hi-fi. We think they will be able to draw a lot more load than this too - and our tests will be ongoing over the next six months as we'll be monitoring the output performance of the turbine at different wind speeds.
If you want to see the turbine in action, it is clearly visible from the riverside walk adjacent to Brentford High Street near Kew Bridge. Ben's boat, The Liss, is pretty much the last boat moored along the bank as you walk away from Kew Bridge. A bit more on noise abatementBeing a steel-hulled boat, in high winds the turbine can cause quite a lot of noise to be transmitted down through the steel mast and then amplified around the boat. Over winter, with stronger winds more common, this became an issue for the people living aboard the boat - it was stopping them from sleeping.
To address this we have subsequently made two improvements to the setup. The first is dampening the turbine mount with some thin strips of rubber. This has removed the worst out of the noise. The second improvement was fitting a stop-switch to the control equipment. This means that if the turbine is causing sleepless nights, the people living aboard can safely isolate, brake and stop the turbine, using a clever 3-stage switch designed by FuturEnergy.
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