Here is a random collection of pictures sent to me by customers with PowerSpout turbines. In many cases they were still in the throes of installing the turbine(s) so please do not judge too harshly if they look a bit messy. It’s just to give you a rough idea of some of the sites where I have helped to make hydro power happen recently.
Most of my customers lately have been in the UK, but I work with people all over the world such as the site in the Congo which was for a hospital. I have a number of customers in Ireland, Portugal and South Africa for example. In most cases I do not get sent any photos but it is really nice to see them when I do.
With the publication of an updated 2023 edition of my metric Wind Turbine Recipe Book it seems appropriate to update my suggestions for sourcing materials. Often the best supplier will be a local one, but I will offer some links to online suppliers below in case this is useful.
This post is mainly for UK readers but if you are in the EU there will be other options that are easier to access such as the Ti-eole shop in France. Ti’eole offer magnets, and steel disks and courses and everything.
Neodymium Magnet Blocks 46mm x 30mm x 10mm thick : Powermagnetstore have N40.
The web site may display low stock, but they tell me this is not accurate.
“We always stock these magnets ” See them also on eBay Guys magnets may have N35 blocks. These are a bit weaker.
If you want to buy from China then I can recommend Lily as a trusted source for magnets [email protected]
Winding wire I buy my winding wire in 20kg reels from EC wire.
For smaller deals, here is an ebay supplier I found quite easily.
Resins, Vinyl Ester, Epoxy etc East Coast Fibreglass Polyfibre
These suppliers also offer the glass cloth you need for reinforcing the resin castings
Mostly I use West Epoxy nowadays for magnet rotor castings for maximum protection of the magnets.
Steel disks Find a local workshop that offers profile cutting services. Bear in mind that it will be much cheaper to buy a larger batch if possible (shared with friends?). I like to get them sent to be galvanized on their way to me. Another option is to get them powder coated but I don’t find this lasts so long in my maritime environment.
It is fairly simple (if slow) to cut your own disks using a grinder (a big polygon works OK). Harder to get a precise result this way, but provided the assembly is balanced at the end there is no problem.
Trailer hubs There are several online suppliers.
Trailertek offer stub axles and hubs for small turbines around 2m diameter
(beware of the seal behind the bearings which wears through due to thrust of the wind, so it is safer to remove this seal as the worn out seal causes a very slack bearing.)
You may wish to replace the bearings with decent ones such as SKF or other major brands.
I have also used AutoW for cheap options. Towsure are another source.
Some good photos from a recent installation trip to a Pacific Island by Michael Lawley and his son Edward show best practice for installing their Coanda intake. Water is impounded in a small pool behind the intake so that it spills over the rounded crest, over an acceleration plate that keeps the flow adhering to the surface in an even layer at a good velocity to optimise the function of the Coanda screen.
So often I see coanda screens with water flying right over them or poured in a jet onto the middle or submerged in slow flow. Correct installation is the key to getting the benefits of this type of screen, with its specially shaped bars that use the surface tension of the water to separate it from solid particles.
Preparing the Coanda site. Lugs on the side of the tank are set into concrete.
Intake in operation. Water flows over the coanda in a smooth layer at the correct speed.
Turbines ready to roll.
Michael Lawley of Powerspout with Ed Lawley
The Coanda screen uses the Coanda effect, which is the phenomena in which a jet flow
attaches itself to a solid surface and remains attached, even when the surface curves away
from the initial jet direction.
I just did a wee video about methods of estimating head and put it on Youtube. It’s a bit rough in places, but I hope it helps.
Shown in this video are the following methods:
Using a contour map (in this case an ordnance survey map taken on streetmap.co.uk)
Using Google Earth Pro to make a track with an elevation profile
Using a Johnson Sight Level that you can buy on eBay or wherever
Using a “clinometer” app on your phone
Using a pressure gauge on a pipe full of water
I did not mention that you can also use the clinometer to measure the angle of slope, and a long tape to measure distances, and thereby you can calculate the drop based on the triangle calculation for each step of the way. This can also work well if the device is calibrated. It also gives you an accurate pipe length.
An accurately calibrated aneroid altimeter can be a possible method on high head sites, but be wary of using GPS altimeters as they are not likely to be very accurate. Nor is Google Earth, to be honest. Each of these methods just gives you another rough indication which is why you should use several of them if possible and see if they agree at all with each other. There are more methods for sure including laser levels and tubes full of water but these are ones that I actually use.
In the end you just need this head measurement to satisfy yourself that your hydro site is going to delivery useful energy. As a ballpark figure, the output in Watts might be about 5 Watts for every metre of head and litre/second of flow. So if you have 100m head and 2 l/s flow then you can likely make 5 x 100 x 2 = 1000W or 1kW of power, which after 24 hours adds up to 24kWh units of electrical energy per day. More than an average home uses.
80W off grid with 5m head.
Wins a prize for the most creative manifold.
380W off grid with 6m head. Note the heavy galvanised grating as turbine base.
660W off grid
1500W grid connected
This one is not so DIY, installed on a Pacific Island. 4 x PLT turbines running at 1750W each, flat out.
Some recent installations that I have helped with remotely. The owners of these turbines were kind enough to share these glimpses of the installation process, and of course they went ahead and tidied them up afterwards, but I rarely get the pictures of the final result.
Report KD 730 can be copied for free from my website: www.kdwindturbines.nl at the menu KD reports. The title of this report is: “Ideas about a 28-pole, 3-phase permanent magnet generator using the housing and winding of a 4-pole asynchronous motor frame size 80”. This generator is using 28 neodymium magnets size 40 * 7 * 3 mm and the magnet costs only about € 25. It is expected that this generator can be used with the original 230/400 V winding for 24 V battery charging if the winding is rectified in delta.
I have added figure 1 out of this report as an attachment and you can use this figure in a blog about this message.
ADDED 16th January:
Hereby I want to draw your attention to two KD-reports about rectification of an AC current.
Report KD 340 describes 1-phase, 3-phase and 2-phase rectification. Originally only star en delta rectification of a 3-phase current were described but recently I have added chapter 3.2.3 about rectification with three separate 1-phase bridge rectifiers. This way of rectification results in a somewhat higher voltage and power than star rectification but the rectifier losses are higher as the current always flows through six diodes.
Report KD 712 describes 5-phase and 9-phase rectification. Originally only 5-phase rectification was described but recently I have added chapter 6 in which rectification of a 9-phase winding is described. It appears that there are two ways to rectify a 9-phase winding and the way which is described in chapter 6.2 is favorable because this results in the highest power. The winding is split into three, 3-phase windings which are rectified separately. The three, 3-phase rectifiers are connected in series. The advantage of 9-phase rectification is that there is almost no fluctuation on the DC voltage and the DC current. This is of interest if the wind turbine is grid connected by a 3-phase inverter because it eliminates the need of using capacitors to flatten the fluctuations.
Several people have admired the finish on the turbine in my recent post about Ivan Juretic’s turbine, so I asked for details. Here is what he told me:
The blades and wooden parts of the tail are painted with a transparent polyurethane bi-component glossy varnish “Wood gloss” of Veneziani company.
I have been using this product for many years and I have a really great experience with it. It intensifies the beauty of wood and is extremely resistant to atmospheric agents over years, but is quite demanding for the application.
It is recommended to be applied in many coats, we’ve applied 10 times with brush, and in between coats the surface need to be over and over abrade with fine sanding paper.
All metal parts are galvanized and then yet protected with two layers of high quality coating based on modified epoxy “Hempel’s Selecta Metalni Efekt DTM”.
This paint is easy to aplicate with air spray, and the painted surface looks great with some twinkling sheen. We applied this paint also on the plywood part of th tail.
Some may say it’s all together too much, an exaggeration, but like what you said, and I believe, attention to the detail is always paying off.
In the attachment I’m sending to you Data sheets of both paints what we used and some additional pictures of the painting job!
In 2108 I reported a turbine build in Croatia by Ivan. It’s based on my ideas but Ivan added some engineering refinements. He just wrote to report that it is still going strong without problems.
That turbine works perfectly, for the third year in a row. And as I report to you in the mountains where it works there are really extreme conditions.
Cold, snow, ice, rain, hail, extreme turbulent wind, I don’t think it can get any worse.
But, no problems at all! It is just working.
After almost 20 months of constant operation we put it down this spring, because we just wanted to check everything and make regular maintenance.
There was little damage just on the blades leading edge, actually in the beginning I stick too short 3M protective tapes (just 30 cm) and now I repainted everything with 3 more layers of the amazing Veneziani Wood Gloss PU protective paint (use to be used for yachts) and sticked twice longer tapes.
Overall, the blades were in very very good shape, you can see it on the attached photo taken before I start reparation. The blades were made from larchwood.
The only other thing we had to change was the bronze bearing ring (blue in the drawing / bronze in the photo) on the bottom of the head because it was quite worn out. Now we’ve made it out of Teflon, and we’ll see how it behaves.
Also, the electrical system and control with your Tristar follower works really great, stable, reliable!
Again, thank you very much for all your help, and support for this amazing project.