Welcome, this is Tim & Terry’s 'page' that is placed up to assist you in the event that you are interested in an alternative power source and do not know where to begin, and we simply seek to assist you in finding your way, be you a home owner needing a little self-sufficient power in these uncertain times, or a group of fishermen living in a coastal village who would like to invest in a community system so as to be able to freeze lobsters or fish fillets each day before sending them away to market, and also use the electricity to pump water from a well and have a light or two. The main reason for this 'Paper' is to assist you into becoming 'personally informed' and able to decide what you need and to become more self-sufficient, because electricity supplies will become more unreliable in many places and you also may live in a place where there is none available. In either event these pages will assist you in what you need to know, being the basics for an alternative power 'system' and the approximate costs involved. Pricing 1 - A 'system' can consist of as little as Aud$ 250, consisting of one truck battery and one small 20 watt solar panel, a regulator and a couple of wires connected to a single 25 watt light bulb. If the battery has a capacity of 90 amps = 60 usable* amps x 12v = 720 watts of energy = 720 divided by 25 (power consumption of 12v light bulb per hour) = 30 hours of light or, 7 hours of light using two 12v x 50 watt bulbs etc. However, your consumption must not exceed the amount your solar panel is replacing each day, and if there is only 10 hours of sun x 20 watts = 200 watts input, a 25 watt bulb would replace the power stored in 8 hours of usage. You may of course use a larger watt solar panel, 60 or 100 watt capacity or multiples if you wish to. Note: 60 usable* amps - if you used up all the 90 amps energy in the battery each day then you would destroy the battery within a month or so. It is best to always use less than its capacity. Example, a deep cycle battery is one with 900 lives so to speak, meaning that it can be 'drained' considerably each day and not suffer as much as a normal vehicle battery but, - - - If you have a big battery storage capacity so that you never use more than 20% of its total energy stored each day, then a deep cycle battery may last you 20 + years. The same battery delivering up 80% of its capacity each day may only last you 4-6 years. 2 - A 'system' - If you wish to have a fridge, freezer, lights, washing machine, TV and computer facility or more, then a 'system' can consist of a 20 panel solar array giving 1,600 watts of energy per hour of sunlight, a 400 - 1000 watt wind turbine for the windy rainy days when there is no sun, and a 1000 amp hr x 24 v battery system having a 1,500 watt inverter to convert stored battery power into 240 v electricity. This with associated turbine tower, solar array supports etc., could cost Aud $ 25,000 or more. If you live by a stream you can use a stream micro hydro turbine to give you continuous energy. So it is simply a matter for you to decide how much electricity you will need to consume per day and how much 'money' you wish to spend. To run a ‘full house’ as given below one would need an average daily input of electricity of approximately 500 watts per hour or 12,000 watts per day. Fridge - freezer - washing machine - small microwave – computer – television - power tools - water pump - bread maker – lights, etc. Wind Turbines This article is written in an attempt to aid the home user who seeks to become self sufficient in electric power, as well as having an 'alternate' water pumping facility, and to raise self-sufficiency 'alternative power' awareness. As all will soon see, the new way will be “Electricity” that will shunt aside all “fumes” that abide in this atmosphere as to God’s “clear way” all draw near. There are many of you who will ahead seek to be true, and as you land acquire you will elevate your way higher and build homes with “renewable energy” in your sight, and thus I this ”beginners” page do write. Clean & green & gold is the new way. Wind turbines are a powerful and useful part of any major home power system. For when it is night time or if it rains for a day or a week then solar panels cease their production of electrical current, but at night or in the wind and rain the wind turbine excels and it can produce a large amount of electrical energy at a far less cost than solar power. I limit my expression in this document to the smaller units for homes, farms and small communities. Remember, a 300 to 500 watt/hr capacity turbine will only deliver that power at 28 mph wind speed. In reality, with lower “average” daily winds it may only be “delivering” a fraction of its rated power. For if the daily average wind speed is only 12 mph, then it may only deliver 50 watts or less current per hour. Generally speaking, for home or farm if one can afford it one would purchase a 1000 watt per hour capacity wind turbine. This machine would produce that amount of energy at its optimum output that is attained at an approximate 28 mph wind speed. More wind speed could increase this 'wattage' by 20% or so to 1200 watts per hour, but if the wind speed average for the day was much lower at say 12 mph, then a turbine of this capacity could still deliver about 200 watts of current per hour to your battery bank. Wind turbines need at least 6 mph wind to begin their generating output. With the above in mind, it is better to opt for the larger machine if possible. (Larger means bigger diameter propeller) The other factor of great relevance that one needs to understand is that wind is like water, in that as it 'streams' along in the sky it can be subjected to interference from the 'ground' that will cause it to slow down or to 'tumble' like water passing over rapids. This takes place in proximity to trees, homes, or other 'ground' obstructions, thus it is of importance to have your machine elevated as high as possible above the ground, for the higher you go the greater the speed of the wind, and the less the machine will be subjected to turbulence that not only slows it down, but also causes undue stress to its components. 25 metres is a good 'tower' height. Calculate your daily power consumption needs against a turbine output operating at a 8metre/sec wind speed (18 mph) and you’ll be fairly “safe,” as you will have an 50% “spare” more current capacity capability to charge emptying batteries as the wind speed increases to the 10 - 14 m/s speeds, enabling the unit to give its full power output. For not only does a wind turbine or solar array need to have the “inherent” capacity to supply the never ending daily output, but if this supply need is diminished due to lack of sun or wind then the power supply “mechanism” be it the turbine or solar modules need to have a charging capacity of at least twice the daily input requirement so as to be able to not only continue the daily supply needs, but to also “catch up” and fill up the battery bank ready for the “next” windless or sunless days. There are many different types of wind turbines available to purchase, and some are better than others, and some are less inclined to need repair than others. The small to 'medium' range home power supply units vary in maximum output from 200 watts through to 1000 watts. I personally recommend the Bergey XL1, having a 2.5 metre propeller with max output of 1200 watts, 1000 watts @ 25 mph. In my opinion it is the best designed and manufactured machine available for the home owner on the world market today.
It can provide enough power for lights, radio, television, fan, water pumps, kitchen appliances, microwave oven, washing machine, fridge, freezer, fax, computer, TV satellite dish, power tools etc., an ideal homestead unit when coupled to a solar array. Coupled to a 24 or 48v battery bank and using an inverter it can run all normal 240 v appliances. All components are made from the highest quality materials to withstand long term wear and fatigue. Note: As solar panels are limited to sunlight hours, it follows that wind turbines have more than twice the amount of time each day to be delivering electricity to your alternative power system. The 'modern' wind generators are designed to be most energy productive at wind speeds in the 15 - 30 mph range. Below 10 mph they produce relatively little power. At wind speeds above 30 mph they 'furl' to avoid structural damage as well as to avoid over speeding and exceeding the generator capabilities. On furling "out of wind," they will lose some of their power output. The windmill exposes a 'huge' windage area to the flow of air as the blade "area" is positioned out on the perimeter of the arc, and thus with its greater "leverage" is power 'productive' from wind speeds as low as 2 mph, but needs to 'furl' at about 18 mph wind speed to avoid structural damage, and due to their need to limit the strokes/min action of the bore 'pumping' stroke they are so 'governed.' (30spm). Their maximum 'fan' revolutions at wind speed of 15 mph are about 100rpm. Thus giving a 'relatively' quiet operation in modern units. At present these low wind speed 'powerhouses' are not manufactured for electricity generation. Note: Cable sizes from the wind turbine to the battery or controller must be of a 'certain' size because if they are to 'thin' there will be a huge loss of available current.
Inverters -
True 'sine~~wave' Inverters are appliances that “convert” DC electrical current stored in batteries as 12v or 24v or 48v DC current into 240v AC or 110v AC current for home appliances. The “form” of the electrical “wave” created in the output AC side varies with the different types of inverters manufactured. There are “square” wave and “Sine” wave inverters available. Square & modified square wave units can be safely used in many electrical appliances, e.g.; workshop tools and equipment and Tv. But any inverter that is not a true “Sine” wave will damage some electrical “boards” and may “blow” fridge/freezer automatic switches over time. For any given “output” capacity, the sine wave will give a far better performance. Square waves are “rough” and “jagged” and sine waves are “smooth.” Square wave inverters cost half the price of a sine wave, and “semi” sine or “modified” square wave units about 75% of the sine wave unit. From my personal experience I can only “suggest” that you purchase a true sine wave inverter if you are going to “power” a computer, audio equipment, freezer etc without “worry.” Some Inverters are designed to direct your power supply directly to the mains Grid, either from your 'stand alone' battery bank system, or directly from your solar panels or wind turbine or, it can be combined to do both.
Notes on Inverters A 12v or 24v 1400w or 2000watt continuous flow inverter will power all the needs of a home ( fridge, freezer, bread baker, Tv, washing machine, computer, fax, vacuum cleaner etc). It would also run a small workshop with drill, band saw, and other tools. You can these days purchase a 12v fridge or freezer wired direct to the battery bank, this uses less power as the electricity does not go through the inverter, for there is a 20% + “loss of useable stored power” when inverting the current from 12v to 240v through an inverter. Remember, if your solar modules or wind turbine are “wired” 12v, then your inverter must also be a 12v one. If wired 24v, then the inverter must be a 24v unit. So when ordering the wind turbine or inverter you must specify as to whether the battery bank is to be 'wired' 12v or 24v etc. Inverter power output capacity. You will see the words “continous & surge” e.g.; 1000W continuous, this means that the amount of power the inverter can supply flowing though it from appliances on a continuous basis is 1000 watts. When electrical appliances are switched “on” there is a surge of current that may be 4 times greater for a split second than its “running” usage, thus an inverter can surge for a few minutes to accommodate this sudden temporary increase each time a freezer switches on, or you switch on the vacuum cleaner. So a 1600W inverter may have a surge capacity of 5000 Watts for a few minutes. All manufacturers give “5 minute surge capacity” & “30 minute capacity” & “continuous capacity.” A true ~ Sine Wave ~ output allows noise free operation of appliances and audio equipment. ~ Maximum power point tracker regulator and controller ~ Solar modules force energy into a battery, and once the battery is full the electricity supply emanating from the PV modules needs to be halted so as to not overcharge the battery. This 'control' mechanism is called a "Regulator" and there are a variety of different types. The maximum power point tracker regulator/controller as listed here is a unit that in fact 'boosts' the available solar panel (PV) watts to the battery. How Does a maximum power point tracker increase Charge Current? A photovoltaic (PV) array is a constant voltage device. Unlike a battery which is a constant current device. As shown on a typical PV module voltage-current curve, voltage remains relatively constant over a wide range of current. A typical 75 watt panel delivers 3.75amps @ 20volts. Traditional PV controllers connect the PV array directly to the battery when the battery is in a state of discharge. When a 75 watt panel is connected directly to a battery charging at 12-14 volts, the PV panel won't provide its maximum power due to it being pulled down to the battery voltage. Maximum power point tracker technology operates in a very different fashion. Under the above conditions it calculates the voltage at which the PV module delivers maximum power, in this case under 17v. It then converts the available power to charge the batteries (typically 12-14V), while extracting the power from the panels at its maximum power point 14-17V. A maximum power point tracker continually recalculates the peak power voltage as operating conditions change. PV output power, now 75 watts, feeds a high efficiency power converter which creates more current to be available to charge the batteries than the panels would produce connected directly and operating at 12-14V. The full 75 watts delivered at 17 volts
would produce a current of roughly 4.5A. A charge current
increase of 1.8 amps or 22 watts or 20%
is achieved by converting the 22 watts that would
have been wasted into useable charge
current.
This example assumes 100% efficiency to illustrate
the principal of operation. Actual boost will be less as
some power is lost in wiring, connections, fuses. In small systems it maybe uneconomical to add a MPPT to charge the batteries as the MPPT is close to the battery voltage and the losses created inside the MPPT tracker (5-10%) and extra cost almost cancel the advantage. Under normal conditions in comfortable ambient temperatures, current increase typically ranges between 10 to 25%, with 30% or more easily achieved with a discharged battery and cooler temperatures. What you can be sure of is that a maximum power point tracker will deliver the highest charge current possible for a given set of operating conditions. When conditions are such that the battery voltage and maximum power point are exactly the same, the tracker will pass the current through but will still have small losses. (between 5-10%) conditions. Some inverters have an inbuilt maximum power point tracker (MPPT) and are able to Grid feed from the solar modules or from battery supply. When set in Battery Mode, it will feed excess power into the grid when the batteries have fully charged at 54V (for 48V model or 108V for 96V model). The PV Edge will continue to regulate the batteries at 54V by increasing the grid feed as solar power increases. Under 54V the inverter will not feed any power and will completely disconnect from the grid after 2min to ensure no power is used from the grid. It will reconnect when the battery voltage rises above 54V again.
Some Grid feed systems
manufacturers have controllers that feed direct from a wind
turbine into the Grid. For a 'Latronics' PVE1200 (1250 watt supply) you
will need to use a 48V wind turbine. If you wish to Grid
feed up to 2500 watts you will need aPVE2500 controller and
the wind turbine will need to be a 96v unit. The controller
has an electronic 'smart brake' which will protect the wind
turbine from over spinning when connected direct to the Grid
if the grid 'fails.' In the event that the turbine is
connected primarily to batteries then it will have its own
regulator/heat dump.
Solar panels (PV modules) Solar modules create electricity and need light, preferably direct sunlight as they cannot operate properly if they become shaded by trees. On cloudy days they can still put out about 20% of their rated power output. Solar modules are the best solution on small home blocks. A combination of solar & wind is good, for there are times when its windy with no sun and other times when its sunny with no wind. The most common 'sizes' of solar modules are 10 watts to 200 watts per hour output. There are two 'basic' types of solar modules, the 'crystalline' silicon cells that are encapsulated behind glass, and the 'Amorphous' silicon that are 'layered' onto thin stainless steel sheets. Due to the inherent 'design' of crystalline modules, they are more subject to power loss from partial 'shading' than the amorphous ones. If an 'area' of a crystalline solar module is 'shaded' by any object such as a 'tree' or 'bird dropping' or yacht mast it will 'shut down' part of its power output, thus one must ensure that its surface is clean at all times and not shaded. The disadvantage of the 'Amorphous' silicon modules is that they are much larger in size than the 'crystalline' modules of the same wattage output. So if you wish to use a large solar 'array' then the crystalline modules are better having less 'windage,' and less likely for structural damage to, and cost of the solar tracking assembly.
If you are intending to place solar modules on your home roof, then if you live on or near to the equator, they needs be placed flattish facing North if you live South of the equator and facing South if you live North of the Equator. (about 5% incline to the Equator at Mombasa). As you travel North or South of the equator the angle of the roof or module mounting will become greater, about 10º slope for each 10º latitude. So if you live 40º South of the equator, then the angle of the roof or solar module support needs be at an angle of 40º from horizontal which will give the best heat absorption in winter. (As in image above taken in Tasmania of a small manually operated solar tracking assembly, top panels are 'amorphous' and the lower one is silica) If you only have a few modules then you can affix them with a movable support so that the module angle can be lessened in summer as the sun comes more overhead, and increase the angle as the sun moves lower in the sky in winter. The use of a solar tracker such as the image above that can be moved by hand or by automated means will give you more daily power output. A tracking system attached to the 'array' is very useful if your home is shaded by trees and you cannot utilise the roof adequately, in this event the array can be placed 5 - 20 metres away in the sun, and the array can be placed high 'up' on a pole so as not to use up ground space. It is best to use an electrically drive 'Linear actuator' that is actuated electronically by an optical light sensor that tracks the sun, and this can give you up to or more than 50% electricity increase per day into your battery bank.
This piece of equipment comes in different lengths from 12" to three feet or more, and it pivots the solar array and keeps the solar modules 'tracking' the sun, and this gives more electricity. A 'module' may weigh about 5 kgs and put out 100 watts of power per hour. This means that it is placing 100 watts of energy into your battery to be stored for later use or present use. If you have 10 hours of sunlight @ 100 watts then one panel stores 1000 watts. This means that you could have 2 x 50 watt bulbs burning for 10 hours a day from one solar panel. If your freezer uses 300 watts per hour when running and needs to operate for 6 hours a day, then your battery bank would need to be 'fed' 300 x 6 = 1800 watts of energy from wind or solar per day for that one item. So it is quite easy to calculate how much solar or wind energy you need per day to operate any given amount of items. If you are intending to place solar modules on a new home roof, then design your home to have one side of the roof “face” towards the equator rather than East or West. This way, modules mounted directly onto the roof will always be facing the sun. If you live on or near to the equator, they needs be placed flattish. Note: If I have used 100 amps out of my battery bank - - - then the battery bank needs (100 amps divided by .8 efficiency) = 125 amps to go back into it in order to bring back (or maintain) a full state of charge. A general rule of thumb is 75% system efficiency, this allows for battery, wiring and inverter losses. These are all BIG losses and must be accounted for if you want your system to operate adequately and to maintain a good service life. Note: Do not forget that your battery is only 80% efficient at best and, the older they get this figure lowers and therefore losses increase. Note: The available current from any solar module can be increased slightly when one uses a Maximiser or solar boost regulator as given on page 11. ~ Deep ‘cycle’ Batteries ~ Batteries used in “remote” power systems are called “Deep cycle.” This means that they can be “cycled” deeply and not suffer damage in the way a vehicle battery would. They differ from the usual vehicle batteries in that they can withstand being “cycled” from “full to low” hundreds of times more than a vehicle battery. If a vehicle battery was “discharged” often its life would be very short. Equally, a deep cycle battery has a “shortened” life if it is left in a “flat or low” state. Flat batteries become “scaly” on the plates due to “sulphation” which over time inhibits their capacity to receive a charge. Thus if you would get a full 20 year life out of your deep cycle batteries then never leave them in a low or discharged state. Stationary deep cycle batteries may give a “false” too low reading if they are not “bubbled” regularly as the acid settles downwards and the top where you test from will be a little “weaker.” The “bubbling” that occurs also “equalises the voltage in each cell” and enables the battery to receive a full charge. To “bubble” a battery it must be full and then “boosted” up from its operational 12.7 - 14v volts to 15v or more if it is a 12v system. This is done automatically today by solar module regulators as well as by the wind turbine regulators that cut off the power supply once batteries are full to avoid battery damage. You need to have a specific gravity tester that is available from any “auto” store. It will give you a good idea as to the “state” of the available current stored in your batteries. If your charging system is too small a supply for your daily “usage,” then your batteries will never “reach” their full “state” and will suffer sulphation damage over time as they “hover” in the SG 1180 down to zero charge state. The readings are as follows: Approximate only guide to battery 'charge' state.
If you have enough batteries, i.e.: a fairly large capacity bank of 2200 Amp hours storage or more, then you may find that they operate in the “full down to 80% full” each day. This will give you full life on the batteries. If you operate them in the “full down to 50% full” range daily, then their life may only be 12 years. If you cycle them down to below their 50% capacity daily then their life may only be 6 years or less. You may only need a small bank of 350 Amp hours capacity depending on your daily needs. Ensure that you calculate these needs and then multiply this by 6 days usage and you will have the right battery size needed for optimum life. Batteries can be “placed” in 12v “parallel” or in “series” to give you 24v or 48v systems. Remember, that you should not charge any battery bank with more than 10% of its total capacity. Thus a 500 Amp/hour bank should not be charged at more than 50 Amps/hr. So you need to select solar/wind units that do not charge faster than that amount or you will overheat the batteries and cause damage. Ensure the water level is at least 1 cm above the battery plates. Batteries must not be filled with “distilled” water, only use “de-mineralised” water for long life operations. If you cannot obtain any due to your “situation” or “circumstance” then collect rain water direct from the sky in a clean plastic container. Deep cycle batteries will need topping up of their 'water' annually or more often in hot conditions, and also need to be kept 'on charge' if not in use for any reason, as all batteries lose a small amount of their stored energy each day. If you have a water turbine that is charging 24 hours a day then your battery bank can be much smaller. The cost of batteries is high, so just try and not “skimp” on the battery volume you buy as it is your “storage” back up. You will need a small room 3 x 2 metres or so to house your system. Batteries must be kept off the cement and preferably sitting on wood planks, and the room needs to be ventilated and shaded so that it remains cool. For if it gets hot then the battery water will evaporate more quickly. The negative side of your battery bank needs to be earthed to the ground. Either drive a 5’ long by half inch copper rod into the ground and connect a 20 mm cable to it or, if the ground is rocky then dig a shallow trench 6” deep by 6 foot long and lay an unsheathed 16 or 20 mm copper wire in it and cover it with soil and wet it for good conductivity. The section going into your battery storage room that is above ground needs to have its plastic cover on so that it does not short other wires. ~ Towers for wind turbines ~ Towers that support the wind turbines need be 'sited' well if you have a large property. Seek high ground and try and find a spot away from high trees. In any event, the top of the tower should be 10 metres above any tree top within 200 metres radius or more if possible. No tower should be of a height less than 3 x lengths of 20’ galvanised pipe = 60 feet. Towers of 80’ are probably the most common, and 100’ or more are also used. The higher you go the less 'turbulence' there is and the smoother the unit will operate and the higher the wind speed will be, and the greater will be its daily current output in watts. It does not matter where you are; the 'steady' wind speed increases considerably the higher above ground you go. Wind gusts due to turbulence resulting from 'swirling' air masses cause great 'side' stresses and undue wear on the machine as well as lowering its charging rate. Distance from the battery compartment is an issue in the 12v systems, too thin a 'cable' wire loses current on the way. If your unit is more than 30 metres from the house then a 24v system is best as the wire needed is much thinner and thus cheaper. If the turbine is going to be 70 - 300 metres away then a 110v unit is needed with a transformer fitted to reduce the voltage to the 24 v or 48 v battery voltage used. Towers are usually built in 6.5metre galvanised pipe sections.* The under 10kg weight turbines can be placed on 2” galvanised pipe up to 20 metres, and 2.5” galvanised pipe for 26 metre towers. The 25 - 70kg turbines need a 3” galvanised pipe if only 20 metres and 4” if higher, and any larger 100-200kg units need a 5” galvanised pipe. Four sections of 6.5 metre lengths give you 26 metres. (80’) Note: galvanised pipe sections.* - 'Pipe' measurement is an internal diameter, whereas 'tube' is an external one. Tube walls are thinner than pipe. If a pipe measurement is given as 3" then its actual external diameter would be close to 3.5 inches. You also need 'joiners' at which lugs are fitted for the stay wires. On the 2” & 3” & 4” tube there are stay wire 'connectors' at the top of each pipe, i.e. 4 sets of four stays for a 4 length tower. The joiner can be a flange threaded on the pipe end and welded or simply welded on. The ends are then bolted together. It may also be a 'slip in' pipe fitting 600 mm long or other on the thinner sizes. At the base of the tower is a base plate having a pivot facility to permit the tower to fold/swivel down, and also an attachment point for the gin-pole. A gin pole is a 2.5 to 4" steel 'post' lying at right angles to the tower, it is in fact a swivel level pole that enables the tower to be 'levered' upwards or lowered down easily. The gin-pole extends out from the base plate attachment to the one stay wire attachment point (C) on image page 9 below that is chosen as the best anchor point to winch it from when elevating. It is used to act as a lever when raising or lowering the tower. It is most important to remember that the end of the Gin pole at the anchor point (C) end is attached from this end to both the anchor point B & B using a strong stay wire. As the Gin pole elevates into the sky it is these two wires that keep it from falling sideways. The 'top' of this end is connected to the tower sections.
Ground works suitable for under 10 kg weight turbines
The 2” galvanised pipe x
60' tower 12" x 3" x 10 mm base & swivel plate is grouted
into a concrete plinth of 2' sq x 2' deep. Note: If this unit is to be raised up to 80' or more then the lowest 2 pipe sections must be 2.5" inner diameter for added strength, or the lower 2" one may 'buckle' with over tightening of wire cable lines.
The
2.5” galvanised pipe x 80' tower
12" x 3" x 10 mm base & swivel plate is grouted into a concrete
plinth of 2' sq x 2' 6" deep. Ground works suitable for under 70 kg weight turbines
The 3” galvanised pipe x
80’ tower 12" x 6" x 15 mm base
and swivel plate is grouted into a concrete plinth of 2' 6" sq x 2'
6"deep.
The
5” galvanised pipe x
80’
tower 14"x
7" x 15 mm base & swivel plate is grouted into a concrete plinth of
3' sq x 3' deep. Each stay wire anchor connector is a 3" x 5/8" x 6' length of steel grouted into concrete, having a 4" diameter closed and welded 'eye' swivel situated just above the concrete, this is to be placed in line with the tower. Note: - In each of the above cases, the concrete anchor point for the wires that coincides with the end of the gin-pole needs to be 20% more in size or volume than given, this is because it has great stress imposed upon it when elevating or lowering the tower. The tower has a 'gin' pole arrangement that enables it to swivel and to be erected section by section by two persons using a 4wd vehicle or 'turfor' winch of 3 tons or more pull or tractor or other mechanical winch with worm gear. The stay wire needs be of 4, 6 or 8 mm diameter or more, depending on which unit you have and how high the tower you use. The turn buckles used to tighten these cables need to be the double closed eye ones that are much stronger than the open hook ended ones. Minimum size is 12 mm with larger 15 mm or more for the bigger units. A tower may cost the equivalent of 100% of the turbine cost or more. If you make it yourself it will cost much less. Note: - The above information is supplied as a guide and from my past experience. Some wind turbine manufacturers supply their own 'standards' guide and may also supply 'kits' to assist you. In the sketch below, point C is the point where the 'gin' raising and lowering pole is fixed, and point A is the 'rear' stay point where the tower 'falls' over when it is lowered. Both points B-B are the side stay points. Prior to raising or lowering the tower, the stay wires going to the sides B - B are slackened slightly by unwinding the turnbuckles enough to slacken the wires. Only the stay wires attached to the gin pole remain under load load during raising and lowering. Below the image it is stated that the 'eye' to which the guy wires are connected using a shackle at points B-B must be level horizontally. For if the tower swivel pin is 1" or more higher that B-B eye point, then when lowering the tower the side stays would become tight, and could cause a dangerous situation. If the tower swivel pin is 1" or more below the level of the eye bolt holes of B-B upon which the guy wire attachment swivels, then on lowering the tower the side stays will become looser. This is better than becoming tighter as long as it is not too much. Also, the same thing occurs if the line of B-B is 'ahead' of tower base centreline and thus situated one or two inches towards 'C,' on lowering the tower the guy wires would be under more tension and the tower would not 'fall,' so it is best to have B-B either directly in line with tower base swivel pin or, 1" to the rear of B-B centreline towards 'A' for then as the tower is lowered the side guy wires become 'slack' a little.
Note: - Try and get guy in ground 'eye' attachments of B & B level horizontally and in line with tower base swivel pin or 1" towards A. Point A must be on the high side of
a slope and C on the low side. B & B level horizontally.
High tensile tower retaining swivel bolt is situated about 6" above cement base.
The A and B and B anchor points are all the same.
Note: The safest way to construct a tower is to raise up one section of pipe at a time. This enable each section to be elevated and have its wire stays adjusted and tensioned exactly as they will be when the final elevating is done, section by section - raised up - tensioned - then lowered, and the next section added. Only this way is it safe. Once all sections are completed then the tower is lowered and the wind turbine affixed and safely raised and ready to 'spin.' Note: If the gin pole is in 2 sections, then commence the operation with only one section lying on the ground towards 'C' and connected to its high tensile tower base bolt. From its end furthest away from the tower are attached two stay wires that go out to points B - B. Note: To commence tower installation. Attach 4 tower cables to the top connector points of the first pipe to be raised after having bolted it to the tower base and pull the entire electrical cable through it - make sure that 3 of the the stay wires are connected first to the anchor points A and B - B with enough 'slack' to permit the pipe to become vertical. The other wire will be attached to the gin pole once the first pipe is elevated. Elevate it by hand slowly if it 3" diameter or less and by crane or 'excavator' if too heavy. Once it is 'up' then attach one stay wire to the end of the first section of the gin pole - adjust all the stay wires using a spirit level to ensure that the pipe is vertical. The lowest tower stay wire on the gin pole side is connected to the end of the first gin pole section. Once the first tower pipe is fully adjusted then the remainder of the gin pole must be affixed and, - - - to its 'top' end must be attached the stay wire that will be attached to the end of the second pipe later when it is added and, to the sides of the added gin pole section end are attached two more side stay wires that go either side to B - B. (slightly slack) At the end of the gin pole you must now attach the 'tow' or winch cable that is fed out slowly as the tower pipe section (1) is pulled over down to the ground ready for fitting pipe (2). The tower is pulled over towards A and as it swivels downwards the gin pole elevates and will stand 'erect' ready to be used as a lever and to elevate the tower once the second pole has been attached in the same way - once the full gin pole has been elevated, it must be adjusted to stand vertically on the B - B axis using the spirit level - its side wires must not be too tight, a little slack is best. On lowering or elevating more sections you will see that it seeks to 'fall' to one side or the other, and this means that one side wire will always be under great tension and the other will be slightly slack. Now the tower is lowered and the first pipe is back on the ground, then feed the entire length of electrical cable through pipe 2 and attach it to pipe one - then find the end of the stay wire that was attached to the end of the gin pole and affix IT to the top of pipe 2. For this will take the load as you elevate pipe 2. Then attach the other 3 stay wires to A and B - B - elevate the tower and adjust the top stay wires as you look upwards standing on the base to ensure that pipe 2 is vertical in line with pipe 1. Now remember to again attach another stay wire to the end of the gin pole that will be fixed to the top of pipe 3 - do this before you again lower the tower to affix pipe 3 to pipe 2. If you forget to do this you will not be able to lift the tower as the gin pole will not be connected to the end of the newly added pipe. This sequence is continued 'up and down' until the entire tower has been correctly adjusted and is ready to be lowered to receive the wind turbine. Note : do not forget that as the tower rises or falls the trailing wires are slack, hence the need to keep a trailing tension rope tight when elevating the tower. For once the tower is nearly vertical, the weight of the gin-pole exerts a sudden pull downwards and could swing the tower over too fast causing it to jerk and then buckle and collapse. I usually have a rope around the 'bumper' of a 4WD that is let out slowly, and once the gin pole begins to exert a downwards pull greater than the turbine end of the tower, then the winching can be halted and the tension rope let out slowly until the gin pole has found the ground. This way there is no dangerous jerking of the tower. This 'rope' may simply be a spare thin cable hanging down from the top of pipe 2 to which you add a section of rope, and it is also used to pull the tower over when lowering it, for the weight of the gin pole needs to be overcome before the tower begins to 'fall' backwards under its own weight. All stay wire ends on the ground end must have large turnbuckles attached so that final tensioning is easily accomplished. Also, if the tower is ever to be lowered then these can be slackened easily prior to lowering the tower. Also, if the stay wires become 'slack' at any time they can easily be tightened. Note: As there will be 4 or 5 turnbuckles at each anchor point, once they are correctly tensioned there must be a 'fence' or 'tie' wire slipped through them all and tied off so that these turnbuckles do not 'unwind' themselves and separate. page 10 Note: Turbine towers situated within 5 km of the ocean need to use stainless steel wire cable or galvanized wire, for if you use standard steel wire rope it will rust very quickly and become dangerous. Note: The pivot pin securing the tower to the base is fixed and needs to be 'set' in concrete before the two sets of stay wire anchoring points sited either side are poured, for the attaching 'eye' in these two opposite sides of the tower that will tilt backwards when the tower is lowered or raised must have their eye centre at the same height of the swivel pin and, must also be at the same horizontal level and on a straight line through the pin hole. This is because if they were not at the same height and not in a straight line, then when trying to drop the tower the wires could become slack or worse, they would become too taught and you would have a problem. Also, if they are not in line with the tower swivel pin but are situated a few inches back towards the gin-pole anchor point, then the wire cables would also tighten when you tried to drop the tower. The gin-pole stay wire anchor point and the other opposite it may be higher or lower than the two side ones as it makes no difference to the raising or lowering of the tower. When erecting a tower on a slope, then have the gin-pole facing downhill so that the tower is lowered uphill, and the two side wire supports are on a level on either side. Note: Erecting towers must be carried out only by someone who is conversant with the process, as it is extremely dangerous if attempted without knowing the reasons 'why' it is dangerous. One reason being that as it is being elevated, the trailing set of wires are hanging loose, and as the gin-pole nears the ground, its weight may suddenly 'fall' as its 'side' effort ‘gravity’ pull weight exceeds the gravity pull of the nearly vertical tower, and if it is allowed to 'drop' this can cause the tower to jerk and buckle and fall. The last 6' or so gap between the gin-pole and the ground must be a controlled lowering as gravity takes over from the winch and it is lowered very gently to the ground. This can be done by hand with small towers and small turbines, but a 4mm safety wire rope attached to the trailing side of the tower top can be used to counteract the ‘falling’ motion of the gin-pole. The trailing wire length needs to be equivalent to the tower height less one length, and is attached to the 'second from top' wire connector. When elevated, the safety wire can be shackled to the side of the tower and tightened with a small turnbuckle. Example, before elevating the turbine a vehicle would be parked 10 metres away from the turbine and the trailing wire would have another 150’ of 10mm nylon rope attached as it would need to be long enough to ensure that the persons keeping pressure on it were standing outside the line of ‘fall’ of the turbine. It would be fed around the bumper of the vehicle, and once the turbine is nearing vertical and the end of the gin-pole is 15’ above ground, the slack is taken up so that there is some tension on the trailing side of the tower, and as the gin-pole is winched down, the safety rope is fed out but kept under pressure so that when the time comes that gravity takes effect on the gin-pole and it tries to fall down, the winch movement is halted and the safety rope is fed out slowly so that the gin-pole does not drop down suddenly and cause a catastrophe. This trailing wire rope can be left in place and used to pull the tower over backwards when next needing to lower it for any maintenance work. The tower is erected section by section, and as each is added, the wires are adjusted and it is then lowered for the next section to be added. Only when all sections have been elevated and adjusted is it lowered and the actual turbine placed on it for its final elevation. The electrical wires are fed through each section as it is added, and exit at the top, 1 foot below the turbine. If the tower is too high for the size of pipe diameter, then when tightening the stay wires the loading on the lower pipe could cause it to buckle and collapse. Note: The one set of tower support wires are fixed directly to the end of the gin-pole, and the gin-pole is attached to the ground anchor point with a shackle and safety bolt. This means that these wires are always fixed to the gin-pole even when raising or lowering the tower. Note: The base of the lowest pipe needs to be drilled so that an earth wire can be attached and buried in the ground, as it operates as a lightening conductor. An earth wire is also clamped to each wire stay a couple of feet above the turnbuckles and also grounded. Note: The higher the tower the better off you will be, for if it is too low then even a large turbine is ineffective. If funds are the issue, then get a smaller unit onto a higher tower. Light units only need thin pipe and are thus cheaper to elevate higher.Note: When elevating each pipe section during the erection stages, the full length electric cables needed for height of tower are fed through from the bottom and clamped at the top of each section. Note: Stay wires must not be over tensioned, and if tensioned correctly at about 25kg load the longer 'upper' ones will be seen to have a slight 'droop.' Over tensioning 12 or 16 wire cables to 50 kg load would impose an added 600 to 800 kg loading upon the lower tower section and the base 'plate' assembly over and above the actual weight of the steel tower, turbine, and wires. This added weight becomes more when the wind speed increases and imposes a side force to the turbine. Note: Using tower pipe that is too thin for the loads imposed causes the lower section to 'buckle' under load and the tower falls with disastrous results. |
