Micro wind turbines

mickdw

Are turbines useful at all compared to pv.

I see lots of too good to be true products advertised but google quickly suggests they are either crap or plain lying about power figures.

Don't see many getting installed but you would imagine they would be useful

unkel

No.

We've discussed it many times before. Some fools like myself didn't believe people wiser and more experienced than me (probably also fools back in their day) and went ahead anyway. It doesn't work. You are either a new generation fool and learn some interesting stuff on the way, but basically you will waste your time and money, or you will heed this advice and don't go there 😂

Unless you live in a one of house on top of a hill with no buildings or trees around, you use enormous amounts of electricity and you don't mind getting planning permission to erect a large mast and to investing a very substantial sum in installation (and then maintenance). Wind only works when it's big. Bigger, biggest.

bullit_dodger

+1 on what unkel says, with an additional piece of info (from a wind engineer) why.

(852) Wind Turbines for Home: Is it Worth It? - YouTube

denismc

Wind turbines are mechanical, therefore they make noise, require maintenance and will eventually break down, As Unkel said wind works if you live in the middle of no-where with no trees and no other buildings.

PV on the other hand is completely passive, once it is installed properly you can pretty much forget about it, it requires no maintenance and will pay for itself much faster.

I think the longest part of my PV installation was erecting the scaffolding, the installation took less than half a day.

UID0

Looked into them about 13 years ago for the company I worked for at the time. They weren't viable unless we went big, and even with the grants available from SEAI (or SEI as they were at the time) who would have paid for about 1/3 of the cost, the payback period was too long.

Micro turbines have their place, and are extremely useful for satisfying low power requirements that are distant from a grid power connection (e.g. electric fences, wireless security cameras, speed warning signs on the side of the road), but in general aren't useful for domestic production. There are exceptions, and if you live in the country and use electricity for heating, you could consider them as wind tends to be stronger in the winter than in the summer, and your electricity demand would also be higher in the winter.

Unless the rules have changed since I was looking at them (2009/10) wind turbines can't be attached to dwellings, so they would have to be attached to a garage or need a mast. At the time, I had been thinking that a small turbine paired with a 12v immersion element could reduce the water heating costs, but it didn't make sense and I didn't go ahead with it.

There's a video on youtube by "Engineering with Rosie" where she explains the problem with urban wind turbines (and compares with solar)

Wind Turbines for Home: Is it Worth It? - YouTube

ELM327

I'm sitting here watching leaves and twigs fly past the windows for the last few days.

It's on my list to investigate. I drew up my plan for the house in the next 5 years and put two wind turbines on it - well, on the plan away from the house! I've so much room for solar PV, wastewater collection + hydro, etc that wind is pretty far down the list in terms of ROI.

TerraSolis

I live on a farm out west - we installed a C&F 11kW turbine back in 2012. It's a beast, but it was an expensive beast.

C&F shut down their wind ops ages ago. This has been a repetitive story across the microwind industry which has few genuine crowds left in the game. SD wind still do good turbines. I'm doing consulting work for a client who's having one installed in Meath.

Ultimately, unless you're a large energy user with some capital to sink and a great location you're infinitely better off with additional PV rather than a turbine.

With that said, our experience with the turbine at home has been good. Small wind isn't all nightmares and it's an absolute savior this year. It will generate in excess of 7 grands worth of elec this year if valued at 18.5c export (worth even more at day rate). However, I'm an energy systems engineers and know a thing or two about keeping it running.

If the industry was in better shape, there might be more potential there. I'm messing around with a cheap IstaBreeze turbine to see if it can be tricked into working reliably in conjunction with my home PV. I'll report back here on what I learn further. One thing is for sure, most of the stuff out there is shite - don't get taken in by it.

ELM327

What is the 11kW system, who installed it for you?

TerraSolis

https://www.boards.ie/discussion/comment/119799433#Comment_119799433

C&F 11kW - installed by C&F green energy (before they shut down years ago).

mickdw

https://www.boards.ie/discussion/comment/119796400#Comment_119796400

Well I do live in a one off house where land owned runs to the top of a hill and literally no neighbours visible so that part is taken care of but I will take the advice and put it down as a non runner.

unkel

https://www.boards.ie/discussion/comment/119808954#Comment_119808954

If you fall into the "unless" category, so the hill, the using enormous amounts of electricity, etc. then it's worth exploring.

graememk

https://www.boards.ie/discussion/comment/119808954#Comment_119808954

Yeah your in the maybe category!

First thing I'd get is a weather station.

Measure your wind.

As usually it needs a good 4-5m/s to get it generating anything.

It's not just thecost of the turbine, it's the tower that holds it, cable, rectifiers, inverters etc too.

I've looked into it a few times, and basically comes down to have more solar and more batteries!

samdeluxjones

https://www.boards.ie/discussion/comment/119799395#Comment_119799395

"I'm messing around with a cheap IstaBreeze turbine to see if it can be tricked into working reliably in conjunction with my home PV."

Where did you get your IstaBreeze? Did you pay VAT & customs on import?

Looking at doing the same myself, after a hell of a lot of research the IstaBreeze looks the best bang for buck and seems to perform as stated judging by a few American lads youtube videos. Other than that very little data..

One of their controllers can be adjusted to suit whatever type of lithium batteries you have so in theory can be connected directly to battery pack that is hooked up to a hybrid inverter.

I'd be very interested in knowing how you get on with this, I'm on the southeast coast so no shortage of wind here.

September

jkforde

https://youtu.be/VnSZ0MHIcvs

These are interesting

samdeluxjones

She's arrived....

TerraSolis

Cool! What kind of tower is she going on?

Dtp1979

If installing these small turbines directly into immersions do you need to use anything in between? Like charge controllers or safety breakers etc?

im looking to install 6-8 small turbines directly into 6-8 immersions of the same rating as the turbines in a buffer tank.

bullit_dodger

https://www.boards.ie/discussion/comment/120046781#Comment_120046781

You'll need some kind of "dump load" (basically a massive resistor coil) too for taking the generated power when the tank is hot - otherwise "Bad-mojo" will happen. :-)

Dtp1979

https://www.boards.ie/discussion/comment/120046851#Comment_120046851

It’s going to be a 2,000 litre buffer tank so very unlikely it will over heat!

whst kind of bad mojo we talking about here?

Nelbert

The energy has to go somewhere (solar inverters are a lot better at this). So if the take doesn't tank it and it's nowhere else to go it'll start frying the components of the turbine. Better to be grid tied to avoid this.

Dtp1979

https://www.boards.ie/discussion/comment/120046978#Comment_120046978

But it’s 2,000 litres! I could always have an overheat thermostat on the buffer that if it got to 60 degrees etc it’d open a zone to dump heat inside. I’m more concerned about what Components I’d need from turbine to immersion.

Nelbert

Why not go turbine/s to house circuit and heat tank with a few standard immersions?

Chris_5339762

We have a small turbine similar to Sams in the garage. There is talk of putting it on the roof and attaching it to a radiator in the bathroom only. The thinking being that if its winter, its cold, but windy, and would generate passive heat.

bullit_dodger

https://www.boards.ie/discussion/comment/120046972#Comment_120046972

It'll basically destroy the turbine if you don't send that current "somewhere". While 2000L is (a lot!) of water, still it's ~80Kwhr to heat it from 25C to 60C. Conceivably if you had 4 turbines doing 500watts each, that's 2kw/hr. If you had two breezy days in a row, the turbines (assuming they were doing the same output all the time, it's possible that you get the tank up to temp.

Then when that happens, you need somewhere to send the power, but it usually a cheap and cheerful simple resistor (dump load)

(1137) Wind Turbine Divert Dump Load Resistors | Missouri Wind and Solar - YouTube

Nelbert

Would be a shame to dump that generation when it could cover your house caseload and more.

Would be an enviable position to be in to be able to cover your typical baseload at all times (while heating your buffer too!).

Dtp1979

https://www.boards.ie/discussion/comment/120047511#Comment_120047511

It seems like a good problem to have! There’s no thermostats on these immersions so it could get up to possibly 85 before I’d get nervous. It’s an open vented heating system so there’s technically nothing to worry about once it’s plumber correctly. I’m a plumber by trade. Do I need to use breakers or and devices in between tte turbines?

I’ll all also have solar thermal heating the buffer and a log boiler which I won’t be depending on long term

bullit_dodger

Yeah, it's a good problem to have.....if the turbines can consistently generate that power. Though once you get the water up to temp, then you'll want to protect your investment so that you can do it again the next day.

So the turbines will create AC, you'll need that to go through a rectifier if you want it to use DC, but I think ultimately (and there are probably people more knowledgable than me here on the forums) I think the best way to go is to go via some form of charge controller which has a dump facility built into it when the "main load" (i.e. your hot water immersion) switches off.

Dtp1979

But what do I need to dump? 2,000L of central heating water is massive no? The buffer itself is the battery no?

Nelbert

Yes but in this case when the battery is full (tank is fully heated) you need to find a home for the electricity still being generated by the turbines.

Some have suggested a controller with a resistor or dump load function. My preference would be to tie in to your main household electrical circuit (and therefore the grid) and cover your electrical usage.

If you are generating enough to power an immersion heater (or two) you'd have enough to power the house and export the remaining to the grid (or batteries if you had them) and not have to worry about dump loads.

If I had the location for it which you seem to I'd do turbine tied to house consumer board (via inverter) and distribute power from there.... An Eddi or similar controlling the water heater (would power up and down with available power beyond what the house needs).

Dtp1979

That all seems great long term and it’s something I’d do in the future once I get more into it. For now I’m trying to concentrate on getting a heating system that will work for free ideally. Elec bills are fine but this is a big house and it has big heating bills. I can’t ever see a scenario where I won’t need to pull from the buffer cause it’s too hot.

now if it is the case that I’m over producing electricity then I’ll definitely look into tying it into the house electricity.

really for now I’m trying to keep it simple and just wire some turbines into the elements. Do I need DC breakers or anything between the turbine and elements?

Nelbert

A breaker with a sign above to say to apply the brake to the turbine first before switching..... Otherwise you're in to generating electricity with no where to go and end up with a fried turbine.

My back of a envelope would be turbine -> breaker with turbine brake warning -> some form of dump load controller -> breaker -> immersion/s

You can isolate each portion then. My suggestion just turns the dump load controller in to an inverter, tied to consumer board breaker which then has another breaker for the immersions.

I really think you need to consider excess electricity generation more. You could end up with a great working system for a few days then fried turbines once the thermostat on immersions cuts them off and the electricity generation fries the turbines. That risk increases in summer when your central heating won't be up to much.

Your water reaching the set temp won't stop the wind from blowing.

Dtp1979

There is no stats on the immersions.

Nelbert

What's the safety cut off for several days of not much demand on the buffer with a constant wind then?

I wouldn't have thought the immersion heater would be a fan of constant power (always on but amount of power would vary) for long periods at a time?

Dtp1979

The safety woukd be a heat dump to the cylinder or house.

Yes the varying power constantly will be the biggest issue to the longevity of the immersions I’d say. Only time will tell

championc

https://www.boards.ie/discussion/comment/120043133#Comment_120043133

Make sure that you balance the blades before you erect it. Bearings will wear far guicker, and potential output will be impacted if not balanced. And of course, you'd end up with severe vibrations too.

samdeluxjones

https://www.boards.ie/discussion/comment/120043377#Comment_120043377

Getting a local fabricator to have a look and come up with something.

The dump load (2 ohm resister) comes with the charge controller which is only for charging lithium batteries in my case.

Have a look at the other options on the site https://en.istabreeze.store/

https://www.boards.ie/discussion/comment/120049053#Comment_120049053

I will check the blades for balance before it is erected yes.

I will have a rubber buffer between the base and the mount to dampen vibrations too.

bullit_dodger

https://www.boards.ie/discussion/comment/120048972#Comment_120048972

I know where your going there with dumping the hot water into the house which would be your "safety valve". On the surface it's not a bad idea and has a lot of merit, but like nelbert above I'd revisit the thinking of not having a dump resistor. What would happen if the immersion coil broke (since you've a plumbing background you know that they fail occasionally), so in that case your immersion couldn't take the load that your turbine is generating, and you would end up frying your turbines(s)....fairly needlessly as it's a relatively simple enough to install a dump resistor. I've not done this myself but it's an easy enough job I believe.

Grid tying in would be the holy grail again as nelbert mentions too, but in this case you complicate the matter a lot. If you don't have an NC6 form involved already, you'll need to get a certified spark to sign off on your circuit as you would be putting into the grid, but leaving the grid tie out of it, and having your wind turbines + immersions isolated away, you simplify the matter as it's a "off grid" solution.

I like the idea though - hoping you get it to work as we need more of these type of projects! Respect.

If you haven't come across it, Graememk built a somewhat similar heating arrangement with the output of his PV panels feeding a 500L buffer tank for the heating.

Aside: Most wind turbines produce AC unless they have a rectifier built into them which does the AC->DC internally inside the turbine itself.

Dtp1979

My turbines are 12v DC

GRAEMEMK? Is that a user name? Definitely interested to see how it works

excellent point about what would happen when the immersion burns out as it’s almost likely to happen. I’d be using maybe 6 immersions. 1 turbine per immersion. That way the system should never break down etc.

can you send me some links to dump resistors or what they are? Do I need 1 per turbine?

graememk

https://www.boards.ie/discussion/comment/120050664#Comment_120050664

It's a me! 😂

Mine is grid tied but with an eddi as a diverter, plumbed in as if it was a oil boiler. Only 500L tho. All PV

"Charging" it on night rate or via the stove in the house.

Dtp1979

https://www.boards.ie/discussion/comment/120050682#Comment_120050682

Very good. How’s it working for you? I had an 800litre that I figured too small and came across a new 2,000litre buffer with coil on DoneDeal for 800 so it was a no brainier.

graememk

https://www.boards.ie/discussion/comment/120050798#Comment_120050798

It's working really well, putting 30ish kwh into it a night, (my night rate is 7.9c)

It's a 500L joule, as big as I can fit where I wanted to put it. Plenty to boost the house in the morning and to get the heating started in the evening(in Nov Dec Jan) once Feb hits the solar should be taking it over and by late spring I'll not be needing much of a fire at all

Dtp1979

https://www.boards.ie/discussion/comment/120051155#Comment_120051155

How many radiators do you have?

graememk

https://www.boards.ie/discussion/comment/120051880#Comment_120051880

...12? Mostly big double radiators.

I keep a majority of the house at 18c, weekdays, just the kitchen and hall is boosted to 20c in the morning for an hour or so but a boost to 21 at 5pm- 11pm. Weekends, Hall, Living room and Kitchen are at 20c.

I have a solid fuel stove in the living room (inset) so a lot of the heat from it goes into the water. It doesn't go out during the winter.

This is a 24 hr output of the heat "demands" from my tado system

Once a room is up to temperature it shuts off.

I have temperature sensors in the tank, Although not really that well spaced out, the "middle top" is about half way up the tank, with the rest spaced evenly across the the lower half.

I run the output through a mixer valve set to 50c so it just doesnt "blow its load" all at once / also to be able to simulate if could work with a heatpump (eg an ecoforest one, R290, that works a bit better at higher temperatures)

Also have sensors on the pipes in, out, and on the flow out of the mixer. I do intend on putting a bypass on the mixer by using a 2 port valve when the tank is below 50.

As im typing this the top of the tank has just dropped to about 50, you can really see the uptick in demand at 9am!

If i put a flow meter on the system, Id be able to calculate the instantaneous kW of the output/demand and also how much kWh of heat into the tank .

Also when it was basically just the living room heating there now, it was a delta-T of about 10c.

Was doing my stats for December, I put about 700kWh into the tank for heating.

My oil boiler is old, So id say if im lucky 75% efficient? Works out about 90l of oil ive replaced with Night rate electric.

Now once the sun starts to pick up, I'm thinking of doing some automation to boost some rooms when the tank gets hot so the immersions dont cut out during the day.

Dtp1979

https://www.boards.ie/discussion/comment/120052010#Comment_120052010

Great thank you. Where did you get those graphs???

do I need a dump resistor for a small panel (175w)?

10-10-20

https://www.boards.ie/discussion/comment/120052010#Comment_120052010

Sorry for going OT.

"If i put a flow meter on the system, Id be able to calculate the instantaneous kW of the output/demand and also how much kWh of heat into the tank ."

Nah, you don't need a flow meter. The way I did it was to just assume that each sensor represented 1/3rd (or 1/4 in my case) of a tank and calculate the potential energy in kW.

Here's how I wrote it in OpenHAB at the time.

        // Calculate the energy value in a hot-tank of water.
        // Formula: (Volume in L * 4 * Difference in temperature) / 3412 = Potential energy in kW.
        // This does not take into account the heating method or efficiency - electric, gas, oil, etc,

        // My tank is 300L, I have four sensors installed on it, one on the top, one a quarter of the way down and so forward.
        // Hence I assigned an equivalent volume of 75L to each sensor.

        if (gHotTankTemperature.state instanceof DecimalType) {

                // Run through each sensor and calculate the energy...

                valEnergy = (75*4*(FF_HT_01 - ColdTemp)/3412)
                FF_HotTank_Energy01 = valEnergy
                //logWarn("hotenergy.rules", "FF_HotTank_Energy01=" + FF_HotTank_Energy01 + "valEnergy=" + valEnergy + "FF_HT_01=" + FF_HT_01)

                valEnergy = (75*4*(FF_HT_02 - ColdTemp)/3412)
                FF_HotTank_Energy02 = valEnergy

                valEnergy = (75*4*(FF_HT_03 - ColdTemp)/3412)
                FF_HotTank_Energy03 = valEnergy

                valEnergy = (75*4*(FF_HT_04 - ColdTemp)/3412)
                FF_HotTank_Energy04 = valEnergy

                // Next, add up the combined four values and commit them to the database.
                valEnergy = (FF_HotTank_Energy01 + FF_HotTank_Energy02 + FF_HotTank_Energy03 + FF_HotTank_Energy04)
                postUpdate(FF_HotTank_TotEnergy, valEnergy)

                // Now calculate the delta in kW from 5 mins back and update the database. This will give us data for a bar-chart on utilisation, +/-
                FF_HotTank_5minsBack = (FF_HotTank_TotEnergy.historicState(now.minusMinutes(5), "influxdb").state as DecimalType)
                valTotEngy = FF_HotTank_TotEnergy.state
                //logWarn("hotenergy.rules", "valTotEngy=" + valTotEngy)
                // Calculate the difference and multiply by 1000 to convery from kW to W.
                valEnergy = ((valTotEngy - FF_HotTank_5minsBack) * 1000)
                logWarn("hotenergy.rules", "valTotEngy=" + valTotEngy  + " minus FF_HotTank_5minsBack=" + FF_HotTank_5minsBack + "= valEnergy" + valEnergy)
                postUpdate(FF_HotTank_Delta, valEnergy)
                }

Then I'd subtract the value from 5 mins previously and use that to calculate a loss over that period. It was usually 7w per 5mins when the tank was around 50 degrees C.

You could improve on this by sub-dividing the tank again and calculating off a pseudo temperature (half-way between one sensor and the lower one), etc.

graememk

https://www.boards.ie/discussion/comment/120052111#Comment_120052111

Home assistant is generating the graphs, everything except the tado is coming in over mqtt.

https://www.boards.ie/discussion/comment/120052291#Comment_120052291

I'll have a look over it later, but surely wouldn't the energy stored be in kWh as it's energy not power 😉

graememk

https://www.boards.ie/discussion/comment/120052111#Comment_120052111

Oh, Solar doesnt need dump resistors, but.. 175w is a drop in a ocean heating a 2000l tank! lol

Dtp1979

https://www.boards.ie/discussion/comment/120053484#Comment_120053484

No it’s not for the buffer. I have one and I’ll be wiring it in to a DC under sink water heater

graememk

https://www.boards.ie/discussion/comment/120053567#Comment_120053567

ah right, Point still stands, PV doesnt need dump loads, the power just doesnt get generated,

Dtp1979

https://www.boards.ie/discussion/comment/120053668#Comment_120053668

So between my turbine and each DC immersion should I have a dump load on each line?

graememk

https://www.boards.ie/discussion/comment/120053681#Comment_120053681

Yeah Its there as a fail safe. Also it will act as a brake if you need to shut it down due to extremely high winds/Maintenance on the immersion/whatever