Small Scale domestic Wind Turbine

YouWantWhat

I'm just looking for some advise on a wind turbine which I am proposing to install. I have done some research, but I'm not very electrically minded and get lost when trying to sort out this side of things. I live in a very windy area and my proposal is to install a simple system which would heat the water in my hot water cylinder. Here's what I'm proposing :

12v / 800watt wind turbine (3phase), to
12v charge controller with dump, to
12v battery, to
240v / 2000watt inverter,
which will be connected to the heating element in the hot water cylinder.

I can install the whole system for under €1000.

Taking that I have plenty of wind, can anyone tell me if what I'm proposing is feasible, and will it work?

Also, what difference would it make if I got a 500w or 1kw windturbine?

Thanks.

quentingargan

Since electricity costs about 15c per kw hr, and you can usually get heat from oil or gas for less than 8c, I am always unsure as to why you would take electricity from a turbine and use it for heat. Especially using batteries that have at best 80% round-trip efficiency.

I am also a bit worried about the quality of the equipment you are proposing. If you are getting turbine, inverter and batteries for under €1K, I suspect it is all Chinese. There have been longevity issues with Chinese turbines in the Irish wind conditions.

On a good site, your turbine will, on average, give about 15% to 30% of its stated output. So your 800W machine may deliver 1000 to 2000 units pe year - if you are lucky. Many sites would be less than 15%.

However, drawing 2kw from the batteries will hammer the efficiency of the battery and shorten its life, unless you have a huge battery bank. Ideally batteries should not be discharged at more than 10% of their capacity, so to pull 2kw you would need a 1,700Ah battery pack.

If you want to have some wind running a battery system, I would put a few lighting circuits onto this system you propose and use it for fun, but I wouldn't go putting a 2kw load on it.

Q

YouWantWhat

Hi Q,

thanks for the reply. You've put a bit of a damper on the project and I've have to put my thinking hat on again. I've passed my proposals to an electrical engineer for his comments and mentioned your comments.

With regards the equipment, I've done a good bit of research and sourced a small company in the USA which make and deliver the turbines and accessories. I'll send you their link on a pm. I'd like to get your comments on them, I think they are very good.

This is what they have priced me for, for just under $900 dollars, delivered :
800 watt rebel 7 blade 12 volt Turbine
combo 2 resistor charge controller 12v
100 amp dc breaker
1 can of green or clear pma spray to paint your whole turbine and inside of pma for extra protection against the ocean

I'm convinced there's a system that will work, it's a shame to be sitting indoors with gales of wind blowing outside, and your paying for electricity and oil!!!

Tifosi

YouWantWhat wrote: »

Hi Q,

thanks for the reply. You've put a bit of a damper on the project and I've have to put my thinking hat on again. I've passed my proposals to an electrical engineer for his comments and mentioned your comments.

With regards the equipment, I've done a good bit of research and sourced a small company in the USA which make and deliver the turbines and accessories. I'll send you their link on a pm. I'd like to get your comments on them, I think they are very good.

This is what they have priced me for, for just under $900 dollars, delivered :
800 watt rebel 7 blade 12 volt Turbine
combo 2 resistor charge controller 12v
100 amp dc breaker


1 can of green or clear pma spray to paint your whole turbine and inside of pma for extra protection against the ocean

I'm convinced there's a system that will work, it's a shame to be sitting indoors with gales of wind blowing outside, and your paying for electricity and oil!!!

Have you considered import duty, VAT

What is the average wind speed in your area.

What is the cut-in speed of the turbine.

What safety mechanism is in place for high wind speeds.

How are you converting 12dc to 400v AC, inverters on each phase?

800w output is quoted at what wind speed normally the highest the turbine can safely operate

You will need to contact the ESB regardless of if your exporting or not

If your not using the electricity generating, say at night will you be storing it for later use, via a battery system.

So much to consider!,

Windy boy

Hello
Will this system work a domestic hot water tank. How long will it take to heat a tank of water

nogoodnamesleft

YouWantWhat wrote: »

I'm just looking for some advise on a wind turbine which I am proposing to install. I have done some research, but I'm not very electrically minded and get lost when trying to sort out this side of things. I live in a very windy area and my proposal is to install a simple system which would heat the water in my hot water cylinder. Here's what I'm proposing :

12v / 800watt wind turbine (3phase), to
12v charge controller with dump, to
12v battery, to
240v / 2000watt inverter,
which will be connected to the heating element in the hot water cylinder.

I can install the whole system for under €1000.

Taking that I have plenty of wind, can anyone tell me if what I'm proposing is feasible, and will it work?

Also, what difference would it make if I got a 500w or 1kw windturbine?

Thanks.

The theoretical maximum you will ever get is approx 59% of rated power as defined by betz law.

I would advise that you invest in an aerometer to determine the avg, range, direction and range of your proposed site. An important consideration when measuring the wind speed is the height of the turbine itself. As the speed varies depending on the height of the turbine.

What is going to stop the turbine from overspeeding? Is there are braking system included? I highly doubt the turbine will be pitch regulated with a purchase price of 1000euro.

Granted the turbine is going to feed a hot water element (essentially a resistive coil) but what about voltage control issues due to gusts, vibration etc.

This type of installation would also require an independent circuit to your ordinary domestic circuit as "islanded" operation is prohibited as per IEC regulations.

You cannot just connect the turbine to an inverter and then to your consumer unit and enjoy green energy.

YouWantWhat

nogoodnamesleft wrote: »

The theoretical maximum you will ever get is approx 59% of rated power as defined by betz law.

I would advise that you invest in an aerometer to determine the avg, range, direction and range of your proposed site. An important consideration when measuring the wind speed is the height of the turbine itself. As the speed varies depending on the height of the turbine.

What is going to stop the turbine from overspeeding? Is there are braking system included? I highly doubt the turbine will be pitch regulated with a purchase price of 1000euro.

Granted the turbine is going to feed a hot water element (essentially a resistive coil) but what about voltage control issues due to gusts, vibration etc.

This type of installation would also require an independent circuit to your ordinary domestic circuit as "islanded" operation is prohibited as per IEC regulations.

You cannot just connect the turbine to an inverter and then to your consumer unit and enjoy green energy.

Hi,

alot of waffle on the forum about wind turbines and almost impossible to get straight facts, just people giving you all the negatives and disadvantages.

Well I bit the bullet and went ahead and bought a system, and it comprises :
24v, 1600watt turbine, 3 phase,
3 phase to 2 phase junction box,
2 x 24v, 500watt inverters to step up the voltage to 240v.

This whole system cost under €1000 - no extra vat or import duties.

The idea is that the 240v invertors are plugged into a power point in the house and sends the current produced into the house grid. However, I did not see any reduction in my house electricity bills, so I bought a 24v immersion heater/element and replaced the one in my hot water cylinder with this one. I then switched off/unplugged the inverters at the mains and all the power produced went straight to the dump load, which was the immersion heater. This works a treat and and we get a good supply of hot water. I have now also bought a 24v radiant heater, which I'm about to connect up - if this works well, it will give us heat when we most need it, i.e. when the wind is howling away.

To answer some questions :
no the turbine does not have a brake - it just goes bollestic in gusts. It has survived several storms and is still in perfect condition (up about 18 months now). The blades have a lifetime guarantee.
Kick in speed - don't know, starts producing power at about 10-15mph.
Tower - used scafolding poles and brackets - cost €80
Was not charged any import tax or VAT.
"you cannot just connect the turbine to an invertor and then to your consumer unit and enjoy green energy" - doing it!!

I've tried to attach a photo of the turbine - not sure if it has worked or not. If not someone might let me know how to attach one.

Good luck.

IMG_5960.jpg

nogoodnamesleft

YouWantWhat wrote: »

Hi,

alot of waffle on the forum about wind turbines and almost impossible to get straight facts, just people giving you all the negatives and disadvantages.

Well I bit the bullet and went ahead and bought a system, and it comprises :
24v, 1600watt turbine, 3 phase,
3 phase to 2 phase junction box,
2 x 24v, 500watt inverters to step up the voltage to 240v.

This whole system cost under €1000 - no extra vat or import duties.

The idea is that the 240v invertors are plugged into a power point in the house and sends the current produced into the house grid. However, I did not see any reduction in my house electricity bills, so I bought a 24v immersion heater/element and replaced the one in my hot water cylinder with this one. I then switched off/unplugged the inverters at the mains and all the power produced went straight to the dump load, which was the immersion heater. This works a treat and and we get a good supply of hot water. I have now also bought a 24v radiant heater, which I'm about to connect up - if this works well, it will give us heat when we most need it, i.e. when the wind is howling away.

To answer some questions :
no the turbine does not have a brake - it just goes bollestic in gusts. It has survived several storms and is still in perfect condition (up about 18 months now). The blades have a lifetime guarantee.
Kick in speed - don't know, starts producing power at about 10-15mph.
Tower - used scafolding poles and brackets - cost €80
Was not charged any import tax or VAT.
"you cannot just connect the turbine to an invertor and then to your consumer unit and enjoy green energy" - doing it!!

I've tried to attach a photo of the turbine - not sure if it has worked or not. If not someone might let me know how to attach one.

Good luck.

IMG_5960.jpg

Direct feed to your consumer unit from the turbine is illegal. The utility has to be able to control infeeds to the grid (to ensure isolation in the event of a fault). Granted your is a small installation however the the regs are still there. A mate of mine has a 30k system on top of a hillside which is maintained by the provider. The control is a simple relay when the mains feed is not present it applies a brake to stop the rotor.

One of the reasons I asked about the braking system is in the event that the thing spins itself to pieces due to centripetal forces, sheer forces acting on the blades, material fatigue over time etc. So when that turbine is spinning at a couple of 100 rpm a minute in say 10 years time would you be confident it will stay in one piece being exposed to Irish weather?

I gave some advice about the engineering aspects that have to be considered at the design phase from a commercial perspective. Being honest I wish I never bothered from your tone.