Hi I am attempting to form a long term plan for further additions to house (cost and time to save etc) I would like to know if you can buy a wind turbine to make a direct connection to an immersion heater, heat dump to be used would be the central heating - store is 320litres. I like the "idea" of a 2kw turbine max 3kw output connected to a 3kw immersion with thermostat removed. I am not skilled in electronics oscilloscopes and rectifiers etc so if complex wiring, soldering required I would seek the help of an electrician, but before I get too far ahead of myself and throw other factors in to the mix like location, average wind speed etc Im just trying to see where they are at, it would be great if you could be sold a kit for an immersion connection with no batteries etc and then get an electrician to complete the setup. Other forums I have read so far forums seem to talk of installations by people with expertise who have made up there own units with gains on windy days. ok thanks

The problem with turbines (and PV) feeding straight into an immersion are that they are essentially constant voltage devices - not quite, but almost. What you want is that as the wind increases the current out of the turbine increases nearly in proportion, with the voltage only increasing slowly. It's the current which provides the force which stops the turbine flailing around too quickly resulting in a RUD¹. I think the voltage is roughly proportional to the rate of rotation (again, not quite but almost).

If you connect a fixed heater to the turbine which is low enough in resistance to absorb all of the power from the turbine in high winds without the voltage (and RPM) getting too high then it'll be so low that it'll likely stall the turbine in more common (lower power but, because they last longer, higher energy) conditions.

I wrote a blog post on the equivalent point for PV the other day:

http://www.edavies.me.uk/2012/11/pv-immersion-gotchas/

which also mentions one reason why not putting the DC from the device through a thermostat would be Very Good Idea. For turbines the additional reason would be to avoid running the turbine off load - which would be a Very Bad Idea (unless it's something like a Proven which can sort itself out when off load).

However, turbines are intrinsically AC devices, typically three phase, so in some cases that DC consideration might not apply.

It's not obvious how to get a load which matches the turbine well for varying wind conditions yet doesn't have electronics in the path which could fail leaving the turbine unloaded. There are different possible solutions which might be suitable in different circumstances.

¹ Acronym learned in the context of SpaceX's recent Falcon9 otherwise mostly successful launch where one engine failed:

http://www.urbandictionary.com/define.php?term=Rapid%20Unscheduled%20Disassembly

Posted By: SeretYou could keep things relatively simple by getting an off-the-rack grid-tied turbine w/inverter and simply cutting the immersion heater in whenever output is above the threshold

And divert to a dump load when it is not.
I have tried for 2 years to get a cheap 'homemade' solution to a problem, should have just bought off the shelf and reaped the benefits.

There is also safety aspects when dealing with all this, I suspect that a normal immersion heater thermostat would arc and soon wield up if directly fed.

But look at your wind resource first, you may find PV is easier, cheaper and more reliable, but then ST is better still for water heating.

Posted By: Ed Davies
Maybe - show me a “properly specced” one. Bet it's not cheap. DC switches tend not to be.

This is the problem I've struck when researching the gubbins to make a lot of these immersion heater ideas work, the hardware makes the whole thing really uneconomical. The gains you're chasing aren't substantial enough to justify anything more than the most basic kit.

That's why I've leaned towards the side of Arduino/R Pi type control of some cheap relay switching. At least the (relatively) expensive part of the system is multiple purpose.

Why are you looking to generate electric to then use the electric to generate heat. A simple frictional heater would do exactly the same and then you dont have to worry about electrics.

Car air conditioning units make good heat pumps for wind turbines due to there ability to handle variable speed. As for turbine a "Southern cross" type water pump tower allows you to connect your pump at ground level.

Thanks for taking the time to respond and post the many suggestions ~I have a good few links to explore. Grid tie has been appealing I know applications here are very slow to get processed would need to check where they are at, thats another thread.

Frictional heat sounds interesting need to investigate to see how this could fit in to my plumbing. The posts have confirmed there is not a simple of the shelf package, hopefully the off the shelf kit to allow a connection to a large or small hot water store in your house will before too long get mass produced by the West making it a cheap supplement to our plumbing systems and common place in our DIY and Hardware Stores espeically in rural areas. Just like with stoves and Solar panels im sure literature accompaning such units could give a good sales pitch despite what the true output would be - a market for someone

I see locally large turbines connected to farms that never seem to stop rotating. LArge turbine and grid connection would be a dream but in saying that a local stud farmer lost his 25000 euro unit in severe weather so they are not immune to storm damage, thanks all for now