Water turbines directly connected to immersion heaters

[krusty]

Hello,

I am looking at using immersion heaters directly connected to a pair of water turbines to run underfloor heating and hot water.

We have a stream running close to our house which should provide enough flow in the winter to power a pair of 1500kw turbines. Less flow in summer but I would then look to turn off one of the turbines as we would only need hot water.

Is it possible to connect the turbines directly to the immersion heaters without the need for batteries, inverters etc?

Would a combined output of 2-3kw be enough to run underfloor heating and hot water for a 2 person, 4 bedroom bungalow? Bearing in mind that 2-3kw would be constant. 

Has anyone does this before? Any recommendations of kit to use?

Cheers

[billi]

hi krusty

the navitron turbines are easy connectable to a 230 Volt AC heater , just plug them in the socket of the turbine  (hope an electrician supplies additional knowledge of fuses etc  )

I have one a 1,1 kw rated and just plug in the electric heater or hairdryer  directly if i or her  wants

Even if the heater or the hairdryer needs more or less power , it works fine (regulator at /in the turbine )

Cannot tell how much heating you need  and if that is sufficient ! Perhaps run a heatpump (but needs support from the grid when starting the compressor ) to tribble your heat output ( hope there is an electiciean arround to help us how to overcome start up current of heatpumps )

Billi

[guydewdney]

3kw is a LOT of water - how have you checked this?

You still need a basic control system - as water levels increase or decrease due to rain etc, it will produce slightly more or less than 3kw - if less, then the load will still be 3kw, but the genny will be making 2.9kw - which slows it down - so it produces less, so it slows more until it stalls.

A basic dump load controller will suffice. yes - it will work. Yes it is enough heat - IF you have enough insulation. I have 6kw - in a 4/5 bed mill, and its enough in the winter - my kitchen door is as airtight as a pair of tights and is 300 years old....

[dhaslam]

Running water is a source of heat as well as power.  It would be easy to rig up a small heat pump using say 1 kw input and use the spare electricity for other purposes or export it. 

[billi]

   i like that Dhaslam ( still someone needs to confirm that the generator can cope with the start up of the heatpump compressor )

You still need a basic control system - as water levels increase or decrease due to rain etc, it will produce slightly more or less than 3kw - if less, then the load will still be 3kw, but the genny will be making 2.9kw - which slows it down - so it produces less, so it slows more until it stalls.

I wouldnot say that it is as critical with the high head turbine i am using , unfortunatelly it is rated 1.1 kw and the max i  ever got was 750 watt (perhaps not enough head ) , so the hairdryer 2000 watt or the hover 1400 watt still did their job , just   slower (tranquile ) , when connected direct to the turbine

Billi

[krusty]

Thanks for all of the responses guys.

3kw is a LOT of water - how have you checked this?

I have been looking at "stream engines" on www.turbineservices.co.uk. They have a way of measuring using a notch in a piece of wood. I measured the stream at the lowest point following the dry spell we had in June and got about 3litres/sec. In winter we would easily get 5 or 6 times this flow. We also have in excess of 20 meters head.

You still need a basic control system - as water levels increase or decrease due to rain etc, it will produce slightly more or less than 3kw - if less, then the load will still be 3kw, but the genny will be making 2.9kw - which slows it down - so it produces less, so it slows more until it stalls.

Can you recommend a controller?

A basic dump load controller will suffice. yes - it will work. Yes it is enough heat - IF you have enough insulation. I have 6kw - in a 4/5 bed mill, and its enough in the winter - my kitchen door is as airtight as a pair of tights and is 300 years old....

We will be renovating the house so it will have loads of insulation 

[krusty]

Running water is a source of heat as well as power.  It would be easy to rig up a small heat pump using say 1 kw input and use the spare electricity for other purposes or export it. 

If using immersion heaters are not viable then a ground source heat pump would be the next option. Can you recommend a system?

[guydewdney]

3lit/sec x 20m x 9.81 (gravity) x 0.7 (efficiency) = 412 watts....

[dhaslam]

The  heat pump is simple.   Navitron now have a smaller one  that uses about 1.3 kW but will take a bit more to get started.   You just need to sink a good  length of pipe in the stream, several hundred metres.   The water will be a few degrees colder than a deep underground system  but the overall cost would be about half  of a deep underground system.     If you need more output it would be better to use two of the smaller heat pumps rather than the next size up but at an output of about 100kWh per day you could probably heat another house as well.    It is best to heat  a buffer tank so that heat transferred to the house can be varied  to suit weather conditions while the  heat pump runs continuously.           

www.navitron.org.uk/product_detail.php?proID=27&catID=98