Roof wind turbine

[Alexphd1]

Came across this. Haven't seen anything like this. Thought looked pretty interesting.

 

https://thepowercollective.ca

[Crofter]

Yes that is very interesting. The obvious downside is that it must be quite sensitive to wind direction.

[ProDave]

My concern would be noise.

[SteamyTea]

Our old leader, David 'scared of UKIP' Cameron had a small turbine on his house.  Was told to take it down. Think his was a Windsave, as sold by B&Q.

 

There are so many reason why small turbines are pointless.

[Alexphd1]

Oh I remember seeing the sales poster at a b&q... the sales figures was pretty impressive and the chimney turbine on dragons den to. Always somebody new with a bright idea.

 

I think classing all small wind turbines is pointless is a bit harsh, it's something I would look into if I had the rite ground. A few kw turbine hooked up to a sunamp (not sure exactly on how to do this) could be a handy bit of kit. 

 

 

 

[Cpd]

I live in an exposed coastal area, with hills on either side of my property facing south west. The hills funnel the wind up the gently sloping ground from the sea and its really quite unusual to not feel a breeze. The hills do cause some morning and evening shadowing so solar is not a viable option. When i get the time and money i would like to put up a small test turbine to gather data but i am sure this is a prime location. Would love to generate electricity from wind. I live in an isolated location but have two houses, a large shed and various caravans / cabins they all churn through the electric......  if i had the data and the available funds i would happily chuck it at a turbine project. I live in hope. 

[Crofter]

Most turbine manufacturers suggest a mean wind speed of 5m/s as the cutoff point for viability.

It's not overly expensive to rig up a data logger- something we looked into quite seriously. A 5kw turbine would have cost about £30k to install, but that was most of our build budget so we decided to do the new house instead.

[SteamyTea]

Small turbines have a very low efficiency, sometimes below 20%.

It is the nature of turbines that power is proportional to the swept area and the cube of the windspeed.

Even 5kW are not brilliant.

There was a spreadsheet by Dr. Michael Hunt (I know) that showed all the efficiencies of most available turbines.

[Alexphd1]

£30k for a 5kw that's a bit (lot!!) more than I was expecting! 

I don't know if we are comparing like for like but 20% is more than PV  efficiency, or am I way off the mark? 

I actually like the look of big turbines but wouldn't want to stay within couple of hundred meteres of one. 

[mike2016]

Hi,
I Read a good book - "Wind Energy for the rest of us: A Comprehensive Guide to Wind Power and how to use it" - by Paul Gipe
Basically the summary is that it's all been tried before, an amazing new urban solutions are unfortunately usually smoke and mirrors. Most are now tied off and non operating. There's a reason the wind industry currently builds wind turbines on 100+ meter towers with 3 very large blades and he explains how this developed very clearly. 
I would suggest checking out the book and see where the industry has come from before making a purchase decision. If you have enough land a standard domestic wind turbine would be a better bet once you have taken an extended set of measurements of the wind power (6-9 months at the proposed height of the turbine) to ensure you can generate the kWh you purchase! 
Wind is great and a free resource but taking advantage of it to generate power (vs pumping water/milling) has taken a century of trial and error to get right . There's always a new never heard of idea that's promoted, particularly over the last decade fooling entire Governments, Departments and companies into chasing them down (New Zealand Pension fund lost $50 million investing in the Ogin ducted turbine) and guess what the Ridgeblade system appears to me to be....a ducted turbine! And how does it handle overspeed in a storm? It can't be furled....there goes your roof!
I may be wrong but you would want to see actual site installations and independent testing results before considering.....
As with all things - it's Buyer Beware....
 

Now if you could mount your house on a turntable so it always favors the best wind direction....

[billt]

1 hour ago, Alexphd1 said:

£30k for a 5kw that's a bit (lot!!) more than I was expecting! 

I don't know if we are comparing like for like but 20% is more than PV  efficiency, or am I way off the mark? 

I actually like the look of big turbines but wouldn't want to stay within couple of hundred meteres of one. 

 

Looks like one of these projects designed to either get investment money from the gullible, or sell ineffective systems to the gullible.

 

You can't compare wind generator efficiency with PV efficiency in any meaningful way. PV efficiency is a measure of how much energy you can collect from the incident light (real world theoretical maximum about 50%, generally 15-20%), wind generator efficiency is a measure of the amount of energy extracted from the wind passing through the swept area of the collector. Betz's law says the theoretical maximum is about 60%. Real world efficiency of the best turbines about 45%. Of course PV output is perfectly linear, wind output is proportional to the cube of the wind speed; low wind speed no energy, high wind speed turbine destroys itself.

 

As well as not generating much energy, those Windsave house mounted turbines had a big problem with noise transmitted directly to the house structure. I'd expect this design to have similar issues.

 

Paul Gipe has a website with lots of information about wind turbines. http://www.wind-works.org/cms/

[Crofter]

1 hour ago, Alexphd1 said:

£30k for a 5kw that's a bit (lot!!) more than I was expecting! 

I don't know if we are comparing like for like but 20% is more than PV  efficiency, or am I way off the mark? 

I actually like the look of big turbines but wouldn't want to stay within couple of hundred meteres of one. 

 

From memory, the actual nacelle and generating bit was only about £12k, but the pole, founds, cabling, inverter etc brought the total up to £32k. You could do some of that work yourself I suppose but I was looking at FiT so everything had to be done by an MCS contractor. That was five years ago, and I think FiT is now so low that a non accredited approach might make more sense.

[SteamyTea]

I worked briefly for a now defunct small windturbine manufacturer.

They were looking at reducing the installed cost from £18,000 down to £12,000 for a 4 kWp turbine.

It was pointed out that even of the actual generator and blades were free, they could still not do it for £12,000.

Probably why they went bankrupt twice.

 

Also worth remembering that that the maximum power of a turbine is generated at a fairly high windspeed.

Try running at 12 m/s.