Generating Electricity in an old Mill

[Moulin Neuf]

We live in a mill - the mill wheel is still in place and we are on a weir.  Does anyone know where we would start in trying to generate electricity?  Who would we have to involve - and how would we do it?  I suppose the other possibility is geothermic heating - I am not sure what it is except it uses water!

Help please

Jan

[Mpprh]

Hi

just worth saying that EDF will buy your surplus electricity.

Peter

 

[Quillan]

OK here we go.

You will require a system that can generate electricity at 240V ac from a rotating device, in your case a water wheel. The thing about ac is that normally the speed of the actual generator decides the frequency of the ac. Domestic electricity is normal 50hz in Europe +/- 5%. This is important because it works the other way round with appliances that have 240V ac motors which include some washing machines, microwaves etc. It's not the voltage that sets the speed (like with DC motors) it's the frequency.

Another area where frequency is important is with things like TV's, video recorders (and stand alone DVD recorders), mains clocks, digital radios, microwaves to name a few. The reason for this is that they all use frequency for one thing or another. A TV for instance uses the mains frequency for the tuner to enable you to tune the TV to a station, a VCR or domestic DVD recorder does the same. A mains powered clock relies of frequency for time accuracy etc, etc.

So the problem you would normally have is that you can't guarantee that your water wheel will rotate at the same speed all the time so by connecting a normal ac alternator to it would create electricity but the frequency would be all over the place.

There is an answer to this and it comes from the auto and marine industry, is a variable speed ac alternator. It's a 240V ac alternator which comes with a box or electronics which maintains a fixed voltage and frequency regardless of speed. To say that they work from 1 to 10,000 rpm would be wrong, they do work at a highish speed usually created by a set of pulleys and belts but the variance in speed can be reasonably large. In  cars, lorries and boats they typically start generating at just above tick over all the way up to the engines maximum RPM. The faster they go the more power you get.

There are two main manufacturers of these alternators, Dynawatt and Electrolux. They vary in output from between 3.5kva and 5 kva. They are also pure sign wave. Why pure sign wave and what does that mean?

Basic 240V alternators generate a quasi signwave electronicly, as do some 12V DC to 240V ac inverters. A quasi signwave is a sort of squarish flat topped wave. This is not good for electronic devices such as TV's and other audio equipment. A TV as I said uses the sign wave to tune it's self and relies for it's accuracy on the peek of the signwave so to have a top that is flat which means it has a leading and trailing edge confuses the TV electronics so it does not know what the true frequency is therefore you can't tune your TV. With a radio of hiFi the problem will show it's self as a constant background hum through the speakers. Some domestic washing machines use a dc motor but it's speed is set by electronics which again use the frequency to make, through other electronic circuits the motor turn so it won't work either.

Here are links to the respective manufacturers.:

Dynawtt.: http://www.dynawatt.com

Electrolux.: Can't find a direct link but try a search on Electrolux+alternator

What will it cost? A typical 3.5kva (14.5 Amp) unit is around £2,500 add another £5/600 for a 5 kva (21 Amp) unit. You will then need other bits like a pulley, mount and belt plus an auto switch unit which will cost around £200 and finally the cost of actual installation. In real terms you ar probably looking at between £4,000 and £5,000 pounds. The auto switch box will put you back on to the mains electricity automatically if you try to draw to much power. This is highly unlikely to happen and assuming you have a gas oven and no electric heating you should generate power for your house around 90% of the time using one of these alternators. There is no reason why you can't double or even tripple your power by adding more units running off the same wheel. Having said that there does become a point when maximum power is drawn where the wheel will slow or even stop turning so assuming it's a big wheel I would think three units would be the maximum you could install.

I have used these products and have actually installed one from scratch so if you want any help PM me. I bought my Dynawatt unit from the UK agent and the guy was really helpful and worked out the size of pulley I needed and actually got it made for me. He also supplied the belt. These are critical parts as they will convert your slow turning water wheel speed to the correct speed for the alternator to give you maximum power at all times.

I think that with one unit, a gas oven and no electrical heating you should get your money back in a couple of years after which there is no cost for your power. As said you could always sell your suplus of to EDF which would speed up the return on your investment.

Sorry it was a bit long and I hope you understood most of it.

Good luck.

[Deimos]

Short of time now but briefly, I also live in an old water mill and have looked into this in some detail. I’ve even had the departmental expert on generating electricity from watermills (yes, we really have one) check it out.

The most appropriate system for any given mill will depend on a wide range of factors (water volumes, height drop, etc. You have two main choices – generator driven off the wheel or turbine. Then there are a load of options within the turbine route that vary depending on flow rates, etc. Which is more appropriate will need to be established (and you may have little choice about which route you take).

There are three main stages to such an installation. Feasibility study, technical design, then install it. These are mandatory and “everybody” gets involved (things like noise from the system, etc.). The good news is that there are significant grants available for the different stages. When I was checking, for the studies you could get 80% paid for you and equipment (same and other renewable energy use) 40%.

The people to check it out with are www.ademe.fr. The services they provide vary by region, but for example, in the Pays de Loire they have specific “experts” and information (see http://www.ademe.fr/paysdelaloire/sup/EnR_micro-hydro.asp#).

In my case they estimated that I could generate 4.5Kw from the mill. However, the nature of the flow rate and drop meant that the most suited generator system would need to be imported from Canada. To be honest with the probably costs for 4.5Kw I decided the money would be far more effectively spent on other renewable energy techniques (disappointing).

Whilst EDF will purchase your excess generated electricity, their rate is not high (lowest in Europe – at least the “old Europe”) so I would not recon on getting too much income from that (but maybe evry little helps).

Pressed for time, but if I can be of further help please do ask (PM) me. Don’t take my post as negative at all as I am really in favour of such systems (and your mill is bound to be very different from mine).

Ian

[Ron Avery]

[quote]Hi just worth saying that EDF will buy your surplus electricity. Peter[/quote]

jJst worth saying that EDF will buy your surplus electricity.

That is just so untrue and an urban myth. Before EDF or any other Electricity supplier will let you put anything back into their grid,  you would have to spend many thousands on HV cabling and fiitration and harmonisation equipment.  You might be able to supply your neighbours on a separate supply feed but who is going to supply and fit the cabling?

[bejay]

Jan.

To my mind many of these alternative energy projects need to be a DIY/ home experimenter challenge if they are to make sense financially at the moment. Now I personally cannot imagine any better fun on this planet than spending some months messing about with a mill wheel and an alternator but I have to accept that this may not appeal to everyone's taste. If you were to 'get in a company' to carry out this work it is going to be expensive. You don't say but does your mill wheel actually work reliably? Without doubt though it is possible to get a worthwhile amount of electricity from an industrial water mill, they are powerful devices.

 

Ron in the Aveyron

This business of feeding electricity back to the grid has puzzled me for some time (but not enough to get me to find an actual answer), Certainly big (container size) diesel generator sets can be synchronised to the grid system but one respectable alternative energy site I looked at talked about simply fitting an  import-export meter and informing your electricity supplier.This was however in connection with a wind powered micro generator and I have assumed that the input is so tiny that the grid can just cope with it and its not much more than a PR exercise. Looks like I'm going to have to find out!

bj

 

 

 

[Deimos]

Sorry, time limited so my comments will be a bit “here and there”.

If you have not already done so, do check the mill wheel for noise (as this will be part of the planning consent/technical study). The owner mill upstream from me spent ages (literally weeks and loads of money) re-building his external mill wheel in Oak. Apparently he made a fantastic job of it (I only saw the photographs). Installed it, got it turning, the load. Then discovered it was too noisy. He ended up taking it down and disposing of it.

The mill wheel is far from the only way to generate electricity from your water. It may easily be that a turbine is more appropriate, particularly as you have a weir. (I don’t have a weir but “branch off a river which supplies 3 mills in “series” – so I guess in-effect my “weir” is upstream).

Noise probably depends on the technology of the bearings (for example, mine of the side away from the gears is a wooden shaft in a “stone cup” type bearing – which I think would be quite noisey).

Another organisation to check with is the “Federation Francais de Amis des Moulins” – I assume you are a member through your local branch. The “expert” who checked-out my mill (via ADEME) was actually the departmental technical expert from the departmental “Amis …” organisation. In his case he has already installed generation (micro-hydro) in his mill though does not sell excess back to EDF.

(Sorry about my comments being bitty but I have 101 things on my mind today).

Regards

Ian

[Quillan]

I was wondering about the noise because the gerator does not make any and then the penny dropped fter reading the last post. I must admit I did notthink about the noise the wheel made.

The system I was talking about was really adapting something that is already used for another purpose and was a known and simple to install product. All that would have been required was some angle iron to make a frame for the alternator, a pulley and belt. Obviously some electrical knowledge would be required to connect the house/mill to the output from the unit and some sort of auto switching box for when either the load went above the alternators capacity or if the wheel stopped. Again these items are available and come with instalation instructions. So if you know what you are doing it would be simple to adapt and install. I thought it a reasonably cheap solution, well in comparison to installing water turbines etc. I think it woud be a good idea to get these people in that are mentioned above just to find out how much power the wheel will support.

[Deimos]

You might find this overview interesting http://www.homepower.com/files/HP103_14.pdf?search=hydro (sorry but you will have to cut and paste it.. American and last year but gives a good overview. Not mill oriented but more turbine type systems.

Ian

[Jc]

In the UK ,the water boards will charge you for extracting water from a river to generate electricity,grind corn etc. but won't pay you for putting it back again afterwards.

[levisiteur]

Just for interest I would like to suggest a different solution!

A low tech idea:

Use the electic for heating - voltage and cycles variation not a problem for this use.(No water shortage in the winter!)

Power up some night stores at night, water heating and convential heating / cooking daytime.

Heat is by far the most expensive bill, whether it comes from wood, oil, or mains electricity.

If you have a flat lineshaft pulley from your waterwheel you may get away with say 3 v-belts around the pulley onto a triple v pulley on your alternater. Brammer belting is usefull because you can change the length to suit. Above 3kw this may need  a more subtantial arangement.

(Home generated electric is as dangerous as mains, fire/electrocution, and needs fuses earths, and if in doubt ..an electrician!)

I have some engineering experiance only, and just giving some food for thought for what sounds like an exciting project.

 Best wishes,

Levisiteur. 

[bejay]

I think that the original posters may have their answer. Quillan is up to £5000 for some of the bits and Deimos has imposed the full weight of French bureaucracy on the project. Coupled with the fact that to be anything like a modern electricity supply the wheel would have to run 24/365, it just isn't a practical proposition. 

I have to agree with le visiteur, Machinemart in the UK will be only too pleased to sell you a 5kV alternator for about £250  this would be fun to play with and might just give you some useful heat

Perhaps we should remind ourselves just why there are so many abandoned/derelict water mills in France.

bj

[Deimos]

[quote user="bejay"]

Deimos has imposed the full weight of French bureaucracy on the project.

[/quote]

I think that the bureaucracy will be helpful rather than a

real hindrance.  Its intent is to ensure

that what is installed will meet expectations and not cause other side

effects.  My impression when I

investigated for myself (both micro-hydro and solar/geothermal/aerothermal) was

that authorities are very positive about these things and try to help rather

than hinder.  Certainly, in my case it

was the nature of the power (only 4.5 Kw) and required equipment (from Canada)

that dissuaded me from progressing rather than admin bureaucracy where there

were plenty of knowledgeable people to assist.

If your department has an “expert” (or Les Amis des Moulin …”

can help, it costs nothing to get an opinion on your particular mill (without

starting the studies).  Also, if you

have a weir, it may easily be viable to generate electricity from that water

level drop through turbines.

I did not intend to discourage if my comments came across as

negative.

Ian

[Moulin Neuf]

Thank you all very much for your help - we have two 'electrical' needs - the house generally or heating an indoor swimming pool.  There is now much food for thought and a winter project  - please do keep ideas and many thanks so far.

Jan

[bejay]

Negative,  not at all. Useful and highly informative more like but I was  rather amused by the number of people that can involve themselves in such a private project. Perhaps I should learn to use emoticons (Nah, too old).

But there is a rather dreary bottom line to this alternative energy and energy conservation stuff and this is that the most cost effective procedure is to reduce your energy consumption (or carbon footprint!).This requires passive processes such as high levels of insulation and direct solar energy etc.  Specially developed eco-houses have spectacularly low energy requirements and although they do contain hi- tec devices much of their efficiency comes from good technical design..

Just think of the energy you have saved for future generations by not having a heavy turbine shipped all the way from Canada.I bet it makes you feel warm all over.

bj

 

 

 

[Quillan]

I think that the important issue here would be what the user is trying to do. By this I mean is he trying to be environmentally aware or is he looking for a cheap source of electricity i.e. to save a few bob on his electricity bill? What is it that is driving him to look at generating his own electricty? Once this question is answered then advice could be given to find a suitable solution.

[bejay]

Quillan

I can't see much of a conflict between the two aims. If Jan can get some electricity out of her watermill then its consequence-free energy and if it can be done cheaply then so much the better. But enough already.

On a slightly different tack if an indoor heated swimming pool is important then a possible direction is a geothermal system using the river as the energy source. But once again this is down to local expertise and detailed information.

bj

[Quillan]

I was thinking along the lines of cost against what they are trying to achive.

If money is not a problem and they heat by oil or woodburner/s then they can create a system from commercially available components without going to environmental specialists to put in place a system which would mean they no longer require to me connected to the outside world for their electricity. They have a waterwheel that will generate elctricity via the system I already mentioned. By further incorporating a Mastervolt 3.5KVA inverter charger, about five 200 Amp leasure batteries and a Amp wind turbine they can create such a system. The wind turbine would top up the batteries when the waterwheel is not running for any reason (service etc) and the inverter charger would give power at the same time. With the waterwheel running the inverter charger would recharge the batteries, cycle them automatically and because it is designed specifically for this it will perform a 5 stage charge to get maximum use out of the batteries. If they wanted to they could add a 200 Amp 12V alternator to the waterwheel which would create enough power for low voltage lighting.

Its easy to install, the brackets to mount the alternators and their respective pullies are the only thing they would need help with and the rest is just a simple plug and play system. It's a well tried system that has been used on boats for years and can be (and has been) adapted to fit anything that has the power and can rotate. Heating the indoor pool can be done cheap enouth by fitting solar heating and can also be used for their domestic hot water. The only issues as far as I can see is cost (I reckon you can do it all for around 8 to 10 thousand pounds), is there enough power in the wheel and the noise of the wheel.

[Moulin Neuf]

We run and indoor pool with electricity - it is expensive and at present closed down.  I have solar panels - the plastic tubes that warm water which is circulated with a pump - quite successful in summer.  However, it is only that we live in a mill and we had absolutely no idea what the potential is.  We intend to stay here until we leave in a box - so it is worth just looking at even if we decide not to do anything.  Thank you for your information - I am meeting with someone who has restored mills locally and we are going to talk.  As you say finance will eventually dictate what we do - certainly we are not looking to make a  profit.

Many thanks for all your comments.

J

[Deimos]

Might seem a really daft question but how long have you

lived in the mill.  French weather can

be variable and by their nature watermills tend to be close to rivers and thus

close to the water level.  Two years ago

the area I live in had exceptional rainfall in a very short period.  The wheel room was “a bit full of water”.  My comment is really that if you have moved

in in the last few years, it might take the locals some time to tell you about

what happened in 19xx.  Thus, anything

you do install and depending on the nature and layout, do bear in mind that

water levels can move up as well as down, and site expensive equipment

accordingly.

Ian

[bejay]

Quillan. What you describe in such interesting detail would clearly provide a very worthwhile electricity supply if there were no other supply available (actually I did wonder at for a time if I had missed the point about our fantasy watermill  and that there was indeed no electricity but it seems there is) but mains power it isn't. I do feel that to take such a direction would be more a political  decision than a technical solution. Also I just can't bring myself to believe that an ancient waterwheel is going to give the more or less continuous running that would be essential to your system. I still stand by my opinion that you get what you can out of the system cheaply or do the job properly.which means a new wheel.

Interestingly it seems that the costs for new installation start at about 5000 euros per kW  which includes installation and, crucially, grid connection and if used about half and half for personal use and grid supply, then costs can be recovered in about a decade. Goodness knows what the details are but a useful 10kW supply is not a ridiculous proposition when one considers what private individuals do spend on property renovation these days.

What an interesting topic.

bj

 

 

[Jc]

Fit a couple of car/truck alternators and 12v. batteries;there are plenty of 12v halogen lighting systems about;should make a good saving on your bills for next to no expense.

[La Guerriere]

Now if you want some fun and your French is half-way decent, do a Google on "microcentrale". There's a lot of relevant info out there on the Wacky Web.

Jim