Affordable DIY Wind Turbines- Produce your own affordable electricity

GG66

xonencentral wrote:

My first suggestion would be to read the thread

As I mentioned, I have read it....it's quite a rambling but great thread (recyled newspaper bricks, solar water heating, lightning in the jacuzzi :eek: ) and I was lurking, dipping in over several evenings as I had time. Eventually, I had to open several pages at once, copy and paste, print it off and read it because it was so long. I spend 9-5 in front of a PC as it is. Mods might want to consider opening different threads as its quite a trawl...

Anyhow, I've have picked what info I can from it. I've also spent considerable time surfing the web and looking up directories. I spotted a sticky where suppliers were listed, was this in DIY? I know there were no wind turbine suppliers listed. It would be very useful for those trying to get a rounded view on costs of wind and PV if those have looked into it could list suppliers.

Xeon, you mention several times that surface power were way ahead on price, so you must have compared it to others. Can't find where you mentioned the other suppliers though. You did mentioned Proven but not which supplier you priced it? I've since found www.westwind.ie supply it but haven't got any idea on prices, will post when I do, anyone else tried them?

I've already had quotes on solar water panels but it would be very useful if there was info on suppliers of Wind turbines, PVs and solar water panels. I'm as enthuastic as you are about getting off grid and using renewable energy but I'm not about to jump in and buy from the one supplier that's continually mentioned by one person who has experience of it. In case that sounds like a swipe, its not, I respect all the time and enthuasism you've taken to post your experiences...so keep it up and I'll contribute what I can when I'm up to speed:)

xonencentral wrote:

Where are you, contact your local energy agency, www.aiea.ie

Thanks for the link, I'm in South Sligo but I note there's no energy agency for the county, nearest one seems over your way in Mayo.

xonencentral

Only joking on the thread thing:

I spent about the last 10 years always toying with building my own system and since I only bought a house a couple of years ago, I really only had the opportunity/location to consider it seriously lately.

There are alot of suppliers out there, particularry in America but one thing that I kept coming accross was problems in Scotland with damage on imported systems. One report I read a few years ago was about an insurance company who would no longer insure domestic turbines unless there rating was a certain survival value and they had recomended Proven as the only turbine who could meet it (who were Scotish). I thought this was a pat on the back situation but I looked more closely at the survival speeds values and they were really low ( typically 40 m/s ish), not going to last long here. It seems that there is also a big difference in quality and functionality (technology), some needing lots of babysitting and then the extreme requiring none as they have electromagnetic braking & a really large survival speed, etc (like mine).

It seems that Proven until lately (in my opinion) were the only manufactuter that Ireland could consider as they seem to design their systems to operate in the high winds of Scotland so hence should be OK in Ireland. But their prices are way outside the range of my wallet, hence the DIY route.

Gladly that has changed, and their is now serious competition.

The other important lesson I learned though was that a quote was not always a quote, i.e. I got a quote from an dealer for XXX but thanks to the web, I realised that there were a number of components missing. The dealer told me that they also supply them for another XXX. It seems alot of them seperate the charging circuit from the electricity producing circuit. (maybe they are embarrassed how expensive they are).oh and VAT is usually missing as well.

You should quote the dealers you mention, the cheapest quote I got was Proven direct for a 600 watt turbine which was going to be a test for planning (which was my biggest fear), its not exactly "pleasing to the eye" and has a noise rating although I haven't ever heard one, the quote was Euro 18,300. Ask for a full quote but installation is a mandatory cost.

WW has prices here http://www.westwind.ie/Typical.htm but read the small print at the bottom.

Can you put up your solar water prices, I'm doing homework on that myself and would apprieciate some pointers.

I think that the Mayo Energy Agency is the one that covers Sligo.

To my knowledge, the are only two wind turbine dealers that are in Ireland, WW and PET. They are dealers for Proven and a couple of others, and surfacepower is the only manufacturer. That's the serious players anyhow.

davidoco

xonencentral wrote:

Can you put up your solar water prices, I'm doing homework on that myself and would apprieciate some pointers.

Got a price from a helpful guy at solarplus for 40 Vacuum Glass Tubes panel. Incudes fittings for roof €2400+VAT. From looking around incl UK it seems a reasonable price for tubes and the fact that your buying them here is a plus (no pun intended) in case you have problems. I intend to source the other parts seperately but solarplus do a handy ready made solar tank with all the controls for €1200+VAT.

Cuauhtemoc

As regards prices see below..this is the only quote i got so far, from Solarplus as well. No tank included in that. They gave that quote based on an approx 1500 sq ft house that required hot water and underfloor heating.

Anyone know how moveable these are?
Unfortunately our main south facing roof would be on an extension we'd be looking to build at earliest a year down the line. Could they be moved easily?


An 80 tube system would be sufficient for hot water and underfloor - the system comes complete with solar digital controller ( for optimum running efficiency of the system, solar pump, exp.vessel , all necessary valves,sensors and probes, and full installation guide, this would cost € 5400 plus VAT.

CJhaughey

Vacuum tubes are easier to move than built-in flat panels however to move pipework is a PITA and does not do much for your roof seal.
also beware of long runs of pipework as well as being expensive it is also a potential heat loss even when insulated with armaflex.
I would wait until the roof is up then put your array in.

xonencentral

Well, 5 days without wind, not as much as a breeze but the drought is over today.

I think the solar panel I borrowed was a major suprise, my battery bank stopped at about 80% full once I connected the panel, we had sun most days which is I suppose typical of the H pressure in winter. I never checked the system in the evening to see how full it had got (too dark) but every moring after a nights use, it was at 80%.

One thing I noticed about a high pressure in summer was there was always lots of wind. I'm guessing the sun is stronger in summer and gets the solar winds going. Amazing to think that solar panels could be more beneficial in winter ?

I have to say the knowledge I am getting about weather is all new. I thought I was weather aware but goes to show, you are always learning new things.

air

I doubt very much that the solar panels would be more beneficial in winter.
The only possible benefit they could have in winter vs summer would be lower operating temperature (pvs operate more efficiently at lower temperatures) but this isn't really relevant in Ireland because our summer temperatures rarely get hot enough to impede the efficiency of PV's.
If you go to http://www.met.ie/climate/sunshine.asp you will see that we have almost double the sunshine in summer as against winter so PVs could not possibly perform better in the winter here.

While your periodic subjective comments on your system are certainly interesting, I think it would be of more value to the thread if you were to install energy meters on your system and post some hard data on the watt hours captured by your solar and wind components.
It would be relatively simple to set up a data logger to log your total energy captured each day and then plot a graph over the year.

xonencentral

I think you missed my point,

For the whole summer I had wind, even on sunny days and no doubt solar PV would have had a big effect in the summer, but we just has 3-4 beautiful sunny days which had a bigger impact for me as I had no wind for those days but the solar PV kept me going and its nearly december.

I had only one borrowed panel, can imagine what several panels would have done.

The solar PV was a bigger benefit for me so far this winter..from a survival point of view.

That was my point, that it still has a valid use in winter on sunny days.:D

Meters cost money, for the moment, I'll have to use my ESB bill for justification.

air

I dont think I missed your point, I fully understand the benefits of a hybrid system from the point of view of providing independence of supply etc.

If a single solar PV panel kept you going on its own (what size is your panel?) then your usage must be tiny.

Lets say its an extra large 200W panel for instance, assuming 5 hours of peak output from the panel (optomistic) that would still only give you 1Kwh of energy per day.
Are you saying that your electricity usage is under 1Kwh per day?

My main point was that your posts seem to lack any kind of technical information that anyone could possibly use to evaluate the relative benefits of different types of renewable energy systems in this country.
IMHO your posts are overly positive and of little value to anyone that is interested in Renewable Energy.

Cuauhtemoc

Just an aside but if anyone's interested SP are having a demo day in the Atlantic homecare store in wexford this saturday 26th.
Going to wander down myself and get a closer look at their systems.

xonencentral

Air, Your absolutely right, I am coming at this from a non technical sense but thats just because I'm a normal consumer who is trying to learn what the system is doing. I'm not a renewable engineer and I'm sure most people who read this forum are similar, but i have taken the jump because I think its the future.:)

With regards solar I was researching this from the US Dept of Agriculture whose solar pumping stations perform better in winter than in Summer due to the heat of the panels.

"Using 6 years of average monthly panel temperature data, the solar panel performance during winter was estimated to be at rated power, but the solar panel performance during the summer was estimated to be only 93.5% of rated power."

http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=182692

I don't typically monitor what my consumption is but at the moment, its
a) Central Heating, 45 watts.
b) Hall LEDS, 9 watts.
c) CFL in sitting room, 12 watts.
d) Satallite, 30 watts.
e) House phone, 2 watts (ave).
f) Outside light, 20 watt CFL.

I've probably forgot something but that's everything we'll use while watching TV, (big screen) and thats on the ESB and that adds up to 118 watts we are using at the moment per hour on our renewable system.

air

With regard to the output of the panels mentioned in that report.
First of all this is in the US where summer time temperatures are high enough to reduce the peak output power of solar panels, this is generally not applicable in Ireland.
Secondly I think it is necessary to make clear to you the difference between power and energy.
Just because the peak output power of the panels is higher in the winter doesnt mean that the energy output will be higher in winter.
Energy = Power x Time so the increased sunshine hours (over double in summer vs winter in Ireland for example) would completely negate a 7% reduction in peak output power in summer.

Looking at it from a consumption point of view your analogy is like saying that you have an 8kw output capable system because you have 4 kettles and can boil them all simultaneously.
Your battery bank could be completely discharged by the time the kettles were boiled.
This would be like having a solar panel array that produced a high peak output but only for a short period of time (such as in the winter).
In both cases the ENERGY output and input respectively are small while the instantaneous power output and input are indeed high.

In conclusion, when evaluating what benefit a particular energy gathering piece of equipment will bring to your system you should look at how many Kwh / Day it will harvest and not its peak power.
This will let you budget for how much ENERGY you have available to you at each time of year.

For example, say you had a 5KW rated windmill that had an annualised mean output power of 1KW (about right for Ireland) then its average energy input to your home per day would be 24KWH per day.
Its of no use to you whatsoever that it has a 5KW POWER rating, it is its energy harvesting potential that is important.

Going back to your solar panel example and assuming for a second that we have the same temperature related output reduction in Ireland that would be typical in the US(we don't).
Taking a 100W panel.
In Winter You Have:
1.5 Hours Sunshine(Average Time)
100W Power Output (Theoretical Power)
=> Your Daily Energy Harvest =0.15Kwh Per Day

In Summer You Have:
5.5 Hours Sunshine (Average Time)
93W Power Output (Theoretical Power -NB Not Reduced in Ireland)
=> Your Daily Energy Harvest =0.515Kwh Per Day

So now you can see that even allowing for this irrelevant (for Ireland) heat reduction factor, your solar panel will still harvest over three times more ENERGY per day in summer than in winter.
Q.E.D.


Looking at the power consumption of your loads, lets estimate your daily energy consumption on your renewable energy side for the current winter period.
Central Heating - 45W x 4hrs per day = 0.18Kwh
Hall Leds - 9W x 8hrs per day = 0.072Kwh
CFL in SR - 12W x 4hrs per day = 0.048Kwh
Satellite - 30W x 3hrs per day = 0.09Kwh
Phone - 2W x 24hrs per day = 0.048Kwh
Outside Light - 20W x 7hrs per day =0.14Kwh

For a grand total of 0.578Kwh of energy per day.

Now based on your affirmation that your solar panel is providing this energy for you on its own at this time of year
and the fact that you have a max of 2.5Hrs sunshine at this time of year then I would surmise that your panel has to be a minimum of 230W.

What size is your solar panel?


Very finally, I think that in order to evaluate the pro's and cons of a renewable enery system a user is going to have to educate him or herself in the basics of power and energy.Shouldnt take too much.

Cuauhtemoc

Xonencentral, do you have an average daily output figure from your turbine?

Just curious as to what i could expect from 2 SP 460w rated turbines and 600w solar panels.

On Air's figures for sunshine the solar would generate i suppose

Summer: 3.3Kwh per day, average
Winter: .9Kwh per day, average

Not sure how to calculate output from the turbine.

2 x 460w running at max output for 24 hours would generate 23Kwh approx.
Would maybe a 3rd of that be a good guess?

Say 7Kwh per day, maybe more in the winter. would i be lucky to get an average of 10Kwh per day throughout the year.

Not much to run a house i'd think. Any average daily household Kwh usage figures about?

air

I think that a reasonable way to estimate the output energy from a wind turbine is to divide its peak output power by 5 and assume that you will produce this level of power on average over the duration of the year.
This is based on me having heard somewhere that AirTricities network produces about 19% of the energy it would produce if each unit was running at full output at all times.

I think that when people are evaluating what type of RE system to go wtih they should look at $/Kwh rather than $/watt as is the current trend.
For example for solar, lets assume an average of 3.5hrs sunshine a day for Ireland (off the top of my head).
Lets say a 100W PV cost 100 Euro (if only
Then the cost per KwH per day would be 100/(0.1*3)= 333 euro per KwH.

For Wind Take a 100W turbine at 100 Euro
The the cost per Kwh would be 100/(.020*24)=208.33 euro per KwH

Of course you wouldnt be paying the capital cost each day but I think that this is a good way of looking at various alternatives - the capital cost required to harvest one unit of energy per day.

It is important to factor in the total cost of your renewable energy system (source of power -pv etc, batteries, controllers, inverters etc) when doing your calculation.

Aside, I'd be interested in hearing peoples experiences on the output of actual PV installations in Ireland.
I may set up my own panel and connect it to a datalogger next year.

air

Sorry Cuauhtemoc, based on my back of envelope estimations you could expect about 4Kwh per day on average from the wind turbines

Cuauhtemoc

Would the smaller turbines not be a higher percentage than 19 as they wouldn't require the same windspeed as the big airtricity ones?

air

I doubt it tbh, I would guess that the airtricity ones would actually have a better operating wind speed range due to the fact that they have a gearbox.
The simple fact is that there is very little energy worth harvesting in slow winds as the energy available is proportional to the cube of the windspeed.

Xone, sorry I spotted from post #301 (damned threaded mode, never spotted it before) that your solar panel is 100W.
I very much doubt that you managed to harvest 750Wh of energy with it in a single day at this time of year.
We hardly have 7.5 hours of light at this time of year not to mind sunshine.
Fromhttp://www.oja-services.nl/iea-pvps/faqs/techn.htm
Does photovoltaic technology need bright sunshine to work properly?
The electrical output of a photovoltaic module is dependent upon the intensity of the light to which it is exposed. So photovoltaic modules will tend to generate more electricity on bright days than when skies are overcast. However, photovoltaics do not need to be in direct sunlight to work, so even on overcast days a photovoltaic module will be generating some electricity.

I think that from this description we can go on using the mean SUNSHINE hours from the Met website as a guide to production hours for PV rather than daylight hours.
Going on this assumption I would imagine that a 100W panel would produce a max of about 300Wh this time of year in Ireland, allowing for some small production outside of sunshine hours.

xonencentral

Great load of info there including as many questions as suggested answers, took me ages to read and understand:

Personally, I think we could easily confuse sunshine with daylight and under-estimate solar potential as is suggested. A good point.

With regards wind turbines and also using wind farms statistics, I do have some practical information. Airtricity state that they get 30% of the rated output per year, i.e. 1 MW turbine gives 300 KW output but there is abig difference between these and small systems. When my local wind farm exceeds 50 mph, it shuts down and my system runs on as it dosen't have this safety issue so the wind farm stats do include this shutdown period. I know that my local windfarm has shut down several times in the last 2 weeks when I was at full wack so I would expect a much bigger % output than the windfarm.

THere was guy on a program on RTE last year in North Dublin somewhere and he had 2kW of solar PV on his roof and he had so much power that he bought no power from the ESB but he was complaining that he could be exporting it to them if he was allowed, I think it was eco-eye with Duncan Stewart. He said that he had to turn off the panels after lunch every day as his battery bank was full. (must be home-made if he had to manualkly turn-off, I wonder how he goes on holidays)
So 2 kW must be very capable, but if you were to use the numbers suggested above, it wouldn't make any sense.

This is what I find with wind power, in practice, it works much better than I would have worked out on paper. Every time I turn on my light, it comes on if you get my drift. My house is operating just the same as when everything was on the ESB.

I'll try and do some tests on the panel, can anybody suggest some, it might help on this forum if I put up some values that are current, i.e. today tomorrow.

Oh, on that subject, another question for the Solar Water guys, a friend of mine told me yesterday that his neighbours have gone on 2 weeks holidays to the canaries, and they have a solar vacumm tube panels on the roof. My friends wife has to go over to the house every lunch time and drain the hot water down the sink in case it explodes ?. Anyone know anything about that,?

air

A 2Kw array may well be adequate, but that all depends on load.
My point is that this guy may find a 2Kw array sufficient for his needs, but what are his needs?
Without hard facts on the electrical energy consumption of his house the statement that he finds a 2Kw array too big for his needs is worthless.
For instance a 10W array would be sufficient for a house's needs if all one used was a single white LED light for reading at night.

With regard to small Vs large wind from the perspective of high wind periods I think that you will find that the amount of time that the wind speed is over 50mph to be so insignificant that any energy harvested by a small wind system during this time would be an insignificant proportion of the total annual energy harvest.

To conclude I would surmise that the main reason that the output of your wind system exceeded your expectations was that you reduced your load considerably.
I have already guesstimated your renewable energy consumption at just over .5Kw per day which is tiny in comparison to the needs of a modern home.

For example boiling a kettle of water (assuming base temp 20degreesC, 100degrees C final temp and 2L kettle) will use about 0.185Kwh of energy meaning that your daily energy usage is equivalent to roughly 3 kettle boils.

Cuauhtemoc

Just some tech specs

Airtricity's 2.3 Mw Siemens turbines
Cut-in wind speed 4 m/s
Nominal power at approx 13-14 m/s (Would appear to be 15m/s on one their charts but they don't show charts for all of the different turbines so 13-14 it is)
Cut-out wind speed 25 m/s
Maximum 2 s gust
55 m/s (standard version)
60-80 m/s (special version)

Surface Power's 460w Turbine.
Cut-in wind speed 3 m/s
Nominal power at approx 12.5 m/s
Cut-out wind speed 60 m/s

I'm still inclined to believe that SP's turbine would have a higher percentage of rated output than those of Airtricity going on those figures. Air's figure 19% Xonencentral 30%, for Airtricity.


They don't specify how long a startup shutdown procedure takes if they hit cut-out point. Do their turbines have to stop completely or can they just slow down and kick in again?

xonencentral

Ah, those dreaded assumptions again, personally I do prefer the practical approach as assumptions rarely work out in practice (just my own experience)

I rang the local met station and they said that in November in my area of the country, 50 mph winds were sustained for significant periods on 17 seperate occasions. They said this was not unusual....Its 32 mph today and I do remember one accassion lately, we had up to 140 kph gusts announced on the radio.

With regards the guy with the house, they showed in on TV and it was a substantial detached 2 story in a leafy suburb and I would expect the guy was wealthy based on the house and would have all the normal appliances (wealthy as he had bought 2 kW of solar in the last 3-4 years).

With regards my current load, my ESB bill was around 420 units during the summer and that included an hour and half of immersion every day (3kw element) so my electrical load on ESB is approx 150 units per bill (much lower)during the winter as we use our central heating for all hot water, that is approx 2,500 Kwh a day on ESB plus whatever on green energy, I expect my next ESB bill to be approx 30-40 euros worst case.

It wouldn't take alot more green energy to get that 2.5 kwh per day over onto my green energy system as well. (104 watts an hour). I will do this over the next few years, bit by bit.

This is how it's working out in practice for me.

Did a couple of simple tests on the 100 watt solar anel, well what I could with my meter:
2:15...Open circuit: Voltage, overcast, 19.65 volts.
3:15...Open circuit: Voltage, in direct sunlight, 20.9 volts.

That seems pretty positive to me for Nov 28th.

Found this which shows how inportant it is to adjust the panel to point the right direction. These were measurements taken with a 100 watt panel mounted flat on an RV roof on a clear day, (RV manufacturers tests) Have a look at the 21 Dec.


Latitude....................21 Dec. 21 March 21 June 21 Sept
Deg.N.....................amphours amphours amphours amphours
25 (S. Florida)............27.0 40.7 49.1 40.7
30 (Tex,N.Fla.)...........23.1 38.9 50.6 38.9
35 (S.Cal, Az.)...........19.2 36.7 52.0 36.7
40 (Mid. USA )...........15.3 34.4 53.1 34.4
45 (W.USA,E.Can,Me.)..11.6 31.7 54.0 31.7
50 (W.Can,Nfld)...........8.2 28.9 54.5 28.9
55 (N.BC, Lab.)............5.1 25.8 54.6 25.8
60 (Yukon,AK,NWT)......2.5 22.5 54.1 22.5

Just a note on your kettle calculation, I just tested mine, 2L of water in my Prima 1800 watt kettle (cheapy kettle) took 2 mins 54 secs. I work that out at 0.087 kWs or 87 watts. (Sorry, but I think practical experiments are the best way to get a real result).

But my goal with my system is the important measure for me, and thats to leave my money in my wallet so things like actually measuring exactly what I am using on green energy might be interesting but it will cost me money to actually measure it and so far I having a great time with the ESB bills I'm getting and the fact that I (at some future point) can tell them to get stuffed. THen onto the Oil-man as my next victim

air

You say

xonencentral wrote:

Ah, those dreaded assumptions again

and yet

xonencentral wrote:

I would expect the guy was wealthy based on the house and would have all the normal appliances

sounds like an assumption to me.

xonencentral wrote:

I rang the local met station and they said that in November in my area of the country, 50 mph winds were sustained for significant periods on 17 seperate occasions. They said this was not unusual....

I never said that this was unusual, rather that the energy that one will harvest in rarer spells of high winds would be less than that harvested during longer spells of moderate wind.

xonencentral wrote:

Did a couple of simple tests on the 100 watt solar anel, well what I could with my meter:
2:15...Open circuit: Voltage, overcast, 19.65 volts.
3:15...Open circuit: Voltage, in direct sunlight, 20.9 volts.
That seems pretty positive to me for Nov 28th.

Yes but what power output was it displaying? What was the current being delivered by the panel? I.E. How many amps was it delivering at this voltage?
Power output of a solar panel is directly proportional to light intensity.

xonencentral wrote:

Just a note on your kettle calculation, I just tested mine, 2L of water in my Prima 1800 watt kettle (cheapy kettle) took 2 mins 54 secs. I work that out at 0.087 kWs or 87 watts. (Sorry, but I think practical experiments are the best way to get a real result).

OK lets go through this, unless I am very much mistaken the figures go like this:
Specific Heat Capacity of Water: 4180Joules/Kg/Degree
Capacity of Kettle : 2L
Power Input: 2000W - (For my calculation)
Starting Temperature of Water: 20degrees C
Finishing Temperature of Water: 100degrees
The total energy required to change the temperature by 80 degrees is as follows:
80degrees*4180joules/kg/kelvin*2kilos=668800joules

Now one joule = 1watt for one second
=> 1kwh = 1000watts * 60minutes in an hour * 60seconds per minute = 3600000joules

So the energy required to boil the kettle is 0.185Kilowatt hours.

Incidentially the time taken to boil it is given by Energy = Power x Time
=> Time = (668800/2000)=334.4 seconds or 5.57 minutes

Please correct me if there are any mistakes above.

---

You claim to have boiled your kettle with 1800W in 174seconds.
In this case the energy used was 1800*174= 313200joules or 0.087 (KILOWATT HOURS )
If you truly had 2L of water then the temperature of your water had to be pretty high to start with.
Temperature Difference=313200/(4180*2)=37.2 degrees

This obviously means that the water in your tap is coming out at 62 degrees.
You didnt fill your kettle from the hot tap by any chance?


With regard to the specs on the 100W panel, what is the significance of the data?

Looking at the figure for 21st December for our latitude (55Degrees North) the output is 5Amp Hours.
This indicates an energy harvest of about 0.1Kwh (20V*5AH)=100VA which is about what I had predicted in earlier posts (I had said 0.2 times the rated power of the panel for this time of year - November).

You seem to have an aversion to theory and you obviously have no technical background whatsoever. Just to enlighten you, theory is ALWAYS right EVERY time unless there is a flaw in your theory.

In my kettle for example I didnt account for heat loss to the atmosphere while boiling (kettles are often silver or white to reduce this) and I also assumed perfectly efficient heat transfer from element to water (almost perfectly true in the case of electrical heating of a fluid).

Some reading up on fundamental physics would be of benefit to anyone that wants to understand the basics of energy etc.

air

xonencentral wrote:

A 0.087 kWhs or 87 watts

0.087 kwhs is NOT equivalent to 87 watts, it is equivalent to 87 watt hours.

PLEASE read up on the difference between power and energy, your posts will confuse people for generations to come

air

Cuauhtemoc wrote:

Just some tech specs

Airtricity's 2.3 Mw Siemens turbines
Cut-in wind speed 4 m/s
Nominal power at approx 13-14 m/s (Would appear to be 15m/s on one their charts but they don't show charts for all of the different turbines so 13-14 it is)
Cut-out wind speed 25 m/s
Maximum 2 s gust
55 m/s (standard version)
60-80 m/s (special version)

Surface Power's 460w Turbine.
Cut-in wind speed 3 m/s
Nominal power at approx 12.5 m/s
Cut-out wind speed 60 m/s

I'm still inclined to believe that SP's turbine would have a higher percentage of rated output than those of Airtricity going on those figures. Air's figure 19% Xonencentral 30%, for Airtricity.

They don't specify how long a startup shutdown procedure takes if they hit cut-out point. Do their turbines have to stop completely or can they just slow down and kick in again?

I can't verify the 19% figure, I think I read it posted here somewhere.
I'd imagine that they shut down completely until the wind drops below a certain threshold level.
FYI a 50m/s is likely to be exceeded less than once every 50 years in Ireland according to the chart on the wall behind me.

Aside from blade and generatory efficiency etc, the difference in what the two turbines harvest in different wind speeds will come down to the amount of time the wind is betweeen 3m/s and 4m/s and 55m/s and 60m/s (the times when the SP unit will generate and the AT won't).
Even 4m/s wind has very little energy in wind (relative to a country that has a 7m/s average wind speed -5.35 times more energy in a 7m/s breeze than a 4m/s one) so I dont think that this is going to be a significant factor.
Also, over the next century I would imagine the wind speed in Ireland will be in the 55-60m/s range for less than 30 seconds (given the data on max gust speeds likely to be exceeded once in 50 years).

Therefore I think we can more or less negate the impact of the differences in operating speed range between the two turbines as a factor having a significant impact on their annual energy harvest.

Finally I'd be inclined to think that a 1million euro plus large scale turbine with a gearbox has a more efficient airfoil, better balancing, bearings etc etc than a home sized unit.
Q.E.D.?

xonencentral

Hi Air,

I have to correct you again, 50 m/s is very high wind speed and rare indeed but it was 50 mph that turbines shut down at which is 22 m/s.

How safe are wind turbines? (This is from Powergen)

QUOTE: Wind power is one of the safest energy technologies. Wind power has a proven safety record. No member of the public has ever been injured by wind power or wind turbines, despite the fact that there are now tens of thousands of operational turbines around the world.
"New modern wind turbines have several built-in safety features. In winds that exceed 50 mph, they automatically shut down. They also require minimal maintenance, and the reliability of wind turbines, measured in terms of availability to make electricity when the wind is blowing, is better than 98 percent."

With regards the output, this is from the Danish Wind Energy Ass.

QUOTE"The Capacity Factor
Another way of stating the annual energy output from a wind turbine is to look at the capacity factor for the turbine in its particular location. By capacity factor we mean its actual annual energy output divided by the theoretical maximum output, if the machine were running at its rated (maximum) power during all of the 8766 hours of the year. Capacity factors may theoretically vary from 0 to 100 per cent, but in practice they will usually range from 20 to 70 per cent, and mostly be around 25-30 per cent."

With regards assumptions, yes I do make the odd one but never about an outcome with many complex variables, experiements are real and the results are always different to the initial theory.

With regards my kettle experiement, anybody can do it and I can assure you my cold tap is not 62 degrees so you need to check your theory. My experiement was real.

I think you missed the point on the solar panels, the RV manufacturer was showing that the direction of the panel was fundentally important. All you had to do to go from 5 amps to 27 amps at 55 degrees on 21 dec was to adjust your panels to mimic the panels at 25 degrees. Hence this would be very important for anybody in Ireland to optimise their solar output.
(Even I learned something with this)

I don't think we should turn this thread into a scientific forum with a load of gobblygook as it will bore the pants off people who like me are just looking to learn about renewables but don't want to become scientists at the same time.

Lets keep it simple for the natives (and I am including myself) .:D

Mothman

xonencentral wrote:

I rang the local met station and they said that in November in my area of the country, 50 mph winds were sustained for significant periods on 17 seperate occasions. They said this was not unusual....Its 32 mph today and I do remember one accassion lately, we had up to 140 kph gusts announced on the radio.

The amount of occasions of 50mph winds doesn't add up.

I've gone through the wind speeds for Belmullet this month and only for 2 hours on the 7th has a force 9 (47-54mph) been recorded at the station.

These are 10 min mean speeds which is the standard measurement. I don't know what your local met station is, but Belmullet is the 2nd windiest station behind Malin Head of the Met Eireann network.

Looking at the wind speeds for Belmullet from Sep 04 to Aug 05, Only on Jan 11th did it ever reach 50mph (Max 55mph) there.

Perhaps its in the definition of "significant periods" which may perhaps be just 1 minute long.

Of course the met service only measure speeds at 10m height. Turbine heights in windfarms are substantially higher, and are probably in more exposed locations, so windspeeds can expect to be higher, but still the amount of times that speeds will reach the 25m/s (56mph) cut out speed of the Airtricity turbines would be very few and far between. Why efficiencies in windfarms will be higher than domestic turbines is because of the height above ground and location.



On the subject of flat panel collecters, a sunny day is heating 150l+ water from 10-11C to 42C. I'm sure that if my 6sqm collectors were angled at near 60deg, than their 30deg, than I would be getting substantially higher temp in tank, probably above 50C.

I do drain off hot water during summer. It goes into kids paddling pool. I don't understand this exploding business. There is a make of flat solar panels where the liquid drains when not in use. This means antifreeze is not needed either. Don't have link at moment.

air

xonencentral wrote:

Hi Air,

I have to correct you again, 50 m/s is very high wind speed and rare indeed but it was 50 mph that turbines shut down at which is 22 m/s.

Apologies, I misread the earlier post, thought the 55m/s was the upper limit on generation.
When did you have to correct me last?

Regardless, give me a figure for the average hours per year over 22m/s.
Given a national average of circa 7m/s I'd say it's low enough, overall I think I would credit the staff at Eirtricity with the intelligence to select turbines with a suitable operating speed range for the country.

xonencentral wrote:

With regards my kettle experiement, anybody can do it and I can assure you my cold tap is not 62 degrees so you need to check your theory. My experiement was real.

So your water has a specific heat capacity of less than 4180 joules / kilogram / degree kelvin then?
Thats pretty amazing, would love to see it.

xonencentral wrote:

I think you missed the point on the solar panels, the RV manufacturer was showing that the direction of the panel was fundentally important. All you had to do to go from 5 amps to 27 amps at 55 degrees on 21 dec was to adjust your panels to mimic the panels at 25 degrees. Hence this would be very important for anybody in Ireland to optimise their solar output.
(Even I learned something with this)

You had me doubled over with this!
The table shows the output of the panels in different LOCATIONS not panel angles.
If you look down the left it gives latitudes in degrees and an associated location (EG Yukon 60degrees North).
This should be obvious as you can see the increasing disparity between the summer and winter outputs of the panels as you move northwards (down the table).

Incidentially to go from 5 AMPERE HOURS | AMPERE HOURS | AMPERE HOURS - (Can you please stop confusing POWER AND ENERGY, CURRENT AND ENERGY ETC ETC) you dont have to just adjust the panel.

Instead you have to move the panel the 6 thousand kilometres or whatever it is from Yukon to Florida!!!!!!!

xonencentral wrote:

I don't think we should turn this thread into a scientific forum with a load of gobblygook as it will bore the pants off people who like me are just looking to learn about renewables but don't want to become scientists at the same time.

Lets keep it simple for the natives (and I am including myself) .:D

I'm sorry but I simply dont think that you have enough of a basic understanding of the physics involved to make a worthwhile contribution to this or any related thread.
Indeed from what I've read so far your posts contain so many glaring mistruths and mistakes that they would have a negative impact on any readers knowledge of the topics covered.

I would suggest that you spend some time reading up on physics on WikiPedia or similar and come back to us.

xonencentral

I dont think these posts are of much value:

But anyhow, my suggestion is that you actually BUY a system and then come on here and tell us all about it. Theory is paper and ink and its a case of garbage in garbage out.

The practical proof is all thats counts in the end and I've done enough experiements to know that theory is only as good as all its inputs being correct and its the experiment which proves the theory not the other way around as you seem to be suggesting.

This is the 30 year average wind data from my area from the met office.

max. gust
91 knots - 46 m/s Jan
93 - 48 m/s Feb
88 - 45 m/s etc
67 - 34 m/s
69 - 35 m/s
73 - 37 m/s
67 - 34 m/s
60 - 30 m/s
84 - 43 m/s
85 - 43 m/s
76 - 39 m/s
89 - 45 m/s
93 - 47 m/s

max. mean 10-minute speed
58 knots - 29 m/s Jan
61 - 31 m/s Feb
58 - 29 m/s etc
43 - 22.12 m/s
47 - 24 m/s
47 - 24 m/s
45 - 23 m/s
44 - 23 m/s
57 - 29 m/s
58 - 29 m/s
50 - 25 m/s
60 - 30 m/s
61 - 31 m/s

mean no. of days with gales
5.5
4.2
3.3
1.1
1.0
0.4
0.3
0.8
2.3
3.6
3.4
4.5
30.5 days in year with gales.

And you still don't get the RV solar situation, so I won't waste my time explaining it any further. BUT surely you are not suggesting that the solar energy 6000 miles away on the planet surface is any different on the same date after travelling all the way from the sun.??

Clue (The Panel is mounted flat on the RV roof so the angle of the panle is perpendicular to the position on the planet surface and hence a different angle to the sun, thus giving different readings.)

Sorry, but I won't go as far as insulting you, I'll leave you down there on your own, come back up when your ready to be cordial.

Takeshi_Kovacs

hi lads , lets not get too caught up in the calculations.. you have to have all the temps, times, weightsand power ratings , correctly measured before you get anything meaningful..

heck i even tried a rough experiment just few mins ago while making the tea..
i used same equations as air and worked backwards to figure out the temp of incoming water, that i was boiling..
yet ended up with -10.5 C water starting off according to the sums!!
so you can see the obvious need for thermometer and such..

Peace makes Plenty......

air

Takeshi, your calcs were spot on, energy is lost during the boiling process when water is turned into steam during boiling. The latent heat of vaporisation of water is quite high so even a few grams of steam would account for a lot of your lost energy.
The rest of the energy would be lost at the air interface between the air and the case of the kettle.

The important point about your calculations is that you found that you needed MORE energy than expected to heat your water. This is perfectly normal and is a fact of life as energy transformations are rarely perfectly efficient (almost never actually).

Xone on the other hand seems to be able to boil water with LESS than the energy required.
A question for you xone - Where is the energy to boil your kettle coming from???

I dont think I can continue wasting my time replying to your posts. You have proved time and time again that you havent got a clue what you are talking about.

The table you posted shows the variation in the energy captured by a horizontal solar panel at different locations (latitudes) at different times of the year.

What exactly do you think it represents?

Perhaps you could try responding to a question that I pose to you instead of posting some irrelevant information from an external site that you quite obviously dont understand.

Capt'n Midnight

Not sure if posted before but..

Hours of sunshine in Ireland - http://cain.ulst.ac.uk/images/maps/sun.gif

Wind maps - http://www.awstruewind.com/inner/windmaps/Ireland.htm

The Ireland wind map was funded by Sustainable Energy Ireland and ESB International.

Mothman

xonencentral wrote:

This is the 30 year average wind data from my area from the met office.

max. gust
91 knots - 46 m/s Jan
93 - 48 m/s Feb
88 - 45 m/s etc
67 - 34 m/s
69 - 35 m/s
73 - 37 m/s
67 - 34 m/s
60 - 30 m/s
84 - 43 m/s
85 - 43 m/s
76 - 39 m/s
89 - 45 m/s
93 - 47 m/s

max. mean 10-minute speed
58 knots - 29 m/s Jan
61 - 31 m/s Feb
58 - 29 m/s etc
43 - 22.12 m/s
47 - 24 m/s
47 - 24 m/s
45 - 23 m/s
44 - 23 m/s
57 - 29 m/s
58 - 29 m/s
50 - 25 m/s
60 - 30 m/s
61 - 31 m/s

These are NOT 30 year average figures. These figures are the absolute max figures recorded in each month Edit:- during the 61-90 period (not "since the station opened in 1956" as I first mentioned.)
Interestingly, only 2 months have had higher gusts since 1990 inc the 80knot gust this month.

Here are the average max gust for each month for the 61-90 period (the period that our current averages are based on)

67 knots - 34 m/s Jan
61 - 31 m/s Feb
61 - 31 m/s etc
51 - 26 m/s
51 - 26 m/s
46 - 24 m/s
43 - 22 m/s
47 - 24 m/s
56 - 29 m/s
60 - 31 m/s
61 - 31 m/s
65 - 33 m/s

I don't have average max 10 min speeds but they are substantially lower than the absolute max figures. The number of gale days are correct, a gale being a mean speed of 17.4m/s, which on average is recorded less than twice every summer.

air

Thanks for posting that Capt, I never even realised there were maps that detailed available.
Do you know if the altitudes for which there are maps represent height above ground level or sea level?

For anyone considering a wind system these charts are basically the single most important piece of information you should use when assessing the viability / benefits of a wind system in your area.
Generally though, its pretty obvious that Ireland has incredible wind resources and it's a pity that we dont tap into it more.
The fact that we have a lot of dispersed one off housing around the country means that small wind could be used by a significant proportion of the population IMHO.

As an aside, the only value of gust frequency tables is in deciding how durable a turbine you need to select for long life in your particular location. As an example Eirtricity would look at these values when trying to decide between the 55m/s and 85m/s gust capable models for each particular location.

Intermittent gusts will have a negligible effect on your annual energy harvest.

css

Wind data for my location is an average of 6-7 m/s, would this make a system unviable?

Mothman

css wrote:

Wind data for my location is an average of 6-7 m/s, would this make a system unviable?

If that is an annual average (though for what height above ground?), there is plenty of wind for a system to be viable.

Go for it!

turbine?

css, have a look at the power curve for various machines, this will show you how power output relates to windspeed, it is available on most manufacturers webpages. 6m/s avg should be plenty if you match the turbine to your site.

css

turbine? wrote:

css, have a look at the power curve for various machines, this will show you how power output relates to windspeed, it is available on most manufacturers webpages. 6m/s avg should be plenty if you match the turbine to your site.

I will look into it more, thanks guys.

sligo_bear

Hello Ladies & Gentlemen,

Great thread, the passion from everybody is great, have been reading for some time.

Just took early retirment from the dreaded yellow van brigade.

I am surprised that their isn't more people coming on with renewable systems in a practical sense, I like to read about other peoples experiences.
I will give my few experiences so far if it helps, I'm not as smart as some people on here and well past getting the books out again.

I have also got a surfacepower system with the full solar for about 3 months now. I live in the middle of sligo county, one of those dreaded dispersed houses outside my local town.

So far, it's been a very pleasent experience and gets great comment from my colleagues at work as you could imagine.

We used to see many renewable systems when we were doing the contract storm repairs in the UK, you'd always see the house with the lights on who wasn't bothered whether we fixed the lines or not. we were always facinated and would stop for the tea and a demonstration. I suppose I always knew what my hobby was going to be and saving money is as good a reason as any I suppose also.

I get alot of wind where I am, and we have been involved in wind power for years at work although most people might not assume that.

Well thats my experience, I'd like to hear more particularry from somebody off-grid as that is something I would like to do, need to make sure the pension dosen't go back to my old employers when money gets scarce.

Bill2

Sligo Bear,

Good to hear someone else has the surfacepower system, can you let us know what your ESB bills were before and what they are now, if you don't mind.. and any other info about the surface power system you think is relevent. Are they all they are cracked up to be.. I'm looking at buying one in the next couple of months or so.. so any info would be greatly appreciated..

Bill..

sligo_bear

Hi There,

Well, I am moving back to the home place, I am originally from Sligo. I have been doing up the house for some years now and I don't have an ESB connection. There was one years ago but I had it made safe as trees had moved in on it.

I have a range and a plentyful supply of turf for heat and hot water and until I got my surfacepower system, I was using the genny and inverter system from the back of my van, alas, van gone now.
I use my green system to run my house completely as its stands, so that is all my lighting, sockets, pumps, etc. I have no fridge or washing machine yet and have been very interested in where to source A++ systems. I would like to stay off-grid if possible but I do need to get a fridge and washing machine and my system is not large enough yet to run the big things all the time.

I think I would like to get a generator to run in conjuction with my system and increase my battery bank. I would only need to run it a few hours a day but it would provide me with a backup system as well.

It's interesting to see how the whole energy subject is coming to light, we have been talking about it at work for years and I suppose if half of everything I've heard happens, then i'd rather be in control of my own energy production. I have a few quid so I best invest it now.

I might be getting older but this might interest some people, I have 2 large bottles of which one I place outside at a time with a clean gauze in a funnel and I collect my drinking water in that and it is the most beautiful clean water I have tasted in a long time. I sterilise everything of course.

Well, today is the end of my retirement course but I'll try and check back 2 or 3 times a week to see what's happening.

turbine?

Hi all, anyone interested in the theory behind wind turbines should take a look at www.iesd.dmu.ac.uk/wind_energy, I only had a brief look through but they cover most aspects of turbine design including power output calculations, aerodynamics and plenty more.

just got Hugh Piggots book, Windpower Workshop and it is a very intersting read, along the same vein as above site, but more specific to small scale and DIY turbines.

Have a good weekend.:D

Takeshi_Kovacs

Hi all, anyone interested in the theory behind wind turbines should take a look at www.iesd.dmu.ac.uk/wind_energy, I only had a brief look through but they cover most aspects of turbine design including power output calculations, aerodynamics and plenty more.

just got Hugh Piggots book, Windpower Workshop and it is a very intersting read, along the same vein as above site, but more specific to small scale and DIY turbines.

Have a good weekend.

just wondering what size of turbine are you going to make 400, 500, 600 watt? also have you any good source or web site for the NdFeB magnets, as i haven't a decent (and cheap) site to buy them off...

also are you charging a battery bank, or will generated electricity go straight to a load such as water heater?

GG66

sligo_bear wrote:

Well, I am moving back to the home place, I am originally from Sligo.

Hi Sligo Bear,

Good move on the retirement, hope you're enjoying it. I've moved home to south county sligo myself a little over a year ago, not near retirement age but like to live the lifestyle whenever I can.

Also glad to hear someone else who can share experiences of surfacepower. I'm building at the moment and I'm looking into an off grid solution (maybe not all at once).

I have also got a surfacepower system with the full solar for about 3 months now

What system did you go for? Is this the one with two wind turbines and 600w solar?

I work from home so I'm primarily interested in running my office from renewables and then whatever home applicances, lights etc. I can after that.

It's interesting to see how the whole energy subject is coming to light, we have been talking about it at work for years and I suppose if half of everything I've heard happens, then i'd rather be in control of my own energy production. I have a few quid so I best invest it now.

I'd be interested to hear what your discussion at work were.

turbine?

Takeshi, the detailed plans in the axial plans booklet are for a 2.4m 500W turbine, which can produce up to 1kW for shorter periods. I looked on the net for magnets and the best site I could find was www.powermagnetstore.com
2" x 1" x 1/2" Price: (10 to 14 items) £5.95. I have to look more on the web but the site is also recommended by piggot on his website.

At the moment the plan is to run power to battery, and invert back to 230V ac. I need to source betteries as of yet, I think golf cart or forklift batteries should be available cheaper than leisure batteries. I cant find any, but I havent gone all out looking either though.
Have looked at some of the electronics such as the bridge restifiers etc, and Radionics seem to have good prices, any advice on a cheaper store or site for electronics and enamelled copper wire would be great.

air

You might be able to get a large amount of enamelled wire for free from the transformer from an old microwave, washing machine etc.
There are lots of old machines that would have huge amounts of neatly coiled copper wire that can be easily salvaged.

sligo_bear

Hello GG66

Not sure how to do the quotes but in answer to your questions

My system is the number 4 system, 300 watt solar as well as the turbine, I want to use a generator to provide primary power and also backup so I can stay off-grid. My experience to date is that, I was quite surprised at the amount of equipment I received for my money, I am still wondering if I was under charged by them, not complaining though. There is simply no comparison between the price of all the equipment I received and what others are charging for complete systems. Installation was very easy and less than 100 euros to complete. Support & Information from the company was very fast but also they seem to know their stuff so far. I don't know what it's producing but it works all the time as if I was on the grid so that was something I wasn't expecting, I'll push it harder when I get a monitor.

Energy & carbon taxation is going to become so expensive that the only future for Ireland (as we have done nothing) is joining up to a nuclear umbilical cord to the UK. This has been planned for years and is the only way our state provider can survive as a giant monopoly. ""Ireland"" has sucessfully closed the alternatives down and I don't agree with that. It's not the fat-cat vested interests and civil servents who will be worried about 1000 euro Electricty bills around the corner as they will just give themselves a pay-rise but the person on the street who will pay dearly as vested interests try and keep their revenue streams intact at our expense.

But that is information everybody knows, what people might not know is that outages are the biggest fear of governments, these outages will stop the economy. Power cuts will become a norm in transmission systems of the future. These are caused by interconnectors and everybody should get used of them happening. We already had a big one with the interconnector between us and NI this year, and everybody has heard of the London shut-down, Manchester, New York/Canada, California, etc all caused by grid instability or energy shortages, (all causing grid instability and BANG, candle power for the rest of the night).

To control and stabilise a national grid, you need to have 100% control "unfortunately" but as we move to primary interconnector supply for the future, then we no longer have 100% control and hence when there is a problem on the other end of the connector, we get shutdown or the whole grid becomes unstable and crashes. It can also take hours to get the grid off-line, fixed/stabilised and then back online.

Security of Supply is the buzz word everybody is pedaling and the government have already accepted the interconnector to the UK nuclear program (which we have heard about for years) and they have been convinced of this issue by the vested interests. If you are a house or small business and not located on the grounds of the local hospital, then buy lots of candles. This is not a perfect solution but Nuclear is the only carbon solution for energy at the moment and no Irish Government (who ever wants to get re-elected) will build our own stations which would be a better solution for the customer as we would have 100% control.

A couple of other interesting titbits,
Your phone line rental will continue to increase as your phone electrical power is supplied down the phone network and will be subject to carbon taxation as power comes from the state company, when the interconnector comes online, you will have a nuclear powered phone line !.
The EU has told all members states to remove fossil fuel VAT subsidy's, it's being fudged here (ireland) at the moment (wait until after the next election) so your electricity bill, heating oil, will go to the standard rate as per the Directive (21% VAT) and what about the night-time electricity rate. (Our view is that if the EU get their way, its gone as well) but GOD forbid that would ever be taken advantage of; your local electricity provider will get a major windfall which would help dearly with our pension fund shortfall, and it would all be the EU's fault of course. (oh, if only this wasn't a public forum)

My view is that we will wake up one morning not to far away and the main news item will be an admission by the oil industry that it has been in decline for a couple of years and the wheels come off the cart. Well, I intend to be self sufficient well before that happens and one of the next big increases on your bill will be the cost of installing a "large" interconnector to the UK among many other things.

Capt'n Midnight

sligo_bear wrote:

A couple of other interesting titbits,
Your phone line rental will continue to increase as your phone electrical power is supplied down the phone network and will be subject to carbon taxation as power comes from the state company, when the interconnector comes online, you will have a nuclear powered phone line !.

FUD
Just how long would it take for a home phone to use a Kilowatt hour ????
And it's not as if Eircom couldn't adsob such a cost relative to the negative publicity they would get. Also the UK aren't planning any more nuclear power stations at present.

PS. 100% national control hasn't prevented power outages in the past and you don't hear about the power outages interconnectors prevent. Am a fan of interconnectors, as they are an alternative to more power stations.

turbine?

Air, I was looking at a transformer from an old microwave (that I dismantletd to see what the magnets were like) and it looks like the coil is sealed in a resin. I'll rip it up more and see if it unwinds easily!!

Was looking on ebay yesterday and there are two lots of the 24 magnets required for the turbine, about 110euro, it's in the states though and I dont know what shipping would be on an order like that.

air

Turbine, yes some of them have resin on them but I've come across the od item with neat coils of wire thats really easy to reuse, keep searching

FYI regarding postage on the magnets, see for yourself at : http://ircalc.usps.gov/

Regarding interconnectors, IMHO they can only be a good thing. For instance, the effects of variability of supply from renewable energy sources (eg wind) is offset the larger the area covered by a grid is.

For example say Ireland, England and France all had 3 x enough wind turbines to satisfy their domestic load at optimum wind speed. Today it might be windier in Ireland than France / England and we could sell them power, tomorrow the oposite could be true.
In this way interconnectors can be used to reduce the requirement for backing each available megawatt of green power with fossil / nuclear to guarantee supply.
(Obviously the above is a gross simplification but I hope it gets the idea across)

Keeks

Can we keep the comments about interconnectors to another thread. This thread has enough off-topic shoots without adding more.

we'll try keeping it to off-grid sustanible options if at all possible ie. anything that will stop you spending money on electricity