G59 Compliance Test

Today the Manweb G59 compliance witness test was completed to the DNO’s satisfaction, so at long last the turbine is signed off. The relay has been set at 264V maximum which should allow some leeway for voltage spike problems. The DNO have also agreed now that we can set a time interval tolerance of 500 ms (ie the voltage spike will have to last longer than 500 ms before triggering a shut-down). Unfortunately however the relay fitted to the turbine does not have the ability to vary the time delay setting, and is set at zero seconds. But we will try this now and see how we get on. In any event we are still waiting for Manweb to reduce the voltage output from the transformer. That adjustment is still due, but all the engineers have been fully engaged with the extreme cold weather that we have been suffering, so it will be after Christmas now before that is done.

Our First FIT Payment

Very exciting! Our first feed-in tariff payment has arrived in the bank. I sent meter readings for 30th November, so Scottish Power have paid for all electricity generated since the commissioning date. Also, because the export meter issue has still not been resolved, we have agreed that they will pay for the “deemed” amount of exported electricity based on 50% of the total generation. This is a better deal than getting paid for actual exported electricity because I can calculate the exported quantity and it is less than the deemed quantity. At 3p per kWh it doesn’t make much difference however, but every little helps!

Anemometer Failure

There has been nothing to write about lately, which has to be a good thing. But this morning, the turbine isn’t running. Logging in to the turbine on the computer reveals the explanation, anemometer failure. My heart sinks, thinking that this is going to be another two weeks without generation while they come out and look, agree that “Oh yes, it’s broken”, then have to wait another week while the part is sent out from Holland. This might be the point in my blog where I reveal, for those who haven’t worked it out for themselves, that the turbine is a WES18 manufactured by Wind Energy Solutions of Holland. So I walk down to the turbine to see that the anemometer is spinning although the display is still reading “Alarm”. I reset the alarm and the turbine starts up.

What has happened is that I have revealed a design feature of the turbine that I was not aware of. As anyone who has been in the UK for the last week or so will know, we are experiencing some cold weather just now. Not exceptional really, though early in the year. Yesterday however the temperature rose to 5 or 6 degrees, and everything began to thaw. The wind had dropped to zero, and there was a great deal of moisture in the air. Then, around midnight, the temperature must have fallen sharply to well below zero, and everything froze up again, including the stationary anemometer. Correctly, the turbine has detected this and shut down. But it has not detected the later rise in temperature and the anemometer unfreezing. Although annoying, this is a deliberate protection measure.

It is conceivable that the frost may have damaged the anemometer bearings such that it would be spinning, but not registering the correct speed. At worst case, the wind speed may increase to a damaging level but the turbine would fail to detect this. In this scenario, considerable damage could be caused to the turbine. Therefore, standard procedure dictates that the turbine should be manually restarted after an anemometer failure, following a visual inspection. One wouldn't have to climb the tower for this, because experience would allow one to assess the wind speed on site and compare it with the anemometer reading.

There is a technical fix available in the form of a heated anemometer, but this would incur more energy use and more expense. Therefore we hope that the weather conditions were rare enough so that the riskof this happening again are minimal.

Feed-in Tariff Progress

At last we seem to be making progress with the “Clean Energy Cash-back” set-up with Scottish Power. All the forms are now completed and an account number has been issued. They have agreed to back date all payments to the turbine installation date, and I have sent them meter readings of generated power. Unfortunately they have still been unable to re-programme the import/export meter to actually display exported electricity, but they are happy to rely on my calculations. At just 3p per kWh, it’s not a great deal of money anyway. So now I am waiting for my first cheque.

Manweb Update

A DNO engineer has been to look at the installation, and seems quite happy to step the transformer output down by one increment. This is 2.5% or approximately 6 volts. He will have to consult with his superiors though. While on site, he also asked why the G59 relay cannot be adjusted so that the turbine is more tolerant of variable grid voltages. Unfortunately we have one guy from Manweb saying “Adjust the G59, that will fix it”, and another Manweb engineer (of equivalent seniority, I asked!), saying that under no circumstances can the G59 relay be changed.

Working Again

The engineers returned yesterday with the replacement revolution monitor, and despite extremely cold, wet and quite windy weather, Neil bravely climbed the tower and replaced the part. It is working again! They have also taken the opportunity to make some changes to the control software, such that if the turbine goes off from a high voltage spike, it will now restart of its own accord. We have also decided to again remove the output limiter, so that given sufficient wind the turbine should now generate up to its rated capacity of 80 kW.

Breakdown

My turbine has stopped working. By logging in to the turbine’s fault log, we learn that the revolution monitor has failed. Without this of course the turbine shuts down, as it won’t know how fast it is going. The engineers came yesterday to fix it, but ironically it was too windy to climb the tower so they sat in the pick-up all day, then went home. They have been back today, and discovered that the monitor is actually broken, so a new one has been ordered up from Holland. Meanwhile we have had some really windy days. It is so frustrating to see the trees blowing about like mad, and the turbine stationary.

Farm Open Day

I went to see a smaller turbine today, on a farm near Newport in Shropshire. The event was organised by a company called Natural Energy (http://www.naturalenergyuk.co.uk/). The turbine was an 11 kW Gaia 133 on an 18m tower. In operation since July, it had generated some 6,500 kWh. That’s pretty good for such a small machine, and statistically this autumn has not been a very windy time.

At last, there is a bit of momentum developing in the onshore turbine market, though there is a long way to go to achieve the Government’s target of 20% renewable generation by 2020. Natural Energy told me that they have about 100 planning applications on the go, so if every other installation company has a similar order book, we will soon begin to see the turbines popping up all over the place.

Newspaper Article

I have succeeded in getting an article in the local newspaper, the Shropshire Star. It is at least a quarter of a page with a nice (though I say it myself!) picture of myself with the turbine behind. Please have a look: http://www.shropshirestar.com/shropshire-business/2010/11/09/shropshire-farmer-turns-to-wind-turbine-power/. It describes my project, and publicises my consultancy role. It went in yesterday’s paper, and today I have received my first enquiry, from a local farmer.

I have also received an email from the local branch of the CPRE (Campaign for the Protection of Rural England) expressing an interest in the turbine. Their website is http://www.cpreshropshire.org.uk/. I would have expected them to be generally against wind turbines, but reading their policy statements it seems that they are positively in favour of “appropriate” developments. I’m not sure what is appropriate, because you can’t avoid the fact that turbines do make a significant impact on the landscape, and by definition they should be sited in order to maximise wind harvesting which means out in the open away from trees and other buildings.

A Very Windy Day

When I went to bed on Wednesday night the wind was just starting to get up, so I was expecting the turbine to have stopped when I looked out of the window yesterday morning. But no, it was still running, and belting round at that! It kept going for the whole 24 hours, and a lot of the time was running at 60 kW plus. If the generator hadn’t been limited to the 60 kW, I am sure it would have produced substantially more than the 1,084 kWh actually recorded.

But oh, can we please get these outstanding issues fixed....................

A Windy Day

Well, it was extremely windy part of the day yesterday, but unfortunately the turbine went off in the evening. I happened to be watching it, so went and re-started it straight away. Also, looking at the activity log, the turbine actually stopped because of excess wind speed. If it measures a speed over 25 m/s, it shuts down to prevent damage. It continues to monitor wind speed and will restart after three minutes if it was just a freak gust that shut it down. It is reassuring to know that this part of its programming is working OK.

At the end of the day, total generation has been 670 kW, a new record.

October Report

Despite the excitement at the end of the month, October has been very disappointing. Total generation has been just 3,635 kWh, not much more than a third of what it needs to be. I have heard from two sources that autumn 2010 is turning out to be historically a very low wind season, and not just in the UK but across all of northern Europe.

Also, in discussion with the Dutch engineers, we have decided to re-introduce the output limiter, but this time set at 60 kW rather than the 30 kW as previously. The weather forecast indicates a windy day tomorrow.

Failed Again!

I’m just back from a weekend away with a friend, not an ordinary weekend as I will explain in a moment. But while I was away, on the Friday night in fact, the wind was blowing a treat, probably the most wind we have had since the turbine has been up. I was busily rubbing my hands and making mental calculations of the amount of money that the turbine was generating. Then, in the morning, I received a text from my brother who lives close by, to say that the turbine was not running. To say that I was disappointed does not capture a fraction of what I felt. To try and do it justice would probably cause some internet bad language filter to overload.

However my brother was able to go down to the turbine and re-start it, and the wind continued to blow quite well most of the day. By looking at the fault log, it appears that the turbine was off for approximately 7 hours out of the 24. Despite this, we managed to generate 473 kWh in the day, a new record! In spite of all the problems, this has given me some encouragement that everything will turn out alright in the end.

I will just explain why my weekend away was no ordinary weekend. The friend who came to collect me actually owns and pilots a small private helicopter, and needless-to-say, I took rather a lot of photographs including these three here.

Output Limit Removed

The turbine has continued to run without shutting down, other than when it is supposed to due to lack of wind, so we have decided to remove the output limiter and allow the machine to generate to full capacity. However this may be academic as wind conditions have continued to disappoint. Our best day this month so far has been just 252 kwh.

Despite flurries of increasingly impatient emails, none of the outstanding issues have yet been sorted. Nobody’s fault really, but so frustrating!

September Report

The turbine has kept running I think without interruption since the output was limited. We haven't had a great deal of wind, though on the 24th September it generated 339 kWh, a record so far. For the whole month of September we have generated 4,149 kWh, enough apparantly for one average household for one year. However we have got to do twice that to achieve budget.

No other issues have yet been resolved. Nothing has yet been done about the noise from the tower, about the electrical interference (we haven’t been able to make a loaf of bread for weeks now!), and we still haven’t heard from Manweb about reducing the mains output from the transformer. Also despite telephoning the man in the Scottish Power Microgeneration department every week, we still haven’t got our Clean Energy Cashback contract in place, and Ofgem still haven’t been able to produce their registration certificates. Oh well!

Unintended Shut-Down: A Temporary Non-Fix

As a strictly temporary measure, the Dutch engineers have decided that the power output from the turbine should be limited to 30 kW. Quite how they achieve this I don’t understand, but they can do it by accessing the control software over the internet from Holland. Even though the energy output from the generator will be much reduced, it should at least keep running because we won’t get those cable-induced voltage spikes. We probably won’t lose too much generation in the short term because we need wind speeds in excess of 8 m/s to go above 30 kW, and we really haven’t seen much of that kind of wind as yet.

The Manweb Data-Logger

We first raised the issue of high voltage peaks with Manweb back in July, and we do now have some further information. When we first contacted Manweb, they did react very speedily, and an engineer was here fitting a recording device the following day. However it turned out that it wasn’t a particularly sophisticated device, and the guy whose job it was to learn about the connection of small generators to the grid was on holiday, so the whole thing got moved back a couple of weeks.

But to cut a long story short, the right man has now had the right equipment connected to the supply for the right period of time, and he has been kind enough to let us have a copy of the data. What it shows is that the voltage levels are within the accepted parameters nearly all the time, though there are a few peaks over the 253 volt maximum. However the data is based on 5 minute averages, so we still don’t really know how high these voltage peaks are. Bearing in mind that the G59 mains interface relay is still set to zero time tolerance, it is not surprising that we are still getting problems. The problems only occur however in high wind conditions, when the turbine is trying to pump out its maximum power. This does suggest that it is the length of the cable from the turbine to the transformer that is actually causing the final bit of the voltage spike which is in turn causing the turbine to shut down.

Looking at the mains voltage data, we think that the output from the transformer can be stepped down without causing the voltage to fall below its minimum limit. This would give a bit of slack to the system, allowing it to cope with cable-induced voltage spikes without shutting down. If Manweb can be convinced of this, we will be well on the way to curing our main problem.

Opportunities for Electricity Use

I don’t yet know how much electricity our turbine will generate. I have structured the budget around an annual generation of 100,000 kWh. If we do 120,000 kWh we will make money, if we only do 80,000, we will not pay off the loan in the 10 year period agreed with the bank. But it is clear that the less electricity we sell at 3p, and the more we use, replacing purchased electricity at say 10p, the better off we will be.

Like many similar farmhouses, we have an oil fired Aga, and oil burning central heating. I understand that some more modern Agas can now be converted to run on a 13 amp electricity supply. For heating, we could install a ground source heat pump, as of course we are not short of land to bury the pipes. Ground (and air) source heating systems use quite a lot of electricity to drive the heat exchanger compressor, but you do get about 2 kWh of heat out for every 1 kWh of electricity put in.

Then there is the car. Most journeys are 40 miles or less, so a plug-in hybrid would enable most of my day-to-day motoring to be electrically driven.

Another unknown is, when will the wind blow? Sod’s law would suggest that it will blow like crazy in the middle of the night when we are not using anything, and be completely still during the day when use is at its maximum. But our very limited experience to date suggests that the wind tends to drop as it goes dark. If this pattern is repeated throughout the year, this will minimise our export and maximise our usage.

Filtration for the Electrical Interference

The engineer has been today to connect some filtration equipment into the control cabinet at the foot of the turbine. We turned it back on and...................it’s still the same! Oh well, back to the drawing board.

The Clean Energy Cashback Scheme

As with the Ofgem application, I have been working on finding someone to buy my exported electricity and pay me the feed-in tariff income for months. Our electricity supplier is currently Scottish Power, so I thought it might be less complicated to use the same company for the FIT, or the “Clean Energy Cashback Scheme” as they call it. All of the main retail electricity companies are required by law to offer the FIT, so it shouldn’t make any difference. The FIT rate and the 3p per kWh rate for exported electricity are also laid down in the regulations, so there is nothing to be gained from shopping around. There is a provision to opt out of the 3p export rate and strike a separate deal, but I have found that any alternative buyer insists on supplying as well as purchasing, and I am half way through a contract with Scottish Power.

In the Scottish Power application form, there is a box to enter the Ofgem registration number. Ofgem told me that it would be sufficient to enter “pending” before my application was processed. However Scottish Power’s “computer says no!”, and even after I had my Ofgem number, Scottish Power were still unable to process my application because they needed the completed registration document, which Ofgem are still unable to provide. It seems the procedure is that Ofgem produces an electronic document which is transmitted for completion to the purchaser, and without this virtual paper trail the Cashback scheme cannot be activated. This actually all makes perfect sense, but again it is very frustrating when it doesn’t work.

Another unresolved issue is the export meter. When the new transformer was installed, it was effectively a new supply with switchgear, fuses and metering equipment. A brand new, state-of-the-art, multi-function programmable meter was provided. However because the Cashback scheme was not activated, they could not program the new meter to record exported electricity. So Scottish Power Retail is now trying to get Dataserve (a Scottish Power company) to re-program the meter, so far without much luck. At one stage it looked as if they were going to have to install a new separate export meter because no one could authorise the re-programming! However they do seem to have got over that particular piece of nonsense now, and hopefully we will have the existing meter programmed correctly.

To give them their due, they have promised that if actual export data is not available, they will negotiate an estimate for which they will pay, and they will back-date all payments to the turbine commissioning date. Fortunately I am recording electricity usage by various parts of the farm business, so I can calculate exported electricity as imported electricity plus generated electricity less usage.

Perhaps the lesson of all this is to avoid having anything to do with Scottish Power! We have been trying to deal with Scottish Power Energy Networks (Manweb), Dataserve and Scottish Power Retail, and they just do not talk to each other despite the fact that they are all part of the same company, Iberdrola of Spain. I now have direct telephone numbers for the relevant people in each company so it is not too bad, but when I had to try to get in through Customer Services it was often actually impossible to speak to the correct department.

Ofgem Registration

As a “small wind” generator, that is with a turbine with a rated output of between 50 kW and 250 kW, I have to register directly with Ofgem in order to obtain the Feed-in tariff payments. If the generator is less than 50 kW, so long as your installer is registered with the MCS (Microgeneration Certification Scheme), the Ofgem registration is done for you.

I have been working on my application for registration with Ofgem for months, in fact I started researching when the government first announced it was consulting on introducing a feed-in tariff scheme last year. At the time, we thought we would have the turbine up and running by April 1st 2010, the date that feed-in tariffs were to be introduced, so I wanted to get my application under way. Ofgem suggested that I apply under the ROC (Renewable Obligation Certificate) scheme, and then transfer to the FIT as soon as it became available. They even set up a specific email address called “ro2fit”. I applied using a complicated on-line form that requested far more information than I was able to supply, and was clearly designed for industrial wind farm developers rather than farmers putting up one turbine.

However today is registration day. A series of phone calls and emails has resulted in my application being successful, and I have today received an email confirming my registration. The exciting bit is my number with Ofgem, FWD00001EN. This may not look exciting, and I’m not sure what the letters FWD represent, but EN stands for England, and 00001 means that my turbine is the very first to be registered.

Just to dampen my enthusiasm a little, all I have is an email because “software issues” are preventing the issuing of the actual certificates themselves. One fact jumps out at me from all of this, is that the whole industry of “small wind” is brand new, and everyone, from the manufacturers, the installers, the electricity retail companies, all the way up to the government themselves, are flying by the seats of their pants, and making up the procedures as they go.

Electrical Interference

Not only do we have the noise problem described earlier, but when the turbine is running slowly, it produces stray voltages at high frequencies. This is having bizarre effects on some electrical equipment in the farmhouse. Fluorescent light tubes buzz like mad, the hi fi buzzes, our super new electronic bread maker won’t work, strangely the interior light in one of the fridges won’t come on. Apparently it is to do with one of the inverters that convert the variable frequency AC voltage from the turbine to DC, and then back to AC again at 50 hz to match the mains. We are waiting for some filtration equipment to be fitted which should cure the problem.

Turbine Noise

The turbine is noisier than it should be. It produces two quite separate sounds, a whooshing noise as the blades rotate, and a humming or ringing noise. The whooshing is fine, no problem and as expected. It is only audible in high winds, and then you have to listen out for it to hear it. It also depends on the wind direction. The farmhouse is about 450 metres away from the turbine. The humming noise is more serious, in that it is more intrusive, and can be heard in a wider range of wind conditions. It appears that the fairly quiet noise from the generator and gearbox is resonating with the column of air inside the tower, and thus the tower is amplifying and broadcasting the noise. The solution is to put foam in the top of the tower, both to prevent the sound travelling down into the tower, and also to change the length of the air column in the tower and therefore reduce the resonance. This will be tried when the engineers come back to do the 6 month service. Watch this space for a resolution.

Unintended Shut-Down

We do seem to be getting more than our share of problems with this turbine. The latest issue is that the turbine’s control mechanism is detecting high voltage spikes in the mains grid. It thinks that this is an alarm situation and shuts itself down. You then have to go into the control panel, tell the turbine that there is nothing wrong, and off it will go again. Mains voltage is supposed to be 230 volts, plus 10%, minus 6%. This is a range of 216 V to 253 V. We are seeing voltages at the turbine well in excess of 253 V, the highest being 294 V. There are two potential causes for this, one is that the grid voltage is high, the other that the length of the cable from turbine to distribution board (approx 450 m) is causing higher resistance which in turn is lifting the voltage. This may all be made worse by the lack of tolerance in the time setting of the G59 relay. Manweb have so far insisted that the delay be set at zero seconds so the briefest voltage spike will trip it out. Manweb have agreed to come and put a data logger on the mains input to see what the incoming voltages are.

More G59 Issues

We still haven’t got this DNO G59 issue resolved yet. It seems that the interface relay between the turbine and grid as fitted by the Dutch manufacturers is absolutely fine for some DNOs but not for Manweb. We have tried in vain to explain this, but each DNO has their own rule book probably dating back to when they were established as independent entities even pre-dating the National Grid. We now have to change the relay, which will hopefully satisfy Manweb and allow the G59 test to be performed.

This has not involved me in any extra cost, other than stress, but I do think that the manufacturers should have done their homework a little more thoroughly before selling turbines into the Manweb area. But they will know for the next one!

Holiday

About 2 days after the installation was completed, my wife and I left for two weeks of well-earned holiday. We had hoped that all would be completed before we went, but we had to leave the machine stationery. Mechanically and electrically everything is in place, but there remains an issue around the interface between the turbine and the grid. Before the turbine can be signed off, the DNO have to perform what is called the G59 witness test. What this means is that if there is a problem on the grid and there is a mains power failure, the turbine has to sense this and also shut down. The reason is obvious of course; if the grid fails, the DNO engineer puts his hand on a cable which he expects to be dead, only there is a wind turbine a few miles down the road still generating power. So the G59 test is to confirm to the DNO’s satisfaction that the turbine will stop under a series of simulated grid failure scenarios.

We are back from holiday, and are now pushing to get this final issue resolved.

Erection Day

I’m not sure if the title of this post is correct, but it does seem appropriate!

The engineers have spent the last week transporting all the components down to the site in the field and bolting the three sections of the tower together ready for lifting. There has been quite a bit of rain in the last few days, so we have decided to put the temporary roadway back in again for the crane. I’d hoped to avoid this, as the cost will be another £2,000, but if we got the crane stuck it would not be good. The crane arrived on time about 11 am. We have hired what is called a “contract lift” which means that the operation of the crane is at the hire company’s risk, not ours. I hope their insurance is good!

I needn’t have worried of course, the lift went perfectly. The tower stood, it fitted exactly onto the bolts protruding from the concrete, and the fitters used a hydraulic powered torque spanner to tighten the nuts down which I had not seen before. They had fixed the turbine blades to the nacelle earlier, so the combined generator, gearbox and hub were lifted as one unit, and duly bolted in place.

There are two cables threaded up inside the tower, the main power cable, and a reinforced CAT5 data cable which also was laid in the trench from the turbine site back to the farm buildings. This turbine will actually be connected to the internet so not only will I be able to monitor its performance from my computer in the office, but it will be accessible to the engineers at the factory in Holland. They will be able to update the control software and make any adjustments as required without leaving the comfort of their own workshop. We have had it running to test, but sadly everyone has gone home now and left it switched off.  It has been a really exciting day today. It feels like we have achieved a great deal, everything and everyone has worked well.

Delivery Day

A very exciting day today: The turbine and tower arrived this morning all packed up on an articulated lorry. A bit of a problem occurred in that we had been lead to believe that we could unload it all with the farm’s telescopic loader. This was completely impossible in that the various components had to be lifted out through the roof of the vehicle, so there was a delay of several hours while we located a crane. Fortunately there was one working not too far away so by 5 pm all the components had been unloaded safely and the control cabinet put away in the dry. The tower was in three sections, the two blades were packed inside one of the tower sections, and the generator and gearbox unit was wedged on top of the tower sections in the lorry. It has also to be said that the quality of some of the pallets that the equipment was secured to, left something to be desired. Now all we have to do is install it on its concrete pad and connect it to the mains.

The New Transformer

Manweb, the local Distribution Network Operator, have been today and spent my £16,000. To be fair, it was a major undertaking, with two cherry pickers, a lorry with Hiab crane, a couple of vans and a Landrover with a foreman. They disconnected the supply to the old transformer, and after going through what seemed like an endless list of health & safety checks, proceeded to remove the old transformer and replace it with the new. We have also taken the opportunity to upgrade the supply, replacing the 45 year old 44 kVA transformer with a 100 kVA. The old one wouldn’t have been any use for the 80 kW turbine anyway.

The interesting thing about changing the old transformer though is that if it had actually failed, Manweb would have replaced it at their expense. But because we needed it changing for the new supply arrangements, we have had to pay the full cost even though the old one was 45 years old and was showing some serious signs of corrosion when they got it on the ground. Manweb’s reasoning was that they wouldn’t have had to pay anything at all if it wasn’t for us, as the old transformer may have lasted another 10 years before failing.

All went well, and the job was completed between 9 am and 3 pm so that our regular dairy milking regime wasn’t disrupted. They also recovered the redundant poles as the new supply is buried underground. So we now have our new electricity supply in place, all ready and waiting for the turbine to be installed.

Laying the Cable

The issue of the cable to connect the turbine in the field with the meter point in the farm buildings has caused us some trouble. My original budget, based on a 50 mm diameter cable was for about £6,000 supplied and laid. However, because of the distance involved, a much larger 90 mm cable has been necessary. This has cost a lot more money, and has all together been more difficult to lay because it is so much heavier. Including excavation and back-filling of the trench, and the cost of the cable itself, this will come in at nearly £17,000, almost three times my budget. Over the life of the turbine, getting the site right in terms of maximum exposure to the wind will be much more important than the cost, but this will stretch my budget quite seriously.

Last week though, has been highly entertaining. We suspended the cable drum from the front bucket of a Case digger, and pulled it out with the second digger. The interesting bit was getting it through a culvert under the road, but we did manage just about. It was fun though, lots of blokes running about shouting stop, go, stop, go, into their mobile phones and all feeling very important! These were mostly from the electrical contractor who were more used to wiring up lights and power sockets in nice warm houses than running round fields in the middle of the country.

Feed-in Tariffs

This may be a case of teaching Grandma to suck eggs, but I thought a word or two of explanation of the feed-in tariff scheme may be appropriate. Although we now consider the US to be a laggard in terms of climate change etc, they have been in the forefront of renewable energy generation for some time. So the first reference I can find to feed-in tariffs (from not very extensive research) is in a speech by President Jimmy Carter in the 1970s.

Essentially the feed-in tariff is a scheme that subsidises investment in renewable energy where the market won’t by itself lead to that investment.

Under the UK scheme, all relevant generators receive two payments for their electricity. The first is the generation tariff which is paid on all energy generated whether it is used on site or exported. This is by far the biggest part of the income stream. The second payment is for electricity exported. This is relatively low, and is set at 3p per kWh. The effect of this is to provide an incentive to use the electricity on site, replacing expensive imported power with cheap home generated power, and also saving the transmission loss, estimated to be about 2%. The feed-in tariff rates vary according to scale and type of technology, but the net effect is intended to provide a return on capital of between 5% and 8% for appropriately sited investments.

Where does the money come from? Well, it’s not from general taxation, but it will come from all the electricity retailers in the UK, apportioned by a process of “levelisation” to each retailer in proportion to its market share. This will increase the retailer’s costs, and will lead to an increase in the price that all consumers pay. Data from Germany, where a feed-in tariff scheme has been in place since 2000, suggests that the increase has averaged out at just €4 per household per month. There is also a suggestion from Spain that the feed-in tariff has actually lead to a reduction in the retail price of electricity because the replacement of natural gas with solar and wind has reduced the demand for and hence the price of the gas.

Over time, it seems certain that the price of finite oil and gas can only rise, whereas the cost of renewable energy will fall as the technology becomes more established. Thus the feed-in tariff acts to accelerate the transition from high to low carbon energy much faster than the market would if left to its own devices.

This link takes you to the feed-in tariffs section on the Department of Energy & Climate Change website:

http://www.decc.gov.uk/en/content/cms/what_we_do/uk_supply/energy_mix/renewable/feedin_tariff/feedin_tariff.aspx

Pouring the Concrete

The foundation is now complete. The roadway was put down on the 4^th of March, and then on the 5^th, when it would have been my Mum’s birthday, the sun shone and the concrete was poured. No lorries fell in ditches or got stuck in mud. No wooden shuttering collapsed under load. Now today the concrete has cured enough to allow the shuttering to be removed, and you can see the foundation slab in all its glory.

Building Up the Re-Bar Structure

On the 5^th February we started. The digger came and the footings were duly excavated.

All the timber shuttering has been installed, and today they have finished building up the reinforcing bar structure that binds the root of the turbine tower into the concrete. Although ground conditions are not ideal, the rain has mostly kept off and we have had no hiccups.


Before bringing concrete to the site, we have to lay a temporary roadway of slatted steel on top of the ground, but we anticipate pouring the concrete next week. Five loads should do it.

The Concrete Foundation Pad

We have had an engineering drawing prepared by the company that undertook the ground investigation. It is almost identical to one of the sample designs provided by the turbine manufacturer. I guess this is reassuring, but it also makes you think, “Why did we bother with all that expensive investigation? I could have told them about the boulder clay anyway!” But you do of course have to do the test drilling, as we could have been on top of a random sand pocket, or saturated conditions lower down. Now we can be confident that the turbine is not going to fall over!

Using the drawing, I have had an alternative quote for the foundation construction from a civil engineering company in Telford. This was substantially higher than the figure quoted by my turbine installation company. Hopefully my choice of installer will be justified, and they can now crack on with the job.