shimself
Member of DD Central
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Post by shimself on Feb 15, 2014 14:06:12 GMT
I just started wondering if one is a better bet than the other; what started me is that one completed project Resil*** was 25% under forecast last year (the first year) and is 14% down this year. I think solar might be more reliable, because of no moving parts, because if one bit goes wrong (panel or inverter) then you only lose a bit of productio, whereas a turbine is more all or nothing.
Anybody got any insights?
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Post by davee39 on Feb 15, 2014 14:24:41 GMT
These projects would not exist without taxpayer subsidies. My suspicion is that Wind consumes more CO2 in manufacture, installation, maintenance and back-up generation than can possibly be saved on the odd occasion when it works. And I do mean odd occasion since my town has been severely blighted by 30 giant towers, about 0.5km offshore which never seem to have more than 3 or 4 turbines running whatever the weather (So YES I am biased). Solar offers more subject to continuing lower panel costs and an end to subsidies. No good to me though - not enough sunshine here to make it viable, even with the subsidies (too much sea fog).
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Post by batchoy on Feb 15, 2014 15:41:24 GMT
These projects would not exist without taxpayer subsidies. My suspicion is that Wind consumes more CO2 in manufacture, installation, maintenance and back-up generation than can possibly be saved on the odd occasion when it works. And I do mean odd occasion since my town has been severely blighted by 30 giant towers, about 0.5km offshore which never seem to have more than 3 or 4 turbines running whatever the weather (So YES I am biased). Solar offers more subject to continuing lower panel costs and an end to subsidies. No good to me though - not enough sunshine here to make it viable, even with the subsidies (too much sea fog). I don't have a big downer on wind turbines per se, but just like you on a local farm of 10 I have never seen more than a couple turning. I use solar panels on my motorhome and it is amazing how little light is needed for them to be generating, and I am a fan of roof top generation, what I am against and is being fought against locally is taking a large chunk of prime arable land out if use and covering it with solar panels.
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Post by karlh on Feb 17, 2014 14:35:27 GMT
I just started wondering if one is a better bet than the other; what started me is that one completed project Resil*** was 25% under forecast last year (the first year) and is 14% down this year. I think solar might be more reliable, because of no moving parts, because if one bit goes wrong (panel or inverter) then you only lose a bit of productio, whereas a turbine is more all or nothing. Anybody got any insights? Hi,This is a good question. There is much less that can influence the performance of a solar debenture - the underlying technology as you point out is robust and sun levels from year to year are pretty constant. This is why the forecast IRR on solar debentures tends to be lower (6.5 - 8%) than returns on our wind Debentures (8-9.5%). Wind turbines are more complex and though the current turbines are based on technology that has been around for many years, it often takes a bit of time to bed down a turbine once it is installed. For instance with the Great Dunkilns turbine the offer document explained that the return in year one would be lower than future years this is because the turbine needs to be fine tuned over the first year to ensure it is set up correctly to best catch the local wind conditions. Great Dunkilns has just completed its first year service this was conducted in two parts in December and January and is expected to improve the performance significantly. However the returns from a wind turbine will still be more volatile than solar because wind though predictable over the long term can vary significantly from year to year. It is also worth noting that all wind turbine manufactures offer warranties based on an agreed power curve. A power curve shows what a turbine can be expected to generate at any given wind speed. The standard warranty that both REGD and High Down (our current wind project raise) offer is guarantee that the turbine will generate 95% of its expected power at the given wind speed. This means if the turbine is out of action or under performing it is the manufacture who foots the bill for this - not the project developer or in our case debenture holders. In terms of carbon pay back. For your average onshore wind turbine the carbon payback is under a year see ( scotland.wwf.org.uk/wwf_articles.cfm?unewsid=5917) and for a domestic solar system is about 1-4 years depending on location see ( blog.abundancegeneration.com/2013/08/how-much-carbon-dioxide-do-solar-panels-save/ ) I hope that helps edit - 18 February. one thing I forgot to add was the wind speeds last year were below average - we had a great summer so solar was up but wind speeds were about 4% below their historical average. [ www.gov.uk/government/uploads/system/uploads/attachment_data/file/275661/et7_2.xls]. This is significant because power output of a turbine does not increase in a linear fashion as this diagram shows www.wind-power-program.com/turbine_characteristics.htm. Wind speeds 4% lower than average will therefore equate to a bigger drop in electricity production. Lower wind speeds combined with the year one bedding down of the turbine should account for most of the drop in production for last year.
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debeast
(o)(o)
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Post by debeast on Mar 5, 2014 11:05:30 GMT
I just started wondering if one is a better bet than the other; what started me is that one completed project Resil*** was 25% under forecast last year (the first year) and is 14% down this year. I think solar might be more reliable, because of no moving parts, because if one bit goes wrong (panel or inverter) then you only lose a bit of productio, whereas a turbine is more all or nothing. Anybody got any insights? Hi,This is a good question. There is much less that can influence the performance of a solar debenture - the underlying technology as you point out is robust and sun levels from year to year are pretty constant. This is why the forecast IRR on solar debentures tends to be lower (6.5 - 8%) than returns on our wind Debentures (8-9.5%). Wind turbines are more complex and though the current turbines are based on technology that has been around for many years, it often takes a bit of time to bed down a turbine once it is installed. For instance with the Great Dunkilns turbine the offer document explained that the return in year one would be lower than future years this is because the turbine needs to be fine tuned over the first year to ensure it is set up correctly to best catch the local wind conditions. Great Dunkilns has just completed its first year service this was conducted in two parts in December and January and is expected to improve the performance significantly. However the returns from a wind turbine will still be more volatile than solar because wind though predictable over the long term can vary significantly from year to year. It is also worth noting that all wind turbine manufactures offer warranties based on an agreed power curve. A power curve shows what a turbine can be expected to generate at any given wind speed. The standard warranty that both REGD and High Down (our current wind project raise) offer is guarantee that the turbine will generate 95% of its expected power at the given wind speed. This means if the turbine is out of action or under performing it is the manufacture who foots the bill for this - not the project developer or in our case debenture holders. In terms of carbon pay back. For your average onshore wind turbine the carbon payback is under a year see ( scotland.wwf.org.uk/wwf_articles.cfm?unewsid=5917) and for a domestic solar system is about 1-4 years depending on location see ( blog.abundancegeneration.com/2013/08/how-much-carbon-dioxide-do-solar-panels-save/ ) I hope that helps edit - 18 February. one thing I forgot to add was the wind speeds last year were below average - we had a great summer so solar was up but wind speeds were about 4% below their historical average. [ www.gov.uk/government/uploads/system/uploads/attachment_data/file/275661/et7_2.xls]. This is significant because power output of a turbine does not increase in a linear fashion as this diagram shows www.wind-power-program.com/turbine_characteristics.htm. Wind speeds 4% lower than average will therefore equate to a bigger drop in electricity production. Lower wind speeds combined with the year one bedding down of the turbine should account for most of the drop in production for last year. Thank you for all that really useful information and the links. Much appreciated. I wondered if you knew why the answer to a wind question thats been puzzeling me for a while (non baked bean realted) ? Why on most wind farms that i pass are the majority of turbines not spinning. Are they a) Broken b) not enough wind to run them all c) too much power being generated to take into the grid d) turned off for some reason e) something else completely. I realise the options aren't mutually exclusive but ad hoc observational experience says that turbines not turning is a common occurrence. any ideas karlh
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Post by bracknellboy on Mar 5, 2014 19:32:09 GMT
Why on most wind farms that i pass are the majority of turbines not spinning. Are they a) Broken b) not enough wind to run them all c) too much power being generated to take into the grid d) turned off for some reason e) something else completely. Yes. Oh, and of course the marvellous: too much wind, (or possibly the wrong type of wind). Oh, and of course: being paid money by the grid to switch them off. I might invest in them, but I sure as hell would not vote to continue the lunacy (IMHO) that is our current approach to energy policy. [Deliberately slightly over the top provocative statement]
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Post by karlh on Mar 10, 2014 18:27:39 GMT
Hi debeast, You have me on possibly my favourite subject  so very happy to provide more info! If turbines are not spinning they are probably broken, being serviced or there is insufficient wind. As you can imagine site operators will be working to ensure they have situated them in a place that has sufficient wind and will work to keep the turbine operational. Turbines earn the vast majority of their money from generating energy, if they are not turning they are not earning. It is worth noting that once a turbine is operating its core cost is capital (project finance), therefore if it is not generating it can quickly run into difficulties. However to date and to our knowledge no wind farm in the UK has become insolvent, which indicates that on the whole though you may see turbines that are not working for periods they will generate enough energy over the course of the year to cover their costs and generate a reasonable return for investors. Something worth checking out is this link this shows how SSE's fleet of thermal plants is performing. Wind turbine not working are very visible and can therefore generate negative press, people do not notice so easily when the thermal plants are offline. I f you look at SSE list of plants you will see many are not operating due to planned outages, while others are not generating for "other" reasons - this is unexpected outages. bracknellboy, you are correct turbines as well as other forms of generation get paid to turn off. The National Grid pay out balancing payment to generators to incentivise them to turn off when supply is out stripping demand. Wind because it is one of the easiest forms of generation to turn off and on is often asked to provide this service to the grid. On the whole this does not happen that often, because the National Grid is very good at forecasting how much energy renewables will supply and how much energy the grid requires plus the first generators turned off are the peak energy generators as these cost considerably more per kWh than any other form of generation including renewables. Interestingly now we have renewables in the mix we use less of the peak energy generators than we did historically and this due to something call the Merit Order Effect is reducing average wholesale electricity prices - something you would never guess from the way the media portray renewables! More broadly we have just had a record month for wind. In February 11% of the UK electricity supply came from wind energy so wind is certainly doing its job and generating lots of clean power - this figure also only counts the generators connected to the grid, a huge proportion of wind turbines feed directly into farms, office blocks or factories and this generation is not counted in this figure. A recent study by the International Energy Agency forecast that most developed world countries can accommodate up to 45% of renewables in the energy mix within current constraints. If you want to keep track of how much energy is being produced by different sources see Grid Watch, it is for the geeks but quite fun!
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Post by elljay on Mar 11, 2014 8:01:56 GMT
If you want to keep track of how much energy is being produced by different sources see Grid Watch, it is for the geeks but quite fun! Reading through I was getting ready to post that link! Does that mean I'm a geek?  
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Post by karlh on Mar 11, 2014 14:01:58 GMT
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Post by oldnick on Mar 11, 2014 14:40:35 GMT
I switched my kettle on and off a couple of times but couldn't shift the needles, so I got bored. I bet if I hacked I could though...
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Post by elljay on Mar 11, 2014 18:26:41 GMT
Yup! Nukes R Us!  Did you see the... sssh! secret control room on Bang last night? 
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Post by elljay on Mar 11, 2014 18:28:26 GMT
I switched my kettle on and off a couple of times but couldn't shift the needles, so I got bored. I bet if I hacked I could though... , what do you know about Stuxnet?
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Post by oldnick on Mar 11, 2014 20:36:01 GMT
I switched my kettle on and off a couple of times but couldn't shift the needles, so I got bored. I bet if I hacked I could though... , what do you know about Stuxnet? It wasn't me, I never touched it, what did you call it again? That should throw GCHQ off my scent. Mind you the number of trigger words that have appeared in this thread so far will probably lead to dawn raids for all of us.
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Post by gusgorilla on Feb 10, 2016 17:28:18 GMT
Although onshore wind power is cheaper at the moment, and slowly getting cheaper still, there is a limit on what can be done to make blade shapes, generator coils and controller algorithms more efficient. Mass production was helping bring costs down also, but this has been killed for in the UK for now. (Some tories, like Tim Yeo, think this "blind unreasoning hostility" is mad - article in the Telegraph). Materials/semiconductor science has been making solar panel efficiency increase at a remarkable rate for many years (although claims it has been doubling every 2.5 years seem overdone to me) and there is much further to go before limits start to be reached. Solar will overtake onshore wind in a year or two. (From the country's POV it should be "solar and wind" not "solar or wind" - there's no sun at night time and still days can be sunny) Can't miss out the other zero CO 2 power source. Nuclear has always been heavily subsidised and the latest plans involve subsidies that dwarf those previously offered to solar and wind. Although juicy subsidies might sound good for investors they are controversial, as is giving them to Chinese, French and Japanese companies. Politically controversial investments are always a massive gamble and cracks are appearing already. Legal challenges to the subsidies are being prepared by pro-renewables groups and the foreign companies are blowing hot and cold - see article in the Independent.
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shimself
Member of DD Central
Posts: 2,560
Likes: 1,169
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Post by shimself on Feb 27, 2016 11:41:52 GMT
Several turbines on AC are miles below forecast, achieving worse than 50%
How can this be (how can it be so wrong)? Will they ever recover?
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so very happy to provide more info!
