Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ?
|
#2
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
|
#3
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 08:15, wrote:
How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#4
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 08:37, The Natural Philosopher wrote:
On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? realistic at midday in June. It is better than you might think in winter direct sunlight since to some extend the cold makes the panel a bit more efficient. You can also push solar panels a bit harder at the risk of cooking them by adding a couple of mirrors either side. Some fold out portable battery chargers work that way. Average about 20W Pessimist! The usual figure for the UK is about 900kWhr per 1kW peak of PV panel which in ballpark terms is about 100W average (taking a year as 9000hr). The further north you go the worse it gets. Even so I am inclined to think that solar is a bit of a waste of time in the UK since it isn't really sunny enough to be worthwhile. At lower much sunnier latitudes where peak solar power generation coincides with peak aircon demand then having an extra layer on the roof providing shade and solar PV power serves a useful purpose. A lot of UK solar generated electricity is immediately dumped into the homes immersion heater because of FIT market distortions. You get paid for half of what you generate irrespective of what you do with it! -- Regards, Martin Brown |
#5
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In message , John
Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. My mathmatical capabilities do not stretch to this sort of problem:-) -- Tim Lamb |
#6
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In article , Martin Brown '''newspam'''@ne
zumi.demon.co.uk scribeth thus On 30/04/2019 08:37, The Natural Philosopher wrote: On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? realistic at midday in June. It is better than you might think in winter direct sunlight since to some extend the cold makes the panel a bit more efficient. You can also push solar panels a bit harder at the risk of cooking them by adding a couple of mirrors either side. Some fold out portable battery chargers work that way. Average about 20W Pessimist! The usual figure for the UK is about 900kWhr per 1kW peak of PV panel which in ballpark terms is about 100W average (taking a year as 9000hr). The further north you go the worse it gets. Even so I am inclined to think that solar is a bit of a waste of time in the UK since it isn't really sunny enough to be worthwhile. At lower much sunnier latitudes where peak solar power generation coincides with peak aircon demand then having an extra layer on the roof providing shade and solar PV power serves a useful purpose. A lot of UK solar generated electricity is immediately dumped into the homes immersion heater because of FIT market distortions. You get paid for half of what you generate irrespective of what you do with it! Well right now. 30/4 at 12:14 not that sunny today Gridwatch is reporting 6.31 GW 16% which is a fair chunk of the UK demand.. -- Tony Sayer Man is least himself when he talks in his own person. Give him a keyboard, and he will reveal himself. |
#7
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
tony sayer wrote:
today Gridwatch is reporting 6.31 GW From 13GW of installed PV capacity. |
#8
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 12:15, tony sayer wrote:
Well right now. 30/4 at 12:14 not that sunny today Gridwatch is reporting 6.31 GW 16% which is a fair chunk of the UK demand.. At 12:14... The problem with solar in the UK is that it doesn't generate power when we need it most. I'm still having mega problems understanding why we can't deliver nuclear more cost effectively. It seem we should be able to do that and keep both TNP and the global warming crowd happy. A reliable base load give us much more scope for load balancing via smart devices. |
#9
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 11:14, Martin Brown wrote:
Pessimist! The usual figure for the UK is about 900kWhr per 1kW peak of PV panel which in ballpark terms is about 100W average (taking a year as 9000hr). The further north you go the worse it gets. Even so I am inclined to think that solar is a bit of a waste of time in the UK since it isn't really sunny enough to be worthwhile. At lower much sunnier latitudes where peak solar power generation coincides with peak aircon demand then having an extra layer on the roof providing shade and solar PV power serves a useful purpose. Well it's only worth-while because of the very generous subsidy for those of us who got in early, though the price of solar panels has of course dropped a lot since so I don't know whether it's still worth-while. In our case the predicted outputs were pretty accurate. We've had a 4kW set of panels on our roof since 2011 and the output each year has been at least slightly above the predictions. No real sign of ageing so far - last year was our best year overall. I just noticed the other day that near mid-day we were getting the full 4kW while the sun was out, which doesn't happen much in winter for obvious reasons. So I'm a satisfied owner so far. -- Clive Page |
#10
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 11:34, Tim Lamb wrote:
how much panel do you need for Hertfordshire sunshine May to October? Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. My mathmatical capabilities do not stretch to this sort of problem:-) There are quite a few programs around that predict average results, but you need to give them lots of information about your location, the azimuth and elevation of the panels, etc. -- Clive Page |
#11
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 11:34, Tim Lamb wrote:
In message , John Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? It might be OK over that period with something like a 300W PV panel to guard against several cloudy days in succession. The main worry will be people nicking it - even the batteries grow legs sometimes Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. My mathmatical capabilities do not stretch to this sort of problem:-) mgh = 600kg x 10ms^-2 x 5m = 3000kJ needed each day Roughly 8h daylight and 3600s in an hour = 29000s so in theory a 100W panel would just be able to keep up if it was sunny every day but allow at least twice that and you will need a charge controller too. Every time I have tried to do solar powered irrigation (but on a slightly smaller scale) lugging a heavy SLA battery out to the field and taking the old one away to recharge has won hands down. Solar panels are a bit cheaper now but I doubt if it is truly worthwhile. OTOH if he has a solar panel just lying around it would extend the period between having to manhandle to battery and recharge it at home. I only needed a 3m head of water and 100L delivered daily. -- Regards, Martin Brown |
#12
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 10:27, John Rumm wrote:
On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. Full midday sun in the summer will reduce the maximum output as the panels are warmed. Maximum output is more likely in full sun on a cool/cold Spring day. -- F |
#13
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 14:01, Tim Streater wrote:
In article , Clive Page wrote: Well it's only worth-while because of the very generous subsidy for those of us who got in early ... Meaning that it was never really worthwhile. Subsidies are always a bad idea as they hide the true cost of something. It might or might not be worthwhile. You need to get some early adopters on board if the mass production cycle is ever to get off the ground. I don't think the economics for solar PV stack up particularly well in the UK - we don't get enough sunshine and when we do in summer there is less not more demand for electricity. Solar thermal is better but also a bit borderline and isn't subsided in the UK so hardly anyone does it. OTOH when thin film perovskite PV comes of age it might even be viable here if it drops the price per 1kW peak by an order of magnitude. https://physicsworld.com/a/caffeine-...e-solar-cells/ They have reached about 20% efficiency and are thermally stable now (although it is still a bit borderline). -- Regards, Martin Brown |
#14
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 13:11, Martin Brown wrote:
On 30/04/2019 11:34, Tim Lamb wrote: In message , John Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? It might be OK over that period with something like a 300W PV panel to guard against several cloudy days in succession. The main worry will be people nicking it - even the batteries grow legs sometimes Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. My mathmatical capabilities do not stretch to this sort of problem:-) mgh = 600kg x 10ms^-2 x 5m = 3000kJ needed each day Roughly 8h daylight and 3600s in an hour = 29000s so in theory a 100W panel would just be able to keep up if it was sunny every day but allow at least twice that and you will need a charge controller too. Every time I have tried to do solar powered irrigation (but on a slightly smaller scale) lugging a heavy SLA battery out to the field and taking the old one away to recharge has won hands down. Solar panels are a bit cheaper now but I doubt if it is truly worthwhile. OTOH if he has a solar panel just lying around it would extend the period between having to manhandle to battery and recharge it at home. I only needed a 3m head of water and 100L delivered daily. Some years ago I tried to use solar lighting in winter for a small stables. Admittedly not with a very big panel. Not very much light is needed in the winter, but it still was a complete failure. Now, like Martin I manage fine with a SLA swapped out every week or so. |
#15
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 11:34, Tim Lamb wrote:
In message , John Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. OK this is entirely guesswork, so make what you want of it... If we work it out from the work required for that lift of water... So Force x Distance = 600 x 9.8 x 5 = ~ 30kJ of energy. Now that ignores the losses associated with the motor, pump, and battery cycling etc. So let's make a few wild stabs... say 60% for the motor, 80% for the battery charge cycle. Pump efficiency is harder to call - could be 50 to 70% for a smaller one. Lets go with 60%. so we could do 30,000 / ( 0.6 x 0.8 x 0.6 ) = ~105kJ Energy input required from the panels. Let's say a typical roof top sized panel can give approx 250W peak. That's perhaps 1.2 kWh per day in summer (20% load factor). 1.2kWh in J is 4.3 MJ. In winter is could be 0.18 kWh (3% load factor) or ~650kJ. That sounds like it ought to be plenty, although the variation from cloud cover can be significant - so some days you may only get a tenth of that - so you would still be relying on the battery to provide potentially several days worth of support worst case in the winter. (and if you have snow cover, then all bets are off!) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#16
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In article ,
Andy Burns wrote: tony sayer wrote: today Gridwatch is reporting 6.31 GW From 13GW of installed PV capacity. But the nuclear lot want a power station running flat out all day every day. -- *Nothing is foolproof to a sufficiently talented fool* Dave Plowman London SW To e-mail, change noise into sound. |
#17
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In article ,
Pancho wrote: The problem with solar in the UK is that it doesn't generate power when we need it most. Then you adjust the output from the generators that don't come from solar? After all, no generator has a constant load 24/7. -- *A 'jiffy' is an actual unit of time for 1/100th of a second. Dave Plowman London SW To e-mail, change noise into sound. |
#18
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In article ,
Tim Streater wrote: In article , Clive Page wrote: Well it's only worth-while because of the very generous subsidy for those of us who got in early ... Meaning that it was never really worthwhile. Subsidies are always a bad idea as they hide the true cost of something. Thus spake a true Tory. Except where that subsidy applies to him, of course. -- *INDECISION is the key to FLEXIBILITY * Dave Plowman London SW To e-mail, change noise into sound. |
#19
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 13:31, newshound wrote:
Some years ago I tried to use solar lighting in winter for a small stables. Admittedly not with a very big panel. Not very much light is needed in the winter, but it still was a complete failure. Now, like Martin I manage fine with a SLA swapped out every week or so. At a stables if you wanted then wind power isn't too bad and you can get 300-500W units intended for topping off batteries in sailing boats. Solar in winter is pretty hopeless. There are bunch of solar powered active radar "please go round the dangerous bend" signs round here which kill their batteries stone dead every winter. In summer they are in fine fettle all day but on a frosty winters morning they are useless and they typically fail about two hours after sunset in mid-winter. -- Regards, Martin Brown |
#20
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
2KW over how much of the hours in a year on average, its not a lot is it?
Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! wrote in message ... How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? |
#22
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
Dave Plowman wrote:
Andy Burns wrote: tony sayer wrote: today Gridwatch is reporting 6.31 GW From 13GW of installed PV capacity. But the nuclear lot want a power station running flat out all day every day. Is there anything wrong with maximising output? |
#23
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In message , Martin Brown
writes On 30/04/2019 11:34, Tim Lamb wrote: In message , John Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? It might be OK over that period with something like a 300W PV panel to guard against several cloudy days in succession. The main worry will be people nicking it - even the batteries grow legs sometimes :-) 500m from the nearest highway. Trees grow along river banks so the panel would probably go on the top of a 12 or 18ft. scaffold pole. The battery/controller could be in a padlocked cabinet. I suppose some sort of time delay would be required as a float over pressure switch would reset as soon as the water had fed back through the pump. Non return valve? Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. My mathmatical capabilities do not stretch to this sort of problem:-) mgh = 600kg x 10ms^-2 x 5m = 3000kJ needed each day Roughly 8h daylight and 3600s in an hour = 29000s so in theory a 100W panel would just be able to keep up if it was sunny every day but allow at least twice that and you will need a charge controller too. I suppose we need to consider pump motor efficiency. Every time I have tried to do solar powered irrigation (but on a slightly smaller scale) lugging a heavy SLA battery out to the field and taking the old one away to recharge has won hands down. Solar panels are a bit cheaper now but I doubt if it is truly worthwhile. OTOH if he has a solar panel just lying around it would extend the period between having to manhandle to battery and recharge it at home. This is likely to be an annual requirement and the cost spread over several years. It might be better to find a commercially available kit. I only needed a 3m head of water and 100L delivered daily. Hmm.. they could drink from the river if the general public had the integrity to keep themselves and their dogs on the footpath. Thanks -- Tim Lamb |
#24
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In message , John
Rumm writes On 30/04/2019 11:34, Tim Lamb wrote: In message , John Rumm writes On 30/04/2019 08:15, wrote: How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Its likely to be a true reflection of the maximum power delivery of the panel when in full midday sun in the summer. In peak summer you might get a load factor as hight as 20% in the uk. In the winter it will be down in low single digits. Averaged across the year its usually estimated to around the range of 10% - 12%. Also peak delivery never aligns with peak demand. Hmm.. My grazing tenant is considering solar PV panels for an unattended cattle watering set up. 12V bilge pumps seem readily available and adequate for the head and flow required. Lead acid battery not a problem but... how much panel do you need for Hertfordshire sunshine May to October? Hot weather conveniently requires more water which, last summer, was around 600litres/day at a head of around 5m. OK this is entirely guesswork, so make what you want of it... If we work it out from the work required for that lift of water... So Force x Distance = 600 x 9.8 x 5 = ~ 30kJ of energy. Now that ignores the losses associated with the motor, pump, and battery cycling etc. So let's make a few wild stabs... say 60% for the motor, 80% for the battery charge cycle. Pump efficiency is harder to call - could be 50 to 70% for a smaller one. Lets go with 60%. so we could do 30,000 / ( 0.6 x 0.8 x 0.6 ) = ~105kJ Energy input required from the panels. Let's say a typical roof top sized panel can give approx 250W peak. That's perhaps 1.2 kWh per day in summer (20% load factor). 1.2kWh in J is 4.3 MJ. In winter is could be 0.18 kWh (3% load factor) or ~650kJ. That sounds like it ought to be plenty, although the variation from cloud cover can be significant - so some days you may only get a tenth of that - so you would still be relying on the battery to provide potentially several days worth of support worst case in the winter. (and if you have snow cover, then all bets are off!) May to October only luckily. Last I heard, he has not yet bought the cattle! Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. Thanks for the maths! -- Tim Lamb |
#25
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 14:29, Jethro_uk wrote:
On Tue, 30 Apr 2019 12:28:13 +0100, Pancho wrote: The problem with solar in the UK is that it doesn't generate power when we need it most. That's if you are obsessed about PV solar (which conveniently is also the only solar you can sell to the grid). Now if it was a case about being *serious* about solar, rather than a greenwashed ponzi scheme, you'd be using solar panels to directly heat water and then keep that stored in your hot tank for used whenever - thus reducing your gas/electric consumption. The point is in the UK we use most energy in the winter. So yes piping hot water in the summer. I don't know about you but I spend very little on hot water. Solar power is an excellent idea, but not in the UK. The point I find irritating is that I'm not seeing sensible energy policy from anyone important. A bit like Brexit, politicians would rather twiddle their thumbs than make a good long term decision that would cause problems for them in the short term. |
#26
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 14:33, Jethro_uk wrote:
On Tue, 30 Apr 2019 14:07:53 +0100, Brian Gaff wrote: A friend has those water panels on her roof and has told me it saves a lot of money on bills for heating water. I guess its lower tech though and lets face it many like the idea of gadgetry! I think it's quite high tech, if you are using the vacuum tubey things My primary concerns are about getting what must be quite a weight of water onto the roof, and the potential for burst pipes. Although I guess if your roof is doing it's job, a leaky setup should be no worry. There's not much weight - at least with the systems that I looked into. The tubes contain little water and there is a separate insulated tank, which can be inside. A small pump pushes water from the bottom of the tank, into the bottom of the collectors and it returns to the tank from the top. The small volume, low flow, lets the water get very hot before returning. The pump flow can be automatically varied to give slower flow when there is less sunlight and so maintain a high return temperature. When there is insufficient sunlight, the pump stops and the water drains back down to the tank (preventing freezing in the tubes). The pump can also be stopped if the tank is getting too hot to prevent boiling in the tubes. I looked into buying the bits separately and making my own control system. I did come up with a simple control circuit and software design when I was looking into it, but I don't think I kept it when I didn't take things any further. SteveW |
#27
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 15:01, Tim Lamb wrote:
Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. An urban dweller asks... If the PV is within the field might the cows decide to test its support as a scratching post? -- Robin reply-to address is (intended to be) valid |
#28
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In article ,
Andy Burns wrote: Dave Plowman wrote: Andy Burns wrote: tony sayer wrote: today Gridwatch is reporting 6.31 GW From 13GW of installed PV capacity. But the nuclear lot want a power station running flat out all day every day. Is there anything wrong with maximising output? There would be if it is wasted? -- *24 hours in a day ... 24 beers in a case ... coincidence? * Dave Plowman London SW To e-mail, change noise into sound. |
#29
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 15:01, Tim Lamb wrote:
May to October only luckily. Last I heard, he has not yet bought the cattle! Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. If you only need summer, then a quarter sized panel would likely do it based on those figures. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#30
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 14:04, Brian Gaff wrote:
2KW over how much of the hours in a year on average, its not a lot is it? A notional 2kW is probably something like 8 full sized panels. Seems a bit excessive for a water trough. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#31
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 13:46, Dave Plowman (News) wrote:
In article , Pancho wrote: The problem with solar in the UK is that it doesn't generate power when we need it most. Then you adjust the output from the generators that don't come from solar? After all, no generator has a constant load 24/7. Which basically means that all solar farms produce 80% (at best) of their installed capacity from gas, and wind farms at least 50%. So if you want "zero" net carbon, then neither is much use unless you can find a way of storing 7TWh of energy! -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#32
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 15:01, Pancho wrote:
On 30/04/2019 14:29, Jethro_uk wrote: On Tue, 30 Apr 2019 12:28:13 +0100, Pancho wrote: The problem with solar in the UK is that it doesn't generate power when we need it most. That's if you are obsessed about PV solar (which conveniently is also the only solar you can sell to the grid). Now if it was a case about being *serious* about solar, rather than a greenwashed ponzi scheme, you'd be using solar panels to directly heat water and then keep that stored in your hot tank for used whenever - thus reducing your gas/electric consumption. The point is in the UK we use most energy in the winter. So yes piping hot water in the summer. I don't know about you but I spend very little on hot water. Even if you use 100L every day of the year, that usually only works out at under £150/year in gas... That kind of throws many of these multi thousand pound schemes for solar hot water into context. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#33
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 15:34, Robin wrote:
On 30/04/2019 15:01, Tim Lamb wrote: Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. An urban dweller asks... If the PV is within the field might the cows decide to test its support as a scratching post? More or less guaranteed - that and trying to push it over. At least there is nothing tempting and green about it for them to try and eat! But they will try to eat any kind of loose cable they can see too. They like scratching themselves on my fence for similar reasons. -- Regards, Martin Brown |
#34
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On 30/04/2019 13:49, Dave Plowman (News) wrote:
In article , Tim Streater wrote: In article , Clive Page wrote: Well it's only worth-while because of the very generous subsidy for those of us who got in early ... Meaning that it was never really worthwhile. Subsidies are always a bad idea as they hide the true cost of something. Thus spake a true Tory. Except where that subsidy applies to him, of course. Even true tory's can understand basic economics... subsidy can be worthwhile when it promotes a behaviour that contributes to a common good. Much like taxation can be be use to fold the costs of externalities back into any practice where they are currently avoided. That forces the true cost of an activity back onto those responsible for it, and restores more realistic market forces. Those that promote subsidy of renewable energy generation will argue that its an industry that is new and hence needs support to reach maturity (an argument wearing thin IMHO), and that there is a common good being achieved from the production of low carbon energy. There are major flaws in the argument that stem from the fact that we currently have no practical use for intermittent energy sources. Hence the delivery of it must be forced to become a continuous. Either the producer of the energy must provide their own storage, or they rely on existing flexible generation capacity elsewhere in the grid to make up the shortfalls. Currently a massive externality the producer is not having to meet. To add insult to injury, most of that flexible generation capacity will be gas powered. So currently, by having grid connected solar, you just lock in a requirement for gas generation which seems to go against much of its whole stated purpose. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#35
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
wrote
How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw howlikel is this to be true/realistic ? Depends on where you put the panel, whether it tracks, and how much cloud you get etc and how far from the equator you install it. As usual, its normally the best you can ever get in the best conditions. |
#36
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
John Rumm wrote:
On 30/04/2019 15:01, Tim Lamb wrote: May to October only luckily. Last I heard, he has not yet bought the cattle! Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. If you only need summer, then a quarter sized panel would likely do it based on those figures. I use a 40w panel to run a Oase Solar 700 pond pump, both are now around 10 years old. On full chat according to the makers figures it will shift 700L an hour using 8watts but that would be max 2m head . From about now to the September in conjunction with an 80 amp hour leisure battery it ran the water feature for quite a few hours a day and some pond lights till about 11pm till a time switch turned them off but there wasnt much reserve if there were some cloudy or rainy days. Later I installed a relay coupled to one of those tiny battery charging panels so when the conditions allowed for some solar generation it closed the circuit from the pump to the battery .That stopped the pump flattening the battery, the solar charge controller would have switched it off eventually it I didnt want it to go that low. From about October to May the charge controller took more power than was being generated so the system got mothballed for the winter. If I was doing it again I would definitely go for a larger panel as they are much cheaper relatively than when I purchased mine. As it I have since got mains to that area of the garden and the battery failed a while back so I have removed the charge controller and battery and the panel is now connected directly to pump. Sun comes out , Water feature runs. There are quite a few solar pond pumps systems advertised , the Oase pump one was quite expensive 10 years ago and many of the complete systems advertised now are a lot cheaper. I suspect I could pee more than most of them. For reliability and to work it will not be cheap. GH |
#37
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
In message , Robin
writes On 30/04/2019 15:01, Tim Lamb wrote: Looking at physical size... roughly 1.6x1.0m bit big to wave about on a single scaffold pole. An urban dweller asks... If the PV is within the field might the cows decide to test its support as a scratching post? Very likely. If they get the frequency correct we could have a useful sine wave:-) -- Tim Lamb |
#38
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
"Pancho" wrote in message ... On 30/04/2019 12:15, tony sayer wrote: Well right now. 30/4 at 12:14 not that sunny today Gridwatch is reporting 6.31 GW 16% which is a fair chunk of the UK demand.. At 12:14... The problem with solar in the UK is that it doesn't generate power when we need it most. I'm still having mega problems understanding why we can't deliver nuclear more cost effectively. Basically because only the french ever did them in much volume and even they are now stuffing it up and doing it much more expensively than they used to. China is doing them cheaply but unsurprisingly no one is too keen on taking a chance with theirs. It seem we should be able to do that and keep both TNP and the global warming crowd happy. But not the panic merchants who hate nukes. A reliable base load give us much more scope for load balancing via smart devices. Yes, particularly in the first world that already has nuclear weapons. |
#39
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On Tuesday, 30 April 2019 08:15:08 UTC+1, wrote:
How realistic are the manufacturers claims for energy produced by their solar pv panels. If they claim 2kw how likel is this to be true/realistic ? I have only seen my PV panels hit rated output only rarely and only for a short period. The KWp is only achieved when the sky is totally clear, the weather is cold and the sunlight is @ 90deg to the panel I have 8Kw of PV, generates just under 8Mwh/year. It all depends on orientation and shading (if any). My situation is almost ideal. They deteriorate as they age. (1%/year allegedly) |
#40
Posted to uk.d-i-y
|
|||
|
|||
Realistic claims for solar pv
On Tuesday, 30 April 2019 12:28:16 UTC+1, Pancho wrote:
On 30/04/2019 12:15, tony sayer wrote: Well right now. 30/4 at 12:14 not that sunny today Gridwatch is reporting 6.31 GW 16% which is a fair chunk of the UK demand.. At 12:14... The problem with solar in the UK is that it doesn't generate power when we need it most. I'm still having mega problems understanding why we can't deliver nuclear more cost effectively. It seem we should be able to do that and keep both TNP and the global warming crowd happy. A reliable base load give us much more scope for load balancing via smart devices. Nobody has a viable/economic solution to dispose of the nuclear waste. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Suspiciously high and random solar water/pv claims at an Enviro Home showhouse. | UK diy | |||
REALISTIC TR-802 8-TRACK DECK-EBAY-one cent ! | Electronics Repair | |||
shematic for realistic sta-860 | Electronics Repair | |||
Realistic MT-400 VHF Receiver Manual | Electronics Repair | |||
pro2020 realistic scanner | Electronics Repair |