Naked Science Forum
Non Life Sciences => Technology => Topic started by: Petrochemicals on 13/10/2022 18:53:53
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In the U.K. the sun does not achieve great angles. In winter the angles are are poor, the length of day minimal and the energy usage highest. Would solar panels be best mounted vertically ?
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It would prevent them being covered with snow, but would only generate electricity when the sun was on the horizon for a few minutes each day. Previous attempts to replace geothermal heating with solar power by erecting vertical rock slabs were unsuccessful even though the inventors placed them in a circle in case the sun ever decided to shine from a different direction.
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The Latitude of London is 51° North.
So a vertical solar panel facing due south would generate more electricity than the same solar panel mounted horizontally (facing straight up).
- Especially if/when there is snowfall or dustfall (as noted by Alan)
- But it would be even better if solar panels in London were elevated by 51° and facing due South.
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The Latitude of London is 51° North.
So a vertical solar panel facing due south would generate more electricity than the same solar panel mounted horizontally (facing straight up).
- Especially if/when there is snowfall or dustfall (as noted by Alan)
- But it would be even better if solar panels in London were elevated by 51° and facing due South.
A bit further investigation shows the latitude is the angle from the zenith ( I did not know that for some reason) and the earths tilt is 23.5. in summer you add the earth tilt angle and in winter you subtract, giving sunny ol' Landan taen a winter sun angle of 27.5 at its highest low, considerably short of the summer optimum angle of 74.5.
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It would prevent them being covered with snow, but would only generate electricity when the sun was on the horizon for a few minutes each day. Previous attempts to replace geothermal heating with solar power by erecting vertical rock slabs were unsuccessful even though the inventors placed them in a circle in case the sun ever decided to shine from a different direction.
Erm, could you elaborate ?
I'm sure you know thermal solar plants are quickly being left behind photovoltaic.
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I was referring to Stonehenge and its cousins.
The stupid people who design solar farms, and the idiots who invest in them, clearly know nothing about how the sun goes round the earth, so they religiously stick to "latitude plus 15 degrees" in the UK and hope that nobody notices.
Interestingly, the same species of moron seems to design houses, so in snowy northern and southern latitudes they have steeply pitched roofs at a minimum of 30 degrees and more where the snowfall is greater, to which they attach domestic solar panels and hope for the best.
Fortunately our Russian friends sell us masses of cheap gas so we don't need renewables anyway.
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latitude plus 15 degrees"
What is the reason given for the "15 degrees"?
On my roof, the panels are mounted flat to the roof, for ease of installation
- we are closer to the equator than snowy countries
- the roof is less steep than in snowy countries.
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Interestingly, the same species of moron seems to design houses, so in snowy northern and southern latitudes they have steeply pitched roofs at a minimum of 30 degrees and more where the snowfall is greater, to which they attach domestic solar panels and hope for the best.
It takes a real moron to realise that you are pretty much stuck with the roof you have and any solar power might be better than none.
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15 degrees is a first approximation for a simple installation.
The variation of zenith angle and day length increases with latitude. The primary object of solar farming is to maximise annual yield, so you get more bang for your buck if you optimise the angle towards summer peak at high latitudes. However the secondary objective is to maximise supply when demand is greatest and prices are highest, which suggests a tweak towards the winter zenith.
https://sinovoltaics.com/learning-center/system-design/solar-panel-angle-tilt-calculation
sets out some principles in more detail
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It takes a real moron to realise that you are pretty much stuck with the roof you have and any solar power might be better than none.
That said, you can adjust a subframe by ± 5° without seriously affecting windage, subject to planning permission.
Whether any is better than none is more a matter of economics than astronomy and physics, particularly if your roof doesn't face south.
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latitude plus 15 degrees"
What is the reason given for the "15 degrees"?
On my roof, the panels are mounted flat to the roof, for ease of installation
- we are closer to the equator than snowy countries
- the roof is less steep than in snowy countries.
You also do not have cold like snowy countries, Australia's biggest problem seems to be too much sun.
If you angle solar panels you create shadow, if you stick the end of one up the shadow is cast over the others, thus you need to either elevate each panel or have a moving array. That may well be cost effective in Australia .
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It takes a real moron to realise that you are pretty much stuck with the roof you have and any solar power might be better than none.
That said, you can adjust a subframe by ± 5° without seriously affecting windage, subject to planning permission.
Whether any is better than none is more a matter of economics than astronomy and physics, particularly if your roof doesn't face south.
Speaking of economics, I wonder how often the gain from a few degrees of tilt offsets the cost compared to just "sticking them on the roof".
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Assuming a 1 m square panel with a bolt at each corner, 5 degree tilt means substituting 20 cm bolts for two of the usual 10 cm ones, and adding a bit of plastic tubing as a spacer.
Given the phenomenal conversion efficiency and reliability claimed for these devices, and the certainty that climate change will abolish clouds and politics will increase the cost of electricity, I guess they would pay for themselves in a few minutes!
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I was referring to Stonehenge and its cousins.
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Ahh, the number of the beast, "This thing all things devours: birds, beasts, trees, flowers; gnaws iron, bites steel; grinds hard stones to meal; slays king, ruins town, and beats high mountain down".
Solar optimised for winter will also have the advantage of producing most on days it is most needed, the sun tends to shine on the cold days when wind is not blowing. In the summer the sunny days are usually hot. Winter cloudy days are usually a bit warmer.
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The problem still remains: no solar power, and less wind power, at night, when you need it most. Woolly sweaters work best, along with a pile of logs. A medium-size dog is also useful, not just for keeping warm but also for catching your food. This is Liz Truss's as-yet-unpublished agenda for the Sustainable Future of Britain: a tried and trusted formula that worked in the Bronze Age.
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The problem still remains: no solar power, and less wind power, at night, when you need it most. Woolly sweaters work best, along with a pile of logs. A medium-size dog is also useful, not just for keeping warm but also for catching your food. This is Liz Truss's as-yet-unpublished agenda for the Sustainable Future of Britain: a tried and trusted formula that worked in the Bronze Age.
I would say night time can be a good time for cooler temperatures, no one wants to sleep in the heat, it is part of the natural sleep process, you cool down. A reasonably insulated house should keep a high enough temperature.
If solar is mounted vertically is it should even out the output over the year, a better angle in winter but longer duration better sunlight in winter, this would make planning far more rational.
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I have slept in a snow hole, and an entire nation occasionally live in igloos. Problem is that there aren't enough seals and caribou to provide every member of the UK population with the requisite parkas, mukluks, etc without upsetting the blasted tree-huggers. The good news is that the coming winter will reduce the population a bit, particularly the poor, and thus lead to a significant growth in per capita GDP and bankers' bonuses, as promised by Die Fuhrerin. Serves them right for voting Labour.
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I have slept in a snow hole, and an entire nation occasionally live in igloos. Problem is that there aren't enough seals and caribou to provide every member of the UK population with the requisite parkas, mukluks, etc without upsetting the blasted tree-huggers. The good news is that the coming winter will reduce the population a bit, particularly the poor, and thus lead to a significant growth in per capita GDP and bankers' bonuses, as promised by Die Fuhrerin. Serves them right for voting Labour.
Non follow.
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It's all about reasonably insulated housing and a sunless winter. First rule of survival is to get out of the wind, which igloos and snowholes achieve much better than Victorian houses, then wrap yourself in insulation - parachute or fur - with a waterproof outer if possible. A woolly sweater and a leather coat is a good combination for the forthcoming Great British Disaster.
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It's all about reasonably insulated housing and a sunless winter. First rule of survival is to get out of the wind, which igloos and snowholes achieve much better than Victorian houses, then wrap yourself in insulation - parachute or fur - with a waterproof outer if possible. A woolly sweater and a leather coat is a good combination for the forthcoming Great British Disaster.
But the question remains, is solar in the winter seasons effective ?
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This graph says winter is poor for solar, yet is this measured at 90 degrees from the level ? [ Invalid Attachment ]
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But the question remains, is solar in the winter seasons effective ?
No. That's why it's called winter. Like it's cold and the days are short. If you go far enough north or south, the sun doesn't shine at all for 6 months.
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If you go far enough north or south, the sun doesn't shine at all for 6 months.
The thread is about the UK
You certainly get less sunshine in winter.
But that sunshine (and the energy it brigs) are more valuable to people.
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But the question remains, is solar in the winter seasons effective ?
No. That's why it's called winter. Like it's cold and the days are short. If you go far enough north or south, the sun doesn't shine at all for 6 months.
I think by way of trigonometry and sun angles, a 90 degree vertically mounted square meter has almost a 4 times greater effective surface area than a panel mounted at the UK average of 35. Sun angle midsummer is 60 where as midwinter is 15.
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But midwinter daylight hours are about a quarter of midsummer, so even assuming no cloud or fog, the yield would be (a) small and (b) at the least useful time.
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But midwinter daylight hours are about a quarter of midsummer, so even assuming no cloud or fog, the yield would be (a) small and (b) at the least useful time.
7 hours 49 minutes on midwinter, 16 hours 39 midsummer. The arc of the sun is considerably lower in winter, but given solar panel orientation is the ruling factor and the optimum operation window is when the sun is at the tangent, the difference should be far smaller, especially if vertically mounted.
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Depends where you are, of course. Lerwick has 6 hours in winter, 18 hours in summer.
Vertical panel less efficient in summer!
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Depends where you are, of course. Lerwick has 6 hours in winter, 18 hours in summer.
Vertical panel less efficient in summer!
Yep but more consistent over the course of a year, as I've said. The weather is one factor, more cloud in winter. sunlight also has to last through a greater amount of atmosphere on account of the angle.
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So you admit that solar energy is pretty useless in winter. Which is why those whose living depends on it, set their p[anels at an optimum angle that is not 90 degrees.
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So you admit that solar energy is pretty useless in winter. Which is why those whose living depends on it, set their p[anels at an optimum angle that is not 90 degrees.
Not admit but it does appear to be a hopeless task. From the good old fashioned engineering toolbox. [ Invalid Attachment ]
This is at 30 degrees from the equator.
[ Invalid Attachment ]
This is at 60.
https://www.engineeringtoolbox.com/surface-solar-radiation-d_1213.html
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From these graphs, it appears better to live at 30° latitude, rather than 60°.
- I live at 34°S
- And I commonly holiday at 28°S
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From these graphs, it appears better to live at 30° latitude, rather than 60°.
- I live at 34°S
- And I commonly holiday at 28°S
I believe it's 30 degrees north from the equator, not the classical latitude, the link also has a graph from the equator.
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In winter the cold days are the sunny days, where as in summer the sunny days are all hotter.