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SunCalc shows the movement of the sun and sunlight-phase for a certain day at a certain place.
Permaculture and traditional buildings : the case for ecological restoration
This solar window is very important because, it is between 9.00 a.m. To harness the maximum possible energy at a given geographic location, the solar window should be clear and not be shaded by trees or any other obstacle between 9.00 a.m. It is for this reason that, before installing any solar device, one should analyze the installation site’s solar window and make sure that, there aren’t any shading obstacles.
Measuring the sun’s position
The thin orange curve is the current sun trajectory, and the yellow area around is the variation of sun trajectories during the year. The closer a point is to the center, the higher is the sun above the horizon. The colors on the time slider above show sunlight coverage during the day.
The four seasons
Using these two measurements of solar azimuth and solar elevation, a chart can be drawn which will show how the sun’s position changes throughout the year. This chart is called the sun path chart and it shows how the sun’s path looks like from the earth’s surface. During summer, the North Pole is tilted towards the sun. As a consequence, the sun’s path is higher in the sky, causing the northern hemisphere to receive more light and heat.
This gives the solar window – the area of the sky when the sun would be between 9.00 a.m. Now, this brings us to the next question – why is the sun higher in the sky in summer? The answer lies in the earth’s rotation about its tilted axis and it orbit around the sun. The earth rotates about its own axis, titled at an angle of 23.5° degrees to its orbital plane and at the same time, travels around the sun in a huge circular path through space.
2024 eclipse calculators: Find out how much you'll see - Mashable
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Posted: Sun, 24 Mar 2024 07:00:00 GMT [source]
How other people use Suncurves
As an example of how to make use of this chart, notice the lowest sun path, the path for Dec 21st. On this day, the sun would be shaded by a tree which stands between 135° and 150° degrees on the compass. You can see sun positions at sunrise, specified time and sunset.
But to actually chart the boundaries of a solar window for a real geographic location, one needs to know, how to measure the sun’s position in the sky. To pin-point the sun’s position on the sky dome, we need to make two measurements. Continuing further in its orbital path around the sun, the earth reaches the other side of the sun, with the northern hemisphere tilted farthest away from the sun.
Other elements of a permaculture design like solar panels are also needed to be placed thoughtfully to obtain maximum exposure to the sun to harvest as much energy as possible. Even animals can derive benefits from thoughtful solar designs, as they too like to have winter warmth and summer shade. Beehives, chickens, fish ponds and livestock, all appreciate sunshine in winter and shade in summer. The chart can be overlaid with the locations of shading obstacles like trees or buildings. Further, one can overlay the sun’s paths of the shortest and longest day of the year. On top of that, the position lines of the hours of the day can also be graphed.
What is Suncurves?
SunCalc is a little app that shows sun movement and sunlight phases during the given day at the given location. Based on realistic 3D data and the time-dependent position of the Sun in the sky. As the earth continues its orbit around the sun, it reaches a point where its tilt is sideways to the sun. This is called as the Autumnal Equinox, where both the day and the night are of equal length with 12 hours each.
The first measurement is the sun’s direction on a compass. A straight line drawn from the sun to the horizon intersects a specific degree on a compass. This angle is a measure of the sun’s azimuth or elevation. The second measurement is the sun’s altitude or vertical angle. The combination of azimuth and altitude describes a specific spot on the sky dome. Now we can see where the sun would be shaded during the year.
Around June 21st, the northern hemisphere is tilted the most towards the sun and is called as the Summer Solstice. On this day, which can be referred as the first day of summer, the sun’s path is higher in the sky than it is on any other day in the year. In addition, because the sun is in the sky for more hours, the summer solstice is also the longest day in the year. These extra hours of sunlight gives the sun more time to heat the earth and this is the main reason for summer to be the hottest season.
In a darkened room, switch on the flash light on a surface, at a direct 90° degree angle. Now, slowly reduce the angle to make it less direct. You will now observe that the size of the lit area has increased, but the intensity or brightness of it has reduced. What it implies is that, direct 90° degree angle provides more intense light than the inclined one. Higher it is in the sky, the more direct and intense the sunlight would be. Accurate timezones, sunrise and sunset for any location worldwide.
Positions, we can exactly pin point the sun’s location at 9 a.m. As the sun’s path moves up and down through the seasons, the sun’s position at 9 a.m. Understanding the sun’s motion relative to a site is an important aspect of a good permaculture design, as various elements like plants, animals and solar devices depend on sun for their functionality.
Let’s draw the sun’s path on summer solstice and winter solstice. As can be clearly seen the two paths are different, with it been longer and higher in the sky in summer and shorter and lower in the sky during winter. The longer the path, longer is the duration of the sun’s stay in the sky. Throughout the year, the sun’s path keeps shifting up and down between these two extremes. The images show the sun path chart for San Francisco, California.
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