Tilt your solar panels to 44.4° facing south in Shandon. That is the most efficient fixed angle for its latitude of 56.01°. The full breakdown, including seasonal and monthly adjustments, is below.
Shandon is in the G84 postcode district, and every angle here is computed at that district's center, 0.8 miles from Helensburgh. At UK latitudes the best tilt moves about a third of a degree per degree of latitude. That is a tenth of a degree across 19 miles, so the figure holds anywhere in G84.
Today, the most efficient tilt for photovoltaic panels in Shandon is 51.4°, facing south. At solar noon the sun sits 38.6° above the horizon. Setting your panels to this angle keeps them as close to perpendicular to the sun as possible, which is where they generate the most electricity.
Your photovoltaic panels need to be angled facing south. Shandon is in the northern hemisphere, so panels catch the most sun facing south.
If you're mounting the photovoltaic panels at a stationary angle, such as on your roof, the most efficient angle is 44.4°.
If you're planning to change the angle of your photovoltaic panels twice per year, the most efficient angle is 31.1° facing south in summer months and 68.2° facing south in winter months.
When changing the angle of your photovoltaic panels each season, the most efficient angle is 27.2° facing south in summer months and 73.9° facing south in winter months, and 52.6° facing south in autumn and spring months.
If you adjust your photovoltaic panels every month, the table below gives the most efficient angle for Shandon throughout the year. The shallowest angle is 32.6° in June, and the steepest is 79.4° in December.
| Month | Optimal tilt | Sun angle at noon |
|---|---|---|
| January | 76.1° | 13.9° |
| February | 67.2° | 22.8° |
| March | 56.4° | 33.6° |
| April | 44.4° | 45.6° |
| May | 35.9° | 54.1° |
| June | 32.6° | 57.4° |
| July | 35.6° | 54.4° |
| August | 44.2° | 45.8° |
| September | 56.2° | 33.8° |
| October | 67.8° | 22.2° |
| November | 76.4° | 13.6° |
| December | 79.4° | 10.6° |
The sun angle at noon is how high the sun sits above the horizon at midday. Facing your panels south at the tilt shown for each month keeps them as close to perpendicular to the sun as possible, which is where they generate the most electricity.
G84
It comes out of your latitude. Shandon sits at 56.01°, which puts the best fixed angle at 44.4°. Near the equator the midday sun is almost overhead, so panels lie close to flat, around 3°. The further from the equator you are, the lower the sun sits, and the steeper your panels have to stand to face it squarely.
The climb is not one for one. At 30° of latitude the best fixed tilt is about 31°, but at 60° of latitude it is about 46°, not 60°. The optimum flattens off toward the poles because the winter sun is low and much of the light arriving is diffuse rather than direct. Every angle on this page comes from a curve fitted to measured optimal-slope data for 52 cities, so it follows that flattening instead of assuming tilt equals latitude. See how the two compare.
The angle is settled. Here is what is worth checking on the panels themselves:
Place names and postcode district coordinates contain OS data © Crown copyright and database right, and Royal Mail data © Royal Mail copyright and database right, used under the Open Government Licence v3.