Solar is generally used as an adjective to refer to the sun… and therefore we talk about:
- Solar – system, energy, power, panels.
- Most of the time, we use the word sun;
– it’s sunny today
– the sun is shining brightly
– but you cannot say it is shining or shiny. - Sunlight is the amount of sun you have per day.
- Sun beams or sun rays are thin shafts of light – a ray of light might shine through your window in the morning.
- Formally speaking, the sun rises in the morning and the sun sets in the afternoon/evening.
- In common English we say the sun comes up and the sun goes down.
- As an idiom ‘make hay while the sun shines’ – make the best of favourable circumstances while they last.
English (UK) 
Polski