Vernal Equinox 2019

Neil Williams

19 Mar 2019

Do you worship Solar? Tilix Smart Energy certainly does! This short blog post celebrates the Vernal Equinox and discusses some of the reasons to get excited about this time of year.

Winter is past and spring is here at last

20 March 2019 marks the Spring Equinox - this is when the northern and southern hemispheres are equally illuminated. The word comes from Latin Aequus, meaning “equal”, and Nox, meaning “night”.

Is there anything more exciting than the first promise of spring? The days are longer, the earth becomes warmer, plant life is stirring and the fauna are more active.

When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the Spring (or Vernal) Equinox, days and nights are approximately 12 hours long, with day length increasing and night length decreasing as the season progresses.

Solar PV Yield

For the solar industry in the Northern Hemisphere, the Spring Equinox marks the beginning of the season of increased yield. The figure shows a month-by-month cumulative production for a typical solar PV installation.

The amount of irradiation is key. Ambient temperature is not a major factor. Therefore solar PV productivity is not affected by the lag between the length of day and the average temperatures in mid and high latitude locations where the warmest part of the summer lags the Summer Solstice. This lag is due to the time required for ground and water to heat up. That is why August is typically warmer than June even though the hours of daylight are considerably less.

Cultural Importance

The Spring Equinox has cultural significance around the world.

The Anglo-Saxon goddess Eostre had a festival lasting several days. Eostre has since evolved into “Easter” in English and “Ostern” in German. Neopagans observe the Spring Equinox as a cardinal point on the Wheel of the Year.

Nowruz (Persian New Year) is a celebration dating back thousands of years. Nowruz is a Farsi word meaning “new day”. More than 300 million people celebrate Nowruz in places that have been influenced by Persian culture through the ages.

Shunbun no Hi is a public holiday in Japan which has its roots in the ancient Shintoism religion. Nowadays the Japanese use it to hold family reunions, visit shrines, seek out cherry blossoms etc. The holiday is also special to farmers and agriculturalists as a day to pray for good luck and fortune for the crops they may grow in the upcoming season.

Holi is a Hindu spring festival which is also known as the “festival of colours” or the “festival of love”. It signifies the arrival of spring. It is an opportunity to meet others, play and laugh, forget and forgive, and repair broken relationships. The Indian national calendar starts the year on the day after the Vernal Equinox.

Enjoy a Rare Full Moon

Skywatchers in the Northern Hemisphere have a chance to see a cosmic triple play on 20 March 2019:

  1. Full moon
  2. Vernal Equinox
  3. Super moon

A full moon has not landed this close to Spring Equinox since the year 2000, and the two celestial events won’t happen less than a day apart again until 2030. The cherry on the cake is that this full moon will be a super moon. That is the moon will be at its shortest distance from Earth, a mere 223,309 miles away, making for an especially good view.

The full moon that appears in March is known as the Worm Moon - after the worm trails that would appear in the newly thawed ground. It is also known as the Crow Moon, when the cawing of crows signalled the end of winter.