Summer Solstice 2021

John Williams

20 Jun 2021

photo credit Dingzeyu Li on Unsplash

We are halfway through the year And In the Northern Hemisphere, today (mon 21st June) is summer solstice. During the solstice the Earth sees the longest day, with more daylight than night-time. Shetland, Scotland’s most northerly point will have 19 hours of light, with a sunrise at 3.38am and sunset at 10.33pm.

Solar Yield

More energy from the Sun lands on the face of the Earth in just one hour than the entire global population uses in one year. We have all the solar power we could want. And as solar energy keeps getting cheaper it becomes accessible to more people. Solar energy is the future, plain and simple.

I envisage a future where all the Earth’s energy needs are provided 24/7 by Space-based solar power (SBSP), the concept of collecting solar power in outer space and distributing it to Earth. Although not economically viable with present-day space launch infrastructure. Its speculated by some technologists that this may change in the not too distant future.

The current record for solar panel efficiency

In 2019, the world record for solar cell efficiency at 47.1% was achieved by using multi-junction concentrator solar cells, developed at National Renewable Energy Laboratory, Golden, Colorado, USA

Latest Innovation

There are now many exciting new solar technologies either in the pipeline or already on the market. These promising technologies will change the way we think about solar energy production. Here are some newly innovative solar products being worked on today:

The UK Space Agency and the Department for Business, Energy and Industrial Strategy began funding research into space-based solar power (SBSP) systems – essentially very large solar-powered satellites that collect solar energy and beam it back to Earth to be injected into the electricity grid. The launch of a functioning SBSP is predicted for 2050.

CITCEA, a technology transfer centre within Spain’s Universitat Politècnica de Catalunya (UPC) is developing a new device capable of managing surplus power in PV installations, making consumption and injection of surplus solar power into the network more efficient.

Tata Power has launched a first-of-its-kind peer-to-peer solar energy trading project in Delhi. The pilot project uses a blockchain-enabled platform for trading electricity produced from over 2MW of solar PV. This is a landmark innovation and a practical demonstration of how solar producers can sell their excess energy directly to consumers.

photo credit Ankit Sood on Unsplash


The history of solstice celebrations can be traced to Scandinavia where midsummer is an important event. So Important that in Sweden there have been serious discussions to make Midsummer’s Eve into the National Day of Sweden, instead of 6 June.

The world’s biggest solstice event occurs at the prehistoric site of Stonehenge in Wiltshire. The 5,000 years old monument on Salisbury Plain is famed for its alignment with the midsummer sunrise. Each year on 21 June visitors from around the world gather at Stonehenge overnight to see the sunrise above the stones. At dawn the central Altar stone aligns with the Slaughter stone, Heel stone and the rising sun to the northeast. For many, the impulse to arrive at Stonehenge in time for the solstice is reminiscent of all those people drawn to the strange rock in Close Encounters of the Third Kind.