We’ve been collecting general weather data for Crondall since February 2006, but in late January 2020 added a solar sensor to allow us to start tracking sunshine hours, solar energy and Evapotranspiration.
Here’s an easy to view monthly overview of the Solar Energy measured in watts / m² (average, minimum and maximum) so you can easily see the variations for the various months (and in time years), as well as scanning the months of any particular year.
As well as the monthly summary, if you’d like to see how each day breaks out within a particular year then select the “daily detail” radio button, and if you’d like to see how the various seasonal averages compare then select the “seasonal summary” radio button where we then summarise as follows:
Northern Hemisphere Meteorological Seasons
Winter: December, January, February
Spring: March, April, May
Summer: June, July, August
Autumn: September, October, November
If you’d like to see how the current month’s data for Temperature and Rainfall compares to the overall average then click here
And if you want to see Crondall’s all time station records for all weather statistics then please go here
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Very useful data. I want to use some of it to help determine how much electricity our shop will generate with a given PV array, and how much of that will have to be sold to the grid. I should be able to get a good idea by using daily insolation and applying a sine wave to find approx hourly data. (I suppose you don’ t have hourly figures do you?).
I think the “solar kWh ” figures look most appropriate. Could you explain what that actually is. Also can ethe figures be downloaded to csv format?
Thanks
Andy
Hi Andy,
Glad you are finding the data interesting and valuable :)
The Solar kwh tab measures the kilowatt hours of solar energy received per square metre which is as you mentioned I think will be the most approriate measure for you.
We actually log the solar every minute, and I’m very happy to send you say the April log file to see if it would suit – just let me know.
Many thanks
Neil
Just have query on your Average Maximum Solar numbers.
Your numbers for Feb to Jun 2021 look like they should be those of 2020.
Covid lockdown cleansed the skies in Spring 2020 shooting up solar as we also had a wonderfully sunny period.
My solar panel readings are daily and don’t suggest 2021 being the best spring.
Hi Mark,
Thanks for the follow up and double checking the data.
I’ve double checked back to the source data and all is being pulled in correctly – maybe our micro climate in Crondall once again has been anomalous to the macro trends?
Feb21 to April21 sunshine hours are also the highest we have recorded in the respective yearly months which is also suggestive of higher average solar.
Thanks again
Neil
https://www.nature.com/articles/s43247-021-00110-0
Abstract
Spring 2020 broke sunshine duration records across Western Europe. The Netherlands recorded the highest surface irradiance since 1928, exceeding the previous extreme of 2011 by 13%, and the diffuse fraction of the irradiance measured a record low percentage (38%). The coinciding irradiance extreme and a reduction in anthropogenic pollution due to COVID-19 measures triggered the hypothesis that cleaner-than-usual air contributed to the record. Based on analyses of ground-based and satellite observations and experiments with a radiative transfer model, we estimate a 1.3% (2.3 W m−2) increase in surface irradiance with respect to the 2010–2019 mean due to a low median aerosol optical depth, and a 17.6% (30.7 W m−2) increase due to several exceptionally dry days and a very low cloud fraction overall. Our analyses show that the reduced aerosols and contrails due to the COVID-19 measures are far less important in the irradiance record than the dry and particularly cloud-free weather.
https://www.bearsbythesea.co.uk/wxsolarseason.php
https://www.herz.uni-bonn.de/wordpress/index.php/2021/10/01/record-high-solar-irradiance-in-western-europe-during-first-covid-19-lockdown-largely-due-to-unusual-weather/
Published in Communications Earth & Environment, Volume 2, 37, 2021:
Spring 2020 broke sunshine duration records across Western Europe. The Netherlands recorded the highest surface irradiance since 1928, exceeding the previous extreme of 2011 by 13%, and the diffuse fraction of the irradiance measured a record low percentage (38%). The coinciding irradiance extreme and a reduction in anthropogenic pollution due to COVID-19 measures triggered the hypothesis that cleaner-than-usual air contributed to the record. Based on analyses of ground-based and satellite observations and experiments with a radiative transfer model, we estimate a 1.3% (2.3 W m−2) increase in surface irradiance with respect to the 2010–2019 mean due to a low median aerosol optical depth, and a 17.6% (30.7 W m−2) increase due to several exceptionally dry days and a very low cloud fraction overall. Our analyses show that the reduced aerosols and contrails due to the COVID-19 measures are far less important in the irradiance record than the dry and particularly cloud-free weather.
https://www.bearsbythesea.co.uk slash wxsolarseason.php
Thanks for responding.
The reports I’ve pasted in back my observation but the bearsbythesea data corroborate your readings.
Do your source readings take into account cloud cover or not? Having visited various data/tools sites such as Nasa, there are so many types of data and sometimes they take into account cloud cover, other times not.
My simple mission was to find out how far below average my kWh production from March to September 2024 is expected to be in comparison to the average for previous years for the Surrey/London border
Difficult to go against the “official” reports but interesting that Bearsbythesea mirrors our data as they are using essentially the same weather software and hardware as Crondallweather – at least in terms of the Davis Vantage Pro2 main system.
I can’t tell if they are using the Davis UV/solar collector or the Tempest system that we use – shouldn’t make a material difference either way.
In terms of cloud cover, no we don’t have any kit that is directly measuring the cloud cover, so our readings are based purely on what is hitting the sensor (which is above the roofline and is not subject to any daytime shadows)
The key question is what angle to the sun are all these measurements taken, a pretty critical detail that seems to be missing…??
Hi Tony,
As mentioned the monitor is up above the roofline and also free of all shadows from trees etc, so it is measuring based on the natural inclination of the sun which of course varies throughout the year.