Forest Fire Smoke and Solar Panels

Forest Fire Smoke and Solar Panels

It seems as if forest fires are becoming bigger and more destructive in recent years.  This is certainly consistent with the theory of global warming caused by carbon dioxide and other greenhouse gases.  Some people disagree with that theory, but be that as it may, there is no doubt that the increasing smoke days affect human health and activity.

One other thing that forest fire smoke affects is solar power, as it stops light from reaching solar panels. Depending on the size of the particles, the light can be scattered or absorbed, via the processes of reflection, refraction or diffraction.  Photons tend to be scattered by the smaller and intermediate sized smoke particles, which can give the atmosphere a hazy appearance.  They can also be absorbed by larger particles, which gives a darkening effect to the sky.  Smaller particles can scatter wavelengths of light differentially, which can give the sun a strange red appearance, much like a sunset, though even redder at times. (Fundamentals of Air Pollution, Williamson).

The picture below gives some idea of this, though the redness of the sun was not well picked up by the iPhone camera that I used.

In my city (Edmonton, Alberta, Canada), we have seen a lot of serious forest fires in the past few years, which have blown tremendous amounts of smoke over long distances.  In fact, it is not unusual to be severely “smoked in” by fires in neighboring British Columbia, though the most recent troublesome fires have been in the far north of Alberta, in High Level (roughly 700 kilometers away) and Lesser Slave Lake (roughly 350 kilometers away). 

That’s a long way to travel, but according to an old text book that I own (Fundamentals of Air Pollution, Williamson), “Some estimates conclude that the mean time for which a particle is a resident in the lower troposphere is about five days”(page 345).  That’s over 100 hours, so if a wind is blowing constantly at 10 km/hour, the particulate matter can travel 1000 km or so.  There would naturally be some dispersal, so the smoke will be relatively diluted compared to the source, but the amount of smoke in the air can still be surprising. 

 

Attached is a graph of my solar panel array’s output during the last week or so of May, 2019.  As you can see, the heavy smoke of May 30 dropped the power output to about only 23% of its pre-smoke levels from about 26 KWhrs to about 6 KWHrs.  The day after, the smoke had cleared quite substantially, so the power was cut to about 65% of its pre-smoke levels.  Then, by the third day, most of the smoke was gone, and the solar panel output had recovered to about 85%.

I should note that on the worst day, the sun was bright red at mid-day, an otherwise clear day.  Visibility was poor – I could just barely see a building about 2 blocks from my office window, which is usually easy to make out, as it is a bright yellow (the University of Alberta Butterdome, a sports facility nicknamed for its shape and colour, which make it resemble a block of butter).

 Here’s a photo of the sun that day, that I took with my iPhone.  Unfortunately, the iPhone camera pixels get saturated pretty quickly, so the red is washed out to yellow in the center of the sun.  The edge effects (sort of pink at the edge of the sun) are more like what the visual appearance was to the human eye over the entire globe of the sun (though even somewhat redder than that).  These edge effects are somewhat reminiscent of solar limb darkening, though, as I stated above, I believe they are mostly a camera artifact, perhaps enhanced by refraction of the sun’s light through some of the smaller aerosols in the smoky sky.

Also attached is a graph from the previous August, which was a very smoky month, due to fires in British Columbia that years.  As you can see, there were two separate multi-day smoke events, one about a third of the way through the month, and another about two-thirds of the way through.  In that case, the first smoke event almost knocked the solar production to nothing for one day (about 10% of non-smoke production) and cut production to less than half for several days in the last part of the month.

The two trend lines show how production averaged over the month, with and without the smoke days included.  As you can see, the trend line without the smoke days tends to be about 3 KWhrs higher than the trend line with smoke days included.   If the total for the month is estimated from the non-smoke trend, the power production is about 540 KWhrs.  Using the trend line with smoke days included, the total is about 465 days.  So, the smoke days cut about 75 KWhrs, or about 14%.  In an industrial scale setup, that would be a lot of power lost, and a lot of money lost.

So, it is ironic that one of the effects of climate change can be to reduce the output of solar power, via forest fire smoke and other warming-related air pollution.  It is almost like that Simpsons episode, where Mr. Burns puts a solar shade over Springfield, to produce more money for his nuclear power plant.  Of course there is no oil company  conspiracy here, just nature reminding us to be mindful of the unintended consequences of ignoring our environment.

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Now that you have read about the effect of raging forest fires, you should relax and take a mental road trip to the seaside.  Newfoundland would be a great place for that.

A Drive Across Newfoundland

U.S.: https://www.amazon.com/dp/B07NMR9WM8

U.K.:  https://www.amazon.co.uk/dp/B07NMR9WM8

Germany: https://www.amazon.de/dp/B07NMR9WM8

Japan: https://www.amazon.co.jp/dp/B07NMR9WM8

Canada: https://www.amazon.ca/dp/B07NMR9WM8

Australia: https://www.amazon.com.au/dp/B07NMR9WM8

India: https://www.amazon.in/dp/B07NMR9WM8

Newfoundland, Canada’s most easterly province, is a region that is both fascinating in its unique culture and amazing in its vistas of stark beauty. The weather is often wild, with coastal regions known for steep cliffs and crashing waves (though tranquil beaches exist too). The inland areas are primarily Precambrian shield, dominated by forests, rivers, rock formations, and abundant wildlife. The province also features some of the Earth’s most remarkable geology, notably The Tablelands, where the mantle rocks of the Earth’s interior have been exposed at the surface, permitting one to explore an almost alien landscape, an opportunity available on only a few scattered regions of the planet.

The city of St. John’s is one of Canada’s most unique urban areas, with a population that maintains many old traditions and cultural aspects of the British Isles. That’s true of the rest of the province, as well, where the people are friendly and inclined to chat amiably with visitors. Plus, they talk with amusing accents and party hard, so what’s not to like?

This account focusses on a two-week road trip in October 2007, from St. John’s in the southeast, to L’Anse aux Meadows in the far northwest, the only known Viking settlement in North America. It also features a day hike visit to The Tablelands, a remarkable and majestic geological feature. Even those who don’t normally consider themselves very interested in geology will find themselves awe-struck by these other-worldly landscapes.

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Alternatively, take a trip to see a total solar eclipse in the western U.S..  The sun is more than just a  peculiar red colour – it actually disappears for a couple of minutes, to be replaced by a fiery ring in the sky.

The Great American Solar Eclipse of 2017

U.S.: https://www.amazon.com/dp/B07BH7WBQ1

U.K.:  https://www.amazon.co.uk/dp/B07BH7WBQ1

Germany: https://www.amazon.de/dp/B07BH7WBQ1

Japan: https://www.amazon.co.jp/dp/B07BH7WBQ1

Canada: https://www.amazon.ca/dp/B07BH7WBQ1

Australia: https://www.amazon.com.au/dp/B07BH7WBQ1

India: https://www.amazon.in/dp/B07BH7WBQ1

Total solar eclipses are spectacular events, so much so that some people get hooked on them. They become eclipse addicts, who pursue these celestial events around the planet, from country to country as the predicted eclipses come and go. Of course, for most people, eclipse viewing is conditioned by the constraints of available vacation time and spare money. So, an eclipse through the heart of United States, during the height of the 2017 summer, brought the experience home for a lot more people than is usually the case.

This is an account of one such set of eclipse observers, journeying from Calgary, Canada to Idaho Falls, USA to take in the 2017 solar eclipse on a beautiful cloudless August day. It includes a description of the trip itself, through the coulees and mountain ranges of Alberta, Montana and Idaho, culminating in an unforgettable eclipse day in Idaho Falls. It also contains a reasonable amount of scientific and literary background on the eclipse phenomenon, and how it has been experienced by people through the years.

The story is about 12000 words, about 60 to 90 minutes at typical reading speeds.