In Part 2 of the series about solar arrays and Chesterfield County, we learned that arrays are subject to fires. One knows the fire hazard in a rural county like Chesterfield, which has Carolina Sandhills National Wildlife Refuge, Sandhill State Forest, Cheraw State Park, and thousands of acres of private forest, farms, and meadows. Fire is a genuine and dangerous situation in our county that needs to be avoided. But what else would happen when a solar does catch on fire? What would happen then? Let’s find out.
The typical voltage entering your house is 220/240 V. A more significant electricity consumer will typically have 440/460 V delivered to them; some might go as high as 600 V for heavy industry. As the voltage goes up, the more hazardous it is to individuals. Like they say, there are old electricians and bold electricians, but there are very few old, bold electricians. But this is not where the discussion of voltage ends. These are only the delivered voltages to customers. The natural hazards come into play with the transmission voltages.
If you look at a power pole in Chesterfield County, you will see a single line running on top of it. This is the high-voltage line, also known as the high-tension line. The voltage this line carries is what is “transformed” into the line voltage that enters your home. This voltage, which you should think of like pressure in a water hose, has to be high enough to drive electricity for miles. The voltage for this transmission line is typically 5, 15, 25, or 35 kV. The abbreviation kV stands for Kilovolts, which is 1000 volts. So, 5 kV is short for 5000 Volts. When you get to this type of voltage, you are talking serious electricity!
The voltage that a solar panel generates must be ramped up to match the voltage of that high-tension wire. Thus, lines carrying thousands of volts of power must also be considered when a solar array catches fire.
If there is one thing that Chesterfield County has, it is dedicated volunteer first responders to protect us from fires. They give us first-class protection from car and structural fires to industrial and forest fires. They do this despite the possibility of personal harm.
A fire at a solar array complex in the county would require our first responders to fight the fire and avoid the hazard of accidental electrocution. Unlike a fire involving electrical current from a power utility in which the company is called to cut the transmission of electricity, those fighting a fire at the array are not offered that “luxury.” They will also have to risk high voltage exposure to bring a fire under control.
Another layer of complexity to the problem is that most of these areas are located well off paved roads, requiring those fighting the fire to gain access over rough terrain. They do this very often in the case of forest or meadow fires, but obviously, they do not include the hazard of electrocution.
Because of these factors, fighting a solar array fire will require additional training and equipment. They will also need training in hazardous material exposure.
With any fire, the possibility of exposure to hazardous chemicals is a grave consideration. In many cases, it is not the fire itself that presents the most lethal potential, but rather what a first responder would inhale or come in contact with their skin.
Here is just a general idea of what a solar array fire can do:
Stormwater runoff has been highlighted as one of the most noticeable impacts of forest fires. After a fire destroys vegetation, the ground’s soil becomes hydrophobic – meaning it cannot absorb water. This means debris and sediment are transported into larger bodies of water, polluting local supplies. Filtering such water sources is often costly and time-consuming.
- Poor Air Quality
For example, large amounts of smoke are released into the atmosphere if a forest burns. This smoke includes microscopic particles – often less than 2.5 micrometers in diameter or around one-seventieth the size of a human hair. These particles are so small that our bodies struggle to filter them out of our airways. Consequently, they get lodged deep in our lungs.
- Serious Damage to Human Health
The World Health Organization (WHO) has highlighted how significantly mortality and morbidity impact depending on the fire’s size, speed, and proximity. The WHO says young children, pregnant women, and older adults are the most susceptible to “health impacts” from smoke and ash. In addition, the WHO explains that smoke and ash from wildfires can significantly affect “those with pre-existing respiratory diseases or heart disease.” Meanwhile, as well as fatalities, wildfires can cause burns, decreased lung function, pulmonary inflammation, bronchitis, exacerbation of asthma, and exacerbation of cardiovascular diseases, such as heart failure.
Those three generalizations sound bad enough, but the nature of the material used in solar panels can make a fire at one a more dangerous proposition.
Now, makers of the solar cells themselves and those who sell the solar panel arrays will tell you that the cells contain hazardous materials, but because the cells are “sealed,” there can be no exposure to these materials. Unfortunately, when the panels are on fire, all bets are off.
A fire will immediately breach the seal and expose the materials to the environment. Once exposed, the fire will cause decomposition of the materials and convert them into airborne particles. The likelihood of these particles being inhaled is highly likely. The manner of the materials will be carcinogenic, and the effects of exposure will not be known for years, while others will be presented immediately.
One material in particular, which most suppliers misrepresent, is Cadmium Telluride. They love to tell the tale, that yes, Cadmium metal is hazardous, but the crystalline compound is not. Well, a quick review of the MSDS (Material Safety Data Sheet) for this compound reveals that is not the truth. This is what the MSDS from Roth Chemical has to say about it:
Trust me, when you see a Category 4 rating, you know something is not to be trifled with. And remember, if there is a fire, this will be an airborne danger and a water runoff issue.
Now, there are even more hazardous materials in a solar panel array, such as Cadmium Sulfide and Lead compounds. But rather than bore you with a list, the previous examples should convince you of the inherent dangers presented by solar array fire to both humans and the surrounding environment.
In part 4 of this series, we will examine the economic consequences of solar array installations.