Remember being advised to find shelter under a tree when it was raining heavily. For a while, you did this until you saw a tree being struck by lightning. What caused that, in your opinion? Alternatively, does wood conduct electricity?
Find out if wood acts as an insulator or a conductor in this article. We will explain if wet wood conducts electricity and highlight factors that have an effect on wood’s electrical conductivity. By determining whether wood is a conductor of lightning, we can explain what might have happened to the tree that was struck by lightning. Finally, we reveal whether wood conducts heat or not.
Is Wood a Conductor of Electricity?
Wood is not a conductor of electricity but in certain conditions it is. Confusing right? Not exactly, if you consider the fact that conductors are materials that allow the flow of electric current. Electrons must be able to move freely through the material for current to flow through it. Wood has a number of electrons.
However, wood electrons are firmly bonded to the atom’s nucleus and are not free to move around. Electrical current works best where electrons are flowing freely with no resistance. Wood cannot conduct electricity because it lacks free-flowing electrons.
There is one exception to this rule though. Dry wood conducts electricity when it comes into contact with high voltage, such as electrical lines. The wood won’t be able to stop the flow of electricity because there is so much electricity flowing in the electrical lines. Because of this, using a wooden ladder near electrical lines is not a sensible move.
Is Wood a Conductor or an Insulator?
Wood acts as a conductor and an insulator. Moisture-filled wood conducts electricity whereas dry wood acts as an insulator. The two concepts are made possible by the way electricity works. The ability of electricity to pass through will depend on how easily the electrons can move.Unlike protons and neutrons, electrons have the capability to move.
The ease with which some materials acquire or lose electrons is what makes them good conductors. On the other hand, insulators find it challenging to absorb or lose electrons. Wood contains hydrogen, which binds the molecules together to keep them compact and stable.
As a result, electrons in dry wood are difficult to separate, making it more difficult for electrons to pass through. However, when certain chemicals, like water, are absorbed into the dry wood, this changes.
However, unless it is contaminated by other elements like dirt or salt, pure water insulates exceptionally well. These impurities are what will allow wet wood to conduct electricity.
Why Doesn’t Wood Conduct Electricity?
Electricity does not flow through dry wood primarily because free electrons are needed for electrical current to flow. Electricity can be conducted thanks to the movement of negatively charged electrons. The bonds between the wood atoms are so strong that the electrons cannot pass through. Light, free atomic particles called electrons can freely move within and around atoms.
Electricity is the movement of an electric charge through a material. The amount of electrons moving through a material without encountering resistance is known as the flow of electric charge. The high level of resistance in dry wood prevents the electrons from passing through.
Wood has a vacuum (void) inside of it, which prevents it from conducting electricity. Since vacuum is an insulating medium, electric current cannot flow through it. Microscopic air bubbles that are left behind when the wood dries out are what cause the vacuum.
Does Wet Wood Conduct Electricity?
Wet wood does conduct electricity. However, the water present, not the wood, is what allows electrical current to flow. Minerals, ions, and salt are among the impurities in water that conduct electric current. Not all wood will conduct electricity while wet, it will depend on the wood species and the applied voltage.
Let’s look at several types of wood that conduct electricity when wet:
|Red maple||Pine tree|
You can read more on wood types: Types of wood
Wet wood is a strong conductor because of the high moisture content it contains. Electrical resistance in wood decreases as moisture content rises. Water conducts electrical currents more effectively when electrical resistance decreases. We can confidently state that moisture in wood has a significant impact on its conductivity.
Factors That Affect The Electrical Conductivity of Wood
Dry wood typically doesn’t conduct electricity very effectively, or, at least not well enough to cause an electric shock. However, when certain factors change, the situation does change.
Let’s examine a few factors that affect a wood’s electrical conductivity:
Any temperature variations have an impact on the electrical conductivity of wood. The degree of conductivity rises with temperature and vice versa. The primary cause is that temperature has an effect on the nature of ions and viscosity (level of resistance to flow). I.e ions are more active at a higher temperature.
Measurement of conductivity levels is crucial since wood conductivity is temperature-dependent. At a specific temperature, the dependence is typically stated as a “relative change per degree celsius” indicated as as%/°C. The term “temperature coefficient” refers to it.
The temperature coefficient will often be either positive or negative.
Wood’s conductivity is greatly affected by its water content. Depending on how much moisture is present in the wood, the conductivity level changes. Moisture increases the electrical conductivity of wood. Therefore, it is advisable to avoid standing close to a wet tree when it is raining. The moist tree will be exposed to the lightning’s electrical current.
When evaluating moisture in wood you use high frequency moisture meters. The frequency meters measure MC(%) using the relationship moisture and dielectric constant or power loss of wood. If the moisture content is less than 8%, the increase in electrical conductivity is slow.
The level of a piece of wood’s electrical conductivity depends on how long or short it is. The conductivity of a longer wooden stick is lower. Electric current can move through a shorter piece of wood more quickly than it can through a longer piece.
4. Special finishes or species
The electrical conductivity of wood changes when some materials that are good conductors of electricity are introduced. Read more about composite wood.
Some wood species with a higher proportion of horizontal fibers are better electrical conductors than those with vertical fibers. Electrical conductivity is better along the grain than across the grain.
5. Current frequency
Electrical conductivity is greatly influenced by two factors: electric currency and current currency. Between the two, insulators serve as a barrier and have the ability to stop the flow of electricity. Even an insulating material like wood will conduct electricity at high voltages.
Watch what occurs when the voltage is high:
A thicker piece of wood will transmit electricity more effectively than a thinner one when it comes to electrical conductivity.
Is Wood a Conductor of Lightning?
Wood is a greater lightning conductor than air. On its way to the ground, lightning current can easily flow through some materials like wood. When it rains heavily, for instance, you are advised against standing close to a tree. The wood will allow a lightning current to travel to the ground’s surface. The strike will have an impact on anyone on the ground.
Wood sap boils along the path of the strike when lightning strikes. Steam is subsequently created and cells explode in the wood. eventually resulting in the tree’s wood and bark peeling off in sections or being blown off.
Water-rich wood is more prone to conduct electricity and attract lightning.
Does Wood Conduct Heat?
Wood is a poor conductor of heat. Heat cannot be transferred through wood since there aren’t any mobile electrons. Wood’s blend of long-chain molecules is particularly ineffective at effectively transmitting heat. Wood atoms do not radiate heat to their nearby atoms. There is no heat flow from convection, radiation, or heat conduction.
Typically, three processes—conduction, convection, and radiation—are used to transfer heat. The most frequent type is conduction, it happens frequently in nature. Heat is transferred through physical contact in conduction.The molecules of a substance move more swiftly when heat is absorbed by that substance. Heat is then transferred to the nearby molecules as the molecules collide with one another.
There is no room for the molecules to vibrate since the atoms in wood are so closely packed. Without vibration, there is no energy transmission that results in heat.
Because heat transmission between materials depends in part on how their surfaces interact, wood is a poor heat conductor. Gaps prevent heat conduction, and wood has microscopic gaps.
Wet wood must be handled carefully since it can conduct electricity. In wood, moisture speeds up the flow of electric current. Dry wood on the other hand is an insulator but can change with high voltage.
The electrical conductivity of wood is influenced by a number of factors, including temperature, thickness, length, current frequency, wood species, and finishes. Another crucial point to remember is that while lightning can travel through wood, wood does not conduct electricity.