What are the causes of power outages?

What are the main causes of power outages? 

A power outage is an unexpected interruption to energy to residential or commercial areas, can be short or long term and can affect large or small areas at once. There are different types of power outages depending on the severity of the outage: blackouts for example concern an entire area experiencing a power shortage, brownouts by comparison are a temporary reduction in relation to system voltage, whereas rolling outages are usually purposeful and cut power in a controlled manner. Duration and scope of power outages can vary and depend on usual levels or service. In the UK for example, which experiences fewer power outages, the average power outage may last for around 2.5 hours, whereas in regions with more volatile weather, infrastructure can become damaged and last for several days.  

Weather-related causes of power outages 

The weather can be a key cause of power outages, both to fossil fuel plants and to renewable energy. In the case of fossil fuel sites, lightning strikes and flooding can damage plants and transmission equipment, leading to power outages until equipment can be repaired. Heatwaves and wildfires can affect all types of energy generating plants, with fires damaging key infrastructure, and heatwaves causing transmission equipment to fail. In the case of renewable energy, heatwaves can actually do more harm than good in the case of solar energy. Solar panels can only produce energy under 85 degrees, meaning that when heatwaves occur, they are unable to produce energy, leading to power outages. While storms, hurricanes, and extreme wind can increase the amount of wind energy generated, it can also damage wind farm infrastructure if too extreme, leading to power outages until the equipment can be repaired.  

Technical failures in the power grid 

As energy technologies advance, ageing infrastructure can struggle to integrate with modern power grids. Upgrading legacy systems—such as retrofitting natural gas pipelines for new uses or combining them with renewables—can increase the risk of equipment failures.

Common failures include:

• Transformer or substation breakdowns

• Cable faults and switchgear malfunctions

Human error and accidental damage 

Accidental damage can often result from human error, sometimes in the case of construction damage to power lines or accidents involving vehicles or machinery. On occasion, utility worker mistakes may cause power outages—this is why it is crucial for employees working on power lines to receive the correct health, safety, and maintenance training.  

Grid overload and high demand 

Our current power grid has not been designed to deal with the various types of energy sources that make up the modern energy mix. Therefore, peak usage periods can strain the grid as it struggles to accommodate dispatchable and non-dispatchable energy sources, leading to power outages when the grid is overwhelmed.  

During periods of extreme weather, such as winter or summer, a dramatic rise or fall in temperatures can cause power outages. This is because extra strain is placed on the grid due to increased use of energy to power either air conditioning or heating, spiking the demand for energy. Sometimes, the energy demand outstrips the supply by so much that it can potentially cause a blackout. To avoid this, load shedding  is employed to prevent system failure, which involves disconnecting certain users from power, causing a deliberate outage for those users. 

Cyberattacks and security threats 

The impacts of digital infrastructure vulnerabilities can be felt when exposed by criminal hackers. This involves attacks on utilities such as energy, which can disrupt the energy supply and potentially lead to power outages. These are particularly dangerous in the case of public services such as hospitals.  

Hacking and ransomware targeting utilities are particularly crucial threats because these companies hold vast amounts of personal data on residential and commercial clients, risking not only a power outage but also GDPR issues.  

Animals and environmental interference 

In certain regions, the local environment can cause havoc to the power network. Animals such as birds, squirrels, or rodents may nest in or near crucial equipment, damaging infrastructure so that energy systems cannot function. During high winds or extreme weather events, tree branches can fall and eventually interfere with overhead lines. Power outages can then occur until the environmental concern is removed. 

How to prevent or minimise the impact of power outages?

Infrastructure upgrades will help to prepare the grid for the impending energy transition, accommodating both dispatchable and non-dispatchable sources of energy, successfully implementing a truly needed grid modernisation. Backup systems, such as generators, are already employed in certain scenarios when equipment fails, but these can often be energy-intensive solutions themselves. A more modern, low-carbon solution is batteries, which can capture excess energy generated during high-output periods and store it for later use during blackouts.  

Smart grid technology can help to modernise the grid and prepare it for a bigger energy mix, switching between fossil, lower-carbon and renewable energy sources during power supply issues more easily. Proactive maintenance can also be employed to help identify problems with the grid before power outages occur. This can be done by integrating the Internet of Things into the total network, diagnosing faults in plants, transmission equipment and remote infrastructure before these problems occur. Historical data during outages can be analysed and proactive maintenance scheduled in, stopping power outages before they happen.  

Preventing outages means modernising the grid, using smart tech, and storing energy with batteries - ensuring resilience in a more complex energy landscape.