Many critical components of our distribution system will reach the end of their life span or be in poor condition by 2032. While we replace these components as needed, replacement rates must increase to ensure the reliability and security of our equipment and facilities.
The potential replacement cost for components is based on incremental cost over 20 years.
- Life span: 30 to 70 years depending on application and type.
- Replace: 3,400* km of 6,100 km cables.
- Potential cost: $900 million.
Underground cables are insulated conductors (power lines) used to distribute electricity from substations to distribution transformers. Unlike overhead power lines, underground cables are typically insulated with a non-gaseous insulating medium (e.g., plastic, rubber, paper, or oil) that can be installed directly in the ground.
Insulating material on underground cables allows them to be installed nearer to each other. Many circuits can also be installed in small right-of-ways through an underground duct line system.
Underground cables are exposed to voltage stress, and heat from loading and environmental elements. Aging depends on the cable type, and can be either mechanical damage caused by external factors or operational stress.
- Life span: 80 years.
- Replace: 350* of 2,400.
- Potential cost: $30 million.
Manholes are concrete enclosures built in underground duct lines for installing and splicing underground cables. They provide a connection point in duct lines to splice underground cable, install new circuits in high density areas, and house the underground secondary network transformers in downtown Winnipeg.
Manholes are subject to environmental conditions such as ground movement and tree roots, and vibrational stresses such as traffic, which may cause mechanical failures.
- Life span: 100 years.
- Replace: 25 km* of 265 km.
Duct lines provide a path for multiple underground high and low voltage cables in a congested area. They are found throughout the province, but are most commonly used for major station feeder egresses and in congested locations such as downtown Winnipeg.
In locations with limited available space, they can route many circuits along narrow corridors. Duct lines can be installed under roads, sidewalks, or street boulevards, and are often installed during opportunities such as major road or bridge repairs.
Duct lines are subject to environmental conditions such as ground movement and tree roots, and vibrational stresses such as traffic, which may cause mechanical failures.
- Life span: 50 years.
- Replace: 170* of 17,000.
- Potential cost: $3 million.
Transformers are an integral part of our electrical distribution system and are required to change utilization voltage levels. Padmount transformers transform voltage levels from medium voltage to low voltage.
Padmount transformers operate under many extreme conditions that affect their aging and potential for failure. Transformer insulation also degrades over time. Ambient temperature, wind, and loading history are factors in the speed of their degradation.
- Life span: 75 years.
- Replace: 117,000* of 1 million.
- Potential cost: $410 million.
Wood poles are an integral part of our overhead electrical distribution system and provide safe ground clearance and mechanical support of power lines and energized equipment. About 250,000 of our province’s wood poles were installed between 1945 and 1960.
Most poles support 1 energized circuit, but multiple circuits may be installed on a common pole structure in urban areas.
Poles are subject to damage from severe weather, general decay, and mechanical damage.
- Life span: 100 years.
- Replace: 6,300 km* of 72,000 km.
- Potential cost: $63 million.
Overhead conductors (power lines) deliver electrical energy from the distribution system to our customers. The majority of conductors are overhead while the rest are underground cables.
As the overhead conductors age, the distribution system becomes more vulnerable to premature failure and lengthy power outages. Conductors have 2 primary modes of degradation: mechanical and electrical.
- Mechanical degradation includes environmental stresses, such as icing and tree contact.
- Electrical degradation includes overloading due to general load growth and high fault levels.
- Life span: 75 years.
- Replace: 4,800* of 142,000.
- Potential cost: $15 million.
Transformers are an important part of our electrical distribution system and are required to change utilization voltage levels.
Distribution class transformers are typically installed on distribution feeders and transform voltage levels from one medium voltage to another, or to low voltage.
Overhead transformers operate under many extreme conditions that affect their aging and potential for failure. Transformer insulation also loses its dielectric strength over time. Ambient temperature, wind, and loading history are factors in the speed of their degradation. Most distribution transformer failures are caused wildlife contact, tree contact, or lightning strike.
Street light standards
- Life span: 50 to 70 years.
- Replace: 11,000* of 58,000.
- Potential cost: $50 million.
Street light standards are typically made of tubular steel or aluminum. These standards provide roadway lighting in urban and high traffic locations Most of Manitoba Hydro street lights are within the City of Winnipeg.
Street lights standards are subject to environmental conditions and mechanical damage. The nature and severity of the damage depends on its location and environment. Corrosion, both above and below the soil surface, is the main contributor to the structural breakdown. Corrosive environments are usually caused by salt spray from traffic but differences in soil chemistry can also add to below grade corrosion.
* Assets are continuously replaced as required. If replacement rates don’t increase, this is the number that will be in poor condition by 2032.