NL Hydro

Turn on the Lights

Electricity powers our homes, our
businesses and our lives. Without
it, we could not enjoy the quality
of life we've come to value in our
modern society.

Welcome to the
journey of electricity!

Click on the arrows intro-arrow at the bottom of the screen to scan from left to right and click on the intro-plus to learn more!

Free electrons, which are found in most metals, are electrical conductors. They can detach from their atoms and zip around transmitting electrical energy from one point to another.

Copper, a cottage, a candlestick – everything
is composed of atoms. Atoms have a nucleus
orbited by one or more electrons, each
with a negative charge.

Wood, glass, plastic, ceramic, air and cotton
are electrical insulators because their atoms
are so reluctant to share electrons.

An atom is the basic unit of a chemical element,
which cannot be broken by any chemical means.
A typical atom consists of a nucleus of protons
and neutrons with electrons circling this nucleus.

An electron is a negatively charged component of an atom. Electrons exist outside of and surrounding the atom nucleus. Each electron carries one unit of negative charge.


Electricity starts with atoms, the basic building blocks that make up everything around us. Orbiting the centre of an atom are electrons, and when the flow of electrons are encouraged to travel from one atom to another,
that's electricity!

There are two wind farms in Newfoundland and Labrador that create enough green energy to power 12,300 homes every year. That reduces GHG emissions by more than 143,000 tonnes!
Learn more about wind power.

Hydro operates 25 diesel plants to provide electricity to many isolated communities along the province's coastline. Learn more about diesel generation.

Over 85% of electricity generated by Hydro
comes from clean, renewable hydroelectricity.
Continue on the journey of hydroelectricity.

The Holyrood Thermal Generation Station provides between 15 and 25 per cent of the island of Newfoundland's annual electricity needs.

Learn more about thermal generation and the Holyrood Plant.

Gas turbines are primarily used in Newfoundland
and Labrador for system back-up, to meet peak demand and for transmission support. Visit
Hydro's website
for gas turbine locations
and capacity.

Learn more about how electricity is generated in other provinces and countries, such as geothermal, solar and tidal generation.

Generation Sources

The way electricity is generated varies. Power can be generated from harnessing gusts of wind, to capturing the sun's rays with photovoltaic cells to diverting water towards a hydroelectric
generating plant.

In Newfoundland and Labrador, large-scale electricity is generated four ways: hydroelectricity, thermal (oil-fired generation), wind and diesel. Roll your mouse over the images to learn more about how electricity is generated in our province and around the world.

On average, 774 million cubic feet of water flows through the turbines at the Cat Arm plant per year. That's equivalent to 1190 mm of precipitation! Since some precipitation is lost to plants, groundwater and evaporation, the area must receive more than 1200 mm of precipitation each year for electricity generation.

Hydroelectricity is considered renewable
because after water is used to make electricity,
it is returned to the river.

On the island of Newfoundland, the largest reservoir development begins at Victoria Lake, located in the west-central interior of the island of Newfoundland. It takes 17 days for water to flow 150 kms from Victoria Lake downstream to the Bay d'Espoir plant.
Learn more about the Bay d'Espoir system!

In some locations, Hydro releases water from its reservoirs to ensure there is enough water in downstream rivers for fish, even if the water cannot be used to generate electricity.

When heavy rainfall and/or snowmelt cause too much water to accumulate in its reservoirs, the water will spill. At these times, Hydro advises people in these areas to be cautious, as water levels and flows may be unpredictable.


A reservoir is a lake used to store water. Some are natural with structures in place to control the flow of water and others are artificial. Dams and dykes contain water that flows naturally in streams and rivers, and allow the water to be released when needed for electricity generation. Nature controls the amount of water in reservoirs - rain and melting snow provides the source of the water in the reservoir.

Hydroelectric plants use water as it travels downstream from a reservoir. The water is held in the reservoir until it is needed for electricity generation. If the reservoir becomes full before water can be used for electricity generation, the water will spill, meaning it will bypass the plant and not be used to generate power.

The Churchill Falls Generating Station in
Labrador is operated by Nalcor Energy Churchill
Falls. It's one of the largest underground
powerhouses in the world. Learn more

Our province has nine hydroelectric plants –
Bay d'Espoir, Cat Arm, Granite Canal, Hinds Lake, Paradise River, Roddickton, Snooks
Arm, Venams Bight and Upper Salmon.
Learn more here!

Bay d'Espoir is our province's largest
hydroelectric facility, and has the ability to
provide enough electricity to heat approximately 144,000 homes every year!

The amount of electricity generated at each
hydroelectric plant depends on the amount of
water that flows through the powerhouse and
the vertical drop, called the head, between the
reservoir and the powerhouse.


Water that flows downstream from a reservoir will make its way to a hydroelectric plant. At this point, water can be used to make electricity.

The intake gate in the dam controls the amount of water that flows through a large water pipe called a penstock to the generating station (or powerhouse) – the more water that is allowed in, the more electricity that is generated.

The generator rotor acts as a large magnet. When the turbine spins, the rotor spins. As the magnetics spins, they pass over copper wires called the stator. The movement of the magnetic field across the stator causes electrons in the copper wire to move. This movement of electrons is electricity!

In the generating station there are turbines (some are shaped like big propellers) that spin when the water passes through them. The turbine is connected to the rotating part of the electric generator called a rotor.

Inside a Hydroelectric Generating Plant

A hydroelectric dam is built to control the amount of water released into the powerhouse for electricity production. Inside the powerhouse is where electricity is generated. Once the water is used to generate electricity, it returns to the river. Check out the diagram of a hydroelectric dam for an explanation of how each component works!

Hydro employees such as mechanics, line workers, and engineers work around the clock to keep the power on. Learn more about a career at Hydro.

Hydro owns and maintains over 3,700 km of transmission lines. See every line across Newfoundland and Labrador with Hydro's map.

A large portion of Hydro's transmission infrastructure is located in remote areas, where line crews must often travel by ATVs, snowmobiles, and track vehicles to make emergency repairs, routine maintenance or upgrade equipment.

The largest transmission line that Hydro operates is a 230,000 volt (230 kV) line that can carry up to 460 MW. The lines from the Churchill Fall Generating Station to Quebec, operated by Nalcor Energy Churchill Falls, is a 735,000 volt (735 kV) line that can carry up to approximately 4500 MW. The largest Alternating Current (AC) transmission line in the world is a 1.2 million volt (1200 kV) line that is being used for research purposes in India. Read more on the world's largest transmission line.


After electricity is generated at a power plant, it travels by wire to a transformer that is located in a terminal station, which converts it to a higher voltage as required
for transmission.

Learn More

There are over 3,334km of distribution
lines in this province!

Hydro delivers electricity to utility, industrial, residential and commercial customers in over
200 rural communities across the province.

Newfoundland Power purchases 90% of its electricity from Hydro and serves over 85% of all electricity consumers in the province. Visit to learn more.

Safety first! Stay away from power lines and substations. Visit for safety tips and information to keep you and your family safe.


Once electricity reaches a substation, the voltage is reduced to a level that can be used to power homes and businesses. Electricity is delivered from a substation to your home through a distribution line.

Before electricity can be used in your house, the voltage is reduced again at another transformer attached to the top of a utility pole near your home or business. The distribution line is connected to your home by a circuit box, which distributes electricity to the outlets in your house.

In Newfoundland and Labrador, on average, 50% of home electricity costs and usage are from electric heat. Other uses of electricity include hot water, cooking and lighting.Learn more about how your electricity rates are set.

Your electricity consumption is measured by a meter on your house. Some are read automatically and some are read by a meter reader, who needs safe and clear access to your meter to ensure accurate readings. Learn more about meter reading safety.

Power outages do happen. Learn more about what can cause an outage and what you can do to be prepared.

Demand for electricity goes up and down at different points in the day. Learn more about how Hydro strikes the necessary balance to ensure the right amount of electricity is available for everyone when they need it.

In Our Communities

Turning on a household appliance or flicking on a switch launches the fascinating chain of events you have just read about. The time it takes for electricity to travel from a power plant to turning on a household appliance is a tiny fraction of a second. Every time you do this, you are demanding electricity, just like when you turn on a faucet and summon water.

While you may not think about where your power comes from, Hydro is working hard to make sure it's always there at your fingertips.

Muskrat Falls will deliver the lowest-cost power
to our homes and businesses and provide stable electricity rates. Power from Muskrat Falls will also eliminate our reliance on burning fuel at the Holyrood plant as well as greenhouse gas emissions from that plant in the future.

The Churchill River in Labrador is a significant source of renewable, clean electricity that has the ability to meet the province's needs and provide stable electricity rates for generations. Learn more about the Lower Churchill.

Each year Hydro invests in the electricity system to ensure reliability well into the future. For example, in 2011, Hydro invested $55 million and upgraded the transmission line that runs from Plum Point to Bear Cove on the Great Northern Peninsula and replaced the fuel storage facility at the Postville Diesel Generating Site on the Labrador Coast.

Growing demand in communities throughout the province and a commitment to ensure the safety of its employees and the public continues to drive Hydro to invest significantly in upgrades, repairs and replacements to electricity infrastructure.

Hydro is making the right kind of investments in its electricity infrastructure now and planning for future investment so that the provincial electricity supply will be safe and reliable well into the future. For example, Hydro invests in upgrading and replacing aging infrastructure at the Bay d'Espoir plant. Learn more about recent capital work at the plant.

The Future

Our economy is growing and demand for residential and business energy continues to rise steadily. We need new sources of power to meet the province's future electricity needs. By 2015, we will need an additional source of electricity to meet the island's "peak demand" (the time of year when consumers use the most electricity), while keeping an appropriate amount in reserve should something go wrong. By 2021, we will no longer be able to count on our current supply to meet the island's annual electricity needs.

The future holds the promise of a clean, sustainable province for the people of Newfoundland and Labrador. Driving renewable energy forward will ensure a positive economy and a healthy environment for many generations to come.