The British company said it plans to invest up to £35 billion ($45 billion) to upgrade the UK's electricity grid.
"The plan includes an unprecedented level of investment... over the five years to March 2031," National Grid said in a statement.
The Labour government, elected in July, has vowed to move away from fossil fuels towards renewable energy, promising among other things to decarbonise the UK's electricity grid by 2030.
The grid has struggled with limited transmission capacity, meaning green energy projects have waited years to connect.
The investment will upgrade the existing grid network and pay for new construction projects that will see electricity transmission capacity almost doubled.
"This plan represents the most significant step forward in the electricity network that we've seen in a generation," said the company's chief executive John Pettigrew.
"We will nearly double the amount of energy that can be transported around the country," he added.
More than twice the quantity of transmission infrastructure -- such as pylons, cables and substations -- built over the last decade will need to be constructed in the next five years, the publicly-owned National Energy System Operator said in a report last month.
The plans announced Wednesday will need to be agreed by industry regulator Ofgem, as its balances the push to upgrade power infrastructure with protecting customers against higher bills.
The government has moved swiftly to take control of key electricity operations from National Grid in a bid to tighten the country's energy security and aid transition to a net zero carbon economy.
The government recently bought Electricity System Operator -- which oversees the balancing of supply and demand in the UK's electricity grid -- for £630 million.
It was launched on October 1 and renamed National Energy System Operator.
National Grid, privatised in 1990, is responsible for transporting electricity in England and Wales, while SSE and ScottishPower share that responsibility in Scotland.
SSE recently announced plans to invest around £22 billion in grid infrastructure and ScottishPower plans to invest £10.6 billion.
“It’s clear that the UK’s network needs upgrading and this statement of intent by National Grid is a good step forward," said Russ Mould, investment director at AJ Bell.
"Whether that's more homes being built, electricity-hungry data centres for all things AI or supporting the transition of industries to an electric world, electricity demands are getting bigger by the day," he added.
In its clean energy push, Labour has launched a publicly-owned green-energy company called Great British Energy to spur investment in renewable projects like wind, solar, nuclear and tidal power.
The new company will receive £8.3 billion of taxpayers' money over the next five years.
