55 Grid Modernization Statistics on Investment, Capacity, and Reliability

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Grid modernization spans transmission expansion, distribution upgrades, digital controls, interconnection, congestion management, and reliability. The statistics below distinguish observed results from forecasts and pathway estimates, with geography and measurement periods stated explicitly.

Key Grid Modernization Statistics

The most broadly useful figures are:

  • In the IEA Current Policies Scenario, 25 million km of additional global lines are required by 2035.
  • The same global scenario projects grid capacity increasing 30% by 2035.
  • The IEA estimates that annual global grid investment must rise from about $330 billion to $750 billion by 2030 on a net-zero-aligned pathway.
  • About 75% of required global annual grid investment is allocated to distribution grids in the IEA’s 2030 pathway estimate.
  • Digital grid technologies could defer an estimated $1.8 trillion of global grid investment through 2050.
  • Emerging markets and developing economies could add more than 2,600 TWh of electricity demand by 2030.
  • Global transmission investment grew 10% to $140 billion in 2023.
  • At least 1,700 GW of advanced-stage global renewable projects awaited grid connection in 2025.
  • About 600 GW of global utility-scale battery projects awaited connection in 2025.
  • U.S. grid congestion cost about $12 billion in 2024.
  • EU grid congestion cost about €4.3 billion in 2024.
  • Dynamic ratings and related controls could connect up to 330 GW without network reinforcement, according to IEA analysis published in 2026.
  • A U.S. dynamic-ratings project avoided a reported $64 million per year in congestion costs.
  • Advanced power-flow control added more than 2 GW of transfer capacity in Great Britain.
  • U.S. electricity customers experienced an average of 11 interruption hours in 2024, including major events.
  • Major events accounted for 80% of U.S. hours without electricity in 2024.
  • ASEAN requires more than $300 billion for grid expansion and modernization from 2025 through 2040.
  • Renewables represent 75% of ASEAN generation-capacity additions through 2040 under today’s policy settings.

Contents

Global Grid Modernization Investment and Capacity Needs

Grid modernization includes both the physical network and the systems that operate it. Transmission carries electricity over long distances, distribution delivers it locally, and digital technologies can increase the usefulness of existing assets without treating every need as new construction.

The IEA’s Current Policies Scenario is a forecast rather than a committed construction program. It requires 25 million km of additional lines globally by 2035, equivalent to a 30% increase in grid capacity under that scenario. The need for modern grids – Modernising Grids in the Age of Electricity

For a net-zero-aligned pathway, the IEA estimates that annual global grid investment would need to rise from about $330 billion to $750 billion by 2030. About 75% of that required annual investment is allocated to distribution grids, showing why modernization is broader than transmission alone. Executive summary – Unlocking Smart Grid Opportunities in Emerging Markets and Developing Economies

Digital controls may change the timing and scale of physical investment. The IEA estimates that digital grid technologies could defer $1.8 trillion of global grid investment through 2050; this is potential avoided or deferred investment, not realized savings.

The same outlook forecasts more than 2,600 TWh of additional electricity demand in emerging markets and developing economies by 2030, described as about five times Germany’s current demand. Executive summary – Unlocking Smart Grid Opportunities in Emerging Markets and Developing Economies

Global measure Period Figure and scope
Additional lines 2035 projection 25 million km, global Current Policies Scenario
Grid capacity increase 2035 projection 30%, global Current Policies Scenario
Annual grid investment Current level to 2030 About $330 billion to $750 billion, net-zero-aligned estimate
Distribution share 2030 pathway About 75% of required annual investment

Transmission spending itself reached $140 billion globally in 2023, up 10% from the prior year, while advanced economies and China accounted for about 80% of the total. The IEA projects that transmission spending would need to exceed $200 billion annually by the mid-2030s under today’s policy settings, or reach $250–300 billion per year in scenarios fully achieving national and global emissions goals. Executive summary – Building the Future Transmission Grid

Grid Congestion, Connection Queues, and Expansion Data

Congestion and interconnection queues show where generation, storage, and demand are arriving faster than network capacity or connection processes can accommodate them. Queue volumes are not build totals: projects can be delayed, redesigned, or withdrawn.

At least 1,700 GW of advanced-stage renewable projects were awaiting global grid connection in 2025, alongside about 600 GW of utility-scale battery projects. In the United States, grid congestion cost about $12 billion in 2024; in the European Union, the estimated cost was about €4.3 billion. Executive summary – Modernising Grids in the Age of Electricity

Germany represented more than half of the EU’s 2024 congestion cost, according to the IEA. EU renewable-energy curtailment exceeded 10 TWh in 2024, an estimate described as enough electricity to power around 3 million homes for one year; the comparison depends on household electricity-use assumptions. The need for modern grids – Modernising Grids in the Age of Electricity

India recorded 2.3 TWh of curtailed solar generation in 2025, a solar-specific observed figure rather than a total curtailment measure. ASEAN electricity consumption is forecast to grow 3–4% annually through 2040 under IEA policy settings. The need for modern grids – Modernising Grids in the Age of Electricity Executive summary – Financing the ASEAN Power Grid

Digital Grid Modernization Technologies and Measured Gains

Digital modernization can include dynamic line ratings, topology optimization, advanced power-flow control, digital twins, and substation digitalization. These measures are intended to improve the use of existing networks, but their results depend on network design, weather, operating rules, and the specific project.

The IEA estimates that dynamic ratings, topology optimization, and advanced power-flow control could connect up to 330 GW of additional generation, storage, and demand without network reinforcement. Connecting the same volume through conventional expansion would require around $100 billion, according to the counterfactual estimate; the 330-GW volume is roughly equivalent to the combined installed generation capacity of France and South Korea. Executive summary – Modernising Grids in the Age of Electricity

Reported project outcomes provide narrower, real-network evidence:

  • Dynamic ratings reportedly avoided $64 million per year in U.S. congestion costs; this is a project result, not a national total.
  • Advanced power-flow control delivered more than 2 GW of additional transfer capacity in Great Britain.
  • A digital twin reduced the time needed to analyze reinforcement options by 70% in one network project.

Most surveyed distribution operators aimed to digitalize more than 50% of their low-voltage substations by 2035. This adoption snapshot came from an IEA 2026 survey with 25 responses—11 transmission and 14 distribution operators across Europe, North America, South America, East and Southeast Asia, and Oceania—and is explicitly not statistically representative. Executive summary – Modernising Grids in the Age of Electricity

U.S. investment figures in the Department of Energy’s 2018 Smart Grid System Report describe 2016, so they are historical rather than current spending. The report’s major investor-owned utilities served about 73% of U.S. electricity customers in that context.

U.S. utility group or category 2016 expenditure
Major IOU transmission and distribution About $48 billion
Major IOU transmission About $21 billion
Major IOU distribution About $27 billion
Major IOU generation and other listed capital categories About $65.5 billion
Major IOU total capital expenditure About $112.5 billion
Public power utilities’ reported expenditures About $7 billion
Electric cooperatives’ reported expenditures About $25 billion

The DOE compilation reported about $144.5 billion in U.S. utility investment in generation, transmission, and distribution infrastructure in 2016. Within major IOUs, transmission investment was about $20 billion in one report comparison and distribution investment reached $27 billion; the source notes that categories and reporting populations differ, so these figures should not be treated as a single modern annual series. Smart Grid System Report 2018

Electric Reliability Statistics Linked to Grid Modernization

Reliability statistics measure customer experience, not modernization spending directly. EIA’s SAIDI measure is the total duration of non-momentary interruptions experienced by an average customer, while SAIFI measures interruption frequency; including major events materially changes comparisons.

U.S. customers experienced an average of 11 interruption hours in 2024, and major events accounted for 80% of those hours. Major-event interruptions averaged nearly 9 hours in 2024, compared with nearly 4 hours annually during 2014–2023; non-major-event interruptions routinely averaged about 2 hours per year in the EIA comparison. Hurricanes in 2024 led to the most hours without power in the United States in 10 years

Reliability measure Geography and period Reported result
Interruption duration U.S., 2024 11 hours per customer
Major-event share U.S., 2024 80% of interruption hours
Highest state duration South Carolina, 2024 Nearly 53 hours per customer
U.S. interruption frequency United States, 2024 1.5 interruptions per customer
Highest state frequency Hawaii, 2024 4.4 interruptions per customer

South Carolina had the highest state average duration at nearly 53 hours per customer in 2024, including major weather events. Arizona, South Dakota, North Dakota, and Massachusetts each averaged less than 2 hours, while South Dakota, Maryland, Illinois, and Massachusetts each averaged fewer than 1 interruption; these threshold statements are not exact values. Hurricanes in 2024 led to the most hours without power in the United States in 10 years

For New England, EIA reported 2024 SAIDI of 419.6 minutes including major events and 112.3 minutes excluding them. The corresponding SAIFI values were 1.382 including major events and 0.951 excluding them, covering reporting utilities in the census division. Electric Power Annual: Table 11.3 Reliability Metrics Using Any Method of U.S. Distribution System by State, 2024 and 2023

ASEAN provides a regional example where demand growth, renewable deployment, transmission, and cross-border interconnection are related but distinct measures. Under today’s policy settings, the IEA projects electricity consumption growth of 3–4% annually through 2040 and says renewables account for 75% of generation-capacity additions through that year.

The region requires more than $300 billion for electricity-grid expansion and modernization from 2025 through 2040, 72% above investment during 2009–2024. This is an investment requirement forecast, not observed spending. Executive summary – Financing the ASEAN Power Grid

Cross-border interconnection has a different investment history:

  • Only around $2 billion had been invested in ASEAN cross-border interconnectors since the first project broke ground in the 1970s, according to the IEA estimate.
  • ASEAN invested $3.6 billion in electricity transmission in 2024 alone.
  • The 2024 transmission investment exceeded the region’s cumulative interconnector investment over more than 50 years, based on the rounded figures and periods reported by the IEA.

These comparisons underline why grid modernization statistics should identify the asset class, geography, period, and measurement type. A forecast for future expansion, a queue of proposed projects, a reliability outcome, and a reported project saving answer different questions even when they concern the same electricity system.

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