China curtailed 360 TWh of clean power in H1 2026, while India held back 8.13 TWh of solar output in Q2 as grids struggled to absorb surging renewable generation
China is generating renewable electricity faster than its power grid can absorb it. India is facing a similar problem. China curtailed an estimated 360 terawatt-hours (TWh) of clean electricity in the first six months of 2026, up 49 per cent from a year earlier, according to an analysis by Global Energy Monitor (GEM) and the Centre for Research on Energy and Clean Air (CREA).
That is enough electricity to power Mexico for about a year.
India, meanwhile, had to curtail 8.13 TWh of solar electricity between April and June because of transmission constraints and grid-security concerns, according to data provided by the Ministry of New and Renewable Energy to Parliament.
The problem is not a lack of renewable power. It is a lack of infrastructure to move, store and use it.
As China, India, Australia and Japan rapidly add solar and wind capacity, their electricity grids are struggling to keep pace. Renewable-power curtailment — when available electricity is deliberately reduced because the grid cannot take it — is emerging as a major challenge for the global energy transition.
That could have a wider economic consequence. If developers cannot be certain that the electricity produced by a solar or wind project can actually be sold, new projects become harder to finance. And if renewable power is repeatedly curtailed, fossil-fuel plants may continue operating to provide reliable electricity when the sun is not shining or the grid is congested.
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China is at the centre of the problem because of the sheer scale of its renewable-energy expansion.
The country has added enormous amounts of solar and wind capacity, much of it in regions where renewable resources are abundant but electricity demand is relatively low. The power then has to travel long distances to industrial and population centres.
That requires transmission infrastructure.
When transmission capacity is insufficient, grid operators have to ask renewable projects to reduce generation even when the electricity is technically available.
China’s official figures show much lower levels of curtailment. The National Energy Administration said 8.6 per cent of solar output and 9.1 per cent of wind output was curtailed in the first half of 2026. GEM and CREA, using weather-adjusted data, estimated that 26.1 per cent of China’s total wind and solar output was rejected during the period, reported by Reuters.
The difference highlights how difficult it is to measure the full scale of the problem.
Analysts say the pressure is also structural rather than temporary.
Another issue is the continued presence of coal-fired power in China’s electricity system. Existing contracts and operating arrangements can keep coal plants running even when renewable electricity is available, further limiting space on the grid for solar and wind power.
The result is a paradox. China is building renewable capacity at extraordinary speed, but the grid is not always able to use what it produces.
India faces the same grid problem
India’s experience is smaller in absolute terms but important because the country is expanding renewable capacity rapidly.
The government told Parliament in July that 8,133 GWh of solar generation was curtailed during April-June. Of this, 2,417 GWh was curtailed in April, 3,235 GWh in May and 2,481 GWh in June.
The government said the curtailment was carried out to maintain grid security and because transmission lines and renewable-energy projects were not being commissioned at the same pace.
The timing is significant. India was facing intense electricity demand during the summer, with peak demand reaching about 270 GW in the April-June quarter. Yet large quantities of solar power had to be held back because the grid could not absorb or transport all of it.
This is one of the most important challenges for India’s renewable expansion.
The country has already reached 50 per cent of its installed electricity capacity from non-fossil sources and is working towards its target of 500 GW of non-fossil capacity by 2030.
That means the next phase of the energy transition will require more than building solar panels and wind turbines.
India will also have to build the transmission network needed to carry that electricity to where it is needed.
Why curtailment matters
Curtailing renewable power sounds less serious than shutting down a power plant. But it has significant economic consequences.
A solar plant that produces electricity but is repeatedly told to switch off cannot earn as much revenue as expected. That can weaken the financial returns on a project and make lenders and investors more cautious.
It can also discourage developers from building projects in areas where grid congestion is already severe.
The effect is already visible in China, where renewable projects are increasingly being paired with batteries. Storage can absorb electricity when solar and wind output is high and release it later when demand rises or grid congestion eases.
For investors, this changes the economics of renewable energy.
The question is no longer simply how cheaply a country can generate solar or wind power. It is whether that power can reach consumers when they need it.
Australia, Japan see the same trend
China and India are not alone.
In Australia’s National Electricity Market, renewable-energy curtailment rose 37 per cent to 2.93 TWh in the first half of 2026, equal to about 7 per cent of wind and solar output.
Japan curtailed 2.35 TWh over the same period, up 34 per cent and equivalent to about 4 per cent of renewable generation, according to electricity-market data cited by Reuters.
The reasons differ from country to country, but the underlying problem is similar: renewable capacity is growing faster than grid flexibility.
Solar generation is concentrated during daylight hours. Wind output varies with weather. Electricity demand, meanwhile, does not always rise at the same time.
Without enough transmission, batteries or other flexible sources of power, the excess electricity has nowhere to go.
Storage and transmission become critical
The rise in curtailment is therefore shifting the focus of the clean-energy debate.
For years, the priority was to build more renewable generation. Increasingly, governments and investors have to think about what comes after the power is generated.
Transmission lines are needed to move electricity from renewable-rich regions to cities and industrial centres. Batteries can shift power from periods of excess supply to periods of higher demand. Better-designed electricity markets can also encourage consumers and industries to use more power when renewable generation is abundant.
India has recognised the importance of transmission capacity in its renewable expansion plans. The government has been working to strengthen the interstate transmission system as it moves towards its 2030 non-fossil capacity target.
The challenge is becoming global. China shows what happens when renewable generation expands at extraordinary speed while grids struggle to absorb it. India is now confronting a similar problem as solar capacity expands and transmission infrastructure catches up.
The clean-energy transition, in other words, is entering a new phase.
The world needs more renewable power. But building more solar panels and wind turbines alone is not enough. The harder task may be building the grids and storage systems needed to ensure that the clean electricity generated actually reaches consumers.
(With inputs from agencies.)
