Putting the billions of FREE curtailed energy to use

Britain paid £1.5 billion in 2025 alone to switch wind farms off, and globally the lost value of curtailed wind and solar passed $20 billion in 2024, a figure IRENA expects to keep climbing as more renewables come online faster than the grid can absorb them.

That is clean electricity that was generated, was available, and simply had nowhere to go. It is not a future resource. It exists right now, in growing volumes, every time the wind blows harder than the grid can take.

We set out to find better homes for it. Below are 20 ways curtailed energy could be redirected toward reducing the effect of warming on the planet. Each is scored on estimated efficiency, practicality today, and how far it has actually been researched or tested, then combined into a single Usefulness Index that weights practicality and maturity above raw efficiency, because an idea only helps if it can actually be built. The list is ranked by that index, most useful first.

1. EAF Steel Recycling (Usefulness 84 | Efficiency 83 | Practicality 8 | Maturity 9)
Electric arc furnaces melt scrap steel preferentially during curtailment windows instead of running virgin ore production. This is commercially proven technology that simply needs smarter scheduling.

2. Flexible Compute at Curtailed Sites (Usefulness 77 | Efficiency 90 | Practicality 8 | Maturity 6)
Data centres running climate models, AI training, or protein folding are sited next to wind and solar farms and ramp their workloads up and down with available power. Modern facilities lose very little energy to overhead.

3. Thermal Batteries for Direct Heat Use (Usefulness 76 | Efficiency 90 | Practicality 7 | Maturity 7)
Curtailed electricity heats sand, molten salt, or refractory brick for storage, then the heat is used directly in industrial processes rather than converted back to power. Skipping the reconversion step keeps losses low.

4. Green Hydrogen Electrolysis (Usefulness 74 | Efficiency 75 | Practicality 7 | Maturity 8)
Electrolysers convert curtailed electricity into hydrogen for industrial feedstock or fuel. The best commercial units now reach efficiencies once thought unreachable outside a lab.

5. Cold Storage Expansion to Cut Food Waste (Usefulness 74 | Efficiency 65 | Practicality 7 | Maturity 9)
Extra refrigeration capacity run on curtailed power reduces spoilage and the emissions embedded in wasted food. The underlying technology is mature and widely deployed already.

6. Water Treatment and PFAS Remediation (Usefulness 69 | Efficiency 90 | Practicality 6 | Maturity 6)
Electrocoagulation and advanced oxidation systems use curtailed power to remove persistent contaminants from industrial and municipal wastewater. The electrochemistry involved is already highly efficient.

7. Biochar Pyrolysis (Usefulness 67 | Efficiency 83 | Practicality 6 | Maturity 6)
Curtailed power drives pyrolysis reactors that turn biomass into biochar for long term soil carbon storage, with bio-oil and syngas as useful co-products.

8. Desalination for Ecosystem Restoration (Usefulness 60 | Efficiency 55 | Practicality 5 | Maturity 8)
Curtailed power runs reverse osmosis plants that direct fresh water toward restoring wetlands, salt marshes, and riparian habitats. Desalination efficiency has improved dramatically over the past decade.

9. Liquid Air Energy Storage (Usefulness 58 | Efficiency 55 | Practicality 6 | Maturity 6)
Curtailed power liquefies air for storage, and a turbine later expands it to regenerate electricity. Round trip performance depends heavily on how well the plant recycles heat and cold.

10. Marine Cloud Brightening (Usefulness 52 | Efficiency 95 | Practicality 3 | Maturity 4)
Spray vessels use curtailed power to lift fine sea-salt aerosols into marine clouds, making them brighter and more reflective. The energy required per unit of cooling effect is tiny once the equipment is running, but almost nothing has been built at scale.

11. Steel Slag Mineral Carbonation (Usefulness 52 | Efficiency 55 | Practicality 6 | Maturity 4)
Legacy steel and iron slag heaps are exposed to steam and CO2 using curtailed power, accelerating a mineralisation reaction that already happens naturally but very slowly. Most of the world's slag heaps remain untouched.

12. Enhanced Weathering Feedstock Grinding (Usefulness 50 | Efficiency 50 | Practicality 5 | Maturity 5)
Curtailed power grinds basalt and other silicate rock for spreading on agricultural land, speeding up natural CO2 absorbing weathering. Far less energy intensive than direct air capture per tonne of CO2.

13. Thermal Batteries for Power Reconversion (Usefulness 47 | Efficiency 40 | Practicality 5 | Maturity 5)
The same sand or molten salt storage as above, but the heat is converted back into electricity through a turbine rather than used directly. The extra conversion step costs a significant share of the stored energy.

14. Green Ammonia as an Energy Carrier (Usefulness 47 | Efficiency 30 | Practicality 5 | Maturity 6)
Curtailed electricity produces green ammonia, a storable and shippable fuel that can later be converted back to power. The round trip losses are considerable, but ammonia travels and stores well.

15. Synthetic E-Fuels (Usefulness 45 | Efficiency 38 | Practicality 4 | Maturity 6)
Curtailed power produces green hydrogen, which is combined with captured CO2 to make e-methanol or e-kerosene for aviation and shipping. Useful where direct electrification is not an option, at a real efficiency cost.

16. Kelp Farming with Powered Upwelling (Usefulness 43 | Efficiency 60 | Practicality 4 | Maturity 3)
Pumps bring nutrient rich deep water to the surface to boost kelp and macroalgae growth, increasing the carbon the ocean draws down as the biomass sinks or is harvested.

17. Electrochemical Ocean Alkalinity Enhancement (Usefulness 43 | Efficiency 40 | Practicality 4 | Maturity 5)
Electrochemical processes increase ocean alkalinity, boosting the ocean's natural capacity to absorb CO2. Effective in favourable regions, though the ecological effects at scale are not yet fully understood.

18. Space Sunshades and Stratospheric Aerosol Injection (Usefulness 34 | Efficiency 70 | Practicality 1 | Maturity 3)
This is our answer to the laser to space idea. There is no real engineering path for beaming captured heat off the planet. The genuine equivalent is increasing reflectivity, either with orbital mirrors at the L1 point or reflective aerosols in the stratosphere. Once deployed, a small amount of material offsets a large amount of warming, but nothing at scale has ever been built.

19. Electro-Stimulation of Soil Microbes (Usefulness 33 | Efficiency 50 | Practicality 3 | Maturity 2)
Buried electrodes powered by curtailed electricity stimulate soil microbial communities, potentially boosting microbial carbon fixation. Related bioelectrochemical systems exist, but this specific application is still largely lab stage.

20. Ice-Making for Permafrost Stabilisation (Usefulness 28 | Efficiency 15 | Practicality 3 | Maturity 4)
Curtailed power runs snow-making equipment to add artificial cover over permafrost and slow local melt. The energy cost is high relative to the modest, localised effect it achieves.

The ideas at the top of this list are not necessarily the most efficient on paper, they are the ones that combine real technical performance with something that could be built and scaled today. The ones further down still could matter, because some of the highest value climate work, like marine cloud brightening or space-based sunshades, will only become useful once far more research and testing closes the gap.

Curtailed power is the cheapest possible way to start closing it, let's start using it properly.