# Gravity storage: Economics Why costs are still guesswork for this young store Source page: https://www.materialinsights.org/energy/e_gravity/sg-econ/ What this tab covers Economics and financial structure: capital versus operating cost, levelised cost of storage, and how the asset earns money. Costs are poorly established. DOE's 2022 assessment puts gravity at a higher levelised cost than pumped hydro or compressed air, and early projects depend on Chinese policy support. #### Capex versus opex Unfavourable Published capital costs for full-scale plants are scarce. The 250 kW Gravitricity demonstrator cost about GBP 1 million, roughly GBP 4,000 per kW (calculated), which says little about commercial scale; Innovate UK grants of GBP 175,000 (2017) and GBP 650,000 (2019) funded the work. Opex is mainly mechanical maintenance; there are no cell or stack replacements. ARES claimed its system would be cheaper than batteries but gave no figure.^[5](https://pvtimes.com/news/energy-storage-project-breaks-ground-in-pahrump-90759/)^[6](https://www.ukri.org/our-work/responding-to-climate-change/moving-towards-net-zero/generating-electricity-by-lowering-weights-inside-old-mine-shafts/)^[7](https://www.solarpowerportal.co.uk/solar-projects/gravitricity-celebrates-success-of-250kw-energy-storage-demonstrator) Gravitricity demonstrator cost about GBP 1 million for 250 kW (about GBP 4,000/kW, calculated)^[7](https://www.solarpowerportal.co.uk/solar-projects/gravitricity-celebrates-success-of-250kw-energy-storage-demonstrator) Innovate UK grants GBP 175,000 (2017) and GBP 650,000 (2019)^[6](https://www.ukri.org/our-work/responding-to-climate-change/moving-towards-net-zero/generating-electricity-by-lowering-weights-inside-old-mine-shafts/) #### Levelised cost of storage Mixed For a 1,000 MW, 10-hour system the DOE/PNNL 2022 assessment estimates about USD 0.13 per kWh (USD 130 per MWh), against USD 0.11 for pumped hydro and USD 0.10 for compressed air. PNNL notes its gravity inputs are 2021 estimates, older than most other technologies in its database.^[9](https://www.energy.gov/sites/default/files/2022-09/2022%20Grid%20Energy%20Storage%20Technology%20Cost%20and%20Performance%20Assessment.pdf)^[10](https://www.pnnl.gov/projects/esgc-cost-performance/gravitational) LCOS, 1,000 MW / 10 h about USD 130/MWh^[9](https://www.energy.gov/sites/default/files/2022-09/2022%20Grid%20Energy%20Storage%20Technology%20Cost%20and%20Performance%20Assessment.pdf) Cost data vintage 2021 estimates^[10](https://www.pnnl.gov/projects/esgc-cost-performance/gravitational) #### Revenue stack and market participation Mixed Fast response suits frequency regulation (ARES was designed to give 15 minutes of regulation at 50 MW), while 4-hour block systems target daily shifting of wind output, as at Rudong where the store charges from an adjacent wind farm. China's National Energy Administration named Rudong and Zhangye as new energy storage pilot demonstration projects, so early revenue rests partly on policy support.^[3](https://energy-storage.news/energy-vault-china-gravity-ess-project-connected-to-grid-starts-building-three-others)^[5](https://pvtimes.com/news/energy-storage-project-breaks-ground-in-pahrump-90759/) ARES regulation duration 15 min at 50 MW^[5](https://pvtimes.com/news/energy-storage-project-breaks-ground-in-pahrump-90759/) #### Sources 1. [Energy Vault China gravity ESS project connected to grid; starts building three others](https://energy-storage.news/energy-vault-china-gravity-ess-project-connected-to-grid-starts-building-three-others) Energy-Storage.news, 2024 2. [Energy storage project breaks ground in Pahrump](https://pvtimes.com/news/energy-storage-project-breaks-ground-in-pahrump-90759/) Pahrump Valley Times, 2020 3. [Generating electricity by lowering weights inside old mine shafts](https://www.ukri.org/our-work/responding-to-climate-change/moving-towards-net-zero/generating-electricity-by-lowering-weights-inside-old-mine-shafts/) UK Research and Innovation, 2023 4. [Gravitricity celebrates success of 250kW energy storage demonstrator](https://www.solarpowerportal.co.uk/solar-projects/gravitricity-celebrates-success-of-250kw-energy-storage-demonstrator) Solar Power Portal, 2021 5. [2022 Grid Energy Storage Technology Cost and Performance Assessment](https://www.energy.gov/sites/default/files/2022-09/2022%20Grid%20Energy%20Storage%20Technology%20Cost%20and%20Performance%20Assessment.pdf) US Department of Energy / Pacific Northwest National Laboratory, 2022 6. [Energy Storage Cost and Performance Database: Gravitational Energy Storage](https://www.pnnl.gov/projects/esgc-cost-performance/gravitational) Pacific Northwest National Laboratory, 2024 ## Other sections - [Summary](https://www.materialinsights.org/energy/e_gravity/index.md) - [Overview](https://www.materialinsights.org/energy/e_gravity/overview/index.md) - [Correlation](https://www.materialinsights.org/energy/e_gravity/correlation/index.md) - [Science and technology](https://www.materialinsights.org/energy/e_gravity/sg-sci/index.md) - [Engineering and performance](https://www.materialinsights.org/energy/e_gravity/sg-eng/index.md) - [Impact and additionality](https://www.materialinsights.org/energy/e_gravity/sg-impact/index.md) - [What to track](https://www.materialinsights.org/energy/e_gravity/tracking/index.md) - [Relationships](https://www.materialinsights.org/energy/e_gravity/links/index.md)