The main cost factors in implementing thermal energy storage (TES) systems include the following:
1. Capital Expenditure (Capex)
- Storage media and containment: A significant portion of TES cost comes from the materials used to store thermal energy, such as molten salt, silica sand, or other media, along with storage containment units like silos. For instance, a large TES system involving particle storage may have costs largely driven by the containment silo (including concrete foundation) and insulation, making up millions per unit (e.g., $12M per 6.4 GWh thermal unit).
- Power conversion equipment: The power rating or converter size, such as heat exchangers and turbines, affects costs. Higher power ratings lead to larger and more expensive energy converters. More robust materials are also needed for higher temperature gradients, which increase expenses.
- Total installed system costs: On a global average, installed thermal energy storage systems cost about $232 per kWh capacity, which is lower than other long-duration storage technologies such as compressed air or lithium-ion batteries.
2. Materials and Construction
- Insulation materials: Insulation is critical to minimize thermal losses and involves substantial costs connected to the design geometry and material prices.
- Construction labor and design: The complexity of engineering the containment silos, foundations, and ancillary equipment directly impacts the total cost.
3. Operational Factors
While operational costs (O&M) are less emphasized than capex, they still contribute to overall economics, particularly in terms of maintenance of heat exchangers and other moving parts.
4. Regional and Policy Influences
Costs vary significantly by region due to factors such as local adoption rates, economies of scale, and governmental policies. For example, China has notably lower costs due to gigawatt-scale deployments and supportive policies, while non-China markets show 54% higher capex for TES.
5. Cost Metrics and Performance
- Cost models also consider power rating, temperature range, and storage capacity, which influence material and converter specifications, directly affecting system costs.
- Estimated costs in some analyses range around $350/kWh capex with a levelized cost of storage around 13.5 cents/kWh thermal, but there can be a variation down to 5-10 cents/kWh for lower cost scenarios.
Summary Table of Main Cost Factors in TES Implementation
| Cost Factor | Description | Impact on Cost |
|---|---|---|
| Storage media & containment | Cost of materials (e.g., molten salt, sand) and silos | Large portion of total capex |
| Power conversion equipment | Heat exchangers, turbines, converters size & materials | Increases with higher power rating & temp. |
| Insulation | Materials to reduce thermal losses | Significant material cost |
| Construction & design | Engineering, labor, foundations | Varies with system size & complexity |
| Operational & maintenance | Equipment upkeep | Adds to lifetime costs |
| Regional policy & scale | Local manufacturing, policy incentives | Can reduce costs substantially (e.g., China) |
| System capacity & rating | Size and temperature range affecting design | Affects materials and converter costs |
In conclusion, the dominant cost factors in TES systems arise from storage media, containment structures, power conversion equipment, insulation, and regional factors that influence economies of scale and policy support. These together define the capital intensity and operational economics of TES implementation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/what-are-the-main-cost-factors-in-implementing-thermal-energy-storage-systems/
