Table 2
Technical characteristics of commonly used commercial thermal storage materials [78,80–83]
| Thermal storage materials | Working temperature range (°C) | Density (kg/m3) | Specific heat (kJ/(kg K)) | Thermal conductivity (W/(m K)) | Material cost ($/kg) | Advantages | Limitations | |
| Sensible thermal | Water | 20‒80 | 1000 | 4.2 | 0.60 | 0.005 | Economical, easy access, environmentally friendly, stable | Low thermal storage density, narrow range of heating source, large heating loss |
| Heat transfer oil | −40‒300 | 800‒900 | 1.5‒2.0 | 0.15‒0.30 | 1.2‒10 | High heat transfer efficiency, easy-to-control temperature, non-corrosive | High price, flammable, easy to decompose | |
| Rock | 100‒1000 | 1500‒2800 | 0.9‒1.1 | 0.85‒3.50 | 0.02‒0.3 | Economical, good thermal stability | Low thermal efficiency, need a heat transfer medium, poor cycle stability, high heating loss | |
| Concrete | 200‒400 | 2000‒2500 | 0.8‒1.0 | 1.0‒2.0 | 1.2‒10 | Wide range of usage temperatures, high strength | High cost, need a heat transfer medium | |
| Latent thermal | Ice | <0 | 917 | 2.1 | 2.2 | 0.05 | Economical, easy access, environmentally friendly, strong stability | Volume change is relatively large, low thermal storage density |
| Molten salt | 300‒850 | 1800‒2100 | 1.5‒1.8 | 0.60‒0.08 | 0.5‒3.0 | Good heat transfer, high heating storage density | Solidifies easily, corrosive, toxic | |
| Hydrous salt | 30‒80 | 1100‒1500 | 1.5‒2.0 | 0.50‒0.6 | 0.2‒1.5 | High thermal conductivity, little change in phase transition volume, low cost | Supercooling phenomenon, corrosion, decomposition | |
| Paraffin | 20‒40 | 800‒950 | 2.1‒2.9 | 0.20‒0.30 | 1.0‒3.0 | High latent heating, stable chemical properties | Low efficiency, poor thermal conductivity, large volume change, flammable | |
| Polyethylene glycol | 15‒45 | 1000‒1300 | 2.1‒3.1 | 0.10‒0.20 | 1.0‒3.0 | High latent heating, compatible with other materials, recyclable, stable chemical properties | Low efficiency, low thermal conductivity, large volume change, flammable | |
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.