Functionalized Nano-porous Silicon Surfaces for Energy …
385
Table 1
Type of energy storage devices with analysis
Type of energy
Power density
(kW/m 3
)
Energy density
(kWh/m)
Electrical efficiency
(%)
Life-time
Typical range
Response time Backup time
Mechanical
a. Pumped
hydroelectric
storage, PHS
f(h
1 ~ h
2 )
3–6 Wh/L
75–80
~50 years
Up to 2.1 GW
1–2 mins
Days
b. Compressed air
energy storage,
CAES
360 MW
2–6 Wh/L
60–80
<50 years
25–350 MW
1–2 mins
Hours
c. Flywheel energy
storage
>707–1767
>282–424
90–95
10–20 years In kW
~1–2 mins
~mins
Thermal
Molten salt
200
40–110 kWh/ton
~90
30+ years
~200 MW
Seconds
Hours
Chemical
a. Fuel cell
Up to 30 kW
300–600 Wh/kg
40–60
1–2 years
Up to 30 kW
Seconds
Days
b. Synthetic natural
gas
1200 kWh/Nm 3
50–60
–
Up to 100 MW –
–
Electrochemical
Battery energy
storage system,
BESS
>106–7067
>70–247
~90
3–6 years
100–20 MW
Seconds
Hours
Electrical
a. Supercapacitor
>176, 678
>53
~90
10–20 years 1–250 kW
Milliseconds
Seconds
b. Superconducting
magnetic energy
storage
>530
>7
~95
~30 years
1–100 MW
Milliseconds
Seconds