Environmental Engineering Reference
In-Depth Information
6.2 Medium power and energy capacities
This section includes BES and FBES. The only major contender from the BES stor-
age technologies for future large-scale projects is the NaS battery. LA and NiCd will
always be used for their existing applications but further breakthroughs are unlikely.
FBES technologies (including VR, PSB and ZnBr) are all currently competing for
the renewable energy market. Demonstration results for these batteries will be deci-
sive for their future. It is worth noting that fl ow batteries are much more complex
than conventional batteries. This is the reason conventional batteries will always
be required. Conventional batteries are simple but constrained (power and storage
capacities are coupled) while fl ow batteries are fl exible but complex (power and
storage capacities are independent but a number of extra parts required). The other
key issue for this category will be the development of EVs. If technological advance-
ments continue within EVs, then large-scale BES will most probably play an impor-
tant role in future energy systems but not as stand-alone systems. Therefore, the
future of this sector is very uncertain as various technologies continue to develop.
6.3 Large power or storage capacities
FES must be optimised to solve storage capacity issues (high speed fl ywheels,
max 750 kW for 1 h) or power capacity issues (low speed fl ywheels, max 1650
kW for 120 s). SCES and SMES are only useful for power capacity issues. There-
fore, FES, SCES and SMES are all used for power issues where a lot of power is
required very fast. These technologies only differ in power capacity. FES is ideal
for small power (up to 750 kW), SCES for medium power (up to 1 MW) and
SMES for large power issues (up to 10 MW). The optimum technology depends
on the power required for each specifi c application. Due to this very specifi c char-
acteristic, these technologies are likely to be used for their specifi c purposes well
into the future such as uninterruptable power supply.
6.4 Overall comparison of energy storage technologies
It is very diffi cult to compare the various types of energy storage techniques to one
another as they are individually ideal for certain applications but no technology is
perfect for everything. Consequently, for the purposes of this chapter, a number of
illustrations are provided indicating the capabilities of each energy storage technol-
ogy in relation to one another (see Figs. 22-26). This is followed by a table outlining
the detailed characteristics of each storage technology (see Table 3) and a table indi-
cating the cost of each technology (see Table 4). Finally, there is a table specifying
the applications that each storage technology is suitable for (see Table 5).
6.5 Energy storage systems
The three energy storage systems that have been discussed above are HESS,
TESS and EVs. The HESS provides an excellent level of fl exibility within an
energy system, by enabling the electricity, heat and transport sectors to interact
Search WWH ::
Custom Search