Environmental Engineering Reference
In-Depth Information
Figure 26: Cost per cycle for each technology [ 37 ].
7 Energy storage in Ireland and Denmark
Ireland and Denmark are very interesting countries as case studies for the deploy-
ment of energy storage systems. They have relatively small national electricity
networks and large wind resources. They differ in that while Denmark is deeply
interconnected to the electricity grids of continental Europe, Ireland as an island
nation is not. Neither have substantial fossil fuel resources, but Ireland in par-
ticular is among the most dependent (92.6% in 2008) countries worldwide on
imported fossil fuels for its electricity generation. In order to reduce greenhouse
gases, Ireland's primary objective is to produce at least 40% of its electricity from
renewable resources by 2020. Currently, Ireland's wind generating capacity has
just surpassed 1000 MW, approximately 13% of the total Irish network capacity
(see Table 6). However, previous reports had indicated that grid stability can be
affected once wind capacity passed 800 MW [3]. As a result, Ireland will need to
address the effects of grid intermittency in the immediate future.
Energy storage for an electric grid provides all the benefi ts of conventional gen-
eration such as, enhanced grid stability, optimised transmission infrastructure,
high power quality, excellent renewable energy penetration and increased wind
farm capacity. The main downsides of energy storage are the additional cost and
the round-trip effi ciency loss which may be as much as 30%. However, the opera-
tion of energy storage systems to store renewable generated electricity produces
no carbon emissions and they do not rely on imported fossil fuels. As a result,
energy storage is a very attractive option for increasing wind penetration onto the
electric grid when it is needed.
However, currently Ireland's solution to the grid problems associated with the
intermittency of wind generation is grid interconnection. EirGrid is in the process
Search WWH ::
Custom Search