conclusions.
Secondly, the different renewable energy technologies result in
different displacement effects in an electric power system. In our
case study, solar PV is expected to displace both coal-fired technology
and natural gas-fired technology, but onshore wind is expected
to displace only coal-fired technology. Therefore, different
renewable energy technologies might be required to have different
LCOE levels to be cost-competitive in the same electric power
system, so the levels of subsidy for the renewable energy technologies
might not be strictly proportional to the levels of LCOEs
for the technologies. In this context, the renewable portfolio (RPS)
policy in the Korean electricity sector applies different credit
multipliers to different technologies when the policy awards renewable
energy certificates (RECs) for each MWh generated. Even
though the multipliers were designed to represent the
competitiveness of the renewable energy technologies by incorporating
not only the costs of technologies but also other factors,
such as potentials, special characteristics, environmental
regulations, and social acceptances, the other factors were qualitatively
reflected. As a result, the policy failed to obtain a positive
evaluation since solar PV was overly deployed but only small capacities
of other technologies, such as wind, were deployed, contrary
to the nation’s expectation. Our new methodology can
quantitatively analyze the effects of the other factors on competitiveness,
so it can be utilized to attain a more efficient design of
the RPS policy.
Lastly, if an electric power system has too many capacities of
conventional technologies relative to the projected demand, they
can be a critical obstacle to the deployment of renewable energy
technologies in the system. Our case study projects that both solar