Innovation in Global Power - Parsons Brinckerhoff

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Renewables – The Risks, Concerns and Potential
Renewable Energy — Sustainable Economy?
By Dominic Cook, Newcastle-upon-Tyne, UK, 44 191 226 2203, cookDo@pbworld.com
This article is based on a
report produced to inform
the debate around the
future mix of power generation
in the UK during the
government’s 2006 Energy
Review by providing an
independent statement of
the costs of power generation
at that time. It not
only reflects the high level
of work done by PB’s
power specialists, it
provides readers with
answers to some questions
clients around the world
contend with.
Table 1: Characteristics and
costs of technologies studied.
1 These are the estimated
engineer/procure/construct (EPC)
costs for each technology excluding
owners soft costs and contingency.
Renewable technologies are at differing stages in their development. Onshore wind generation,
for example, is regarded as being virtually competitive in its own right without external support
given the right combination of project specifics. This stage of advancement contrasts with those
of other renewable energy generation technologies that struggle to break out from the prototyping
stage and find convergence on a single implementation model (for example, wave/tidal).
The technologies that are considered in this article are:
• Coal pulverised fuel
• Gas-fired combined cycle gas turbines
• Coal IGCC
• Nuclear
• Onshore wind
• Offshore wind
• Wave
• Tidal.
• Biomass
This list includes technologies that are available currently and those that are considered to
comprise the next generation of renewable generation. They were compared using a discounted
cashflow model of the technology capital and operational costs over a typical project life.
Long-term gas and coal fuel prices were assumed to be 37 pence/therm and $49/tonne.
Whilst there are local cost factors that affect the analysis, the main factor is the relative price
for each energy source.
Technology Summary
The characteristics of the various power generation technologies reviewed are discussed
below and summarized in Table 1.
Coal pulverised fuel. Conventional
pulverised fuel (PF) combustion is
a common form of generation
technology found throughout the
world. It is well proven and considered
to be a mature technology.
The key design features of a conventional
PF plant are the pressure
and temperature at which steam is
generated. The majority of plants
installed to date operate at subcritical steam conditions; however, supercritical and advanced
super-critical boilers are becoming the technology of choice for new coal plant construction.
A new coal-fired PF plant will have to meet environmental legislation to be considered a
“best available technology” and will have to meet environmental legislation through the fitment
of emissions control systems. These are important aspects of all types of coal PF plant, and
the associated costs can be minimised through the specification of the fuel to be burned.
Combined cycle gas turbine (CCGT). In a CCGT power plant, the hot exhaust gases from
the gas turbine are delivered to a heat recovery steam generator (HRSG) where heat energy
in the gases is transferred to water, which is then converted to high-pressure, high-temperature
steam. This steam is then delivered to a steam turbine. About two thirds of the electrical
power is derived from the gas turbine and one third from the steam turbine.
Our study assumed the use of a “state-of-the-art” heavy-duty gas turbine based CCGT because
of the high cost of gas fuel and the high level of competition between electricity generators.
45 PB Network #68 / August 2008