Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments
4.0 Renewable Energy Technology
Screening
4.4.1 Cost of Energy
The levelized cost of energy is a measure of the total life-cycle cost of a project or
technology to generate power. Because the cost of developing a facility can vary
considerably, even with modular technologies such as solar photovoltaic or wind energy,
a range of project costs and performance assumptions were used to develop levelized cost
estimates for each renewable energy technology. The multi-fuel generation technologies
were evaluated separately as a fuel has not yet been selected for each of these
technologies and the levelized cost of generation is heavily dependent upon the fuel cost.
Black & Veatch used the technology cost and performance assumptions developed in the
previous section, which are summarized in Table 4-3 for the three year timeframe. The
values shown in the table were chosen as representative of the technology application in
Kauai.
Of the renewable energy technologies evaluated, wind power has the lowest
capital cost per kW installed at $1,200-1,600/kW. This has resulted in a 30 percent
annual increase in wind installations worldwide over the last five years. System costs
have gone down as single turbines have achieved megawatt sizes. In comparison,
conventional biomass and geothermal technologies have capital costs in the range of
$2,600-3,900/kW and $3,300-5,200/kW, respectively. The high cost of biomass plants
has to do with their relatively small size, extensive fuel and ash handling requirements,
and the need for a robust plant design to handle the variability in the fuel quality.
Geothermal power plant costs and complexity are highly dependent on the temperature of
the geothermal resource, its proximity to the surface and the quality of the brine to be
handled. Due to their extensive material handling and emissions control requirements,
waste to energy technologies have a substantially higher capital cost than biomass plants,
ranging from $6,500 to 11,700/kW. The small size of a potential waste to energy plant in
Kauai also increases its relative costs due to economies of scale. Hydroelectric power
plants have a wide range of capital costs from $1,700–5,700/kW. Given the turbine
technology used for power production is quite mature and costs are low, the civil work
that needs to be done to build dams and penstocks tends to be the driving factor behind
the capital cost of these systems. Photovoltaic systems are by far the most expensive
renewable energy technology with capital costs from $8,300–10,500/kW and a capacity
factor of only 20 percent. These systems are currently too expensive to be applied
competitively at utility scale. However, they have found a niche in the remote power
supply market for rural electrification, water supply, and other applications.
21 March 2005 4-5 Black & Veatch