Saturday, 23/11/2024 | 10:20 GMT+7
Concentrating solar power could meet 10% of electricity demand, according to an esteemed American study, although the wider development of this technology will require the construction of several power plants for back-up
Concentrating solar thermal power could meet from 2% to 10% of future electricity needs, depending on climatic conditions of the different regions.
This is the finding of a recent US study that was compiled by the Pacific
Northwest National Laboratory Department of Energy, the University of Maryland
and NASA, which introduced a new assessment method to analyze interactions
between solar thermal and electrical systems. The aim is to overcome one of the
greatest difficulties of economic models that were used up to now for the
energy evaluation of solar power, which practically did not take into account
the source’s natural variability compared to network loads.
Regarding concentrating solar power, there are essentially two parameters that
must be considered: the number of sunny days and the amount of light in those
days. That is, the key to a reliable assessment of solar power consists in the
exact knowledge of the amount of hours of the day in which the plants have
operated and of what action is taken to compensate the energy that was not
injected into the grid when the plants were not producing.
The study found that, even considering a substantial development of thermal
storage systems and their cost reduction, the widespread adoption of
concentrating solar power will require a large number of back-up solar thermal
power plants. The latter, for environmental and other type of needs, will
preferably be gas or biomass-fuelled, but will significantly affect the total
cost of concentrated solar energy, compared to the long term increased cost
that is expected for all fuels.
SP technologies hold a promise of clean, domestic power around the world. CSP
systems convert the thermal energy in sunlight into electricity. Global use of
this technology is projected to grow substantially in the near future with
numerous plants under construction worldwide. The potential of solar power
technologies is difficult to evaluate, however, because the energy-economic
models used to inform decision-makers are not designed to simulate variable
renewable resources. The results of this study can be used to produce more
realistic estimates of their potential contribution.
The operation of CSP power plants and their interaction with electric loads, by
time of day and season, were analyzed to determine how this technology could be
realistically incorporated into energy-economic models. A key characteristic of
CSP power plants is their ability to supply reliable power through the use of a
low-cost backup option referred to as hybrid plants, whereby natural gas, or
even biomass, can be combusted in a low-cost boiler or heating unit to supply
power on cloudy days.
Plant performance depended on two key parameters: the number of cloudy days in
which power plants cannot operate, and the average amount of sunshine on
operational days. This research showed that an accurate characterization of the
number of such "no operational" days is key to a realistic
characterization of this technology. No existing data sets provided global
estimates of this parameter, so the necessary values were estimated using
regressions developed from the U.S. National Solar Radiation Database in
conjunction with a global solar resource data set developed by NASA. The
technology representation and data developed in this work were then implemented
in the Global Change Assessment Model (GCAM) to examine how CSP technologies
might compete with other electricity supply technologies in 14 global regions.
The methodologies and data developed in this research can potentially be used
in many energy-economic models to more realistically examine the potential of
CSP technologies. A detailed study of the potential of renewable energy more
broadly using this and related work using the GCAM model is underway at PNNL.
The work reported here highlighted the importance of estimating new solar
resource parameters, which may be possible with the next generation of solar
resource assessments being conducted by NASA. The role of CSP backup operation
should be more thoroughly examined in detailed renewable energy analyses.
Finally, the report stresses the need for further studies in order to better
assess how much solar energy used for industrial purposes is truly available in
the various regions of the Earth. Subsequently, this will allow to examine the
technical and economic aspects regarding to what extent parallel thermal power
plants are needed for back-up. Nevertheless, although there have been other
more optimistic studies in this field, the possibility that in a few decades
concentrating solar alone will be able to meet up to 10% of electricity needs,
that is suggested by this report, appears significant.
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