ABSTRACT
In a carbon-dioxide constrained
world, the primary methods to produce electricity (nuclear, solar, wind, and
fossil fuels with carbon sequestration) have low operating costs and high
capital costs. To minimize the cost of electricity, these plants must operate
at maximum capacity; however, the electrical outputs do not match changing
electricity demands with time. A system to produce intermediate and peak
electricity is described that uses light-water reactors (LWRs) and high- temperature
electrolysis. At times of low electricity demand the LWR provides steam and
electricity to a high-temperature steam electrolysis system to produce hydrogen
and oxygen that are stored. At times of high electricity demand, the reactor
produces electricity for the electrical grid. Additional peak electricity is
produced by combining the hydrogen and oxygen by operating the high-temperature
electrolysis units in reverse as fuel cells or using an oxy-hydrogen steam
cycle. The storage and use of hydrogen and oxygen for intermediate and peak
power production reduces the capital cost, increases the efficiency of the peak
power production systems, and enables nuclear energy to be used to meet daily,
weekly, and seasonal changes in electrical demand. The economic viability is
based on the higher electricity prices paid for peak-load electricity. Moreover,
the hydrogen produced can be supplied to the refinery industries through
pipelines. However, the primary use of hydrogen is to produce electricity. Significant
development work is required before the technology is commercially implemented.
IF U NEED FULL PAPER SEND A REQUEST TO
CREANOVA [CREATIVE & INNOVATIVE ENGINEERS]
E-mail: creanovaengineerz@gmail.com
Conclusions
In a carbon-dioxide
constrained world there are many options to produce electricity (solar, wind,
nuclear, fossil fuels with carbon dioxide sequestration). However, all of the
major options (1) have high capital costs and low operating cost that necessitate
operating at full capacity for economic electricity production and (2) do not
produce electricity that matches variable real-world electrical loads. Methods
to produce variable electrical loads to match electricity from capital- intensive
technologies are required. One set of options is using nuclear reactors to
produce hydrogen at times of low electricity demand, storing that hydrogen, and
using that hydrogen for peak power production. If such a peak power system was
to be built today, the reactor would be an LWR, traditional electrolysis would
be used for hydrogen production, and a hydrogen version of the combined cycle
natural gas plant would be used to convert hydrogen to electricity. The
round-trip efficiency of electricity to hydrogen to electricity would be
between 40 and 50%. With near-term improvements in electrolyzers and the use of
oxy-hydrogen steam cycles, the round-trip efficiency would increase to between
50 and 60%. HTE has the potential to further increase round-trip cycle
efficiency by using heat to partly substitute for electricity in the
electrolysis process. Round trip efficiencies may exceed 60%. Simultaneously, a
HTE system can in principle be operated as a fuel cell for conversion of
hydrogen to electricity. This capability dramatically reduces capital costs—a
high priority because peak power systems operate for a limited number of hours
per year. Moreover, the hydrogen produced by the HTE process can be transported
and used in refinery industries effectively and economically. There are significant
challenges in particular; the successful commercialization of the
high-temperature-electrolysis fuel-cell technology is required. There are a set
of auxiliary technologies that can improve performance and economics if
successfully developed. These include bulk oxygen storage technologies and
various oxygen-hydrogen to electricity technologies. Most of the other key
technologies are available. The development of peak-power electric technologies
would significantly enhance the competitiveness of all high capital, low-operating cost electric generation technologies—base load nuclear, fossil fuels with carbon
sequestration, wind, and solar.
