Page 20 - PEN eBook May 2023

SMART ENERGY SMART ENERGY

Modularization for improved reliability can come CONCLUSION
in several ways. Figure 8 shows a parallel PCS. The SiC-based power electronics are helping revolutionize
modules in each parallel leg can be hot-swappable both storage and grid distribution systems, making the
storage/converter modules, and the battery parameters use of distributed, renewable energy generation much
within each leg do not have to be well-matched. The more practical. Key bottlenecks still remain, particularly
scalability here is still limited by the voltage gain within in long-duration energy storage, the manufacturing of
each of the DC/DC converter stages. large-storage–capacity Li-ion batteries and passive
components like magnetics that go into the PCS
A series-connected PCS is depicted in Figure 9. This stages.
has advantages of creating a higher DC-link voltage,
enabling reduced conduction losses from cabling. This
architecture is more forgiving for even modest gain in
Enabling Clean
DC/DC converters.

Nuclear Fuel

How fusion could help play a role in solving the global

issue of nuclear waste

By Greg Piefer, CEO and founder of Shine Technologies.

National support for nuclear energy in the United If it could be recycled, it can be reused—again and
States is the highest it has been in years. A 2022 again—in the same reactors where it originated.
survey by ecoAmerica showed that more than
61% of Americans believed “a lot more” or “more” Imagine how much better the public response to
money should be spent on next-generation nuclear nuclear waste would be if we made it clear that
technology. Climate change, geopolitical challenges instead of creating new waste, we’d be using old waste
and rising energy costs are among the factors in the to refuel our reactors again and again.
changing sentiment.
With economic, security and climate matters in mind,
Figure 8: A parallel PCS (Source: Muller) Figure 9: A cascaded, series-connected PCS (Source: Muller)
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And yet the same barriers to nuclear power that 35 members of Congress in November penned a letter
have existed for decades continue to persist today. In to Jennifer Granholm, the United States Secretary of
the same survey, the two largest public concerns to Energy. They asked the Department of Energy (DOE)
upgrading nuclear technology were waste disposal and to accelerate development of technologies that may
health/safety. increase sustainability of the U.S. nuclear fuel cycle
through recycling. They asked the DOE to report on
The buildup of spent nuclear fuel continues to be a its work to advance technologies that might be used
significant issue both socially and economically. The to reduce fuel security risks, be economically viable
International Atomic Energy Agency reports nearly and help manage nuclear waste produced by the U.S.
References 400,000 tons of spent fuel were generated between reactor fleet.
1954 and 2016. The United States currently has an
estimated 86,000 metric tons of spent nuclear fuel, Nuclear and fusion technology companies can play a
▶ Mueller, J. (2021). “Enabling Energy Storage for Grid Applications Through Advanced Power Electronics.” a number that is growing by about 2,000 tons per role in the future in both recycling spent nuclear fuel
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IEEE Energy Conversion Congress and Exposition. year. There are currently just two acceptable storage so that it can be reused and transforming long-lived
▶ 2Zhu, Y., Yao, J., & Wu, D. (2011). “Comparative study of two stages and single stage topologies for grid-tie methods for that spent fuel—either in specially radioactive waste into shorter-lived materials.
photovoltaic generation by PSCAD/EMTDC.” Proceedings of the 2011 International Conference on Advanced designed pools or in dry cask storage—onsite at
Power System Automation and Protection. reactors across the country. FUSION MAY DRAMATICALLY ALTER
LONG-LIVED ISOTOPES
▶ 3Salem et al. (2022). “A Comprehensive Review on Multilevel Inverters for Grid-Tied System Applications.” RECYCLING RADIOACTIVE WASTE Computers were once expensive machines that
Energies 2022. Spent nuclear fuel isn’t actually “spent” at all; it still took up entire rooms or buildings and were used only

has more than 90% of its energy capacity available. in niche applications. But the technology provided

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