| 1. |
- Crispin, Xavier
(författare)
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Carbon nanotubes get high
- 2016
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Ingår i: NATURE ENERGY. - : NATURE PUBLISHING GROUP. - 2058-7546. ; 1
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Waste heat can be converted to electricity by thermoelectric generators, but their development is hindered by the lack of cheap materials with good thermoelectric properties. Now, carbon-nanotube-based materials are shown to have improved properties when purified to contain only semiconducting species and then doped.
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| 2. |
- Jewell, Jessica, et al.
(författare)
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Comparison and interactions between the long-term pursuit of energy independence and climate policies
- 2016
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Ingår i: Nature Energy. - : Springer Science and Business Media LLC. - 2058-7546. ; 1:6
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Tidskriftsartikel (refereegranskat)abstract
- Ensuring energy security and mitigating climate change are key energy policy priorities. The recent Intergovernmental Panel on Climate Change Working Group III report emphasized that climate policies can deliver energy security as a co-benefit, in large part through reducing energy imports. Here, using five state-of-the-art global energy-economy models and eight long-term scenarios, we show that while deep cuts in greenhouse gas emissions would indeed reduce energy imports, the reverse is not true: ambitious policies constraining energy imports would have only an insignificant impact on climate change. Restricting imports of all fuels would lower twenty-first-century emissions by only 2%–15% against the Baseline scenario as compared with a 70% reduction in the 450 scenario. Restricting only oil imports would have virtually no impact on emissions. The modelled energy independence targets could be achieved at policy costs comparable to those of existing climate pledges but a fraction of the cost of limiting global warming to 2 ◦ C.
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| 3. |
- Liu, Jing, et al.
(författare)
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Fast charge separation in a non-fullerene organic solar cell with a small driving force
- 2016
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Ingår i: NATURE ENERGY. - : NATURE PUBLISHING GROUP. - 2058-7546. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Fast and efficient charge separation is essential to achieve high power conversion efficiency in organic solar cells (OSCs). In state-of-the-art OSCs, this is usually achieved by a significant driving force, defined as the offset between the bandgap (E-gap) of the donor/acceptor materials and the energy of the charge transfer (CT) state (E-CT), which is typically greater than 0.3 eV. The large driving force causes a relatively large voltage loss that hinders performance. Here, we report non-fullerene OSCs that exhibit ultrafast and efficient charge separation despite a negligible driving force, as E-CT is nearly identical to E-gap. Moreover, the small driving force is found to have minimal detrimental effects on charge transfer dynamics of the OSCs. We demonstrate a non-fullerene OSC with 9.5% efficiency and nearly 90% internal quantum efficiency despite a low voltage loss of 0.61V. This creates a path towards highly efficient OSCs with a low voltage loss.
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| 4. |
- Olauson, Jon, et al.
(författare)
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Net load variability in Nordic countries with a highly or fully renewable power system
- 2016
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Ingår i: Nature Energy. - 2058-7546. ; 1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Increasing the share of intermittent renewable energy (IRE) resources such as solar, wind, wave and tidal energy in a power system poses a challenge in terms of increased net load variability. Fully renewable power systems have previously been analysed, but more systematic analyses are needed that explore the effect of different IRE mixes on system-wide variability across different timescales and the optimal combinations of IRE for reducing variability on a given timescale. Here we investigate these questions for the Nordic power system. We show that the optimal mix of IRE is dependent on the frequency band considered. Long-term (>4 months) and short-term (<2 days) fluctuations can be similar to today’s, even for a fully renewable system. However, fluctuations with periods in between will inevitably increase significantly. This study indicates that, from a variability point of view, a fossil- and nuclear-free Nordic power system is feasible if properly balanced by hydropower.
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