Abstract
A large-area thermoelectric generator (TEG) utilizing a folded thin-film concept is implemented and the performance evaluated for near room temperature applications having modest temperature gradients (<50 K). The TEGs with the area of ∼0.33 m2 are shown capable of powering a wireless sensor node of multiple sensors suitable e.g. for monitoring environmental variables in buildings. The TEGs are based on a transparent, non-toxic and abundant thermoelectric material, i.e. aluminium-doped zinc oxide (AZO), deposited on flexible substrates. After folding, both the electrical current and heat flux are in the plane of the thermoelectric thin-film. Heat leakage in the folded TEG is shown to be minimal (close to that of air), enabling sufficient temperature gradients without efficient heat sinks, contrary to the conventional TEGs having the thermal flux and electrical current perpendicular to the plane of the thermoelectric films. The long-term stability studies reveal that there are no significant changes in the electrical or thermoelectric properties of AZO over several months, while the contact resistance between AZO and silver ink is an issue exhibiting a continuous increase over time. The performance of the TEGs and technological implications in relation to a state-of-the-art thermoelectric material are further assessed via a computational study.
Original language | English |
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Pages (from-to) | 1292-1298 |
Journal | Renewable Energy |
Volume | 147 |
Early online date | 18 Sept 2019 |
DOIs | |
Publication status | Published - Mar 2020 |
MoE publication type | A1 Journal article-refereed |
Funding
This work was supported in part by the European Union's Horizon 2020 Research and Innovation Program 2014–2018 as part of the TransFlexTeg project under Grant 645241 and in part by VTT Technical Research Centre of Finland Ltd.
Keywords
- Aluminum-doped zinc oxide
- Atomic layer deposition
- Finite element method
- Large-area thermoelectric generator
- Thin-film TEG