For years, rain and cloudy weather have been the sworn enemies of photovoltaics. Now, that may be about to change. Scientists in Spain have developed a hybrid perovskite-based PV module that works both in full sunlight and in the rain.
Perovskite cells have been talked about for years as an alternative to silicon-based photovoltaics. Further research is needed to fully unlock the commercial potential of this material. However, we already know that a PV panel made of perovskites is potentially cheaper and more efficient than classic silicon modules, and can also operate in conditions other than sunny weather. The latter has recently been proven by scientists from the Institute of Materials Science in Seville (ICMS) in Spain.
The result of their work is a thin protective layer applied using a plasma method, which not only seals the cell, but also allows it to obtain energy from… falling raindrops. The layer is only 100 nanometres thick, which is 800 times less than a human hair.
The coating serves a dual purpose: it protects the chemistry of the perovskite cell and increases light absorption. At the same time, it acts as a triboelectric surface, converting the kinetic energy of falling drops into electricity.
PV in the rain? Now it’s also possible with perovskites
Experiments conducted at the ICMS laboratory confirm the effectiveness of the solution. A single raindrop generates a potential difference of 110 V. This is enough to power a small portable device. According to the authors of the study, cited by the website Interesting Engineering, the entire device is hybrid in nature.
Our invention is an advanced solution combining the photovoltaic technology of perovskite solar cells with triboelectric nanogenerators in a thin-film configuration, thus demonstrating the feasibility of implementing both energy harvesting systems – says Carmen Lopez, ICMS
The hybrid device copes well with fluctuations in temperature and humidity. Low resistance has been the biggest problem in the development of perovskite technology so far. The work of researchers from Spain is potentially adapted to work in harsh weather conditions.
Sensors, bridges and the Internet of Things
What devices can be powered by this technology? Scientists point to external LED circuits or sensors placed in the open air. By combining energy from the sun and falling raindrops, such small devices can be powered entirely by the modules. The technology also has potential in precision agriculture and meteorology, as well as in monitoring the condition of structures such as bridges.
The team has particularly high hopes for the Internet of Things sector. Energy-autonomous sensors operating in the field without access to the power grid have been an engineer’s dream for years. Now it seems closer to realisation.
