The fern, the train, 3D printing and other wonders of the sun

A number of scientific discoveries and technological innovations in Australia and the United States are showing us the (very near) future of solar energy.

by Eni Staff
02 March 2020
6 min read
by Eni Staff
02 March 2020
6 min read

The solar-powered train

The metropolitan region of Brisbane, south of Australia's Gold Coast, is famous for its waves that attract large numbers of surfers and its long sandy beaches, to which tourists flock in their droves during the summer months. Visitors to this part of Australia also get the opportunity to try out a new and fully sustainable transport service since the non-profit Byron Bay Railroad Company brought to fruition plans to create the first train powered exclusively by solar energy. As well as its eco-friendly dimension, the project also involved the reclamation of a section of railway that had been in disuse for several decades and the reuse of an old convoy dating back to 1949 that was used to transport the many immigrants fleeing a Europe destroyed by the World War II in search of a new life in New South Wales
Lightweight, flexible solar panels capable of producing a total of 6.5kW of power were installed on the roof, allowing the train to travel just over 3km in under ten minutes. This short connection is vital to an area that relies so heavily on tourism, connecting the town of Byron Bay to the Elements resort, with the idea for this green train actually coming from the resort’s owner, Brian Flannery.

The Byron Bay Railroad Company's solar powered train

How it works

A 30kWp solar system has been installed halfway along the route to offset the shortage of solar energy available on the rare cloudy days that the area experiences, meaning that the convoy is able to make up to 5 trips without needing to stop at the station to recharge. Furthermore, as is the case with hybrid cars, the braking system makes it possible to recover around 25% of the energy that the train requires to accelerate,
but that's not the only place it gets its energy; a series of batteries has, in fact, been installed to eliminate one of the two diesel engines and can be recharged when the train is stationary at the platform. The other diesel engine is used only when there is insufficient solar energy
The unique characteristics of this geographical area has been a key factor in the success of the project, with the connection spanning an entirely flat part of the region. The decision to use a 1949 convoy also proved to be the right one, with its light structure - the same structure used to build aeroplanes during the World War - making the train much lighter in weight and meaning that it naturally takes less energy to move it.
The train is already in operation, running every hour with the capacity to seat 100 passengers, and the Byron Bay Railroad already hopes to expand the route and increase the frequency with which the service runs.

Research into overcoming overly large and inefficient structures

Staying with Australia, research conducted by the RMIT University and published in Scientific Reports could represent a turning point in the history of solar power. The University has developed a prototype electrode capable of recharging itself using solar power, meaning that it is not that far-fetched to imagine being able to recharge small technological devices such as tablets and smartphones without using electricity. The researchers involved are setting their sights further afield and believe that they could apply their work in an increasing number of fields, even going as far as using their technology to power cars and houses, in the not too distant future. Researcher Litty V. Thekkekar and Professor Min Gu have created a series of supercapacitors that make it possible to increase energy storage capacity up to 3000%.

Learning from the leaves that waste not a drop

This research was inspired by the observation of the fractal structures that occur in nature, from the snowflake to the spiral of a cabbage, although what really fuelled the research was the observation of the structure of the fern leaf - a unique structure that allows the leaf to collect every single drop of water. The two researchers reproduced the pattern of the leaf on graphene, resulting in excellent high-performance energy accumulators. This unusual conformation actually makes it possible to fill all available space within the accumulator with energy, increasing energy conservation capacity up to 30 times and minimising dispersion
The research undertaken by the RMIT University is still pioneering, but experiments of this kind can lead to us considering a not too distant future in which we could see slimline, flexible and high-capacity solar storage systems that could be used to provide energy to increasingly large structures, beginning with smaller devices.

Could 3D printing help when it comes to solar panels?

The price of solar panels may have fallen particularly significantly in recent years, but the cost of the support structures on which they are mounted has remained relatively high. These mounts are generally produced using aluminium alloys and can cost up to 50-55% more than the solar cells themselves. In a recently published study, however, US researchers showed that the cost of solar panel mounts can be reduced by 83-92% by producing the special plastic support arms using a 3D printer.

A whole year exposed the elements: no sweat

During the study, two researchers from Michigan Technological University used a basic 3D printer called RepRap to produce a series of plastic mounting brackets that they then used to hold a series of 1kW photovoltaic panels. The plastic components functioned as expected and were able to support the photovoltaic battery in exactly the same way as traditional aluminium brackets would have done. Furthermore, whilst the metal brackets cost around $575, the 3D printed plastic version costs just a fraction of that amount - around $95 if using PLA plastic, which is normally sold at around $50 using recycled plastic.
The plastic mounts connected to the solar panels were tested for a whole year and left outside, exposed to the elements in the northern United States. The 3D-printed mounts for the solar cells had maintained their strength and resistance after twelve months and were still able to support the anticipated loads as required.