Solar cell technology has progressed to the point where solar cells are able to be incorporated into many different materials for multiple applications. In this insight we explore some of these applications.
A number of companies have developed glass that incorporates photovoltaic solar cells that can be used in windows, floors, roofs, skylights and facades. Typically, the glass has the same mechanical properties as glass used in construction, but also has active solar qualities that enable the glass to generate electricity.
The potential for solar glass is large with some commentators1 estimating that by 2020, 8.3 billion square metres of glass will be installed in new buildings annually. Adding to the scale of the use of glass in modern buildings, government regulations in a number of jurisdictions are mandating reduced emission standards for new buildings. For example, the European Union has a directive requiring all new buildings to meet a ‘nearly-zero-energy’ standard by the end of 2020 while Japan also has a requirement that all new public buildings to be zero energy by 2020.
The leading products on the market are not as efficient as photovoltaic cells because they must be at least partially transparent. One of the leading manufacturers of solar pv glass is Spanish company Onyx Solar which incorporates thin-film silicon solar panels into photovoltaic glass by using lasers to etch patterns into the panel, making them more transparent. The company’s products range from opaque to 30 percent transparency. This compares to sunglasses which range from 18 to 45 percent transparency.
The glass provides the same thermal and sound insulation, and natural light as conventional architectural glass and has been used in lieu of conventional glass on building façades, curtain walls, atriums, canopies and terrace floors. Recent projects which have incorporated the glass include the Dubai Frame skyscraper where Onyx installed 1,200 square metres of amorphous silicon photovoltaic glass in a yellow-good colour. The total installed power capacity is 38kW, expected to generate approximately 33,000 kWh annually, enabling the building to generate a large proportion of the energy it needs to operate. Another project is the Miami Heat Stadium which has skylights incorporating 300 crystalline silicon photovoltaic glass units generating 34,500 kWh of power annually for the building’s operation. In Australia, photovoltaic glass has been used in Melbourne Grammar School’s Geoff Handbury Science and Technology Hub, at La Trobe University Victoria and in North Sydney in the refurbished Sydney Coal Loader park.
Solar tents have become common at camp sites throughout the world. Flexible solar panels built into the fabric of the tent enable campers to power appliances, lighting and heating and cooling.
Such tents and mobile solar units have also become important in military and combat situations. Transporting fuel and diversions or stops to refuel become very dangerous exercises in combat situations. Diesel convoys are hazardous and vulnerable with one in 40 fuel convoys in Iraq in 2007 resulting in death or serious injury and in Afghanistan the same year, one in 24 convoys suffered casualties2. Soldiers are able to use solar power to charge batteries used in communications, GPS and night vision goggles. Reduced need for fuel also means less reliance on generators which are noisy and easily detectable. Some of the tent products used by military are capable of providing 1.8kW to 5.4kW3.
Solar-powered trash and recycling compactors
A number of US cities have installed solar-powered trash and recycling compactors4. The solar panels are located on top of these large bins and power a battery and system that compacts the rubbish, monitors the volume of waste in the bin and communicates with the central authority as to when the bin needs emptying.
The bins better contain and manage waste, compacting when the sensor indicates waste is at certain levels. Vendors of these products advertise that the bin can hold up to eight times the volume of waste of a similarly sized bin without compaction capacity5.
The compaction system and increased capacity together with the real time communication system indicating that the bin needs emptying significantly reduce the costs of garbage collection and the traffic problems associated with servicing garbage bins on a fixed roster.
Companies involved in this field claim the battery and system can operate for up to four weeks regardless of weather6.
Melbourne is currently using these waste bins in its CBD area following a successful trial in 2017. There are 397 such bins which have replaced 772 litter bins in the Melbourne CBD. Previously CBD bins were emptied several times a day, but the new bins are serviced once overnight, greatly reducing costs and traffic congestion7.
Solar paneled cars
This year Hyundai released a version of its Sonata hybrid that has solar panels incorporated into its roof. The car maker claims that the panels can provide up to 60% of the power for the car’s battery if the roof was exposed to sunlight for six hours a day.
Commentators have questioned the value of the benefit given the additional cost and weight8, but Hyundai says that this technology is just the start of energy generating technology to be applied to vehicles in coming years - “The solar roof is the first of these technologies, and will mean automobiles no longer passively consume energy but will begin to produce it actively”, said Jeong-Gil Park, Hyundai engineering and design chief9.
Other companies that have and are developing vehicles with solar panels include Toyota, Karma Automotive and Dutch start-up Lightyear10.