The current global environmental situation, with levels of air pollution in their all-time high, is the main reason why more and more projects are focusing on tackling the most worrying issue: the widespread and ever-increasing use of fossil fuels, like coal and oil, for energy generation. Since they are extracted in massive amounts, exported widely and generate considerable amounts of energy, the issue of the polluting gases released from the process falls out of the spotlight, but their effects on the environment are too severe to keep ignoring them.
With numerous iterations of technologies looking to take advantage of renewable resources like wind and sunlight, these have been deemed too inefficient or cost-ineffective to be implemented widely, to the current point of being considered as not enough to achieve the milestones set by the Paris Agreement.
This is why projects have focused on improving on existing systems or developing their own gathering technologies from the ground up. StorEnergy is a project focused on creating extremely efficient solar generators by revolutionizing the mechanisms of energy collection and storage.
Better Tools, Better Outcome
When we think of solar energy, the image that comes to mind is of large, dark panels installed in large numbers in a field, so they can receive as much sunlight as possible. This image is of photovoltaic cells, which use a combination of chemical reactions to generate electricity directly from sunlight, and they represent the current standard for solar generation despite their elevated cost of production and maintenance, and their reduced efficiency.
However, these are not the only way we can generate electricity from the sun. Taking advantage of the heat radiated from the sun, Concentrated Solar Power (CSP) technology uses sets of mirrors to redirect this energy, an ancient concept that is experiencing a resurgence, into a conventional system of steam turbines to generate electricity, and StorEnergy sees this field as the perfect opportunity.
Since there are no chemical reactions involved, maintenance costs are greatly reduced, so most of the efforts can be directed into the design of a device that can concentrate the largest amount of energy into the receptor. This is where a field known as non-imaging optics comes into play. Compared to regular optics, used in the development of glasses, microscopes, and telescopes, where the light rays are directed to create a high-fidelity image of a target object, the goal of non-imaging optics is to redirect and transfer energy in an optimal way.
With this in mind, StorEnergy has developed a series of solar concentrators that take advantage of affordable materials and efficient layouts to achieve a total reflectance of 93% of the visible spectrum of light, all while achieving longer lifetimes than regular photovoltaic cells, and their modular approach makes it a scalable solution to fit clients of all sizes and needs.
A Complete View
Even if CSP systems are fabricated with durability and efficiency in mind, their production cost is still higher than traditional photovoltaic cells. This, along with the drawback of intermittency, pushed StorEnergy to develop a system of thermal storage that brings the overall price of their solution to a more reasonable level. With a cost of $10 per kWh, rounding up to a cost of $3,700/kW for 16 hours of storage, and the ability to store GWh for 12 months with losses of <1%, this system is what brings their project to a competitive level in contrast to current solutions.
Energy from the solar field in a form of hot air from the receiver is transported to the storage. Heat is directed into the first chamber, once that is fully charged the direction is changed to the second chamber. Hot air from the storage is extracted and via a heat exchanger steam is generated
However, the storage temperature is required to be 800°C, and traditional CSP systems are unable to reach said temperature, which is why StorEnergy has also developed their own model of collector for the concentrators. This new part, called “Exergy Receiver”, not only implements ceramics with high thermal resistance, but also draws in ambient air that flows through the ceramics and exits the receiver at 900°C, enough to make full use of their storage system, and energy extraction only takes place after it is stored, enabling StorEnergy to guarantee a constant output with no fluctuations.
StorEnergy technology offer a paradigm shift in lowering cost of CSP and making renewables competitive even with fossil fuels. StorEnergy can build small systems from 1MW to larger 50MW+. The storage is scalable from 10MWh to GWh. Once the storage is built and sealed, the lifespan is 50+years with little maintenance.
Along with other improvements to traditional CSP technologies, like self-cleaning mirrors, and higher land coverage, StorEnergy offers the best solution in terms of cost, output, and annual capacity. They have already performed pilot installations for different clients in central Serbia, with which they have proven to be effective when replacing natural gas- and electricity-based systems, on top of their projects for heating, cooling and water supply solutions, which could be the first steps towards building a name in the future of renewable energies.