It is commonly known that the future of energy is renewable, sustainable and clean. This is mainly due to the increasing concerns about the effects of climate change and the diminishing energy resources – especially fossil fuels. Stored energy systems offer an alternative to fossil fuels and provide a clean and sustainable source of energy.
The principle of a stored energy system is rather simple. There is a reservoir of energy (usually a hydropower dam or large gravity-based water storage system), and a solar-powered device (usually a solar cooker) that generates electricity. When the grid system – typically national – gets overloaded due to high demand and insufficient supply, the electricity generated by the solar cooker is stored in the reservoir. When demand is low, the reservoir provides power to the grid system and to the load. If there is sunlight, the solar cooker will generate electricity even when there is no demand – storing green energy in this manner is considered sustainable.
Researchers have developed, tested and validated several different types of solar cookers that store energy. One of the more sophisticated devices is the so-called Stored Energy Solar Cookstove (SESS). Developed by the Global Development Group (GDG), an international non-profit organization, the SESS is designed to offer a variety of advantages – some of which make it the most suitable solar cooker for tropical regions. In this article, we will discuss some of these advantages and whether or not they actually work in practice.
How Does the SESS Work?
The SESS is a hybrid device that combines solar (photovoltaic) and thermoelectric (Peltier) technologies. Thermoelectric devices are those in which electricity is generated by the – generally – heat source and not the – generally – light source – as in photovoltaic cells. A Peltier device – also known as a bipolar transistor – is capable of converting thermal energy (heat) into electrical energy. Simply put, a typical solar cooker functions on the same principle as the sun – that is, it generates electricity through the process of – generally – converting sunlight directly into heat. The SESS, however, is more advanced than the typical solar cooker due to its integration of a Peltier device – which allows for the generation of electricity even in low light conditions – and a rechargeable battery.
The solar photovoltaic portion of the SESS allows for the generation of electricity when there is direct sunlight – usually between 9 am and 5 pm – whereas the Peltier generator – the part that transforms heat into electricity – functions at all times and in all conditions. The result is a device that never needs to be recharged and that draws no power from the grid system.
Why Is the SESS Suitable for Use in Hot Climates?
The most advanced solar cookers, such as the SESS, have been designed and tested to function in the harshest of conditions – including high temperatures and direct sunlight. The development of such devices was driven by the desire to cook food on a long camping trip – frequently known as a wilderness camping trip – and to do so with minimal resources. A major disadvantage of most traditional solar cookers is that they become inefficient at higher temperatures – typically above 75 degrees Fahrenheit – and are thus unusable above that point. The SESS, on the other hand, was specifically designed to function at temperatures above 75 degrees Fahrenheit – even above 85 degrees Fahrenheit – the perfect environment for cooking food in nature. As a result, the SESS is one of the most efficient and practical solar cookers available today.
Does the SESS Really Store Energy?
The SESS stores a certain amount of energy, which can range from a few watts to more than 100 watts. To put this in perspective, a typical 100-watt solar panel would generate enough electricity to run a small refrigerator. The amount of energy stored in the SESS depends on many factors – such as how large the reservoir is, how long the sunlight remains and how high the ambient temperature is. The larger the reservoir and the longer the sunlight, the more energy the SESS will store.
In addition to the above, how high the ambient temperature is also determines how much energy the SESS will harvest. Obviously, the hotter it is, the more power it will generate. The ability of the SESS to store large quantities of energy makes it particularly suitable for use in regions that experience a lot of sunshine – such as the equator – and high temperatures – such as in the desert.
How Can the SESS Be Reconnected To The Grid?
As we discussed above, the solar portion of the SESS is a fully functional photovoltaic device that operates independently of the temperature of the environment – it can produce electricity at any time and in any weather conditions. The Peltier portion of the SESS, however, requires a direct electrical connection to the grid system – typically a 9-volt battery is sufficient – in order to generate electricity when the grid becomes overloaded. As a result, the SESS is not a self-sufficient unit and is dependent on the grid for its overall functionality. This makes it suitable for use in regions that are not wired yet and for situations in which the grid is unreliable or not available – for example, during a power outage or an earthquake.
How Is The SESS Safe To Use?
One of the major advantages of the SESS is that it is extremely safe to use – even in the case of a mishap – due to the integrated rechargeable battery and the use of low-voltage electronics. If you compare this to other solar cooking devices, you will notice that most have none of these safety measures – making them extremely dangerous to use especially in situations involving open flame. The fact that the SESS uses low-voltage electronics makes it extremely safe to use around water – as long as proper precautions are taken – even in the case of a spill or leak. Another advantage of the SESS is that it is very easy to clean. Even if the device was manufactured under unhygienic conditions, it can be disinfected with simple soap and water – no special cleaners are required. For this reason, the SESS is often referred to as a green energy source because it produces very little to no toxic waste during its entire lifecycle. The batteries, for example, can be recycled and used again – which in turn reduces landfill waste.
Overall, the SESS is a safe and practical device that can generate electricity in remote locations – including campsites – and in hard to reach places – such as in the wilderness or even underwater. Its small size and modularity make it easy to carry and – even more importantly – to store wherever you go. This in turn makes it ideal for use in emergencies, such as when the grid system collapses and you need an alternative energy supply to cook your food. Another practical use for the SESS is that it can provide continuous power for long periods of time allowing you to keep cooking even after the sun sets. This is extremely useful in the case of a power outage and the need to keep the electricity on in order to cook food – especially in regions that rely heavily on solar power for their electricity grid.
The Disadvantages Of the SESS
The SESS is an excellent energy source for those seeking to go green and reduce their carbon footprint. It provides many advantages – some of which make it perfect for use in hot, dry climates and some that make it suitable for use in remote locations. Even so, there are a few disadvantages that users should be aware of.