A Solar Power Tower (or Solar Array) is a type of Concentrated Solar Power (CSP) plant that was pioneered in the 1980s. As the name implies, a Solar Power Tower uses a central tower (principally made of steel or concrete but sometimes glass or composite materials), surrounded by smaller towers, also filled with solar panels. Solar panel manufacturers like SunPower and Heliodyne provide standardized panels that can be used in different types of CSP plants. As a result, the industry has developed a specialised tower that can be efficiently delivered and integrated into solar facilities around the world.
Advantages
The primary advantage of a Solar Power Tower is that it’s a concentrated solar power system that can be erected using standard construction techniques, such as cranes and bulldozers, without specialised equipment. This makes it much cheaper, and thus more practical, to construct. In addition, because of its size and concentration, a Solar Power Tower can generate more energy than a comparable panel-based system, making it more efficient.
CSP plants, as a rule, are built over a large area; usually, several hundred thousand solar panels are installed across a few acres. As a result, they produce massive amounts of power – up to 2 megawatts (MW) or more – which is transmitted through large transmission lines. A single line can handle the whole output of a medium-sized plant.
Disadvantages
Despite their many advantages, CSP plants suffer from some notable disadvantages. First of all, they need a high degree of cleanliness – otherwise, the efficiency of the system will diminish. Dust particles or minute debris on the surface of the solar panels will act as tiny lenses, dramatically reducing the solar power conversion efficiency.
Secondly, CSP plants require a large amount of land, especially if they’re built near a residential area. In most places, this is still far too expensive; as a result, CSP plants are generally confined to larger cities and towns where land is more readily available. The high cost of land acts as a significant barrier to the widespread adoption of CSP.
Applications
Applications for Solar Power Towers are almost endless, as reflected by the many different structures that have been designed to fit this unique and valuable form of solar energy.
Some of the more significant applications include:
- Battery storage (such as for automobiles or appliances)
- Distributed generation (such as for small communities or rural areas)
- Peak-load power (such as for schools or healthcare facilities)
- Residential applications (such as for water supply or backup power)
Cost Effective
Because of their size, concentration, and efficiency, Solar Power Towers make an expensive investment compared to other types of solar technologies. However, the payback is rapid – in some cases, as little as four years – and the economics are very favourable. In fact, many CSP investors are able to earn a profit, in excess of 20% per year, on the back of their investment. This attractive figure makes the technology very competitive – particularly when compared to the escalating costs of traditional energy sources.
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In most places, the construction cost of a Solar Power Tower is about the same as a standard residential building – the difference being that the structure is taller and has more floors.
Integration Of Wind And Solar
In some instances, it’s desirable to integrate the resources of the wind and the sun. This can be achieved by installing a Small Wind Power Tower, either alongside a Solar Power Tower or independently, on a separate area of land. When connected to the grid, the combined output of the Wind/Solar Tower can be fed into a Power Plant, which is connected to the local utility provider via an electric meter.
The advantages of integrating wind and solar resources are many. First of all, because they’re on a separate piece of land, they don’t compete for space with other built-on structures. Another advantage is that the two tower types work in conjunction with each other – the presence of a Wind/Solar Tower, for example, enables the efficient transfer of energy from the wind to the sun (via the photovoltaic portion of the system). As a result, a properly integrated Wind/Solar/Power Plant can produce more energy than the sum of its individual parts – in some cases, as much as 10% to 15% more.
Scalability
Perhaps the most significant advantage of a Solar Power Tower lies in its scalability. Because they’re based on standardized technologies and manufacturing techniques, Solar Power Towers can be constructed quickly and efficiently – which makes them ideal for mass production. As a result, the cost of a small-scale Solar Power Tower is only a fraction of the price of a conventional residential power plant.
Resilience
Resilience, or the ability of a system to return to its initial state after a period of disturbance, is another significant advantage of a Solar Power Tower. As mentioned previously, because of their size, concentration, and efficiency, Solar Power Towers can generate large amounts of energy – in excess of 2MW, in some cases. As a result, they have the ability to supply significant amounts of energy for short periods of time – often, just one or two hours. This makes them well-suited for use in applications where frequent outage is impossible (like hospitals or government facilities), or for use during peak hours, when the demand for electricity is at its highest point.
The above are just some of the advantages of a Solar Power Tower. Due to their many applications and the many different structures that have been designed to fit this unique and versatile form of energy, it’s clear that there are many opportunities for this exciting new technology.