DIY solar energy concentrator. Solar concentrators

(Canada) has developed a universal, powerful, efficient and one of the most economical solar parabolic concentrators(CSP - Concentrated Solar Power) with a diameter of 7 meters, both for ordinary homeowners and for industrial use. The company specializes in the production of mechanical devices, optics and electronics, which helped it create a competitive product.

According to the manufacturer itself, the SolarBeam 7M solar concentrator is superior to other types of solar devices: flat-plate solar collectors, vacuum collectors, and trough-type solar concentrators.

External view of the Solarbeam solar concentrator

How it works?

The automation of the solar concentrator tracks the movement of the sun in two planes and directs the mirror exactly at the sun, allowing the system to collect maximum solar energy from dawn to late sunset. Regardless of the season or location of use, SolarBeam maintains sun pointing accuracy of up to 0.1 degrees.

The rays incident on the solar concentrator are focused at one point.

Calculations and design of SolarBeam 7M

Stress testing

To design the system, 3D modeling and software stress testing methods were used. Tests are performed using FEM (Finite Element Analysis) techniques to calculate stresses and displacements of parts and assemblies under the influence of internal and external loads in order to optimize and verify the design. This precise testing allows us to confirm that SolarBeam can operate under extreme wind loads and climatic conditions. SolarBeam has successfully simulated wind loads up to 160 km/h (44 m/s).

Stress testing the connection between the parabolic reflector frame and the stand

Photo of the Solarbeam concentrator mounting assembly

Stress testing of a solar concentrator rack

Production level

Often, the high cost of manufacturing parabolic concentrators prevents their mass use in individual construction. The use of stamps and large segments of reflective material reduced production costs. Solartron used many innovations used in the automotive industry to reduce cost and increase output.

Reliability

SolarBeam has been tested in harsh conditions north, provides high performance and durability. SolarBeam is designed for all weather conditions, including high and low ambient temperatures, snow load, icing and strong winds. The system is designed for 20 or more years of operation with minimal maintenance.

The SolarBeam 7M parabolic mirror is capable of holding up to 475 kg of ice. This is approximately equal to 12.2 mm of ice thickness over the entire area of ​​38.5 m2.
The installation works normally in snowfalls due to the curved design of the mirror sectors and the ability to automatically perform “auto snow removal”.

Performance (comparison with vacuum and flat plate collectors)

Q / A = F’(τα)en Kθb(θ) Gb + F’(τα)en Kθd Gd -c6 u G* - c1 (tm-ta) - c2 (tm-ta)2 – c5 dtm/dt

The efficiency for non-concentrating solar collectors was calculated using the following formula:

Efficiency = F Collector Efficiency – (Slope*Delta T)/G Solar Radiation

The performance curve for the SolarBeam concentrator shows overall high efficiency across the entire temperature range. Flat solar collectors and evacuated ones show more low efficiency when higher temperatures are required.

Comparison charts of Solartron and flat plate/vacuum solar collectors

Efficiency (COP) of Solartron depending on the temperature difference dT

It is important to note that the above diagram does not take into account heat loss from wind. In addition, the data above indicates maximum effectiveness (at noon) and does not reflect effectiveness during the day. The data is based on one of the best flat plate and vacuum manifolds. In addition to high efficiency, SolarBeamTM produces an additional 30% more energy due to dual-axis sun tracking. In geographic regions where low temperatures prevail, the efficiency of flat-plate and evacuated collectors is significantly reduced due to the large absorber area. SolarBeamTM has an absorber area of ​​only 0.0625 m2 relative to the energy collection area of ​​15.8 m2, thereby achieving low heat loss.

Please also note that due to the dual-axis tracking system, the SolarBeamTM concentrator will always operate at maximum efficiency. The effective area of ​​the SolarBeam collector is always equal to the actual surface area of ​​the mirror. Flat plate (stationary) collectors lose potential energy according to the equation below:
PL = 1 – COS i
where PL energy loss in %, from the maximum at displacement in degrees)

Control system

SolarBeam controls use EZ-SunLock technology. With this technology, the system can be quickly installed and configured anywhere in the world. The tracking system tracks the sun to within 0.1 degrees and uses an astronomical algorithm. The system has the ability to general dispatch via remote networks.

Emergency situations in which the “plate” will automatically be parked in a safe position.

• If the coolant pressure in the circuit drops below 7 PSI
• When the wind speed is more than 75 km/h
• In the event of a power outage, the UPS (uninterruptible power supply) moves the plate to a safe position. When power is restored, automatic sun tracking continues.

Monitoring

In any case, and especially for industrial applications, it is very important to know the health of your system to ensure reliability. You must be warned before a problem occurs.

SolarBeam has the ability to monitor through the SolarBeam Remote Dashboard. This panel is easy to use and provides important information SolarBeam status, diagnostics and energy production information.

Remote configuration and management

SolarBeam can be remotely configured and quickly change settings. The “plate” can be controlled remotely using a mobile browser or PC, simplifying or making on-site control systems unnecessary.

Alerts

In case of an alarm or need for maintenance, the device sends a message via e-mail designated service personnel. All warnings can be customized according to user preferences.

Diagnostics

SolarBeam has remote diagnostic capabilities: system temperature and pressure, energy production, etc. At a glance you can see the operating status of the system.

Reporting and Charts

If energy production reports are needed, they can be easily obtained for each plate. The report can be in the form of a graph or table.

Installation

SolarBeam 7M was originally designed for large-scale CSP installations, so installation was made as simple as possible. The design allows for quick assembly of the main components and does not require optical alignment, making installation and commissioning of the system inexpensive.

Installation time

A team of 3 people can install one SolarBeam 7M from start to finish within 8 hours.

Accommodation requirements

The width of SolarBeam 7M is 7 meters with a 3.5 meter setback. When installing several SolarBeam 7M, each system must be allocated an area of ​​approximately 10 x 20 meters to ensure maximum solar collection with least amount shading.

Assembly

The Parabolic Hub is designed to be assembled on the ground using a mechanical lifting system, allowing for quick and easy installation of trusses, mirror sectors and mounts.

Areas of use

Generating electricity using ORC (Organic Rankine Cycle) installations.

Industrial desalination plants

Thermal energy for a water desalination plant can be supplied by SolarBeam

In any industry where a lot of thermal energy is required for the process cycle, such as:

• Food (cooking, sterilization, alcohol production, washing)
• Chemical industry
• Plastic (Heating, exhaust, separation, ...)
• Textile (bleaching, washing, pressing, steam treatment)
• Petroleum (sublimation, clarification of petroleum products)
• And much more

Installation location

Suitable locations for installation are regions receiving at least 2000 kWh sunlight per m2 per year (kW*h/m2/year). I consider the following regions of the world to be the most promising producers:

• Regions of the former Soviet Union
• Southwestern USA
• Central and South America
• North and South Africa
• Australia
• Mediterranean countries of Europe
• Middle East
• Desert plains of India and Pakistan
• Regions of China

Model specification Solarbeam-7M

• Peak power - 31.5 kW (at a power of 1000 W/m2)
• The degree of energy concentration is more than 1200 times (spot 18cm)
• Maximum temperature at focus - 800°C
• Maximum coolant temperature - 270°C
• Operational efficiency - 82%
• Reflector diameter - 7m
• The area of ​​the parabolic mirror is 38.5 m2
• Focal length - 3.8m
• Electricity consumption by servomotors - 48W+48W / 24V
• Wind speed during operation - up to 75 km/h (20 m/s)
• Wind speed (in safe mode) - up to 160 km/h
• Azimuth sun tracking - 360°
• Vertical sun tracking - 0 - 115°
• Support height - 3.5m
• Reflector weight - 476 kg
• Total weight -1083 kg
• Absorber size - 25.4 x 25.4 cm
• Absorber area -645 cm2
• Coolant volume in the absorber - 0.55 liters

Overall dimensions of the reflector

Briefly:
1) The capacity of CSP (Concentrated Solar Power) stations worldwide increased by 1 GW in 2012. Every year this market is growing by >100% (not a typo!).
2) Installed capacities: 2.8 GW, 2.9 are under construction, 7 GW are planned.
3) The most popular technology is parabolic reflectors, but tower concentrators and Fresnel lens concentrators are gaining popularity.

Now more details. The market is growing like this:


(in light brown and brown: installed and annual installed capacity (GW) of CSP. Source: Photon International 12/2012)

How will CSP technologies develop? Let's look at this picture:


(explanation of the “legend” from left to right: general, parabolic reflectors, towers, parabolic dishes, linear Fresnel reflectors. The first diagram is for the end of 2012, the second: under construction, the last: planned)

Obviously, parabolic reflectors are "today", but concentrator towers will be popular "tomorrow". The largest project under construction in this area today is the 392 MW Ivanpah Solar Electric Generating Station in southern California. 170,000 mirrors will focus light onto the towers.

CLFR is gradually winning back the market: there is an increase from 1 to 7%. The largest project in this area is 100 MW in Rajasthan by Avera Solar.

What are parabolic reflectors?

This is a system where parabolic mirrors, turning along their axis, focus Sun rays on the heat-absorbing tube. This system allows you to concentrate 100 times and heat the coolant (special oil) up to 400 degrees. Through a heat exchanger, the hot oil releases energy to the steam, which, in turn, rotates the turbine. Newer systems in this area may include a battery in the form of a molten salt tank (up to 8 hours). The system is already well known (since the 80s).

Disadvantages and advantages:

1. proven technology.


2. But, high costs relative to other, “green” sources (for example, PV).


3. But, low coolant temperature.


4. But, in some cases, such systems require the provision of water, which is not easy in desert conditions.


5. But, the installation site should not have a slope of more than 1%.

Disadvantages and advantages:

1. Allows to reach higher temperatures, higher efficiency, lower energy cost than parabolic reflectors.


2. Do not require ultra flat landscapes (can be installed at a gradient of 5%).


3. The energy reserve in the tank with molten salt is up to 15 hours.


4. But, the history of using such systems is shorter and therefore the risk of lending is higher.


5. But, the price is still high.

What are concentrator systems with linear Fresnel reflectors?
It's more simple systems compared to parabolic channels. They concentrate the light 30 times, and use water instead of oil for heat transfer.

Disadvantages and advantages:
Simple design, low energy cost.
But, high technological risk: the technology has not yet been tested like parabolic reflectors.

Today, concentrators are fighting for their existence: solar panels, which are becoming cheaper and have already become commonplace, are putting pressure on this market.

• 1 installed watt from concentrators today costs about $5 (parabolic concentrators),


• 1 installed watt for concentrator towers is about $7 (the price remains the same if the energy is stored in sand melt for 6-7 hours, $10 if the supply is for 12-15 hours).


• 1 installed watt for regular panels is about $1.

However, we should not forget that this is a much younger industry that is following the path of traditional photovoltaics made 10 years ago. There is potential for price reductions in this area and I am confident that there will be enough “place in the sun” for all technologies.

But I also remember the optimism with which Siemens took up concentrators (Siemens recently announced the cessation of work in this area) and I remember the enthusiasm in the field of thin-film silicon photovoltaics. In both cases, the window of opportunity closed with a bang for many pockets.

Let's talk about the shortcomings. Mirrors need to be cleaned. Moreover, their surface must be ideal and must remain so. all the time station operation.


(cleaning

Published 08/09/2013

Everyone is interested in alternative energy large quantity great minds. I'm not an exception. 🙂

It all started with a simple question: “Can a brushless motor be turned into a generator?”
-Can. What for?
-Make a wind generator.

A windmill for generating electricity is not a very convenient solution. Variable wind force charging device, batteries, inverters, a lot of inexpensive equipment. In a simplified scheme, a windmill copes “excellently” with heating water. Because the load is ten, and it is absolutely not demanding on the parameters of the electricity supplied to it. You can get rid of complex, expensive electronics. But calculations showed significant design costs to spin up a 500-watt generator.
The power carried by the wind is calculated by the formula P=0.6*S*V 3, where:
P– power, Watt
S- Area, m2
V– wind speed, m/s

A wind blowing 1 m2 at a speed of 2 m/s “carries” 4.8 watts of energy. If the wind speed increases to 10 m/s, the power will increase to 600 Watts. The best wind generators have an efficiency of 40-45%. Taking this into account, for a 500 Watt generator with a wind of, say, 5 m/s. The area swept by the wind generator propeller will be required to be about 12 sq.m. Which corresponds to a screw with a diameter of almost 4 meters! A lot of money is of little use. Add here the need to obtain a permit (noise limit). By the way, in some countries the installation of a wind turbine must be coordinated even with ornithologists.

But then I remembered about the Sun! It gives us a lot of energy. I first thought about this after flying over a frozen reservoir. When I saw a mass of ice more than a meter thick and measuring 15 by 50 kilometers, I thought: “That’s a lot of ice!” How long does it have to be heated to melt it!?” And the Sun will do all this in fifteen days. In reference books you can find the energy density that reaches the surface of the earth. A figure of about 1 kilowatt per square meter sounds tempting. But this is at the equator on a clear day. How feasible is it to utilize solar energy for economic needs in our latitudes (central part of Ukraine), using available materials?

What real power, taking into account all losses, can be obtained from it? square meter?

To clarify this issue, I made the first parabolic heat concentrator from cardboard (focus in the parabola bowl). I covered the pattern of sectors with regular food foil. It is clear that the quality of the surface, and even the reflective abilities of the foil, are very far from ideal.

But the task was to heat a certain volume of water using “collective farm” methods in order to find out what power could be obtained taking into account all the losses. The pattern can be calculated using an Excel file that I found on the Internet from those who like to build parabolic antennas on their own.
Knowing the volume of water, its heat capacity, initial and final temperatures, you can calculate the amount of heat spent on heating it. And, knowing the heating time, you can calculate the power. Knowing the dimensions of the concentrator, you can determine what practical power can be obtained from one square meter of surface on which sunlight falls.

As a volume for water, we took half an aluminum can, painted black on the outside.

A container of water is placed at the focus of a parabolic solar concentrator. The solar concentrator is oriented towards the Sun.

Experiment No. 1

was held around 7 a.m. in late May. Morning is far from an ideal time, but just in the morning the Sun shines through the window of my “laboratory”.

With a parabola diameter 0.31 m calculations showed that a power of the order of magnitude was obtained 13.3 Watt. Those. least 177 Watt/sq.m. It should be noted here that the round open jar far from the best the best option to get a good result. Part of the energy goes to heating the can itself, part is radiated into environment, including being carried away by air currents. In general, even in such far-from-ideal conditions, you can at least get something.

Experiment No. 2

For the second experiment, a parabola with a diameter of 0.6 m. Metallic tape purchased at hardware store. Its reflective qualities are marginally better than aluminum food foil.

The parabola had a longer focal length (focus outside the bowl of the parabola).

This made it possible to project the rays onto one surface of the heater and obtain a higher temperature in focus. A parabola easily burns through a sheet of paper in a few seconds. The experiment took place around 7 a.m. in early June. Based on the results of the experiment with the same volume of water and the same container, I received the power 28 Watt., which corresponds approximately 102 Watt/m2. This is less than in the first experiment. This is explained by the fact that the sun's rays from the parabola did not fall optimally on the round surface of the jar everywhere. Some of the rays passed by, some fell tangentially. The jar was cooled by the fresh morning breeze on one side, while warmed up on the other. In the first experiment, due to the fact that the focus was inside the bowl, the jar was heated from all sides.

Experiment No. 3

Having realized that a decent result can be obtained by making the right heat sink, the following design was made: a tin can inside painted black has pipes for supplying and draining water. Hermetically sealed with transparent double glass. Thermally insulated.

The general scheme is:

Heating occurs as follows: rays from the solar concentrator ( 1 ) penetrate through the glass into the heat sink can ( 2 ), where, falling on a black surface, it is heated. Water, in contact with the surface of the jar, absorbs heat. Glass does not transmit infrared (thermal) radiation well, so heat radiation losses are minimized. Because the glass warms up over time warm water, and begins to radiate heat, double glazing was applied. Perfect option, if there is a vacuum between the glasses, but this is a difficult task to achieve at home. The reverse side of the can is thermally insulated with polystyrene foam, which also limits the radiation of thermal energy into the environment.

Heat sink ( 2 ) using tubes ( 4,5 ) is connected to the tank ( 3 ) (in my case plastic bottle). The bottom of the tank is 0.3m above the heater. This design ensures convection (self-circulation) of water in the system.

Ideally expansion tank and the tubes must also be thermally insulated. The experiment took place around 7 a.m. in mid-June. The results of the experiment are as follows: Power 96.8 Watt, which corresponds approximately 342 Watt/sq.m.

Those. The efficiency of the system has improved by more than 3 times only by optimizing the design of the heat sink!

When carrying out experiments 1,2,3, aiming the parabola at the sun was done manually, “by eye”. The parabola and heating elements were held by hand. Those. the heater was not always in the focus of the parabola, since the person’s hands get tired and begin to look for a more comfortable position, which is not always correct from a technical point of view.

As you may have noticed, efforts were made on my part to provide disgusting conditions for the experiment. Far from it ideal conditions, namely:
– not an ideal surface of the concentrators
– not ideal reflective properties of concentrator surfaces
– not ideal orientation to the sun
– not ideal heater position
– not the ideal time for the experiment (morning)

could not prevent us from obtaining a completely acceptable result for installation from scrap materials.

Experiment No. 4

Further a heating element was fixed motionless relative to the solar concentrator. This made it possible to increase the power to 118 Watt, which corresponds approximately 419 Watt/m2. And this is in morning hours! From 7 to 8 am!

There are other methods of heating water using solar collectors. Collectors with vacuum tubes are expensive, and flat ones have large temperature losses in the cold season. The use of solar concentrators can solve these problems, but requires the implementation of a mechanism for orientation to the Sun. Each method has both advantages and disadvantages.

Solar energy can be collected and used different ways. One of the simplest and most effective is a mirror reflector and concentrator. It is not difficult to make it yourself.

The reflector reflects the sun's rays and concentrates them on a container of water. It heats up and boils, producing a stream of steam. The design of the device is quite simple, the main thing is that the mirrors automatically rotate to desired angle and watched the Sun.

The resulting steam is sent, for example, to an oven for cooking, through pipes to heat a house, to a turbine to generate electricity, to an engine, a refrigerator, etc. In fact, if you look at any manufacturing process, almost any part of it can be converted to steam.

Homemade Solar-OSE steam generator on linear mirrors controlled by an Arduino board at the French makers conference POC21, dedicated to homemade environmental projects.

Recently, the authors made publicly available instructions for assembling the device under a Creative Commons license. This compact 1 kW device is perfect for small businesses, especially in rural areas. If you combine several modules, the power increases several times.

According to the makers, the cost of all parts of the steam generator will be approximately $2000, but there is different variants savings.

Estimated assembly time: 150 hours. One week, three people.

The instructions provide full list and dimensions of all materials, as well as the tools necessary for work.

According to the principle of operation, solar concentrators are very different from. Moreover, thermal solar power plants are much more efficient than photovoltaic ones due to a number of features.

The task of a solar concentrator is to focus the sun's rays on a container containing coolant, which can be, for example, oil or water, which absorb solar energy well. Concentration methods vary: parabolic-cylindrical concentrators, parabolic mirrors, or heliocentric tower-type installations.

In some concentrators, the sun's radiation is focused along the focal line, in others - at the focal point, where the receiver is located. When solar radiation is reflected from a larger surface to a smaller surface (receiver surface), heat, the coolant absorbs heat as it moves through the receiver. The system as a whole also contains an accumulating part and an energy transmission system.

The efficiency of concentrators is greatly reduced during cloudy periods, since only direct solar radiation is focused. It is for this reason that such systems achieve the most high efficiency in regions where the level of insolation is especially high: in deserts, near the equator. To increase the efficiency of using solar radiation, concentrators are equipped with special trackers and tracking systems that ensure the most accurate orientation of the concentrators in the direction of the sun.

Since the cost of solar concentrators is high and tracking systems require periodic maintenance, their use is largely limited industrial systems electricity generation.

Such installations can be used in hybrid systems in combination, for example, with hydrocarbon fuel, then the storage system will reduce the cost of generated electricity. This will become possible since generation will occur around the clock.

Parabolic cylindrical solar concentrators They are up to 50 meters long and have the appearance of an elongated mirror parabola. Such a concentrator consists of an array of concave mirrors, each of which collects parallel solar rays and focuses them at a specific point. Along such a parabola, a pipe with coolant is located so that all the rays reflected by the mirrors are focused on it. To reduce heat loss, the pipe is surrounded by a glass tube, which is stretched along the focal line of the cylinder.

Such concentrators are arranged in rows in a north-south direction, and they are, of course, equipped with solar tracking systems. The radiation, focused into a line, heats the coolant to almost 400 degrees; it passes through heat exchangers, producing steam, which rotates the generator turbine.

To be fair, it is worth noting that a photocell can also be located in place of the pipe. However, despite the fact that with photocells, the size of the concentrators can be smaller, this is fraught with a decrease in efficiency and the problem of overheating, the solution of which requires the development of a high-quality cooling system.

In the California desert in the 80s, 9 power plants were built on parabolic-cylindrical concentrators with a total capacity of 354 MW. Then the same company (Luz International) also built the hybrid station SEGS I in Deggette, with a capacity of 13.8 MW, which additionally included natural gas furnaces. In general, as of 1990, the company had built hybrid power plants with a total capacity of 80 MW.

The development of solar generation at parabolic cylindrical power plants is being carried out in Morocco, Mexico, Algeria and other developing countries with funding from the World Bank.

Experts ultimately conclude that today parabolic-cylindrical power plants are inferior both in profitability and efficiency to tower- and plate-type solar power plants.

- These are parabolic mirrors, similar to satellite dishes, with which the sun's rays are focused onto a receiver located at the focus of each such dish. At the same time, the temperature of the coolant with this heating technology reaches 1000 degrees. The coolant liquid is immediately supplied to the generator or engine, which is combined with the receiver. Here, for example, Stirling and Brayton engines are used, which can significantly increase the performance of such systems, since the optical efficiency is high and the initial costs are low.

The world record for the efficiency of a parabolic disc solar plant is 29% efficiency achieved when converting thermal energy into electrical energy in a disk plant combined with a Stirling engine at Rancho Mirage.

Thanks to modular design, solar systems disc type are very promising; they make it easy to achieve the required power levels for both hybrid consumers connected to utility grids and autonomous ones. An example is the STEP project, consisting of 114 parabolic mirrors with a diameter of 7 meters, located in the state of Georgia.

The system produces medium, low and high pressure. Steam low pressure is supplied to the air conditioning system of the knitting factory, medium-pressure steam for the knitting production itself, and high-pressure steam directly for generating electricity.

Of course, solar dish concentrators combined with a Stirling engine are of interest to owners of large energy companies. So the Science Applications International Corporation, in collaboration with a trio of energy companies, is developing a system using a Stirling engine and parabolic mirrors that can produce 25 kW of electricity.

In tower-type solar power plants with a central receiver, solar radiation is focused on the receiver, which is located at the top of the tower. Around the tower there are a large number of heliostat reflectors. Heliostats are equipped with a biaxial sun tracking system, thanks to which they are always rotated so that the rays are stationarily concentrated on the heat sink.

Receiver absorbs thermal energy, which then rotates the generator turbine.

The coolant liquid, circulating in the receiver, transfers steam to the heat accumulator. Typically, water vapor works with a temperature of 550 degrees, air and other gaseous substances with a temperature of up to 1000 degrees, organic liquids with a low boiling point - below 100 degrees, and liquid metal - up to 800 degrees.

Depending on the purpose of the station, steam can rotate a turbine to generate electricity, or be directly used in some kind of production. The temperature in the receiver varies from 538 to 1482 degrees.

The Solar One tower power plant in Southern California, one of the first plants of its type, initially produced electricity through a water-steam system, producing 10 MW. Then it underwent modernization, and the improved receiver, now operating on molten salts, and the heat storage system became much more efficient.

This led to thermal storage tower power plants marking a breakthrough in solar concentrator technology: electricity in such a power plant can be produced as needed, since the thermal storage system can store heat for up to 13 hours.

Molten salt technology makes it possible to store solar heat at 550 degrees, and electricity can now be produced at any time of day and in any weather. The Solar Two tower station with a capacity of 10 MW became the prototype of industrial power plants of this type. In the future - the construction of industrial stations with capacities from 30 to 200 MW for large industrial enterprises.

The prospects are colossal, but development is hampered by the need for large areas and the considerable cost of constructing industrial-scale tower stations. For example, in order to locate a 100 megawatt tower station, 200 hectares are needed, while a nuclear power plant capable of producing 1000 megawatts of electricity requires only 50 hectares. Parabolic-cylindrical stations (modular type) with low capacities, in turn, are more cost-effective than tower ones.

Thus, tower and parabolic concentrators are suitable for power plants with a capacity of 30 MW to 200 MW, which are connected to the grid. Modular disc concentrators are suitable for autonomous power supply networks that require only a few megawatts. Both tower and disc systems are expensive to manufacture, but provide very high efficiency.

As we can see, parabolic concentrators occupy an optimal position as the most promising solar concentrator technology for the coming years.