Details Published: 10/12/2015 08:32

Free step by step guide contains all necessary information to create a 0.5 kW solar concentrator with your own hands. The reflective surface of the device will have an area of ​​about 1 square meter, and the cost of its production will cost from $79 to $145 depending on the region of residence.

Sol1, got this name solar installation from GoSol, will take approximately 1.5 cubic meters space. The work on its production will take about a week. The materials for its construction will be iron corners, plastic boxes, steel rods, and the main working element - a reflective hemisphere - is proposed to be made from pieces of an ordinary bathroom mirror.

The solar concentrator can be used for baking, frying, heating water or preserving food through dehydration. The device can also serve as a demo efficient work solar energy and will help many entrepreneurs developing countries start your own business. In addition to helping reduce harmful emissions into the atmosphere, GoSol solar concentrators will help reduce deforestation by replacing burned wood with clean energy from the sun.

The GoSol instructions can be used not only for the creation and practical application, but also for the sale of solar concentrators, which will help significantly reduce the threshold for access to solar energy, which is mainly generated today through photovoltaic solar panels. Their cost remains extremely high level in regions where it is often simply impossible to obtain energy by other means.

Free instructions for the solar concentrator are available on the GoSol website, and to receive it you will need to leave your email address to which updated information will be sent. If you want the “solar” initiative to move faster and on a larger scale, then you can support the company financially - the startup also accepts cash contributions, the reward for which will depend on the amount of the donation.

written after reading an article in Photon International 12/2012. All photos and data from this source.

Briefly:
1) Power 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%. Most big project in this area it is 100 MW in Rajasthan from Avera Solar.

What are parabolic reflectors?

This is a system where parabolic mirrors, turning along their axis, focus the sun's rays on a 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 temperature coolant.


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%.

What are hubs - towers?
This is a system where often thousands of rotating mirrors track the sun and focus energy onto an energy receiver. You can concentrate energy 1000 times. Tower height from 5 to 165 m. Mirrors from 1.1 to 120 sq. m. Temperature from 440 to 550 degrees Celsius. Water or molten salt is used to transfer heat.

Disadvantages and advantages:

1. Allows you to achieve more high 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?
These are simpler 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 cost energy.
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 concentrating 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.

Generation of 1 kWh will cost 14-35 cents. According to the goal of the US Department of Energy, in 2020 the cost of electricity. energy from concentrators in southern California should be 6 cents.

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

The problem of using solar energy has occupied the best minds of mankind since ancient times. It was clear that the Sun is a powerful source of free energy, but no one understood how to use this energy. If you believe the ancient writers Plutarch and Polybius, the first person to practically use solar energy was Archimedes, who, with the help of certain optical devices he invented, managed to collect the sun's rays into a powerful beam and burn the Roman fleet.

In essence, the device invented by the great Greek was the first solar radiation concentrator, which collected the sun's rays into one energy beam. And at the focus of this concentrator, the temperature could reach 300°C - 400°C, which is quite enough to ignite the wooden ships of the Roman fleet. One can only guess what kind of device Archimedes invented, although, according to modern ideas, he had only two options.

The very name of the device – solar concentrator – speaks for itself. This device receives the sun's rays and collects them into a single energy beam. The simplest concentrator is familiar to everyone from childhood. This is an ordinary biconvex lens, which could be used to burn out various figures, inscriptions, even entire pictures, when the sun's rays were collected by such a lens into a small point on wooden board, sheet of paper.

This lens belongs to the so-called refractory concentrators. In addition to convex lenses, this class of concentrators also includes Fresnel lenses and prisms. Long-focus concentrators built on the basis of linear Fresnel lenses, despite their low cost, are used very little in practice, since they have large sizes. Their use is justified where the dimensions of the concentrator are not critical.

Refractor Solar Concentrator

The prism solar radiation concentrator does not have this drawback. Moreover, such a device is also capable of concentrating part of the diffuse radiation, which significantly increases the power of the light beam. The triangular prism, on the basis of which such a concentrator is built, is both a radiation receiver and a source of an energy beam. In this case, the front face of the prism receives radiation, the back face reflects it, and radiation comes out of the side face. The operation of such a device is based on the principle of total internal reflection of rays before they hit the side face of the prism.

Unlike refractory concentrators, reflective concentrators operate on the principle of collecting reflected energy into an energy beam. sunlight. According to their design, they are divided into flat, parabolic and parabolic-cylindrical concentrators. If we talk about the effectiveness of each of these types, then the highest degree of concentration - up to 10,000 - is provided by parabolic concentrators. But to build systems solar heating Mostly flat or parabolic-cylindrical systems are used.

Parabolic (reflective) solar concentrators

Practical application of solar concentrators

Actually, the main task of any solar concentrator is to collect the sun's radiation into a single energy beam. And you can use this energy in various ways. You can heat water using free energy, and the amount of heated water will be determined by the size and design of the concentrator. Small parabolic devices can be used as solar oven for cooking food.

Parabolic concentrator as a solar oven

You can use them to provide additional lighting to solar panels to increase power output. And it can be used as an external heat source for Stirling engines. The parabolic concentrator provides a focal temperature of about 300°C – 400°C. If, for example, a stand for a kettle or a frying pan is placed at the focus of such a relatively small mirror, you will get a solar oven on which you can very quickly cook food and boil water. A heater with a coolant placed at the focus will allow you to quickly heat even running water, which can then be used for household purposes, for example, for showering, washing dishes.

The simplest scheme for heating water with a solar concentrator

If in focus parabolic mirror If you install a Stirling engine of suitable power, you can get a small thermal power plant. For example, Qnergy has developed and launched QB-3500 Stirling engines, which are designed to work with solar concentrators. In essence, it would be more correct to call them electric current generators based on Stirling engines. This unit produces an electric current of 3500 watts. The output of the inverter is a standard voltage of 220 volts 50 hertz. This is quite enough to provide electricity to a house for a family of 4 people, or a summer cottage.

By the way, using the operating principle of Stirling engines, many craftsmen make devices with their own hands that use rotational or reciprocating motion. For example, water pumps for a summer residence.

The main disadvantage of a parabolic concentrator is that it must be constantly oriented towards the sun. Industrial helium installations use special tracking systems that rotate mirrors or refractors following the movement of the sun, thereby ensuring the reception and concentration of the maximum amount of solar energy. For individual use It is unlikely that it would be advisable to use such tracking devices, since their cost can significantly exceed the cost of a simple reflector on a regular tripod.

How to make your own solar concentrator

The easiest way to make a homemade solar concentrator is to use an old satellite dish. First you need to decide for what purposes this concentrator will be used, and then, based on this, choose the installation location and prepare the base and fastenings accordingly. Wash the antenna thoroughly, dry it, and stick a mirror film on the receiving side of the dish.

In order for the film to lay flat, without wrinkles or folds, it should be cut into strips no more than 3 to 5 centimeters wide. If you intend to use the concentrator as a solar oven, it is recommended to cut a hole with a diameter of approximately 5–7 centimeters in the center of the plate. A bracket with a stand for dishes (burner) will be passed through this hole. This will ensure that the container with the food you are preparing does not move when the reflector is turned towards the sun.

If the plate is small in diameter, then it is also recommended to cut the strips into pieces approximately 10 cm long. Glue each piece separately, carefully adjusting the joints. When the reflector is ready, it should be installed on a support. After this, you will need to determine the focus point, since the optical focus point at the satellite dish does not always coincide with the position of the receiving head.

Homemade solar concentrator - oven

To determine the focal point, you need to equip yourself with dark glasses, wooden plank and thick gloves. Then you need to point the mirror directly at the sun, catch a sun bunny on the board and, moving the board closer or further relative to the mirror, find the point where this bunny will have minimum dimensions- a small point. Gloves are needed to protect your hands from being burned if they accidentally fall into the area of ​​the beam. Well, when the focal point is found, all that remains is to fix it and install the necessary equipment.

Options self-made There are many solar concentrators. In the same way, you can make a Stirling engine yourself from scrap materials. And this engine can be used for a variety of purposes. How much imagination, desire and patience is enough?

The main task of a solar collector is to convert energy received from the sun into electricity. The operating principle and design of the equipment are simple, so technically it is easy to make. Typically, the resulting energy is used to heat buildings. Making a solar collector for heating a house with your own hands must begin with the selection of all components.

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Design and operating principle

Heating a home by converting solar energy into electrical energy is usually used as an additional source of heat, rather than the main one. On the other hand, if you install a high-power structure and convert all the appliances in the house to electricity, then you can only get by with a solar collector.

But it is worth remembering that heating using solar collectors without additional sources heat is possible only in the southern regions. In this case, there should be quite a lot of panels. They must be positioned in such a way that shadows do not fall on them (for example, from trees). The panels should be placed with their front side in the direction that receives maximum sun exposure throughout the day.

Solar Energy Concentrators

Although today there are many varieties of such devices, the principle of operation is the same for all. Any circuit takes solar energy and transfers it to the consumer, representing a circuit with a sequential arrangement of devices. The components that produce electricity are solar panels or collectors.

The collector consists of tubes that are connected in series to the inlet and outlet. They can also be arranged in the form of a coil. Inside the tubes there is process water or a mixture of water and antifreeze. Sometimes they are simply filled with air flow. Circulation occurs due to physical phenomena such as evaporation, changes in the state of aggregation, pressure and density.

Absorbers perform the function of collecting solar energy. They look like a solid black metal plate or a structure made up of many plates connected to each other by tubes.

Materials with high light transmittance are used to make the housing cover. Often this is either plexiglass or tempered types ordinary glass. Sometimes used polymer materials, but making collectors from plastic is not recommended. This is due to its large expansion from heating by the sun. As a result, depressurization of the housing may occur.

If the system will be operated only in autumn and spring, then water can be used as a coolant. But in winter time her must be replaced with a mixture of antifreeze and water. In classical designs, the role of coolant is played by air, which moves through channels. They can be made from ordinary corrugated sheets.

Experience in operating a solar battery made independently (solar battery part 3).

If the collector needs to be installed to heat a small building that is not connected to the autonomous heating system of a private house or centralized networks, then it will be suitable simple system with one circuit and heating element at its beginning. The scheme is simple, but the feasibility of its installation is disputed, since it will only work in sunny summers. However, it does not require circulation pumps and additional heaters.

With two circuits, everything is much more complicated, but the number of days when electricity will be actively generated increases several times. In this case, the collector will process only one circuit. Most of the load is placed on a single device that runs on electricity or another type of fuel.

Although the performance of the device directly depends on the number of sunny days per year, and its price is too high, it is still very popular among the population. No less common is the production of solar heat exchangers with your own hands.



Classification by temperature indicators

Solar systems are classified according to various criteria. But in devices that you can make yourself, you should pay attention to the type of coolant. Such systems can be divided into two types:

• use of various liquids;
• air structures.

The first ones are used most often. They are more productive and allow you to directly connect the collector to heating system. Classification by temperature is also common, within which the device can operate:



DIY solar battery Part11

The last type of solar system works thanks to a very complex principle of solar energy transfer. The equipment requires a lot of space. If you place it on country dacha, then it will occupy the predominant part of the site. To produce energy, you will need special equipment, so making such a solar system yourself will be almost impossible.






DIY making

The process of making a solar heater with your own hands is quite exciting, and finished design will bring a lot of benefits to the owner. Thanks to this device, you can solve the problem of heating rooms, heating water and other important household tasks.



Materials for self-production

An example is the process of creating a heating device that will supply heated water to the system. The cheapest option for producing a solar collector is to use basic materials wooden block and plywood, as well chipboards. As an alternative you can use aluminum profiles And metal sheets, but they will cost more.

All materials must be moisture resistant, that is, meet the requirements for use on outdoors. Well made and installed solar collector can last from 20 to 30 years. In this regard, materials must have the necessary performance characteristics for use throughout their entire service life. If the body is made of wood or chipboards, then to extend its service life it is impregnated with water-polymer emulsions and varnish.

Review: Homemade solar panel (battery).

The necessary materials for manufacturing can either be bought freely on the market, or a structure can be made from scrap materials that can be found in any household. Therefore, the main thing you need to pay attention to is the price of materials and components.

Arrangement of thermal insulation

To reduce heat loss, insulating material is placed at the bottom of the box. You can use foam for it, mineral wool etc. Modern industry provides big choice various insulation materials. For example, good option will use foil. It will not only prevent heat loss, but will also reflect the sun's rays, which means it will increase the heating of the coolant.

If you use polystyrene foam or polystyrene for insulation, you can cut grooves for the tubes and install them in this way. As a rule, the absorber is fixed to the bottom of the housing and placed along insulating material.

Collector heat sink

The heat sink of the solar collector is the absorbent element. It is a system consisting of tubes through which the coolant moves and other parts, usually made from copper sheets.

The best material for the tubular part is copper. But home craftsmen have invented more cheap option - polypropylene hoses, which are twisted into a spiral shape. Fittings are used to connect to the system at the inlet and outlet.

It is allowed to use various materials and means at hand, that is, almost any that are on the farm. A do-it-yourself thermal collector can be made from an old refrigerator, polypropylene and polyethylene pipes, panel radiators from steel and other available materials. An important factor When choosing a heat exchanger, the thermal conductivity of the material from which it is made is considered.




The ideal option for creating a homemade water collector is copper. She has the most high thermal conductivity. But using copper tubes instead of polypropylene does not mean that the device will produce much more warm water. On equal terms copper tubes will be 15-25% more efficient than installing polypropylene analogues. Therefore, the use of plastic is also advisable, and it is much cheaper than copper.

When using copper or polypropylene, all connections (threaded and welded) must be sealed. Possible arrangement of pipes is parallel or in the form of a coil. The top of the main structure with tubes is covered with glass. When shaped in the form of a coil, the number of connections is reduced and, accordingly, the possible formation of leaks, and also ensures uniform movement of the coolant through the tubes.

You can use more than just glass to cover the box. For these purposes, translucent, matte or corrugated materials are used. You can use modern acrylic analogues or monolithic polycarbonates.

During production classic version can be used strained glass or plexiglass, polycarbonate materials, etc. A good alternative would be to use polyethylene.

It is important to consider that the use of analogues (corrugated and matte surfaces) helps reduce bandwidth Sveta. In factory models, special solar glass is used for this. It has a little iron in its composition, which ensures low heat loss.

Installation storage tank

To create a storage tank, you can use any container with a volume from 20 to 40 liters. A scheme with several tanks that are connected to each other into one system is also used. It is advisable to insulate the tank, otherwise the heated water will quickly cool down.

If you look at it, there is no accumulation in this system, and the heated coolant must be used immediately. Therefore, the storage tank is used for:

• maintaining pressure in the system;
• replacing the front camera;
• distribution of heated water.

Of course, a solar collector made by yourself at home will not provide the quality and efficiency characteristic of factory-made models. Using only available materials, there is no need to talk about a high efficiency. In industrial samples, such indicators are several times higher. However, the financial costs will be much lower here, since improvised means are used. A DIY solar installation will significantly increase the level of comfort in country house, and will also reduce costs for other energy resources.

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 the desired angle and follow 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 some manufacturing process, then 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.