Methods of solar heating of a private house

The principle of operation of a solar power plant at home

A solar power plant is a system consisting of panels, an inverter, a battery and a controller. The solar panel transforms radiant energy into electricity (as mentioned above). Direct current enters the controller, which distributes the current to consumers (for example, a computer or lighting).An inverter converts direct current into alternating current and powers most electrical household appliances. The battery stores energy that can be used at night.

Video description

A good example of calculations showing how many panels are needed to provide an autonomous power supply, see this video:

How solar energy is used to generate heat

Solar systems are used for water heating and home heating. They can provide heat (at the request of the owner) even when the heating season is over, and provide the house with hot water for free. The simplest device is metal panels that are installed on the roof of the house. They accumulate energy and warm water, which circulates through pipes hidden under them. The functioning of all solar systems is based on this principle, despite the fact that they may be structurally different from each other.

Solar collectors consist of:

• storage tank;
• pumping station;
• controller
• pipelines;
• fittings.

According to the type of construction, flat and vacuum collectors are distinguished. In the former, the bottom is covered with heat-insulating material, and the liquid circulates through glass pipes. Vacuum collectors are highly efficient because heat losses are kept to a minimum. This type of collector provides not only heating with solar panels of a private house - it is convenient to use it for hot water supply systems and heating pools.

The principle of operation of the solar collector

Popular manufacturers of solar panels

Most often, products of Yingli Green Energy and Suntech Power Co. are found on the shelves.HiminSolar panels (China) are also popular. Their solar panels produce electricity even in rainy weather.

The production of solar batteries has also been established by a domestic manufacturer. The following companies do this:

• Hevel LLC in Novocheboksarsk;
• "Telecom-STV" in Zelenograd;
• Sun Shines (LLC Autonomous Lighting Systems) in Moscow;
• OJSC "Ryazan Plant of Metal-Ceramic Instruments";
• CJSC "Termotron-zavod" and others.

You can always find a suitable option for the price. For example, in Moscow for solar panels for a home, the cost will vary from 21,000 to 2,000,000 rubles. The cost depends on the configuration and power of the devices.

Solar panels are not always flat - there are a number of models that focus light at one point

Battery Installation Steps

1. To install the panels, the most illuminated place is selected - most often these are the roofs and walls of buildings. In order for the device to function as efficiently as possible, the panels are mounted at a certain angle to the horizon. The level of darkness of the territory is also taken into account: surrounding objects that can create a shadow (buildings, trees, etc.)
2. Panels are installed using special fastening systems.
3. Then the modules are connected to the battery, controller and inverter, and the whole system is adjusted.

For the installation of the system, a personal project is always developed, which takes into account all the features of the situation: how solar panels will be installed on the roof of the house, price and terms. Depending on the type and scope of work, all projects are calculated on an individual basis. The client accepts the work and receives a guarantee for it.

Installation of solar panels must be carried out by professionals and in compliance with safety measures.

As a result - the prospects for the development of solar technologies

If on Earth the most efficient operation of solar panels is hindered by air, which to a certain extent scatters the radiation of the Sun, then in space there is no such problem. Scientists are developing projects for giant orbiting satellites with solar panels that will operate 24 hours a day. From them, the energy will be transmitted to ground receiving devices. But this is a matter of the future, and for existing batteries, efforts are directed towards improving energy efficiency and reducing the size of devices.

3 Main types

Large installations are able to provide electricity to the entire house, and if necessary, completely heat it. But this applies only to small private cottages, they will not be able to heat multi-storey buildings.

As for the equipment, it may vary depending on the model. As a rule, the basic set includes:

• vacuum solar collector;
• a special controller that monitors work efficiency;
• a pump with which the coolant is supplied;
• a tank with a volume of 500-1000 liters for hot water;
• electric heater or heat pump.

Before installing collectors, it is necessary to calculate how much power they need in order to fully satisfy all needs. When calculating, it is worth considering the area of ​​​​a private house, the number of people living, as well as energy consumption. For example, for a small family of three, on average, from 200 to 500 W / m² will be required per month.

If you plan to provide a home with hot water, then energy costs will increase.For efficiency, you can make a combined version of the heating system. In this case, households will be insured and will not be left without heating in emergency and unforeseen situations.

Do-it-yourself heating in a private house: the best option

In the scheme of steam heating of a residential one-story or two-story house, there is a heating boiler, radiators and a closed circuit of pipes through which a liquid heated to a certain temperature (antifreeze, water) circulates. For a one-story building, the simplest gravity system is suitable, the principle of operation of which is based on the laws of physics.

In it, the coolant circulates by gravity due to the hydraulic pressure obtained by the combination:

• pipes of various diameters;
• inclusion in the circuit of an expansion tank of a closed (expansomat) or open type;
• height difference between the return (return) and direct (supply) pipelines.

Benefits of a Gravity Flow System	Minuses
The system does not need an electrical network to function.	Do-it-yourself installation is difficult, because you need to check the angles of the pipeline
Low material costs	You have to visually assess the amount of liquid in the expansion tank and, if necessary, replenish
maintainability	Effective in houses up to 150 m²

For houses of a large area of ​​​​any number of storeys (1-2 floors), a heating scheme with forced circulation is chosen:

• pump;
• expansion tank of any type, installed near a solid fuel boiler (membrane type) or at the top of the heating circuit (open).

Popular heating schemes	Peculiarities
Single pipe	The batteries are connected in series, the speed of the coolant is set by the pump, to control the heating intensity of the convectors, shut-off and control valves are installed: thermostatic valves, air vents, radiator regulators, balancing cocks (valves)
Two-pipe	The coolant is supplied, discharged to the battery by different pipes; during installation, a parallel scheme for connecting radiators is used. This ensures the same heating intensity
"Spider" (gravity flow)	The boiler is placed in the basement, and the expansion tank is installed in the attic. At the same time, the rule is observed: the level difference is not more than 10 m. The heated water moves up the riser to the tank, from which it is supplied to the radiators through vertical pipes. The coolant that has given up heat goes into a horizontal line and returns to the boiler
"Leningradka"	The main pipe runs along the floor along the perimeter of the house, hot liquid (antifreeze, water) passes successively through each radiator included in the circuit
Radiation	Hot water is distributed to radiators through a manifold

Collector heating system

The greatest efficiency and return can be achieved by installing collectors instead of solar modules - outdoor installations in which water is heated under the influence of solar radiation. Such a system is more logical and natural, since it does not require heating of the coolant by other devices.

Consider the design and principle of operation of devices of two main types: flat and tubular.

Flat version for DIY

The design of flat installations is so simple that experienced craftsmen assemble handicraft analogues with their own hands, buying some of the parts in a specialized store, and building some from improvised material.

Inside a steel or aluminum insulated box, a plate is fixed that absorbs solar heat. Most often it is covered with a layer of black chrome. The top of the heat sink is protected by a sealed transparent cover.

Water is heated in tubes laid in a snake and connected to the plate. Water or antifreeze enters the box through the inlet pipe, heats up in the tubes and moves to the outlet - to the outlet pipe.

The light transmission of the cover is due to the use of a transparent material - durable tempered glass or plastic (for example, polycarbonate). So that the sun's rays are not reflected, the glass or plastic surface is matted (+)

There are two types of connection, one-pipe and two-pipe, there is no fundamental difference in the choice. But there is a big difference in how the coolant will be supplied to the collectors - gravity or using a pump. The first option is recognized as inefficient due to the low speed of water movement; according to the principle of heating, it resembles a container for a summer shower.

The operation of the second option occurs due to the connection of a circulation pump, which supplies the coolant forcibly. The solar energy system can become a source of energy for the operation of pumping equipment.

The temperature of the coolant when heated by a solar collector reaches 45-60 ºС, at the outlet the maximum indicator is 35-40 ºС.To increase the efficiency of the heating system, along with radiators, “warm floors” are used (+)

Tubular collectors - a solution for the northern regions

The general principle of operation resembles the functioning of flat counterparts, but with one difference - the heat exchange tubes with the coolant are inside the glass flasks. The tubes themselves are feather, sealed on one side and resembling feathers in appearance, and coaxial (vacuum), inserted into each other and sealed on both sides.

Heat exchangers are also different:

• a system for converting solar energy into thermal energy Heat-pipe;
• a conventional tube for moving a U-type coolant.

The second type of heat exchangers is recognized as more efficient, but not popular enough due to the cost of repairs: if one tube fails, the entire section will have to be replaced.

The Heat-pipe is not part of a whole segment, so it can be changed in 2-3 minutes. Failed coaxial elements are repaired by simply removing the plug and replacing the damaged channel.

A diagram explaining the cyclical nature of the heating process inside the vacuum tubes: the cold liquid heats up and evaporates under the influence of solar heat, giving way to the next portion of the cold coolant (+)

After analyzing the technical characteristics of collectors of various types and summarizing the experience of their use, we decided that flat collectors are more suitable for the southern regions, and tubular collectors for the northern regions. Installations with the Heat-pipe system have proven themselves especially well in harsh climates. They have a heating capacity even on cloudy days and at night, "feeding" on a minimal amount of sunlight.

An example of a standard scheme for connecting solar collectors to boiler equipment: a pumping station provides water circulation, a controller regulates the heating process

Increasing the efficiency of solar modules

The efficiency of solar systems can be improved by using one of the following methods:

1. Changing the location of modules. Sometimes, to increase the efficiency, it will be enough to correctly position the modules relative to the directivity vector of the sun's rays. This usually requires deploying all modules to the south. If the day in the region is long, you can also use the surfaces directed to the east and west side - there is also enough light that is converted into energy.
2. Changing the angle of inclination. The documentation for the modules always indicates the recommended tilt angle at which the efficiency of the system will be maximum. In practice, this value can vary significantly depending on geographic location and other individual characteristics.
3. Selecting a location for installation. Most often, solar modules are installed on the roof of a building - this is the easiest, most affordable and obvious option, but not the most effective. The best thing to do is to prepare a swivel base in advance and install the panels on it so that the devices follow the sun's rays as they move.

The last point deserves special attention. Of course, modules installed on the roof are not useless - after all, there are no obstacles for the sun's rays in this case, so they easily reach the device and are converted into the required type of energy.

The problem is that the arrangement of modules perpendicular to the sun's rays has maximum efficiency over a short period of time.

Rotary devices that track the current direction of the beams allow you to get rid of such problems. True, such devices also have negative sides - in particular, we are talking about the extremely high cost of rotary systems. In addition, in some cases, the acquisition of such equipment does not affect the efficiency of the system in any way - for example, if climatic conditions were not properly taken into account. The costs in this case will be completely inappropriate.

According to approximate calculations, in order for the rotary elements to pay off, their number must be at least eight. Of course, you can use a smaller number of modules (about 3-4), but they will be a profitable purchase only if you connect them directly to the water pump, in other cases, the increase in efficiency will be insignificant.

Calculation of the energy efficiency of solar panels

When calculating the required area of ​​​​solar panels, it must be taken into account that one square meter of such equipment will give about 120 watts to your network. Now walk around your house and estimate how much power your household electrical appliances and equipment have. It would also be reasonable to estimate how much energy savings can be obtained by replacing some devices with energy efficient ones. After that, you can start calculating the required number and area of ​​​​solar panels, trying to take into account the time of solar activity in your area.

Heating a private house from solar energy

In addition to extracting electricity from solar energy, our luminary may well heat your home. Of course, you can use the simplest way and connect the electric heating system to solar panels. But most likely it will be rather inefficient, especially given the not very large number of sunny days per year at our latitudes.

It would be best to combine a system for generating electricity using solar panels and an autonomous heating system based on heating the liquid with solar heat, which then enters the heating radiators of your home.

How solar heating works

The heating collectors will be the key link in such an autonomous solar heating system. These are specialized devices that, with minimal losses, transfer solar radiant energy to a coolant, which can be water or a special antifreeze.

solar heater circuit

An important advantage of such a high-tech approach is that such a system will work effectively even in the most severe climatic conditions, its efficiency does not decrease even at low negative outdoor temperatures.

Such systems, also called solar collectors, have proven themselves, for example, in the northern regions of China - in areas with a very harsh climate. Moreover, in those regions they are installed even in apartment buildings.

After heating in the collector, the coolant usually enters the storage tank, which is equipped with excellent thermal insulation. The temperature of the liquid in such a tank is maintained for quite a long time.If ordinary tap water is used as a heat carrier, then, in addition to heating, such a liquid can also be used for domestic purposes, for example, for washing or washing dishes.

Norms and requirements for autonomous heating

Before designing a heating structure, it is necessary to look into SNiP 2.04.05-91, which sets out the basic requirements for pipes, heaters and valves.

General norms boil down to ensuring that the house has a comfortable microclimate for the people living in it, to properly equip the heating system, having previously drawn up and approved the project.

Many requirements are formulated in the form of recommendations in SNiP 31-02, which regulates the rules for the construction of single-family houses and their provision with communications.

Separately, provisions related to temperature are stipulated:

• the parameters of the coolant in the pipes should not exceed + 90ºС;
• optimal indicators are within + 60-80ºС;
• the temperature of the outer surface of heating devices located in the direct access zone should not exceed 70ºС.

Pipelines of heating systems are recommended to be made of brass, copper, steel pipes. The private sector mainly uses polymer and metal-plastic tubular products approved for use in construction.

Pipelines of water heating circuits are most often laid in an open way. Hidden laying is allowed when installing "warm floors"

The method of laying the heating pipeline can be:

• open. It involves laying on building structures with fastening with clips and clamps. It is allowed when constructing circuits from metal pipes.The use of polymer analogs is permitted if their damage from thermal or mechanical impact is excluded.
• Hidden. It involves laying pipelines in strobes or channels selected in building structures, in skirting boards or behind protective and decorative screens. Monolithic contour is allowed in buildings designed for at least 20 years of operation and with a service life of pipes of at least 40 years.

The priority is the open method of laying, because the design of the pipeline route should provide for free access to any element of the system for repair or replacement.

Pipes are hidden in rare cases, only when such a solution is dictated by technological, hygienic or constructive necessity, for example, when installing “warm floors” in a concrete screed.

When laying the pipeline of systems with natural movement of the coolant, it is necessary to observe a slope of 0.002 - 0.003. Pipelines of pumping systems, inside which the coolant moves at a speed of at least 0.25 m/s, do not need to provide slopes

In case of open laying of the main, the sections crossing unheated premises must be provided with thermal insulation corresponding to the climatic data of the construction region.

Autonomous heating pipelines with a natural circulation type must be installed in the direction of the coolant movement, so that the heated water reaches the batteries by gravity, and after cooling, moves along the return line to the boiler in the same way. The mains of pumping systems are built without a slope, because. it is not necessary.

The use of various types of expansion tanks is stipulated:

• open, used for systems with both pumping and natural forcing, should be installed above the main riser;
• closed membrane devices, used exclusively in forced systems, are installed on the return line in front of the boiler.

Expansion tanks are designed to compensate for the thermal expansion of the liquid when heated. They are needed to dump excess into the sewer or corny into the street, as is the case with the simplest open options. Closed capsules are more practical, because they do not require human intervention in adjusting the pressure of the system, but more expensive.

An open type expansion tank is installed at the highest point of the system. In addition to providing a reserve for expanding the liquid, it is also entrusted with the task of removing air. Closed tanks are placed in front of the boiler, air vents and separators are used to remove air

When choosing shut-off valves, preference is given to ball valves, when choosing a pumping unit - equipment with a pressure of up to 30 kPa and a capacity of up to 3.0 m3 / h.

Budget opening varieties need to be replenished periodically due to the standard weathering of the fluid. Under their installation, it is necessary to significantly strengthen the attic floor and insulate the attic.

Radiators and convectors are recommended to be mounted under windows, in places convenient for maintenance. The role of heating elements in bathrooms or bathrooms can be played by heated towel rails connected to heating communications

Heat accumulation in hot rock, concrete, pebbles, etc.

Water has one of the highest heat capacities - 4.2 J / cm3 * K, while concrete has only one third of this value.Concrete, on the other hand, can be heated to much higher temperatures of 1200C by electrical heating, for example, and thus has a much higher overall capacity. Following from the example below, an insulated cube approximately 2.8 m across may be able to provide enough stored heat for one home to meet 50% of the heating demand. In principle, this could be used to store excess wind or photovoltaic thermal energy due to the ability of electrical heating to reach high temperatures.

At the county level, the Wiggenhausen-Süd project in the German city of Friedrichshafen attracted international attention. This is a 12,000 m3 (420,000 cu.ft.) reinforced concrete thermal storage unit connected to a 4,300 m2 (46,000 sq. ft.) solar collector complex that provides half of the hot water and heating needs of 570 homes.

Siemens is building a heat storage facility near Hamburg with a capacity of 36 MWh, consisting of basalt heated to 600C and generating 1.5 MW of power. A similar system is planned for construction in the Danish city of Sorø, where 41-58% of the stored heat with a capacity of 18 MWh will be transferred to the district heating of the city, and 30-41% as electricity.

ft.), covering half the need for hot water and heating for 570 homes. Siemens is building a heat storage facility near Hamburg with a capacity of 36 MWh, consisting of basalt heated to 600C and generating 1.5 MW of power. A similar system is planned for construction in the Danish city of Sorø, where 41-58% of the stored heat with a capacity of 18 MWh will be transferred to the district heating of the city, and 30-41% as electricity.

Basic information about homemade solar collectors

Professional units have an efficiency of about 80-85%, but you need to take into account the fact that they are quite expensive, and almost everyone can afford to purchase materials for assembling a home-made collector.

In this regard, everything depends on the design features, which are determined and calculated individually.

Assembly of the unit does not require difficult to use and hard-to-reach tools and expensive materials.

solar collector

Solar Collector DIY Tools

1. Perforator.
2. Electric drill.
3. A hammer.
4. Hacksaw.

There are several varieties of the considered design. They differ from each other in efficiency and final cost. Under any circumstances, a home-made unit will cost an order of magnitude cheaper than a factory model with similar characteristics.

One of the best options is a vacuum solar collector. This is the most budgetary and easiest option in its execution.