Attitude towards alternative sources Energy in our country is gradually beginning to change. Just a few years ago it was perceived as a fad, but now it’s all more people are starting to collect information on how they can save on their bills public utilities. One of interesting directions — street lighting on solar powered. It is difficult to say whether it is possible to save money on this matter - it depends on many factors. But make the lighting from solar energy Can. Even in two ways.
Outdoor lighting - complex system and it is divided into several components:
Not all parts are necessarily present in any one, but all of them can be. Most, or even all, of this system can be powered by solar panels. Moreover, solar-powered street lighting can be done in two ways:
Is it profitable to use solar panels to illuminate the area? The answer can only be given on a case by case basis. The efficiency of solar systems depends very much on the region and the number of sunny days. And the economic benefit (payback) comes from electricity tariffs.
System calculation
If it is decided to make solar-powered street lighting reliable - with batteries, first of all, you need to replace all the lamps and lanterns with LED ones that operate on 12 V. Why is this so? Because the batteries give out constant voltage, and some of them are just 12 V. You can power 220 V lamps from this system, but you will also need an inverter that converts 12 V to 220 V. And this is an additional expense. Therefore, it is advisable to choose just such lamps, lanterns and lamps.
Finding the power and number of solar panels
In order for the system to be reliable, it is necessary to calculate the power of the solar panels and the capacity of the batteries that will provide it. The calculation procedure is as follows:
Next, it’s a matter of choosing solar panels. You choose, find out their area, count the number of pieces. Their total area should be no less than that of ours. It is even advisable to have a reserve, since there are always periods with worse characteristics than average.
Batteries
It is also necessary to calculate the capacity of the batteries, which should provide energy to the lamps in case of prolonged bad weather. Here you will also need weather forecaster data. But you will already need the most long period bad weather. Also, for the calculation, you need daily energy consumption to maintain performance (point 3 in the previous section).
The calculation is simple. We multiply the daily consumption by the number of days of bad weather. We get the reserve that the batteries should provide. Next you need to look for batteries with suitable characteristics. You just need to take it with a 30-40% capacity reserve, since a full discharge shortens the life of the batteries. Therefore, it is undesirable to discharge them too much.
Batteries for solar panels - yes different sizes and parameters
Sometimes manufacturers indicate only the possible energy reserve, which is expressed in A/h (ampere hours). This value can be converted into W/hours if multiplied by the operating voltage of the battery (indicated in the specifications). For example, Ventura GP 12-26 battery - voltage 12 V, capacity 26 Ah. You can convert it to watt hours like this: 12 V * 26 A*h = 312 Wh.
Controller selection
Let's start by figuring out why a controller is needed in this system. If you connect the solar panel directly to the battery, it will begin to charge when electricity is supplied. When the maximum charge voltage is reached (depending on the type of battery and its temperature), it must be turned off. If there is no controller, this must be done manually. If you turn it off at the wrong time, this will lead to boiling of the electrolyte, shortening the battery life. So you need a controller.
Solar controllers come in three types:
In fact, choosing a solar panel controller is simple: best option- MPPT, not bad - PWM. In extreme cases, ONN/OFF is also suitable, but it is better not to use it.
When choosing a controller, you should also pay attention to the fact that it can adjust the system parameters depending on the temperature of the battery. To do this, it must have a heat sensor. It can be built-in or remote. Remote models show more correct data, so give preference to such models.
System calculation example
To calculate the system solar lighting on the street it was clearer, let's give an example. It is necessary to provide energy to lamps with a total power of 10 W, voltage of 12 V. The longest operating period is 14 hours, the lowest level of insolation in the year is 1.21 kWh/m2/day. The calculation is as follows:
When selecting equipment, you can even look at larger battery ratings and greater performance or area of the solar system. Sometimes, paradoxically, more productive equipment costs less. Also, it’s not a fact that after a while you won’t want to add load to the system. So the supply will come in handy.
Price issue
Solar-powered street lighting in this design is not a cheap undertaking. For example, for the calculation example given, you can select the following equipment:
- 250W polycrystalline solar cell manufactured by Chinaland Solar Energy. Cost 15160 rubles.
- Tracer MPPT Charge Controller (100V), 20A, 12/24V, manufactured by Beijing Epsolar Technology. 8640 rubles.
- Gel battery GX12-150, 150 Ah, GEL, manufactured by Delta - 21,230 rubles or GX12-200, 200 Ah GEL costs 26,160 rubles.
In total, the equipment costs a little more than 45 thousand rubles. But you will also need brackets for installing a solar battery (2-3 thousand rubles), sealed connectors and special wires for solar power (this is another 1-2 thousand rubles). The idea is really not cheap.
To completely convert street lighting to solar energy, it is required large number batteries...
How can you reduce costs? Purchase equipment domestic production directly from the manufacturers. For example, batteries can be purchased from Zelenograd Telecom STV, inverters and controllers from MAP Micro Art LLC. Also, instead of special batteries, they buy 12 V car batteries; they do not have the same characteristics, they need to be changed more often, but they are much cheaper. Even taking into account the fact that they need to be changed every 2-3 years. Under such conditions, solar-powered street lighting can cost half as much.
Street lighting using lamps/lanterns with solar panels
If you use solar-powered lanterns or lamps with built-in batteries, no other equipment is required. But the system turns out to be not reliable enough to do, for example, security lighting. But such lamps are very easy to install; they do not need to be connected to power sources. They are completely autonomous. That is, there is no need to lay cables connecting light sources into one system, and this is a significant expense item and a large amount of work.
Solar street lighting - on different tastes, for various purposes
Installation of solar cell lamps/lanterns
A solar-powered lamp has practically the same structure as the system described in the previous paragraph: there is a panel with solar converters, a small battery and a mini-controller. All this is compactly packed into a housing.
The battery, depending on the design and power of the lamp, can be mounted on the top of the lampshade (as on small garden solar lamps) or placed slightly to the side (this is usually done on lanterns with powerful lamps, since significant charging power is needed).
The battery is located next to or inside the case. There are two types: cheaper models are equipped with nickel-cadmium elements (designated NI-CD), more expensive ones are usually equipped with nickel-metal hydride (designated NI-MN). To make the lamps shine longer, it is better to purchase lamps with batteries of the second type. But they cost more. Since they are usually made from more expensive materials, they are assembled to a higher quality.
Appearance and material
The first thing you have to pay attention to is external design. There are a lot different forms and styles, so you can find a solar lantern to suit every taste. But, from experience, than simpler form, the more reliably it works. The point is that for normal operation The lamp body must be sealed, which is why complex form difficult to achieve. Therefore, solar-powered street lighting is best done using lanterns of laconic shape.
The body and leg of the lamp are made of metal or plastic. Plastic models- the cheapest, most of them are made in China, and most often they illuminate only themselves and quickly fail. Count on more or less long term not worth using.
Solar cell lanterns made of metal are much more expensive. But such solar-powered outdoor lighting is more durable. The metal can be painted steel, aluminum alloy, stainless steel (shiny or matte, blackened). More expensive materials, higher quality LEDs and solar cells are used here. Prices, however, are also significantly higher.
How to choose according to technical parameters
After you have decided on the external parameters, you need to delve into technical details. First of all, pay attention to the lamp power, type and capacity battery. Normal manufacturers indicate the number of LEDs and their overall brightness. The greater the power of the lamp, the large area it will illuminate. But there should be more powerful battery- to ensure the required operating time.
Normal lamps can work for 8-10 hours (when fully charged). But such a duration of illumination is not always necessary - when the nights are short, street lighting can work for 5-6 hours, or even less. To ensure that the lighting does not work “idle”, light sensors are built into the lamps. This is quite a useful option, so we’ll pay attention to it too.
terms of Use
Many solar-powered lanterns and street lighting fixtures have a serious drawback: they do not withstand frost well. As a rule, these are flashlights in the cheap and mid-price range. If they are used at temperatures below +25°C, their service life is significantly reduced. They fail even faster if they operate at sub-zero temperatures. So such lamps are only suitable for dachas - during the dacha season. Please note that not all manufacturers warn about this. Additional information often has to be requested.
The height of solar lanterns may vary. These are already more solid “frost-resistant” models
If solar street lighting needs to work all year round, look for “frost-resistant” models. They exist, but in a higher price range. They use frost-resistant solar cells and batteries and are made of steel. Accordingly, they cost more.
The main source determining natural light is the Sun. The spectral composition of solar radiation at the boundary of the atmosphere is usually approximated by the radiation of a black body with a temperature K. The true distribution of energy in the spectrum of solar radiation is somewhat different from the distribution for a black body with K: in the region of 0.4...0.75 μm, the Sun emits more energy, than a black emitter at K, in the ultraviolet region it is less, and in the infrared region the differences are insignificant. The Sun as an emitter is a sphere and theoretically emits a diverging stream of rays, however, due to the great distance of the Sun, its radiation on the earth's surface practically represents a stream of parallel rays. Energy illumination created sun rays on a plane perpendicular to them outside earth's atmosphere at the average distance from the Earth to the Sun, is characterized by the solar constant.
The illumination of natural landscapes is determined by the height of the Sun above the horizon and the influence of the atmosphere. The height of the Sun for an area with geodetic latitude and longitude is determined by the following calculation formula:
where is the declination of the Sun on the date of observation; – difference in longitude of the Sun and the observer (hour angle).
The difference in longitude (degree) is related to local time by the relation 
, where is time in hours and its fractions.
At a given moment in Moscow time, the value is determined by the following equalities for winter and summer time, respectively:
where is the equation of time (time correction) in fractions of an hour.
The solar declination is specified in a table, but can be determined analytically with sufficient accuracy for modeling: , where is the time in days from the daytime equinox (March 22) to the shooting date. Values are determined by nomogram or tables.
To simulate realistic images in natural light, it is also necessary to determine the azimuth of the Sun, for the calculation of which , and are used:
In image synthesis procedures, it is advisable to use a unit vector indicating the direction to the Sun. If we use a right-handed topocentric coordinate system, in which the axis is directed to the north, and the axis is perpendicular to the Earth’s surface and directed to the zenith, then the vector components along the axes will be determined by the following relations:
(1.3.4)
Note that to characterize the position of the Sun, along with height, the zenith distance is used.
The influence of the atmosphere is manifested in the weakening of direct solar radiation and its dispersion. In accordance with this, the illumination of the earth's surface is determined by two light fluxes: weakened direct radiation and scattered radiation of solar radiation coming to the Earth.
The significant instability of the properties of the atmosphere, a significant number of factors causing its variability, do not allow us to give an accurate forecast of illumination. Approximate models with a limited number of parameters characterizing the optical properties of the atmosphere are usually used. The mean standard atmosphere model is widely used for calculations. The spectral illumination created by the Sun near the Earth's surface on an area perpendicular to the sun's rays, with a cloudless sky and a standard atmosphere, is determined by the formula
, (1.3.5)
where is the spectral illumination created by solar radiation at the boundary of the atmosphere; – optical depth of the atmosphere.
The generalized parameter can practically be used in the range 
, within which the weakening of direct solar radiation is mainly due to molecular and aerosol scattering (Fig. 1.3.1).
Rice. 1.3.1. Attenuation of direct solar radiation in the atmosphere:
1 – solar radiation at the boundary of the atmosphere; 2 – solar radiation at the earth’s surface; 3 – aerosol dispersion; 4 – absorption in the atmosphere
For this range, the wavelength dependence for a standard atmosphere is described by the empirical formula
where is the optical depth of the atmosphere at nm. When calculating according to (1.3.6), the values are substituted in nanometers.
Several standard values are usually used in calculations. For a moderately turbid atmosphere it is 0.3. Low atmospheric turbidity corresponds to high turbidity.
The illumination created by direct radiation from the Sun on an arbitrarily oriented site is determined by the angle between the unit direction vector to the sun and the unit normal vector to the site:
, (1.3.7)
where is the scalar product of vectors and .
The image synthesis program must take into account the condition of non-negative illumination
If conditions (1.3.8) are not met, this side of the site is not illuminated: . The unit normal vector to the site must be directed from the surface whose illumination is being calculated. This means that, in principle, the platform is characterized by two unit normal vectors and , defining its two sides. It's obvious that .
Note that from general formula to determine the illumination (1.2.23), the formula given in the literature for the illumination of the earth's surface directly follows. For horizontal earth surface 
and therefore .
The illumination created by scattered radiation is determined by the brightness of the sky. The importance of taking into account scattered radiation is due to the fact that it determines the illumination of areas of the scene that are in the shadow.
The brightness of an arbitrary point in the sky is a function of four basic parameters: the height of the Sun, the transmission of the atmosphere, the zenith distance of the point in the sky and the angle between the direction to the Sun and to given point firmament.
Calculation of the illumination of an arbitrarily oriented area, taking into account the true brightness distribution of the sky, requires numerical integration using a tabular specified functions. This greatly complicates the procedure for calculating the illumination of points on the picture plane. The calculation procedure can be significantly simplified if the brightness of all points in the sky is assumed to be the same and equal to some average value. The average brightness of the sky can be approximated by the dependence of the form
The value depends relatively weakly on and . In some cases it is assumed to be constant. A more accurate approximation can be obtained by assuming 
. However, the differences in the results obtained based on more accurate models and those presented above are small. The maximum differences reach 20% only at a significant height of the Sun ().
To determine the illumination from the sky of an arbitrarily oriented area, consider the general scheme for determining the illumination created by an extended source (Fig. 1.3.2).
Rice. 1.3.2. Determining the illumination of an arbitrarily oriented area by the sky
In accordance with (1.2.16), the illumination from the sky of the site is determined as follows: , where is the projection of the visible part of the celestial sphere onto the illuminated plane in which the site lies. to 
. Outside this range the values are practically zero.
Although the transition from an energy system to a lighting system does not cause any fundamental difficulties, for systems in the visible range it is more convenient to use calculation formulas that express the illumination directly in the lighting system. For such calculations, a relation can be used, based on the one known in , but supplemented by taking into account the inclination of the illuminated area:
Where 
– illumination of the plane perpendicular to the rays of the Sun at the boundary of the atmosphere in the lighting system of units; – coefficients characterizing transparency and dispersion in the atmosphere.
For average parameters of the standard atmosphere; . In accordance with (1.2.29), the maximum illumination of a horizontal area on the earth's surface for standard conditions is 106,000 lux (at ).
The amount of natural light is greatly influenced by the nature of cloudiness. The presence of clouds causes a significant increase in scattered radiation. When the clouds are broken, the illumination “in the Sun” turns out to be 10...30% higher than in cloudless weather, and the illumination in the shadow can increase up to twice the value. This circumstance is the reason for the significant scatter in the experimental data on illumination in the shadow and justifies the use in computer graphics of relatively simple models for calculating illumination, the use of correction factors that increase the value of illumination in the shadow compared to those calculated at solar angles.
Increasingly, owners country houses thinking about using free sources energy. Installing solar-powered lamps helps save on electricity. If desired, you can create a lighting system for the entire house that is powered by solar panels.
Advantages of autonomous solar lighting on the street
Before describing the advantages, it should be noted that often autonomous street lighting is only partially dependent on sunlight, since some areas of the site will have to be illuminated permanently. This is due to the fact that solar-powered lamps do not always illuminate the space brightly enough.
Solar-powered lamps have several advantages:
- The described devices for dachas do not need to be connected anywhere; they work autonomously. After installation, they are ready to use and do not require additional work. Such devices are turned off automatically thanks to sensors.
- Solar-powered lamps do not require special care. Sometimes it is necessary to wipe the photocells from dust and dirt.
- Durability. The described devices can operate for more than 10 years.
- The lamps are safe as they operate on low voltage.
- If lamps are purchased for a summer residence, you can find lamps. Which can be installed temporarily, but winter time remove them indoors.
Thus, garden lamps that run on solar panels can save a lot of money that could have been spent on lighting.
Disadvantages of autonomous lighting
The disadvantages of the described devices include:
- Solar-powered street lights do not provide bright enough light. That is why they cannot be used as security lighting. There are powerful devices, which are quite bright, but they are very expensive, so not all land owners are able to purchase them.
- The number of hours of work directly depends on weather conditions. During a cloudy day, the lamps do not store enough energy, so it only lasts for several hours.
- Reliable, powerful lamps are more expensive. At the same time, such devices work longer and create a brighter luminous flux.
- Solar panels can only operate within a certain temperature range. Such products do not tolerate frost well and high temperature V summer time. They are most often used in regions with temperate climates.
Despite all the disadvantages described, autonomous lighting allows you to save a large amount of money on lighting a large area.
Solar lamps
Street lamps may differ in many ways, but they all consist of the following components:
- Solar panel. This device necessary for converting solar energy into electrical energy. The panel always faces upward to better capture sunlight.
- A battery needed to store energy during daylight hours.
- Lighting unit, which consists of a lampshade, a lamp and a housing.
- The controller needed to turn the lamp on and off. This happens thanks to ambient light sensors.
- A fixture required for hanging or installing a luminaire.
Autonomous lighting for home
Lighting for the home is created on the principle of a solar station. Photomodules are placed on the roof of the house. Additional equipment is usually located in the technical room.
During system operation, solar panels generate electricity, which is then stored in batteries. After this it is spent on lighting fixtures.
The device has a charge controller that monitors the battery condition. Thanks to this element, the system does not overcharge and reverse discharge. The device contains an inverter that converts D.C. into alternating voltage supplied to the power grid. When using solar panels, the lamps in the house are replaced with LED ones.
If 12 V lamps are used, an inverter is not required. It should be noted that 12 V lighting is safer and does not require the use of high-quality wiring. Solar-powered electricity can also be used for lanterns located on the site. But when creating a lighting system, it must be taken into account that the energy consumption of all devices should not exceed the generated power.
In the absence of knowledge, many will find it difficult to organize high-quality lighting. But if you know a few basic rules, even an inexperienced person can carry out such work.
First you need to draw up a project that will show the location of all the lamps. At the preparation stage, it is also important to decide on the type of solar panels. Thanks to the plan, you can choose the most suitable place for the location of lights. This will allow the lights to be evenly distributed.
If installing lawn lights, it is best to do so along the sidewalk or road. Such lamps not only illuminate the space, but also help create a certain style plot. But we should not forget about
If you want to create a lighting system in the garden, it is best to use special garden devices, which work autonomously without connecting via wires.
How to choose a lamp for street lighting
If you want to buy a device that works thanks to sunlight, you need to consider in detail the technical characteristics of the lamps. First of all, you need to pay attention to power. When purchasing a flashlight, it is important to find out how far the device shines. The number of products purchased will depend on this. It should be noted that in the case of LED lamps, the power does not mean much.
To understand how bright a certain device will be, you should compare the power of the products with the power of standard incandescent lamps, but convert this parameter to Lums. After this it will be possible to understand. What wattage lamps do you need?
1W models produce about the same amount of light as 20W incandescent bulbs. That is why such devices are usually used for lighting garden paths and lighting of the gazebo.
In addition, you should pay attention to the protection class and the material from which the case is made. In order for street lighting to work for a long time and reliably, it is necessary to choose products in a housing that is protected from moisture and dust. Thanks to this, the flashlights will be used for a long time and will not require replacement of components.
It is advisable to choose lighting devices with a protection class of at least IP44. In addition, you should pay attention to the material of the case. Most often, lamps are made of impact-resistant plastic and metal.
Types of lamps by installation method
When purchasing devices powered by sunlight, you should consider all types of such products according to the type of installation. This will help you understand which devices are more convenient to install on the site and in the house. Devices purchased for street lighting are divided into the following types:
- Products installed in the ground. Such lamps are usually created on legs with a height of 20 cm to a meter. To install them, just stick the leg into the ground.
- Pole lamps. Such models are taller and require more serious installation work. To do this, you need to dig a hole and compact the soil after installation. Some products are designed for installation on surfaces such as asphalt and tile.
- Wall lamps. Such devices can be installed both on the wall of the house and on fence posts.
- Hanging. Most often they are fixed in gazebos and on the porch. Some property owners hang such devices on the branches of large trees.
- Built into the ground or other materials. Such lamps allow you to illuminate paths and stairs. The light from such devices does not dazzle the eyes, and the illumination level remains quite good.
- Decorative devices. Such lamps in the daytime look like decorative elements garden, and at night they emit light. They can be placed anywhere in the garden. But when installing, you need to take into account that they greatly influence the design of the garden, so it is important to install them in certain places.
Taking into account the features of all the described lamps, you can choose the right products for own plot and not only make it illuminated at night, but also decorate the space.
Light traps
If you want to create a solar lighting system in your home, you should purchase light traps - this is the name given to products that consist of several mirrors and direct the sun's rays to the least lit areas of the room. By installing them correctly in your home, you can significantly increase the level of illumination during the day.
15.06.2005The only source of natural light is the sun...
It emits direct sunlight, some of which is scattered in the atmosphere and creates diffuse radiation. Thus, a distinction is made between light falling directly from the sun and light from the “sky” - sunlight scattered by the atmosphere.
Natural light varies depending on the time of day, weather conditions and time of year. Main feature natural lighting - the variability of the intensity and spectral composition of its radiation. Changes in illumination are influenced by natural and random factors.
Regular factors influencing the variability of natural light are the height of the sun above the horizon and geographic latitude. Random factors are determined by the state of the atmosphere - clear, rain, fog. A random additional factor is the reflection of light from the ground and surrounding objects.
As the sun rises, the intensity of the light increases and its color temperature .It is noteworthy that due to the refraction of the sun's rays in the atmosphere, we see the sunrise a little earlier and the sunset a little later than is actually the case. Calculations show: when we see that the lower edge of the Sun has touched the horizon, in reality it has already set.
The rays that make up sunlight, violet, blue, cyan and green, are refracted in the Earth's atmosphere more strongly than yellow and red. Therefore, the first rays at sunrise are blue and green, just like the last ray of the setting sun.
Due to scattering in the atmosphere, the blue beam is not observed. The green beam is a rare sight. It can be seen in very clean, calm and homogeneous air, when there are no upward convection currents in the atmosphere up to the horizon. Most often, the green beam is observed on the shore of a calm sea.
Table 1.2.
|
Spectral characteristics of natural light |
|
|
Daylight phases |
Color temperature of radiation, K |
|
Direct sunlight at sunrise and sunset |
2200 |
|
Direct sunlight one hour after sunrise |
3500 |
|
Direct sunlight early morning and late afternoon |
4000.. .4300 |
|
Sunlight at noon in summer |
5400... 5800 |
|
Absent-minded daylight in the shade in summer |
7000 |
|
Diffused daylight in cloudy weather |
7500... 8400 |
|
Light from the blue sky |
9500.. .30000 |
|
|
|
Depending on the height of the sun above the horizon, natural lighting is divided into periods of effective, normal and zenith lighting.
The period of effective lighting is characterized by low illumination and a high content of orange-red rays in natural light. At sunrise and sunset they are equivalent to the light of incandescent lamps (see Table 1.2). Their color temperature is 3000...3200°K.
The period of normal lighting is favorable for the eyes. At this time, the illumination changes smoothly and the spectrum of natural light changes slightly.
The period of zenith illumination is characterized by the greatest difference in illumination of horizontal and vertical surfaces. It is unpleasant to the eye due to the high contrast between the illuminated areas and the illumination in the shadows. High contrast in zenith lighting is most acutely felt in southern latitudes.
Table 1.3.
|
Illumination of the earth's surface at different periods of the year and hours of the day, % |
|||||||||
|
Months |
Time of day, hour |
||||||||
|
June |
|||||||||
|
May - July |
|||||||||
|
April - August |
|||||||||
|
March - September |
|||||||||
|
February - October |
|||||||||
|
January - November |
|||||||||
|
December |
|||||||||
|
Data given for middle zone(latitude 55°) |
|||||||||
In cloudless weather, in the absence of haze, fluctuations in illumination associated with the influence of atmospheric factors are small. The relative average characteristics of natural light in clear weather depending on the time of day are given in Table. 1.3.
The nature of natural light is significantly influenced by the state of the atmosphere - the density of clouds, their height and location in relation to the sun, haze, fog, rain, snow. At the same time, the illumination of objects, the contrast and spectral characteristics of light change.
For example, in the presence of cumulus clouds, the illumination of unshaded objects illuminated by the sun increases by 25%, and the illumination in the shadow increases by two and a half times. The contrast of lighting is reduced by approximately two times compared to lighting in cloudless weather. When there is continuous cloudiness, a significant decrease in illumination and lighting contrast is observed.
As the sun rises, not only the intensity of the light gradually increases, but also its color temperature. Particles suspended in the air scatter less rays of the short-wave part of the spectrum - violet, blue and cyan. An increase in the proportion of blue rays leads to an expansion of the short-wave part of the spectrum and, consequently, to an increase in the color temperature of daylight.
Color temperature is a measure of the objective impression of color of a given light source. By definition, color temperature characterized by light sources with a continuous spectrum of radiation that emit light from a heated body.
Winter and summer time
A person tends to get up at dawn in order to make the most of the daylight hours. This is where the idea of summer and winter time, which is now used in many countries around the world, originates. Combining waking hours with daylight hours allows you to save energy consumption: in the spring, the hands of the clocks running according to standard time are moved forward an hour, and in the fall they are set again according to standard time.
In Fig. Figure 1.6 shows the change in light and dark times of day during the year for latitude 50° (latitude of Kyiv). The border between light and dark time It is generally accepted to consider the beginning or end of the so-called civil twilight, that is, the time when the Sun dropped below the horizon by 6°. In the evenings, the city streets should be lit by this time. The graph shows sunny true time.
The average person gets up at 7 am and goes to bed at 11 pm local time. On the graph, the waking time of such a person is marked by two horizontal dotted lines. Since March, he gets up after dawn. By moving the clock forward, he is forced to get up earlier (solid horizontal lines). This is justified by the fact that he will get up during daylight hours and spend less electricity on lighting.
Returning to winter time in October does not lead to energy savings. As it turned out, this is done solely so that in winter people do not get up much earlier than sunrise. Therefore, the transition to winter time does not seem justified.
It is rational to return to maternity time, abandon the annual change of clocks and live with a constant reference, which will differ by one hour in comparison with standard time. This rhythm of life, from a biological point of view, is most favorable for humans.
IN lately More and more people have to think about saving energy. Prices for electricity and gas are constantly rising, we have to think about using free energy sources. Owners of private houses and summer cottages can benefit greatly from solar-powered street lighting.
Pros and cons
Sada, local area requires high costs— it is necessary not only to install the lamps, but also to lay the cable. More reliable, and this is a large volume earthworks, plus significant costs for the cable, since it must be in a protective sheath, or better yet, armored. But that’s not all - during operation you have to pay hefty electricity bills - the lighting works every day, for 6-8 hours. Solar-powered street lighting can partially solve the problem.
Advantages
Why partially? Because the most “critical” areas (gates, parking, entrance doors) will have to be illuminated permanently - it’s more reliable. But on the rest of the area you can install solar-powered lamps. They have a number of advantages.
Flaws
As you can see, there are many advantages, the main one being energy savings and very simple installation/dismantling. But there are also disadvantages:
As you can see, the option is not ideal, but it really helps to save on electricity, because standard lighting of critical areas is far from half the cost of general lighting yard and garden.
Solar street lights can have different shape, appearance, installation method, but they all consist of a specific set of elements:
As you understand, the operating principle is as follows: during daylight hours, the sun's rays are captured solar panel, where they turn into electrical energy and is transferred to the battery. At dusk (illuminance 20 Lux) the controller turns on the power supply, led lamp lights up. In the morning at dawn (at illumination of 10 Lux) the lighting is turned off.
Selection of solar-powered street lighting fixtures
IN trading network There are LED street lamps with a very wide range of prices - from one hundred rubles to tens of thousands. Sometimes there are models that look almost the same, but are very different in price. How do we understand this and how to choose lighting fixtures for solar-powered street lighting? It's simple - you just need to look at the technical specifications. They make all the difference.
Power
When arranging lighting, it is necessary to consider how much light the lamp can produce. The number of lamps and the distance at which they need to be installed from each other depend on this. IN technical specifications Usually the power is indicated in watts, but in the case of LED lamps it doesn’t say much.
To understand the level of illumination, you can compare it with an analogue of a conventional incandescent lamp - their power is more or less clear to us, and you can also convert this indicator into Lums (Lm) - a unit of measurement of illumination. This way you can really evaluate how effective this particular lamp will be.
As you understand, models with a power of 1 W do not provide much light - about the same as a 20 W incandescent lamp, therefore they can only be used for illumination or marking of an area - marking paths, illuminating gazebos, etc.
Protection class and housing material
In order for solar-powered street lighting to work for a long time and reliably, it is necessary that the housing and the light block (shade) be protected from dust and moisture. It is desirable that the protection class is not lower than IP44 ( more numbers- this is good, less is bad).
It is also worth paying attention to the material from which the lamps are made. Usually this is a special impact-resistant plastic or metal. If "metal" is different from stainless steel or aluminum, it is better to give preference to plastics. They definitely don't rust and long time maintain good appearance.
Type and method of installation
Based on the installation method, LED street lamps are divided into several groups:
- Installation in the ground. This is a group of lamps on legs of different heights - from 20-30 cm to a meter and above. Their installation is extremely simple - they are simply stuck into the ground in the right place.
The most extensive group - lamps are simply stuck into the ground
- Pole lamps. As a rule, these are taller models with a leg height of 1.5 meters and above. They can also be installed on the ground, but require more serious installation measures - they have greater height and weight. You will have to make a hole, insert a post into it, fill it with soil and compact it. There are models for installation on hard surfaces - tiles, asphalt, etc.
- Solar wall lights. Available in different styles- from the classic “lantern” design, to models in modern style. Can be mounted on a wall, fence, fence posts.
- Hanging. There are also many options - there are models that can be attached to the ceiling, beam, etc., and others that can be hung on branches.
- Built into the ground, paths, stairs. Very practical models that allow you to illuminate even stairs, and they illuminate not from above, as usual, but at the level of the steps. Interesting and practical solution- with this option, the light does not blind the eyes, and the illumination remains good.
Staircase lighting - convenient, economical and beautiful
- Decorative. Made in the form of various figures. During the day, they look like ordinary decor; at night, they also emit light. Installation in in this case no - they just put the lamp in the place intended for it.
The choice of solar street lights for street lighting is really wide. There is a wide range of styles, sizes, and prices, so you can choose.
Autonomous solar-powered street lighting
Despite a lot of advantages, street lighting using individual solar-powered lamps has a significant drawback: the energy reserve in the batteries is scanty. After a cloudy day, it lasts only a few hours. On a clear sunny day, the “excess” energy disappears, since the battery capacity is limited and it is not able to accept more. The problem can be solved by installing a powerful solar battery, connecting a battery and lamps to it. In this case, you can use any LED lamps, which can operate from 12 V.
The advantage of this solution is that there is a certain amount of energy reserve (depending on the battery capacity), which guarantees operation even after a cloudy day. Flaws - high price and the need to lay cables, since everything needs to be combined into a single system.
Solar street lighting: photo ideas
This section contains interesting, in our opinion, ideas for illuminating the area and lamps powered by solar panels.
