The Story Of Solar Water Heating Engineering Essay

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The first part will be written about the emergence of solar energy, their types such as flat and vacuum, as well as home heating systems, active and passive. Describe which types of sun and where best to use, as well as systems that tell you how to use solar collectors such as the Baltic countries: Lithuania, Latvia, Estonia, is also believed to tell about their use in Denmark. Retailers tell how much solar systems installed within those countries, which is their cheapest installed within, some of the countries are the most sunshine per year, as well as the time investment pays off.

The second part describes about the things that we global warming as we can to help everyone, I'll try to explain why it is important for us to speak and how that relates to a solar heating. It also explains briefly how to arrangement of the solar collectors on the roof to the sides and the angle is best fitted.

I will try to analyze the benefits of solar energy for us and the consequences. I also analyze economic issues such as: the cost of heating a house, wood or wood briquettes incisions, the cost of gas for heating or electricity and are least harmful to the environment.

At the end of the dissertation I will try to express their opinions, or as your house would use solar heating.

2. History



The story of solar water heating began in the 1760s in Geneva, Switzerland, where Horace-Bénédict de Saussure, a Swiss naturalist, observed that it is always hotter when sun rays pass through a glass-covered structure, whether in a coach or a building, than into a site unprotected by such material.

 The Swiss scientist had demonstrated, for the first time, the greenhouse effect.Carbon dioxide in the atmosphere, like the glass covers of his box, allows sunlight to easily pass to the Earth's surface. Like the black bottom of de Saussure's box, the Earth's surface heats up when struck by sunlight. The longer heat waves that had entered the box as sunlight find it difficult to escape through the glass, just as they cannot easily pass through carbon dioxide blanketing the sky. The Earth, like de Saussure's box, gets hotter than usual. That's why we call the phenomenon global warming.

 De Saussure speculated, "Someday some usefulness might be drawn from this device for it is actually quite small, inexpensive and easy to make."But more than a century passed before de Saussure's hope wasrealized.

 In 1891, Clarence Kemp, an American plumbing and heating manufacturer, placed a black-painted water tank inside a glass-covered box with a similar design to de Saussure's. As the bottom of the box heated, the colder water inside the tank absorbed the heat and became hot enough to be drawn for bathing or dishwashing. Here was the first commercial solar water heater. Kemp called it the Climax. As California had lots of sunshine, in the late 19th century thousands of citizens affluent enough to be willing to pay for hot water but who had no local or cheap source of fuel were willing to spend $15 for Kemp's invention.

 The Climax had one drawback: The water was heated and stored in the tanks, which were exposed to the elements at night and during bad weather. Under such conditions, they cooled down sometimes to such a degree that customers would have to forego a morning bath or washing up for breakfast with hot water.

 In 1909, William J. Bailey found a way out of the dilemma: separating the solar heating of the water from its storage. His solar collector consisted of water pipes attached to a black-painted metal plate inside a glass-covered box and connected to an insulated remote storage tank located above the collector. As the sun heated the water, it became lighter than the heavier, cooler water entering from the bottom, forcing the hotter water to naturally rise into the storage tank and remain warm during the night and the following morning. Bailey called his company the Day and Night Solar Water Heater Company to emphasize his product's advantage.

Day and Night solar water heaters soon drove the Climax out of business to dominate the burgeoning solar water heater business in California, Arizona and Hawaii.

The discovery of plentiful oil and natural gas in southern California in the 1920s killed the local solar water heater business.

 But Bailey's configuration - separation of solar water heating and storage - lived on to become the design of choice for millions throughout the world relying on the sun to heat their water. It first moved to Florida, where real estate in the 1920s was selling like hot cakes but no means existed to heat water cheaply and reliably. The only means besides solar - electricity - was too dear. By World War II, solar water heaters dominated the rooftops of Miami and its surroundings.

 The number of solar units on the island increased over the last 30 years by a factor of nearly 3,000, making Barbados the third highest per-capita user of solar water heaters in the world. The Barbados example shows that incentives pay for themselves. For a minuscule investment, the nation has saved tens of millions of dollars on oil it would have otherwise had to import, not to mention gained the added security of greater energy independence and cleaner air.

A recent observer commented, "The island now has most houses and buildings fitted with solar panels for water heating. In comparison, another West Indian island, Trinidad and Tobago - similar to Barbados in every way but having extremely low electric rates - has had little success in promoting the use of solar water heaters."

A sunny climate is not required for success in solar water heating. Austria is tied with Barbados for per-capita use of solar water panels.

 The disaster at the Soviet Union's Chernobyl nuclear plant and concerns over global warming added fuel to the solar flame. Lobbying by concerned citizens got various Austrian states to provide subsidies. Seeing solar water heaters go up on neighbors' houses started a snowball effect. Manufacturers that had been producing electric water heaters jumped into the solar business. By the mid-1990s, Austrians began extending their solar water systems to also provide heat for their homes. Under such friendly conditions, the use of solar heating panes has grown tenfold since 1984.

3. Solar collector types and systems (; Denmark)

3.1.Solar collectors types - flat and vacuum

Flat solar absorber consists of (solar radiant energy absorbing plate), thermal insulation, transparent protective coating and pipes for the heat transfer medium .

Good thermal insulation ensures greater collector efficiency and prevents heat loss. Solar panels on the environmental impact keeps a special impact-resistant glass , which also contributes to cell insulation properties. Cover spends shortwave solar radiation and trap infrared radiation .

Vacuum solar collector consists of a separate sealed tubes, and inside the copper plate heated to sunlight, store energy. These collectors there is no insulation, since each tube is a vacuum , becoming the most effective thermal insulation, so heat loss from the entire break.

Vacuum solar collectors are best suited for use in colder climates, where the sun content is not so great. For example, in Europe solar collectors are distributed as follows: 80 to 85 percent. flat and 20-15 per cent. vacuum. This is due to the fact that the vacuum solar collectors are more expensive, while the southern regions where the solar energy radiated much more heat loss is not felt, so enough of the flat panels and energy.

3.2. Passive and active systems

Solar water heaters can be either active or passive. An active system uses an electric pump to circulate the heat-transfer fluid; a passive system has no pump. The amount of hot water a solar water heater produces depends on the type and size of the system, the amount of sun available at the site, proper installation, and the tilt angle and orientation of the collectors.

Solar water heaters are also characterized as open loop (also called "direct") or closed loop (also called "indirect"). An open-loop system circulates household (potable) water through the collector. A closed-loop system uses a heat-transfer fluid (water or diluted antifreeze, for example) to collect heat and a heat exchanger to transfer the heat to household water.

Passive systems rely on heat-driven convection or heat pipes to circulate water or heating fluid in the system. Passive solar water heating systems cost less and have extremely low or no maintenance, but the efficiency of a passive system is significantly lower than that of an active system, and overheating and freezing are major concerns.

Active systems use one or more pumps to circulate water and/or heating fluid in the system.

Though slightly more expensive, active systems offer several advantages:

The storage tank can be situated lower than the collectors, allowing increased freedom in system design and allowing pre-existing storage tanks to be used.

The storage tank can always be hidden from view.

The storage tank can be placed in conditioned or semi-conditioned space, reducing heat loss.

Drainback tanks can be used.

Superior efficiency.

Increased control over the system.

Modern active solar water systems have electronic controllers that offer a wide-range of functionality, such as the modification of settings that control the system, interaction with a backup electric or gas-driven water heater, calculation and logging of the energy saved by a SWH system, safety functions, remote access, and various informative displays, such as temperature readings.

The most popular pump controller is a differential controller that senses temperature differences between water leaving the solar collector and the water in the storage tank near the heat exchanger. In a typical active system, the controller turns the pump on when the water in the collector is about 8-10 °C warmer than the water in the tank, and it turns the pump off when the temperature difference approaches 3-5 °C. This ensures the water always gains heat from the collector when the pump operates and prevents the pump from cycling on and off too often. (In direct systems this "on differential" can be reduced to around 4C because there is no heat exchanger impediment.)

A-passive system B-active system

Some active SWH systems use energy obtained by a small photovoltaic (PV) panel to power one or more variable-speed DC pump(s). In order to ensure proper performance and longevity of the pump(s), the DC-pump and PV panel must be suitably matched. Some PV pumped solar thermal systems are of the antifreeze variety and some use freeze-tolerant solar collectors. The solar collectors will almost always be hot when the pump(s) are operating (i.e. when the sun is bright), and some do not use solar controllers. Sometimes, however, a differential controller (that can also be powered by the DC output of a PV panel) is used to prevent the operation of the pumps when there is sunlight to power the pump but the collectors are still cooler than the water in storage. One advantage of a PV-driven system is that solar hot water can still be collected during a power outage if the Sun is shining. Another advantage is that the operational carbon clawback of using mains pumped solar thermal (which typically negates up to 23% of its carbon savings) is completely avoided.

An active solar water heating system can also be equipped with a bubble pump (also known as geyser pump) instead of an electric pump. A bubble pump circulates the heat transfer fluid (HTF) between collector and storage tank using solar power and without any external energy source and is suitable for flat panel as well as vacuum tube systems. In a bubble pump system, the closed HTF circuit is under reduced pressure, which causes the liquid to boil at low temperature as it is heated by the sun. The steam bubbles form a geyser pump, causing an upward flow. The system is designed such that the bubbles are separated from the hot fluid and condensed at the highest point in the circuit, after which the fluid flows downward towards the heat exchanger caused by the difference in fluid levels. The HTF typically arrives at the heat exchanger at 70 °C and returns to the circulating pump at 50 °C. In frost prone climates the HTF is water with propylene glycol anti-freeze added, usually in the ratio of 60 to 40. Pumping typically starts at about 50 °C and increases as the sun rises until equilibrium is reached, which depends on the efficiency of the heat exchanger, the temperature of the water being heated, and the total solar energy available.

3.3. Passive direct systems

An integrated collector storage (ICS or Batch Heater) system uses a tank that acts as both storage and solar collector. Batch heaters are basically thin rectilinear tanks with a glass side facing the position of the sun atnoon. They are simple and less costly than plate and tube collectors, but they sometimes require extra bracing if installed on a roof (since they are heavy when filled with water [400-700 lbs],) suffer from significant heat loss at niWght since the side facing the sun is largely uninsulated, and are only suitable in moderate climates.

A convection heat storage unit (CHS) system is similar to an ICS system, except the storage tank and collector are physically separated and transfer between the two is driven by convection. CHS systems typically use standard flat-plate type or evacuated tube collectors, and the storage tank must be located above the collectors for convection to work properly. The main benefit of a CHS systems over an ICS system is that heat loss is largely avoided since the storage tank can be better insulated, and since the panels are located below the storage tank, heat loss in the panels will not cause convection, as the cold water will prefer to stay at the lowest part of the system.

3.4.Active indirect systems: drainback and antifreeze

Pressurized antifreeze or pressurized glycol systems use a mix of antifreeze (almost always non-toxic propylene glycol) and water mix for HTF in order to prevent freeze damage.

Though effective at preventing freeze damage, antifreeze systems have many drawbacks:

If the HTF gets too hot (for example, when the homeowner is on vacation,) the glycol degrades into acid. After degradation, the glycol not only fails to provide freeze protection, but also begins to eat away at the solar loop's components: the collectors, the pipes, the pump, etc. Due to the acid and excessive heat, the longevity of parts within the solar loop is greatly reduced.

Most do not feature drainback tanks, so the system must circulate the HTF - regardless of the temperature of the storage tank - in order to prevent the HTF from degrading. Excessive temperatures in the tank cause increased scale and sediment build-up, possible severe burns if a tempering valve is not installed, and, if a water heater is being used for storage, possible failure of the water heater's thermostat.

The glycol/water HTF must be replaced every 3-8 years, depending on the temperatures it has experienced.

Some jurisdictions require double-walled heat exchangers even though propylene glycol is non-toxic.

Even though the HTF contains glycol to prevent freezing, it will still circulate hot water from the storage tank into the collectors at low temperatures (e.g. below 40 degrees Fahrenheit), causing substantial heat loss.

A drainback system is an indirect active system where the HTF (almost always pure water) circulates through the collector, being driven by a pump. The collector piping is not pressurized and includes an open drainback reservoir that is contained in conditioned or semi-conditioned space. If the pump is switched off, the HTF drains into the drainback reservoir and none remains in the collector. Since the system relies upon being able to drain properly, all piping above the drainback tank, including the collectors, must slope downward in the direction of the drainback tank. Installed properly, the collector cannot be damaged by freezing or overheating. Drainback systems require no maintenance other than the replacement of failed system components.

4. Solar heating energy efficiency in buildings

4.1. Sun architecture

Solar architecture world practice principles apply to project imports a low-energy, passive and other types of modern

buildings. Solar architecture was known in the old civilizations - in Greece, Rome, China. One of the oldest uses of solar energy in buildings are examples of the Pueblo Indians of Heaven Fairtrade town (North America). Massive earthen buildings were oriented to the south.

According to the modern concept of solar architecture links the use of energy efficiency and passive (direct) and active solar energy use payment methods.

According to the principles of solar architecture design of buildings must comply with the

three basic requirements:

Buildings shall be designed so that solar energy flow into the building, when it comes to heat, and virgin space in which unwanted heat.

This is achieved by properly orienting buildings and styled wider shelter.

Buildings must accumulate solar energy - heat buildup, which you can use when the sun does not shine. This massive structure used

stone, clay, brick - walls, floors, partitions constructed and so on.

It can be anticipated and special tanks, materials (such as water or phase transformation solutions).

Buildings should be efficient in the use of solar energy: to receive and accumulate

more solar energy and slow to dissipate. This is mainly due to the building

thermal insulation, reducing heat loss.

The use of solar energy, the direct method is effective when taking into account the


optimal building orientation - along the axis east-west with a possible 30 deviation from it;

50-70 per cent. all building windows and other transparent enclosures designed the south side of the house, while the north - no more than 10 percent.;

the building must be well insulated and sealed;

accommodation arranged the south side of the sideline -the north

The necessary shadow forming elements of a building or other means of

overheating in summer (at a certain distance planted hardwoods, blinds, canopies

and so on.).;

4.2. Solar collectors

Solar radiation energy is transformed into heat collectors, it is the heating system carries heat carrier (which may be air, water or other liquid). Solar heat can be used for water, swimming pools and areas


The most common flat plate collectors (Figure 11.1. Above) consist of absorber, absorbing solar energy, pipes carrying the heat carrier.

Absorber built into the insulated box with transparent surface (usually glass) it falls through the sun's rays. Between the absorber and heat storage in capacity of circulating water and environmentally friendly antifreeze mixture. A usually solar collector is the temperature gauge. When the fluid temperature in the collector is higher than the temperature of the water storage tank, the controller activates the circulation pump and heat carrier begins to circulate in the system.

Flat-plate collectors can be mounted on the roof, built on the ground, hung on the wall. Every element of a flat plate collector can be improved in order to improve device performance. It is important to absorption of the glass aggregate solar ignore (used with a low iron glass) pipe thermal conductivity coefficients and other factors.

In order to reduce the heat loss due to convection collector inside, was to create a vacuum collectors. vacuum manifold (Figure 11.1. Below) absorber placed in a pressure-resistant glass tube, the which evacuated. This vacuum flask (tube), similar to a thermos. External selective boron silicate glass, as well as windowed envelope, letting in a wide range of solar the spectrum of light and retain heating in the house. The inner tube covered flask special black absorbent coating to absorb the entire solar spectrum and convert it to heat. Pipes are connected with each other top. Vacuum solar collectors come in several forms, depending to the way in which solar energy is transferred to heat transfer. The most distinct these modifications to the installation and features of interconnecting piping.

Figure 11.1.

Above - the flat-plate collector:

1. Glass.


3. Absorber.

4. Frame.

5. Thermal insulation.

At the bottom - the vacuum manifold:

1. Heat carrier.

2. Pipe and absorber.

3. Easy to evaporating liquid

the inner tube.

4. Thermal insulation.

5. insulated with heat

collecting tube.

6.Heat exchanger.

You can also use solar concentrating mirror reflector, but the vacuum manifold design is expensive, sometimes it is difficult for the wind (acts as a sail), but the same effect can be achieved by fitting more collector tube (24 tubes without the reflector will work as well as 20 with reflector).

Vacuum manifold inner tube is a special low-temperature easily evaporating liquid. With the sun shining and the temperature increases, steam rises to the heat exchanger and the heat releases heat transfer and cools. Then the vapor condenses and flows into the pipe down. These collectors reach higher temperatures tan's flat panel, they are more efficient, but more expensive. Some vacuum collectors operating effectively and misty days, too, for both heating systems. Some vacuum tube collectors can easily increase the amount after the date of service of the system.

There are no glass solar panels: they are made of black polymer tubes are relatively cheap, and used only in the summer. They are usually heated water in swimming pools.

Vacuum manifold prices in 2011. ranged from 1000 to 3000 Lt/m2, 400 to 800 LV/m2 flat plate collectors cost 500-900 Lt/m2 0.100 to 300 LV/m2. Solar thermal energy price - 0.13 to 0.50 Lt / kWh, 0.50-1 LV / kWh

Solar collectors can only be used for water or space heating only used in both cases.

Hot-water heating system (Figure 11.2). Consists of solar collectors, storage tank, piping, pumps, controllers, sensors, additional heating devices, etc.., it comes to needs and designate. For a good solar collector does not mean good overall system performance. that hot water heating system to be effective, it is important to properly evaluate the hot water needs. If it is estimated that one person uses approximately 50 liters of hot

of water a day, it's one person needs about 1.2 to 1.5 m2 of solar collectors.

Storage tank purpose - build up heat to a hot water sufficient for several days (in the summer), so the volume is 1.5-2 times higher than one daily requirement (75-100 liters per person). It is important to obtain container, suitable for solar system: in most household water built-enamel coil heaters with a thick pipe with only a few turns. This type of heat exchangers for boilers connected, but not the solar panels. Water heaters are useful to have multiple-coil heat exchangers that can be connected and biomass, and other boiler or electricity. The system may have impact on water quality if the water is cool, too, the water tank can accumulate a lot of sediment, which complicates the heat transfer, it is recommended to use a water filter or heater, which can be cleaned.

A suitable location for the arrangement of the solar collector roof slope facing the south side

(± 30 °).

Roof pitch may be 40-60° - resulting in heat production in different seasons. If the roof is flat, the use of special trays erecting the collector at the right angle. Some of the vacuum manifold

tubes with absorbing surface can be easily operable by the sun, even if improper roof slope.

Practical experience in Lithuania and other European countries has shown that the new-year through solar collectors can meet about 50 percent. hot water requirements throughout the year. In winter, prepare 100 percent. Hot water from the sun in our latitudes there is difficult. Well, at 100 percent. hot water is prepared the summer, the order is often the chosen individual parts of the system. But are already examples and Lithuania, where solar collectors are used not only hot

water handling, but also for space heating. In this case, the collector area is higher, and the hot water is used to heat the excess summer pool or supplied neighbors.

Solar thermal energy is used successfully in modern buildings similar to the Lithuanian climate conditions. For example, in 1960. apartment building was built in Norrkoping (Sweden) population, 50 percent of the repair water heating energy required to get the 93 m2 of solar collectors,

installed on the roof of the building.

Figure 11.2. Hot-water heating system:

1. Solar collectors.

2.Volumetric water tank.

3. Additional heater.

4. Pump.

5. Shower.

5. Solar heating energy Demand in Buildings in the Baltic Country

5.1. Lithuania

Perennial observational data, the average annual total solar radiation quantity, catching horizontal surfaces in Lithuania is about 1000 kWh/m2. It's almost the same as in Denmark and more than in Sweden, where the use of solar energy especially popular. The solar energy is sufficient to allow efficient use of solar systems for domestic hot water preparation. This allows you to save 50 - 60 percent costs used for heating water a year.

About 88 percent. annual solar energy incident perpendicular to the surface of the Earth, has seven months - March, April, May, June, July, August and September. The distribution of solar energy in solar panels let you adjust the work to the building heating seasonal - winter, hot water is obtained from individual domestic central heating systems, non-heating season - from the sun. Solar illumination time is the longest beach and shortens the eastern border. Average number of hours of sunshine coast is about 1900 hours. Annually. The country's eastern outskirts, it shall not exceed 1700 hours. The maximum number of hours of sunshine is in Nida. Best practice -vacuum collectors manifolds, otherwise they can be called solar heaters, are usually divided into two types. By absorbing solar cell technology solar collectors are flat plate and vacuum. Flat, less efficient production of solar energy absorbing metal plates placed in a well-insulated box and closes the window. Another type - vacuum solar heaters to reach the high efficiency vacuum components. Currently, the most advanced 3-layer "glass - glass type vacuum tube with a design like that familiar glass thermos. Compared with 1 layer of tubes, they achieved higher maximum temperatures, they last longer, have a higher efficiency test. Vacuum solar advantages especially manifested in our climatic conditions and less effective in the South, and some properties of flat-plate collectors with a vengeance enough.

Solar heaters can be integrated and distinguished. Integrated vacuum solar heater elements are installed in a single unit with a water tank. The distinguished heaters, solar collectors installed in the south side of the roof of the building and the water tank can be placed anywhere in the building. Container and the collector connected piping and circulator pumps, controllers manage their work. The system itself is filled with anti-freeze, human health and environmental non-hazardous liquid.

Both of these types of vacuum solar heater is high efficiency. Differences in their external appearance, installation complexity and cost. Integrated heaters payback period of 3-5 years, the distinguished solar system approximately 2 times longer. Both types of heaters life of 10 to 15 years, depending on the quality of components and materials used. However, the market also occurs in very low-quality products, which life may be even lower than the payback time. Solar heating is not advisable to buy from a seller who does not provide long-term guarantees.

The latest solar collector is very popular in transfer of thermal energy from the vacuum tube to the heated fluid way - through heat pipes. It is made by special technology device that the vacuum pipe walls gathered heat very high speeds transmit heated liquid. Such a vacuum with heat pipe inside the solar energy absorbing element design is highly efficient, durable and resistant to temperatures from -40 C to 300 C. This element of breach of overall system performance does not stop because the liquid does not flow through it - with manifold combines them "dry". Savings opportunities for all

Solar heaters can be installed in all types of buildings - detached houses, blocks of flats, hotels, industrial or public buildings - anywhere you need hot water. Especially high economic efficiency can be achieved by installing large-scale projects when heated a few thousand liters of water: laundries, hotels and coffee shops. Then the system payback time even shorter.

"Green Heat" their solar heaters used solely in accordance with the most advanced 3-layer technology of certified factories produced vacuum components and high efficiency, long-lasting heat-pipes. This allows products to give a long, five-year warranty period and a 15-year time vacuum elements. Working exclusively in the solar energy field, with their partners in other parts of the world experience, it is most efficient energy solutions for everyone - from cottages to apartment, from rural tourism to a large hotel.

5.2. Latvia


Solar system is effective, economical, and environmentally and socially friendly way to heat energy.Latvian conditions, intensity of solar radiation is sufficient to ensure a summer full of warm water for 4-5 people family, autumn and spring months provide support warm water in 60-70% of heating and up to 30%.

The challenge that must be resolved solar plant developers and installers are the most efficient way to collect solar energy, accumulate and transform it into a usable form with the fewest costs.The cheapest and therefore the most popular type of solar energy is for hot water production for domestic consumption. In order to use solar energy for heating purposes is a form of energy storage tanks larger and more complex heating system. It should be noted that during the winter the sun's energy intensity is much lower than in the summer, and the Latvian latitudes, its efficiency is relatively low.

The solar collector system, the main components are:

solar collectors

storage tank

expansion vessel

control unit


Average Latvian is:

about 1800 sunny hours per year

the maximum intensity of solar radiation in the summer months is 1100W/m2

the average intensity of solar radiation from May to September is 700-740W/m2

the average intensity of solar radiation in April and October 200-240W/m2

the average intensity of solar radiation from November to February is 40-50W/m2

Through the solar collectors circulates coolant (anti-freeze). Energy of solar radiation to pass through the glass collector aizsargvirsmai be diverted to heat and special heat circulating system.This energy is transmitted through a heat exchanger to the water storage tank and accumulated.Hot water tank is kept till the moment.

There are two main types of collector termo solar - plate and vacuum. Plate collectors are mainly used seasonally - from spring to autumn. In winter collector plate production capacity will reduce the heat loss at the expense of the environment. Energy production throughout the year is recommended to use a vacuum manifolds.

Vacuum solar collectors adsorb not only when the sun is shining brightly, but the perception of diffuse solar radiation that reaches the earth through the clouds.

5.3. Estonia


Really "Päikselõõsalist" beach weather really is often in just a week or two-year section, but it's not important for the purposes of solar heating - heat can also be changed in the cloud, the October weather is gloomy radiation reaching the earth. Proportion of your energy is just below. Estonian conditions, whether it is worth considering solar heating at all be excited or not is a question that we are trying to find the answer. 

should first make it clear to a lot of heat to change in radiation reaches the surface at all in theory. Numbers that different heating system for sales people article about me in the collection of fed, I would not spend a printed black. Let's look at better unbiased research agencies in the numbers. Agency for Research of the European Commission (DG Joint Research Centre ) data will reach an annual average of solar radiation in Estonia 1150 kWh / m². Surprisingly, it is only 18% less than the average in France (1386 kWh/m2), and less than two times less than in the central part of Italy (Tuscany, 1563 kWh/m2). Only in the central Mediterranean, Malta is rising rocky almost twice as much solar radiation as English (2006 kWh/m2). 

Reason why we ourselves warm and sun in gold not scout the world's people do not know, lies in average temperatures. In Tallinn, the average annual temperature is 6.2 ° C, then in Paris, the figure is 11.6 degrees. While the sun, or see Paris and Tallinn more nearly equal, then the proximity of the Arctic Ocean and the north winds cooling rapidly, and our own collar thermometer difference in the Estonian indigenous to the northern land. Land, where as if solar perspective. 

Explain which of the numbers or their own sense of believing, we plunge into the solar heating technologies - whether and how much the outside temperature affects the efficiency of the system?

Price and cost

price of solar heating system consists of three parts: the collector (s) of the accumulator, and the pump automation, installation and connection costs. The whole system of real prices starting 

 EEK 40 000, leaving aside dubious savings projects. In practice, the single-family house will probably cost more than 50,000 euros. 

Revenue is to be the reduction in heating costs. Whether it be a smaller electric bill or fuel oil amount. Profitability rule is: the more complex and integrated the original system technically, the shorter the payback period. Perhaps it is just as rearing water warming system, the profitability of a longer, when the heating system is being extended systems, profitability shorter. But even the most optimistic salespeople do not dare to offer a faster return on scheme than 8 years. Typically offered back period 12-15 years. 

Calculating return is taken into account; the average solar heating will be back to 40% of the energy for tap water. The seemingly low percentage is due to the winter and summer months, a big difference. The beginning of April until the end of August when the heat fluctuates with variable amount of radiation in a

daily average of around Wh/m2 4500-5500, November to February, when it is less than 700 Wh / 2 a day. This means, however, that in July will be 80% of its solar heating of potable water, then only 5% in December. And even then, if the system is at all possible to keep the course. Typically, solar time March September / October until the end. 

Separate problem is the design of the system also avoids overproduction. When the winter months, thinking one might add to the solar collectors, and thus increase the number of kWh, which is able to produce low-light months, then in the summer or not able to do anything with the energy from just - a little water consumption alone, no need to heat, the cylinder will soon be "full" and so may increase the heat exchange fluid temperature of 180-200 ° and allowed to deteriorate. Glycerin for boiling the air out of the mass, and in practice this means paraffin-like repair technicians and system through the convening washing. Southern Europe is also used to prevent automated solar cover - if necessary, after the blinds. Profitability equation but it add one more variable, and in this way is not known to anybody gone. 

Profitability is often a tricky thing - the leading user of solar heating ... Germany. This is of course due to non-equatorial climate, but on a national energy policy. In Germany the pellet or solar receive state support for the implementation of thousands of euros. Nice - at least one market in Europe, forcing hardware manufacturers to compete and lower prices. 

Summary is to be feared that, in the sun is enough to supply heating. Enough though. But putting aside the prices and profitability, and considering the fact that the state does not involve the use of renewable energy grants and incentives, it is now particularly sensitive to human mission Heating Systems - an investment will pay for itself financially to 10-15 years, a cleaner environment than that.

6. Solar heating energy Demand in Buildings in the Denmark ( Denmark;

The sun in Denmark shines 1,800 hours a year. The energy beams down upon us all year round, regardless of whether we choose to use it or not. The effect is naturally strongest in summer when the sun is high, but the sun's rays also pierce the winter or when it's cloudy.

solar heating system uses the sun's energy to heat water. In summer months, the solar heating system provides enough energy to heat all the water that a family needs. The rest of the year gives solar a grant for housing energy by preheating the water in the water heater. Overall, solar supply 60-70% of the energy that a family needs for hot water. The sun is clean, renewable energy - it's just about using it.

There are currently over 30,000 solar heating systems in use in Denmark, and the number is still growing. The vast majority used to heat water for the household: bath, washing etc. And it is also possible to get solar heating of the house. Via under floor heating. Solar can very easily be used together with the house other energy source, whether in the case of natural gas, oil boilers, wood-fired boiler or electric heating. How it works A solar heating system converts solar energy into heat in a simple and closed circuit without emitting CO2 or other harmful substances atmosphere. The system consists of an outdoor or more solar collector, which is connected with the water heater inside the housing. The collector contains water with antifreeze, which is heated by the sun's rays and pumped to the water heater. This gives it its heat and run back to the collector.

6.1. Economy

A solar heating system for a single-family house typically costs 25-45000 million in acquisition. Then you could save annually from 1000-2500 million in energy costs, depending on what kind of energy you have.

The life expectancy of a solar heating system is 20 years, however, the hot water tank and auxiliary equipment such as pumps have a shorter life, usually 10-20 years. Acquisition of a solar system will economically be particularly advantageous if it is installed simultaneously with the replacement of such. the old hot water tank, an old boiler or by conversion from electric heating to other forms of heating. The price of the solar system may in such cases be roughly halved.

6.2. Performance and economy

With solar calculator you can get an estimate of the performance and economics of solar systems larger than plants for single-family homes

7. Global Warming


How we can help?

Many people I accepted that global warming is caused by human controlled factors, such as: large plants, cars, home used gas heat and so on.

Even if we stopped emitting greenhouse gases (GHGs) today, the Earth would still warm by another degree Fahrenheit or so. But what we do from today forward makes a big difference. Depending on our choices, scientists predict that the Earth could eventually warm by as little as 2.5 degrees or as much as 10 degrees Fahrenheit.

A commonly cited goal is to stabilize GHG concentrations around 450-550 parts per million (ppm), or about twice pre-industrial levels. This is the point at which many believe the most damaging impacts of climate change can be avoided. Current concentrations are about 380 ppm, which means there isn't much time to lose. According to the IPCC, we'd have to reduce GHG emissions by 50% to 80% of what they're on track to be in the next century to reach this level.

Many people and governments are already working hard to cut greenhouse gases, and everyone can help.

One of stabilization steps is reducing GHG emissions from a variety of sources with technologies available in the next few decades, rather than relying on an enormous change in a single area. They suggest 7 wedges that could each reduce emissions, and all of them together could hold emissions at approximately current levels for the next 50 years, putting us on a potential path to stabilize around 500 ppm.

There are many possible wedges, including improvements to energy efficiency and vehicle fuel economy (so less energy has to be produced), and increases in wind and solar power, hydrogen produced from renewable sources, biofuels (produced from crops), natural gas, and nuclear power. There is also the potential to capture the carbon dioxide emitted from fossil fuels and store it underground-a process called "carbon sequestration."

Promoting Renewable Energy and Energy Efficiency. Europe is home to several powerhouses of renewable energy and energy efficiency. Norway, Austria, Portugal, Spain and Germany among others have had great success increasing the amount of renewable energy produced in their countries through the use of feed-in tariffs. Feed-in tariffs provide a specific, guaranteed price for electricity from renewable energy sources-typically over a 10-20-year period. These tariffs have led to a massive increase in the amount of renewable energy projects in these countries. Norway gets over 99 percent of its electricity from renewable sources, often producing more than it requires and exporting the energy to other countries. More than 16 nations in Europe produced 15 percent or more of their electricity from renewable sources in 2007.3

8. Climate Data


The greenhouse effect has always existed. Since then, more than three billion years ago the Earth formed an atmosphere. If there were no atmosphere and the greenhouse effect, the average temperature of the planet would be 33 degrees lower. So, be thankful for the climate atmosphere. However, greenhouse gas emissions have evolved over time. It was originally carbon dioxide levels were much higher due to a more active volcanic activity. In case of vegetation, carbon dioxide began to decline. Current emissions of greenhouse gases is the largest in all of 800,000 years. This is the period when we already know quite accurately the carbon dioxide fluctuations. They are determined by ice core bubbles locking atmospheric gaseous composition. Hence to determine the evolution of the atmosphere. Glacier data as accurate.

Earth's climate system - a complex and highly dynamic. Various ecosystems absorb or emit carbon dioxide and other gases. Such as methane. In addition, mankind also pollute the atmosphere a wide range, volatile chemicals. Therefore, researchers are constantly measuring the gas exchange changes the dynamics. This takes place in winter and summer, Africa and Europe.

The man was able to discharge into the atmosphere of such components, which previously did not exist in general. This chlorine, and hydrogen fluoride. They appeared only after the Second World War. They are very aggressive, very effectively which greenhouse. Thousands of times more effective than carbon dioxide. Therefore, not only need to think about it. As a result, the future looks very bleak and uncertain. Thinning of the ozone layer, threatens the entire Earth's ecosystem.

Global challenges and efforts

Perhaps we have all heard that the Earth's forests are the lungs. Trees and plants in general - are among the benefactors having helped to change the Earth's atmosphere that brought it to oxygen. During photosynthesis, the sun is shining; the leaves of plants absorb carbon dioxide and release oxygen. But not always. Tree dies he becomes a source of greenhouse gases. Therefore, among the various ideas on how to reduce carbon dioxide emissions into the atmosphere is even planned to bury fallen, dead trees.

Such cycles exist, but before their time was tens of thousands of years. Now the cycle is measured in dozens of years. Pace of change has increased hundreds of times. Nature therefore is unable to adapt. This affects not only the industry, but also in food production, forestry etc. Rising sea levels also pose a significant risk to Asia and Europe. Is it possible to change something, and when you feel the effects?

9. Solar collector location


The two most commonly used systems captured by the solar collector and flat vacuum tube collector. There is also a growing popularity of the Nordic countries are just starting to collect vacuum tubes and the simple reason that it is the outside temperature is low. Intake manifold temperature, and therefore cannot be cooled by the ambient temperature absorber temperature. Vacuum tube solar heating system with heat produces more stable and diagrams, drawings collector mounting angle at the top it is possible to obtain more stable. When the collector angle of 50 °, then it is clear that we can Midsummer Maximum heat output of solar heating offers us, in November and March, in which case we get very little heat. A smart collector angle is increased by 70 °, and the third section of the manifold dimensions of this case, we have a little more energy during the cold months and summer, when we heat minimally use their excess solar angle and energy will be reduced.

10. How do you need know what size solar collector you need?

 When determining what size collector you need, A rule of thumb is to provide about 1m2 of absorber area per person in the household. you must consider two key factors: insolation level and energy requirements. Energy requirement will usually take into consideration the volume of water and rise in temperature required. Once you know these factors you can determine the size of collector you require. The bigger the collector you have, the more hot water, but you should make an economically sound decision. Generally it is wise to select a size which will provide you with 90% of your hot water needs in the summer.

Although it may seem strange to use a value of only 90% for summer solar contribution, it is for good reason. It is normal to size based on 100% of your summer hot water energy needs, with a percentage provided throughout other months, lowest obviously in winter. That is based on normal water usage, but often, and particularly in the summer, water usage patterns may not be that normal, with cooler than normal showers taken in hot weather, and greater possibility of the house being vacant for one or two days each week (weekends). As such, using a target value of 90% will probably actually result in a system that is able to supply more than 100% of your hot water needs in the summer, without excessive heat production, which can lead to water loss via pressure release and a waste of energy.

INLIGHT Solar collectors come in a set of standard sizing of 12, 15, 20, 25, or 30, depending on your region. Of course you can also combine collectors to increase the size.

11. Analysis

11.1. The environmental impact (

Many people themselves understand that solar collectors are one of the least polluting the environment, but als solar energy is considered to be one of the cleanest and renewable sources of energy among the available sources but is has some environmental impacts too. Solar energy uses photovoltaic cells to produce solar power. However, manufacturing the photovoltaic cells to produces that energy requires silicon and produce some waste products. Inappropriate handling of these materials may lead to hazardous exposure to humans and the environment. Installing solar power plants may require large piece of land, which may impact existing ecosystems. Solar energy does not pollute the air when converted to electricity by solar panels. It is found in abundance and does not help in global warming.

Photovoltaic cells


Photovoltaic cells11.2. Advantages of heating the solar collectors (;

The amount of energy through the sunlight enters the earth's surface is 10,000 times greater than its consumption. Using only 0.01% of the solar energy would cover all the world's population. Experts in the use of solar energy alternative energy sees the greatest potential. Specific topical use of solar energy has become in modern times, when mankind searching for solutions to reduce climate change-causing industrial emissions, and trying to replace the mineral's energy use to ensure the environmentally clean, renewable energy resources. 

Solar energy can be used for electricity and heat production. Solar energy Latvian, like neighboring Lithuania and Estonia, has become popular only in the past 3-4 years.

Solar energy advantages:

Money saving;

installation of initial investment, further energy from the sun is practically free of charge;

payment period for the initial investment can be very short, depending on the amount of electricity that is used in home;

the installed system produces more electricity than it needs, the service provider company can buy it as a complement to your cash account;

if you have only one electricity bill, solar energy and save money on it;

Solar energy needs no fuel;

Solar energy does not depend on the tank, so it can not be affected by the rapidly increasing fuel pricing;

savings are immediate and for many years used later.

Friendly to the environment;

Solar energy is clean, renewable (unlike gas, oil and coal) and continuous, helping to protect our environment;

Solar energy does not pollute our air by dividing the atmosphere of carbon dioxide, nitrogen oxide, sulfur dioxide or mercury, as do many of the traditional electronic generation;

thus, solar energy does not contribute to global warming,

It actively promotes the reduction of harmful gas emissions green residential neighborhood;

Solar energy is produced to where it is needed;

without fuel, solar energy thus do not contribute to any costs associated with the restoration or fuel transport or storage of radioactive waste.

Independent / semi-independent;

Solar energy can be used to compensate the service provider supplies electricity consumption. That way you will not only reduce your bill, but will ensure the power supply housing office or the occurrence of power outages, but will ensure the power supply housing office or the occurrence of power outages;

Solar energy can be run completely independently, without any connection to the electricity and gas grid. Thus, the system can be connected to remote placements, such as holiday log cabin, thus making it much more practical and cost-effective;

Solar energy reduces our dependence on foreign and / or centralized sources of energy, caused by natural disasters or proper international events affect, thereby contributing to a sustainable future.