Solar energy usage in lithuania




Solar SYSTEMS for domestic use

Small solar heating systems for domestic hot water

The solar collector

The storage tank




"Solar" swimming pools (Outdoor Pools)

"Glazed" solar collectors


Sollar collectors companies popular in lithuania

company “Energie Solaire SA”

Company “Nova Solar GmbH”

Company “Viessmann”

Company "BUDERUS"

company “Thermo solar


company “Strigis”,


Manufacturers of domestic hot water solar systems in Lithuania

International programmes






Lithuania has a sufficient solar, wind, hydro, biomass and geothermal resources. Lithuania is situated between 54-56° of Northern Latitudes, and it is the same as UK, Southern Denmark, Southern Sweden. Global radiation has been measured at two locations in Lithuania: this is in Kaunas at 54.54 N and Silute 55.21 N, 200 and 40 km from the West coast respectively.

The duration of sunshine, measured throughout eleven stations in Lithuania, depends on the distance from the sea mainly and differs by 250 hours, even the distance from the coast to the eastern border is not more, than 350 km. (see fig.1). Average yearly solar radiation on the horizontal surface is 968 kWh/m2 in Silute and 1025 kWh/m2 in Kaunas, where the measurements of the solar radiation have been provided for the 45 years since the 1955. Monthly distribution of total solar radiation in two locations (see fig.2) shows the very big difference between summer and winter, as Lithuania is rather far to the North.


Fig.1. Duration of sunshine in Lithuania


The duration of sunshine and the level of solar radiation is comparable or even better than in Czech republic (1720 h/y, 1030 kWh/m2), Germany (1650-1400 h/y), or Sweden (820-1050 kWh/m2). The largest part, 87,6 % (910 kWh/m2) of the yearly solar energy we get in March - September, so the first step to commercialisation could be seasonal solar hot water systems.


Fig 2. The sums of the medium direct. and disperse radiation onto the horizontal surface in Kaunas (medium cloudiness)




The United Nations Conference on Environment and Development (UNCED), also known as The "Earth Summit", held in 1992, considered strategies reconciling the imperatives of environmental protection and worldwide development and adopted in Agenda 21 an international program of action for global sustainable development into 21st century.

On UNESCO initiative and with the close support of a group of Heads and Government, a World Solar Commission was established in 1995 to provide high-level leadership.

PSP The Worlds Solar Summit held in 1997 launched The "Word Solar Programme 1996-2005 in which take part 104 States. This programme, conceived as a concrete follow-up of the recommendations of the Earth Summit.

The Lithuania has very few fossil sources of energy. The fossil sources are imported. On the other hand it has a sufficient solar, wind, hydro, biomass and geothermal resources. Lithuania has a scientific, technological and industrial potential for renewable energy development.

The development of renewable energy in Lithuania is guided by National program on increasing of energy consumption effectiveness, the implementation of which lasts from 1992. The one of priority directions is utilization of biomes and other renewable sources of energy such as hydro, geothermal, particularly - wind and solar.

The Lithuanian National Commission of UNESCO in common with Institute of Lithuanian Scientific Society under support by UNESCO carried out "The participation program 1998-1999" and has developed this "Lithuanian National Solar Program 2000-2005" and will take an effort to introduce it into World Solar Program 1996-2005.

The such national project of LNSP is developed. In fact this is Lithuanian program of a renewable energy obtaining nor only solar energy (photovoltaic, heat), but a biomes (plant biomes, bio fuel, bio oil), wind, hydro and geothermic as well. For this reason Lithuanian national solar program becomes Lithuanian renewable energy program.

The main goal of the Lithuanian National Solar Programmed as well, as Word Solar Program remains: to develop not only perspective researches, to create very effective technologies, to develop industry, to built demonstrations power systems, but, as it is very important, - to develop people education, to establish information set and communications, to implement sustainable renewable energy legislation.

The Lithuanian National Solar Programme 2000-2005, as a part of the World Solar Program 1996-2005 (directed by UNESCO under United Nations), and as national program, correlated with EU White Paper: Energy for the Future: Renewable Sources of Energy, 1997, would become as a background for LITHUANIAN STATE PROGRAMME OF THE RENEWABLE SOURCES OF ENERGY




Solar heating systems in Lithuania include solar collector systems to be used in commercial and residential applications producing heat below 120 şC. These systems are:

- Domestic hot water (DHW) for single-family houses as well as multifamily houses

- Small (private) swimming pools

          In all countries the basic need is domestic hot water. The amount of collectors per system is about 4 - 6 m˛ per family in a Northern climate. In principle, these systems can be applied to most buildings, also in densely populated urban environments. It is also easy to make these systems most economic because they will be dimensioned to produce hot water during the summer season. In Lithuania well-designed DHW systems can produce 60% of the DHW needs.

Investigation of the technologies and the equipment from the European countries and calculations of the possible cheapest price level of the DHWS from the imported components did not let us to get any payback of these systems. The only way to promote (and to try to start to make a business) solar energy utilisation in Lithuania was to start the manufacturing of collectors, pump blocks and domestic hot water accumulation tanks. Solar collector is manufactured from the copper absorbers, covered with black chrome selective surface, with the absorption coefficient 0.96 and the emission 0.098 at 100 °C.  The collector body is constructed from the aluminium profiles, cover is made from low iron tempered glass, insulation - mineral wool. Accumulating tanks are constructed from stainless steel with copper coil as the solar part heat exchanger and the supplementary ceramic electrical heater in a stainless steel pocket.

Plain collectors absorb up to 550 kWh/m2 thermal energy during one year if they are oriented to the south and optimal inclination to horizon is bout 45 degrees. These solar absorber strips and plane collectors are buying from different countries and from different companies: Stiebel Eltron (Germany), Nova Solar GmbH (Germany), Solsam Sunergy (Sweden) and others.

Into table 1 we give dynamics of increasing of solar collectors and DHWS into Lithuania during 2000-2001 years.


Table 1. Dynamics of increasing of solar collectors and solar collectors systems into Lithuania (during 2000-2001 years)


Measure units

Installations, year



Solar collectors




Solar collectors systems






Heating of swimming pools is generally considered to be one of the most suitable and economical applications of solar heating. Simple and cheap plastic collectors, sized roughly between 25 % and 50 % of the surface of the pool, can be used for all sizes of outdoor pools. For indoors - pools to be used also under the winter season, glazed solar collectors are to be preferred.



Solar SYSTEMS for domestic use


Small solar heating systems for hot water


A domestic hot water system consists of a solar collector connected by a piping system to a water tank. In the solar collector, the energy of the sun is transformed to heat absorbed by a liquid in the channels of the solar collector. This liquid transports the heat through a piping system - the solar collector - to the tank, where heat is transferred by a heat exchanger to the domestic water system.


The solar collector


          The solar collector is often placed on the roof, but can just as well be situated on a framework placed on the ground, on carports, pergolas or gables. The best sitting is due south and the optimum tilt in Lithuania is approximately 40 - 50° from the horizontal. The solar collector typically consists of 1 to 3 modules. The total area for a single-family plant varies from 4 to 6 m2, depending on consumption, the orientation and efficiency of the solar collector (fig 3).

In principle, the solar collector consists of a black metallic plate containg channels - the absorber - mounted in a protective casing. The solar collector liquid circulates in the absorber, which absorbs the heat from the plate and the pipes, and transfers the heat to the water tank. The absorbers are normally constructed from the following:


-          Copper piping rolled into an aluminium plate

-          Channel plate made of stainless steel

-          Plastic piping (polypropylene) fixed on fibre board.



Fig 3. Solar collector of the DHWS system on the roof of Lithuanian Energy Institute


In order to reduce heat losses a coating layer of glass or plastic is placed over the absorber, and the absorber is insulated with mineral wool at the sides and underneath. In addition, the absorber can be given a selective extra coating in order to reduce its heat radiation.

There are two systems, passive solar system and active solar system. Water circulation in passive system is performed due to the density difference of cold and hot water. System functions reliably, regulate it and it is not necessary to use any additional regulator for control. Heat is accumulated in tank-accumulator while natural heat circulation is performed. System has two loops. One loop is filled with not free able liquid in order to avoid system damaging in winter. The only requirement for system mounting – the bottom of tank-accumulator has to be not lower than 0.5 meter than the highest point of collector.

In active solar system absorption, accumulation and distribution of solar energy are performed automatically. Electronic temperature regulator periodically switches on/off circulative pump and accumulate heat in the tank-accumulator. Pump is switched on when temperature in the upper part of solar collector exceeds temperature in the lower part of tank-accumulator by a definite number of degrees, and is switched off if latter difference of temperatures is less than that defined by regulator. System has two loops. One loop is filled with not free able liquid in order to avoid system damaging in winter.


The storage tank


The storage tank is tall and slim, made of steel, and well insulated. Its volume is 40 to 60 litres per m2 absorber area. The tank is as a rule built into a cabinet, and the outer measurements of such cabinets are quoted.

Solar energy is transferred to the domestic water in the storage tank by means of a heat exchanger, which is either a coil at the bottom of the tank, or a plate-exchanger outside of the tank. In both cases, cold water is lead into to bottom of the tank, and hot water is tapped from the top of the tank, to which it naturally rises.



Fig. 4. Solar collectors integrated into building roof (Klaipeda region)


          By means of an extra coil in the upper half of the tank, heat can be transferred from oil, gas-or wood burning boilers, or district heating, during winter. During summer, this coil is generally not in use, since it is normally advantageous to close down the boiler and instead obtain supplementary heat from the electric heating element during periods with little sunshine.

          If the storage tank is not of stainless steel, it is normally protected against corrosion by a layer of enamel or another suitable material, possibly with an protection anode too.




In order to pump the solar collector liquid from the solar collector, through the heat exchanger into the storage tank and back again, a small circulation pump is normally used. Self-circulating plants without any pump are also to be found. However, these required the storage tank to be placed higher than the solar collector, which can be difficult in climates with strong winters.




          The liquid in the solar collector expands when it is heated up, and an expansion tank is therefore necessary. An open expansion tank must be placed at the top of the plant, whilst a pressure expansion tank can be placed alongside the tank.




          The most normal method is by differential control. When the temperature at the top of the solar collector exceeds the temperature at the bottom of the storage tank by more than 5 to 10oC, the pump will start up and the solar collector liquid will circulate. There are, however, more simple forms of control, where the pump is started and stopped by a time switch, in accordance with light intensity or when the temperature in the solar collector reaches a certain level.

In order to see how the plant is operating, it is an advantage if the top temperature in the tank is displayed (in addition to an indication of the temperature at the top of the solar collector and at the bottom of the storage tank for control purposes).


"Solar" swimming pools


Outdoor Pools


Outdoor swimming pools are intended to be used throughout the summer, from May to September. The water in the pools receives solar radiation directly, but the heat gained is insufficient to compensate thermal losses. So the water must be heated in order to prolong the period of use and a solar system can supply the heat that is lacking.

The variations in the frequentation of a swimming pool during the season shows that outdoors pools are only used if the ambient air temperature is higher than 18  C. The number of swimmers is in direct relationships with the weather.

When the weather is good, the solar installation heats the water in the pool for a potentially large number of visitors and when the weather is bad, there are few visitors. Therefore, it is possible and recommended to use a solar system without back up heating in outdoor swimming pools. The temperature of the water is left to vary in relation to the prevailing climatic conditions, as a well-designed solar system will heat the pool quickly when the weather is good and provide the necessary comfort for the majority of the visitors.


"Glazed" solar collectors


The conventional "flat plate" solar collector consists of an absorber plate, with its hydraulic circuit, that receives the solar radiation and transforms it into heat. The absorber plate is fixed in a watertight case, behind a sheet of glass, thermal losses are reduced by both the green-house effect of the glazing and the thermal insulation of the casing. This type of collector can work efficiently, throughout the year, heating a heat transfer fluid up to 50  C more than the ambient outdoor temperature.

As these collectors are used in winter, they need to be protected from freezing. Therefore, the hydraulic system of the solar installation needs to have two independent circuits, linked by a heat exchanger:

   the "primary circuit" is the circuit flowing through the collectors using an anti-freeze heat transfer fluid

   the "secondary circuit" is the swimming-pool water or the domestic hot water circuit.


The heat exchanger is an apparatus that makes it possible to transfer heat from the primary circuit to the swimming-pool water circuit. Whatever the type of heat exchanger, it is always the cause of heat loss and a drop in overall installation efficiency. Heat exchangers are only used for installations that function throughout the year.

Many companies manufacture solar collectors in most European countries. All types of glazed collectors can supply domestic hot water as well as heat for a swimming pool. However, it is always recommended to choose products that conform to national standards and for which test results are available.




Sollar collectors companies popular in lithuania



company “Energie Solaire SA”


Address of company

C.P. 353
Z.I. Ile Falcon 3960 Sierre,

tel         ++41274552212

fax        ++41274552202



Energie Solaire is a Swiss company founded in 1973, specialized in thermal solar energy. Since 1980, it produces stainless steel solar absorbers used in the construction of solar collectors and collectors without glass cover, more specifically for the Solar Roof AS, which turns a roof into a efficient solar collector matching perfect architectural integration


Solar Roof


Technical data

Type: Stainless steel absorber with water foil, with controlled draining, with selective plating

Dimensions and physical characteristics (standard model)

Over-measured length

2480 mm ± 2 mm

Active length

2240 mm

Length of the overlapping ends

120 mm


860 mm ± 1 mm

Active surface area

1.93 m2


9.8 kg/m2

Inner volume

2.52 l/m2

Diameter of the connection parts

ISO G 3/8”

Thermal capacity (water filled)

20 kJ/m2

Pressure resistance control

6 bars

Maximum operating pressure

3 bars

Nominal flow

40 l/h m2

Pressure drop at nominal flow

±400 Pa

Selective coating characteristics

Absorption >= 0.94
Emittance <= 0.18

Heat carrying fluid:

without chlorine ions or chlorates; demineralised water with propylene glycol anti-freeze and containing a corrosion inhibiting product

Caution during filling operation:

The proof ness test of the collector field must be done with demineralised water.

The filling must be performed immediately before the final system start-up.


Solar collector XX-Sel


Technical data

Active surface area



Inner volume of the absorber


l/ m2

Max. service pressure



Nominal flow


l/h. m2

Minimal flow


l/h. m2

Pressure drop at nominal flow

< 400


Max. stagnation temperature



Total weight: kg




> 0.94



< 0.07



AS+stainless steel, black chromium selective coating




Solar glass

Low iron Glass with reduced reflection grade; float ESG; thickness: 4 mm





PU with aluminium sheet (free of CFC)




Company “Nova Solar GmbH”


Address of company

Postfach 1149
D-68805 Neulußheim / Germany

Tel +49 (0) 6205 - 392847
Fax +49 (0) 6205 - 392848



Excellent welding joint – highly efficient heat transfer

The “plasma-beam-welding method”, operating at process temperature of over 20 000oC and developed specially for the productions of copper absorber fins, assures an excellent welding joint resulting in highest heat transfer between the copper tube and copper strip.


Excellent mechanical strength and handling

A slight amount of corrugating of the absorber strip increases its rigidity and the strength of the fins. The residue-free removable PE foil protects the highly selective surface during the assembling and mounting of the absorber plate



SunCollect copper absorber fins are produced in different lengths up to 7500 mm as per customer’s specification (even longer, on request) They are also produced in any width using copper tubes of different diameters, e.g. 8 mm, 10 mm and 12 mm etc

The fins are available with several highly selective coatings

Available selective surfaces

Black chrome IP (improved process)

Absorbtion           0.95 ± 0.02

Emission               0.08 ± 0.03


Absorbtion           0.95 ± 0.02

Emission               0.05 ± 0.02


Absorbtion           >0.94

Emission               >0.06


Selective surfaces dimensions


Absorber fin with push out


Absorber fin with push out and pipe extension


Absorber fin with pipe extension


Absorber fin, standard cut




Company “Viessmann”


Address of company “Viessmann UAB”

Geležinio Vilko 6 A
2009 Vilnius
Telefon: (02) 68 32 95
Telefax: (02) 68 32 96


Solar collectores



Vitosol 100
Solar flat collector with Sol-titanium coating
Collector surface area: 1.7 and 2.5 m2.

Vitosol 200
Vacuum tube collector, direct flow, with Sol-titanium-coating
Absorber surface area: 2 and 3 m2.

Vitosol 300
Vacuum tube collector on the heat pipe principle
Absorber surface area: 2 and 3 m2.


Technical data




Absorber area




Total dimensions













Weight (incl. insulation)




Vacuum tube solar collector based on heat pipe principle.
Absorber surface area:- 2 and 3 m2
Thanks to the highly effective Sol-Titan coating, the vacuum tube collector Vitosol 300 can even utilize diffused solar radiation. It is therefore suitable not only for domestic hot water applications, but also as a back-up for central heating purposes.
The benefits at a glance:


1. High level of operational reliability and a long service life thanks to the use of high-grade, corrosion-resistant materials such as special solar glass, copper and stainless steel. Durable, vacuum-tight glass-to-metal seal.

2. High efficiency thanks to the Sol-Titan coated absorber and vacuum collector tubes.

3. Short installation times assured by a systematically standardized installation system for all collector types.

4. The condenser has a flexible connection to the vacuum tube via a stainless steel corrugated pipe. The individual tubes can be adjusted for optimum alignment to the sun during original placement.

5. The dry connection of the collector tubes allows for individual tubes to be mounted and disassembled without having to drain the solar heating system.

6. Proven Viessmann plug-in system for connecting several collectors to form one collector panel with a total surface area of up to 65 ft2 - 6 m2.

7. A fully integrated solar system:

·         Vitosol 300 vacuum tube collectors
·         Vitocell-B 300 hot water storage tank
·         Solar-Divicon pump station
·         Solartrol-M control unit in customized control panel.




Company “Buderus”


Address of company

Buderus Aktiengesellschaft

Bereich Personal

Sophienstrasse 30-32

35576 Wetzlar

Tel.: 06441/418-1709







Technical data of solar collectors


Logasol SKN 2.0-s

Logasol SKN 2.0-w







Total liquid content l



Floor space, m2


Absorbing surface, m2:


Total weight: kg


Temperature max. oC







670,- bis 732 Euro


Heat insulation: 40 mm thick basalt felt with glass-fibre side insulation

Conversion layer: highly selective, aluminium oxide-based layer pigmented with colloidal nickel

Absorber: aluminium segments with copper piping





company “Thermo solar


Address of company

Thermo solar

Regierungsplatz 539
84028 Landshut
Tel. ++49 871-274103
Fax ++49 871-274104



Technical data of solar collectors

Standard-collector 250 N


Technical Data


Dimensions: 75 x 1034 x 2040 mm
Floor space: 2,03 m˛
Total weight: 42,5 kg
Collector casing: corrosion-proof Al + Mg alloy moulding
Total liquid content: 0,94 l
Heat insulation: 40 mm thick basalt felt with glass-fibre side insulation
Absorbing surface: 1.75 m˛
Conversion layer: highly selective, aluminium oxide-based layer pigmented with colloidal nickel
Absorber: aluminium segments with copper piping


High-Performance-collector 300 N

Technical Data


Dimensions: 75 x 1038 x 2040 mm
Floor space: 2 m˛
Total weight: 48 kg
Collector casing: corrosion-proof Al + Mg alloy moulding
Total liquid content: 1.4l
Heat insulation: 40 mm thick basalt felt with glass-fibre side insulation
Absorbing surface: 1.75 m˛
Conversion layer: highly selective, aluminium oxide-based layer pigmented with colloidal nickel
Absorber: aluminium segments with copper piping


300N2 P

Vakuum Flat Plate Collector 400 V


Technical Data


Dimensions: 75 x 1040 x 2040 mm
Floor space: 2 m˛

Total weight: 48 kg

Collector casing: corrosion-proof Al + Mg alloy moulding

Total liquid content: 1.5 l

Heat insulation: Vacuum, filled with Cryptongas
Absorbing surface: 1.74 m˛

Conversion layer: highly selective, aluminium oxide-based layer pigmented with colloidal nickel

Absorber: aluminium segments with copper piping

300N2 P







Address of company


Bakanausko st. 20

3018 Kaunas, Lithuania.

Tel.+ 370 7 392311,

Fax. + 370 7 392096,




At present plain solar collectors for water heating are produced in Lithuania, because it is economically inexpedient to use expensive foreign solar collectors in our country. Plain collectors absorb up to 550 kWh/m2 thermal energy during one year if they are oriented to the south and optimal inclination to horizon is bout 45 degrees. (in Lithuania).


Solar collector -1,9 V, (V-1,9 H)


Solar collector V-1,9 V, (V-1,9 H) 



Technical data

All surface area, m2                                                                   1,95

Effective surface area, m2                                                          1,73

Dimensions, mm                                                                       1967 x 987 x 102

Weight without fluid, kg                                                             40

Fluid volume, l                                                              1,0

Frame                                                                                      Painted aluminium profile

Heat insulation                                                              60 mm mineral wool

Transparent cover                                                                     4 mm hardened glass

Absorber cover                                                                        selective, “black chrome”

Absorbtion                                                                               Min. 0,96

Emission                                                                                   Maks. 0,098

Working temperature, °C                                                         100

Max. temperature when no circulation °C.                                 180

Max. pressure, bar                                                                   10,5


“TERMA” produces accumulative water heaters for hot water preparation. Accumulative water heaters are mounted in water heating solar systems, which accumulate heat amount for 1-3 days. Electric braziers can be mounted in accumulative water heaters for extra heating of water. Accumulative water heaters have vertical construction made of ferrous metals. Mineral wool covered with imitation leather is used for isolation. Heating coils of solar system and hot water are made of copper pipe.

akum.jpg (10802 bytes)



Accumulative water tank







Address of company

Vinčų st. 1-6, Kaunas 3019


Tel./fax. +370 37 234901



Solar collector type S2


Technical data


Total dimensions:

2060 X 1060 X 80 mm

Absorber area: 

2,0 m2


38 kg 

Capacity of fluid:  

1,1 litre

Speed of fluid:   

0,5 litre/min/ m2


Price of solar collector - 360Euro



Text Box:          Solar Collector S2




Manufacturers of domestic hot water solar systems in Lithuania




Leadership:              Vykintas Šuksteris, director

Konstantinas Marcinkus, deputy director



Bakanausko g. 20

3018 Kaunas


Tel:.  370 37 392311

Faks: 370 37 392093






Leadership:              Albertas Barčius, director



Zilvyciu 22,

5800 Klaipėda


Tel. 370 26 400033

Fax. 370 26 412187




Leadership:              Liudas Charževskis, director



Vinčų g. 1-6

2350, Kaunas


Tel: 370 37 234901

Fax. 370 37 234901






International programmes


Feasibility study for reconstruction of the energy system at Kacergine Sanatorium.


This project proposal contains a complete reconstruction of the energy system at the sanatorium in Kacergine. The existing boiler house with oil fired old coal boilers is replaced by a new prefabricated bio energy boiler installation. An installation of solar thermal panels will provide heat for summer load of tap water and part of heat consumption during spring and autumn. The existing heat distribution from the boiler house to all connected buildings is replaced with new well-insulated pipes including substations for secondary heating systems in all buildings. One of the points with this project besides giving Kacergine Sanatorium an energy efficient system is to demonstrate large-scale solar energy installation in Lithuania.

Kacergine is located just outside of the city of Kaunas. The Kacergine Sanatorium is hosting about one hundred children living there for different periods to be treated for their diseases. The sanatorium was built in the beginning of the 1960's. The buildings are poorly insulated and where originally construction for summer use only.

The heating system and installed equipment is in poor condition. The boiler boilers are originally constructed for coal, traditional design with housing made of bricks and heating tubes at the top. The boilers have been converted for burning oil by a simple installation of oil burners standing on a floor rack at the front. It is very difficult to make a reasonable estimation of the efficiency of the heat production but it is probably fairly low. The cost for fuel is a large expense for the sanatorium. Summer 2001 a team from J&W made a visit to Kacergine with purpose to examine the technical status of the energy system as a baseline for this project proposal. Inspection of the distribution system indicated leakage in a number of sections. Lack of insulation material and visible corrosion on pipes and valves was documented. Possible location of new boiler and solar panels was identified.

The purpose with this project is to improve the energy system at Kacergine Sanatorium in order to reduce the energy cost for the administration and to reduce the environmental impact from energy production. The objectives can be stated in following notes:

• Increase energy efficiency in production, distribution and use of energy in buildings. The objective is that the new energy system reduces the cost for energy with at least 40%.

• Reduction of C02 emissions by conversion of energy production from fossil fuels to renewable energy by introducing bio energy and solar energy.

• Demonstrate an integrated solution with bio energy and solar energy in combination as a technical and economical viable system. (This kind of integrated systems is used by some housing companies in western Sweden)

• Establish co-operation between Swedish manufacturers and local producers of solar panels.


Present situation:

The existing heating equipment consists of old boilers designed for coal firing. The boilers have been provided with oil-burners of simple design. The pipe-system is in a poor condition with detected leakages and heat losses. The amount of leakage has unfortunately not been possible determine during visits. The reason for this is that there is no adequate measuring of feeding water consumption.

The buildings are badly insulated. The average energy use has been calculated from noted oil consumption. Energy use is between 365 and 530 kWh/m2 yearly. Consumption varies very much between years mainly due to technical problems at the boiler house and also due to bad quality of oil in some shipments. The consumption is approximately three times higher than correspondent buildings in Sweden. Other reasons for this are the bad insulation in buildings and pipes. To illustrate present situation you can estimate an energy reduction by 15-20 % just by insulation of all attics to Nordic standard. It is necessary to work out a plan for energy efficiency measures in conjunction to this project.

Proposed project:

A new prefabricated boiler for wood chips will replace the existing boiler house. The new equipment, a complete installation including all necessary auxiliary components as heat exchangers and circulation pumps, is mounted in a container housing. New pre-insulated pipes will replace the existing distribution network. All connected buildings will be equipped with sub stations containing heat exchangers, circulation pumps and regulation facilities.

Large-scale solar panels will be mounted on ground fixtures near by the boiler house. The solar installation will be dimensioned to coupe with the summer load for hot tap water consumption. A storage tank will be connected to the solar system on the return pipe from the distribution network.

This system will work in an integrated mode between bio boiler and the solar system, The solar system will during summer be able to produce all capacity needed for tap water production. The benefit of the solar/bio system is that it is possible to close down the boiler for annually maintenance work during summer

The results of this project can be used for dissemination of integrated solar/bio systems in Lithuania. The technology is replicable in many applications. Block buildings with dwellings outside district heating networks, hospitals and hotels with high consumption of hot water represent potential applications of interest. The project is also of interest for demonstration of solar installations on larger scale. Today you can only find solar heating on one-family houses within Lithuania.

The total investment including costs for consultants will be funded as a grant by STEM. (Swedish National Energy Administration)

Present information of oil consumption is varying between 100 and 145 tonnes. The reason for this is not completely clear. There are indications of technical problems and also difference in number of guests during the years. The capacity of the present system is not sufficient. It is not possible to maintain normal indoor temperatures when the outdoor temperature is very low. This situation indicates heat losses in the network and buildings.

Environmental benefits in this project are reduction of CO2, NOx and SO2.

Reduction of CO2 emissions is calculated to be 314 tonnes/year. The calculated reduction of CO2 is based on a coal content of 86 % in the oil and an oil consumption of 100 metric tons a year.

The reduction of SO2 will be about 2 tonnes/year. The calculated reduction of SO2, is based on a sulphur content of 1,1 % and an oil consumption of 100 metric tons a year.

Since the present NOx-emissions are unknown it is not possible to do estimations of reduction of NOx-emissions.

To increase reliability in these figures it is proposed to conduct measuring of existing emissions during ongoing heating season.