Wind energy in stand-alone usage
In contrast to wind parks that are connected to the public energy grid, the ROPATEC windrotor was designed for the stand-alone usage. By stand-alone usage, we mean when the public network does not meet one's energy needs, and an individual supply is required.

Very often, this need is met with noisy and environmentally polluting diesel power units. In windy regions, the use of ROPATEC wind rotors has proven to be an appealing investment in both an economical and environment-friendly sense.

What is the cogeneration

The concept of co-generation means the combined production of electric energy and heat. Unlike the classic power plant, where heat produced in the creation of energy escapes into the environment, a co-generation unit uses the heat produced for heating and thus saves both fuel and money needed for its purchase.
Electricity in all power stations originates in the spinning of electrical generators with the help of turbines. The heat necessary for the production of steam, which drives the turbine, mainly comes from the burning of coal or the fission of atomic nuclei. Most of the heat is not used however, and is released into the atmosphere.
The effectiveness of production in heating power stations runs at around 30%; the most modern steam-gas power plants at around 50%, and of course, with further losses of around 11% during the transformation and transfer of electricity from a distance. In co-generation units the electricity is generated in the same way as in other power plants - the spinning of an electric generator, and that with the aid of rotary gas-burning motors. Motors in co-generation units are built as standard around natural gas, but can also burn other liquid or gas fuels


Pre-Feasibilty Technical analysis

Are you going to build or reconstruct a heating system? Are you considering the possibility of using co-generation? Evaluation of suitability of using the co-generation unit is always a case of individual approach. A detailed economic and technical analysis always has to go before the proposal for a type of co-generation unit and the way of its operation. The following scheme should only help you in your primary considerations about suitability of using co-generation in the planned project.

Does the site have simulta-neous heat and power requirements? NO? Cogeneration may not be cost-effective
Does the site have a fossil fuelled boiler or equivalent? NO? Cogeneration may not be cost-effective
Have all other cost saving measures been considered? NO? Undertake a detailed review of site energy uses and implement efficiency improvements before considering cogeneration
Does the minimum site electrical load exceed 10 kWe? NO? Cogeneration may not be cost-effective
Does the minimum site heat load exceed 20 kWt? NO? Cogeneration may not be cost-effective
Does the number of hours when the electrical
and heat loads are simultaneously above 10 kWe and 20 kWt exceed 5000 hours annually?
NO? Cogeneration may not be cost-effective
Proceed to more detailed feasibility analysis. We will help you!


Hardly had the public got used to the expression co-generation and had designers begun plans for equipping boiler rooms with co-generation units, than a new expression, which is far from being a household word, began to appear - tri-generation. Translated, it means the combined production of electricity, heat and cooling; technologically it is about connecting co-generation units with an absorptive cooling unit.

Tri-generation scheme
This is advantageous from the operational point of view of co-generation units, because it allows the use of heat even in summer outside the heating season, and in this way prolongs the annual running time of the unit. It is just this lowered possibility of using heat from co-generation units in the summer which leads to the use of smaller units than would otherwise be suitable. If we are then able to change heat into cooling, nothing stands in the way of co-generation units working to the full even through summer. The produced cooling can be used everywhere where air-conditioning is needed - in banks, hotels, business and administration centers, hospitals, sports halls etc. Air-conditioning equipment can be of two types:
- compressor - an electric motor runs the compressor
- absorptive - run on steam, gas, heat from hot water

The advantage of absorptive cooling (apart from the above mentioned possible connection with the co-generation unit) compared with compressor cooling is that it needs lower quality and even cheaper input heating energy than the more expensive input electric energy for compressor cooling. Absorptive cooling is also quiet, simple and reliable. The disadvantages are mainly the higher investment costs compared with compressor cooling, and bigger dimensions and weight.

The basic principal of the absorptive circuit is the replacement of compression by heat procession in which the cooler absorbs a suitable material (absorbant) at low pressure, then transfers to another exchanger working at higher pressure where the cooler by the input of heat into the liquid is released (expelled) again. The result is a cooler with higher pressure which resembles condensation. What happens in the condenser and evaporator is similar to a steam circuit.

How does it work in practice?

Absorptive cooling has three circuits among which a change of heat occurs. The first is the heating water circuit which is the drive medium for internal heat exchange. This circuit was connected to the heat source, in our case a co-generation unit. The second circuit is a cold water circuit which is directly connected to the cooling circuit - similarly as in central heating, but cold water flows instead of hot water, and which cools the air in rooms - and in it removes heat from the area. The third circuit is the cooling water circuit which removes water with heat for cooling. Cooling most often takes place with the help of cooling towers.

The deciding influence on the size and price of cooling equipment is held by the temperature of the hot water circuit. It is generally true that the higher the temperature of the hot water, the smaller and cheaper is the cooling equipment. Most industrially produced equipment works with a temperature of around 90 to 135C. The cold water circuit works with temperatures necessary for the removal of heat from rooms, and this is around 7 to 15C. The cooling water circuit which takes heat away from cooling equipment has temperatures of 20 to 45C.


Tri-generation in Tedom.

In order for test for ourselves the concrete possibilities of tri-generation we decided to air-condition the office area of the administration building. Installed a York International WFC 10 absorptive unit for cooling, and this was built to use hot water with a low temperature, e.g. connected to a co-generation unit. A Premi 22 co-generation unit with a max. heat output of 45.5 kW works in this case with a heat drop of 95/75C; individual heating / cooling circuits have these parameters: hot water 95C, cold water 8C, cooling (tower) water 24C. This equipment has been working in our firm since 1998 and proves that tri-generation can be used with low output co-g



Solar energy

Each day more solar energy falls to the Earth than the total amount of energy the planet's 6 billion inhabitants would consume in 27 years. Currently we harness about 1% of this energy
Photovoltaics are one of the fastest growing solar energy technologies. Photovoltaic devices, commonly called solar cells or modules, use semiconductor material to directly convert sunlight into electricity. Solar cells have no moving parts-power is produced when sunlight strikes the semiconductor material and creates an electric current.
PV modules have no moving parts, are virtually maintenance-free, and have a working life of 20 - 30 years.
The PHOTOVOLTAIC (PV) effect was discovered by a French natural scientist Alexandre Edmond Becquerel in 1839 when he discovered that electric current can be generated when certain structures are exposed to light (he dipped platinum plates into liquid electrolytes). The Americans Adams and Day in 1876 using a selenium crystal have done the demonstration of the effect. The efficiency in this case was only slightly above 1%. In 1905 Albert Einstein formulated an explanation of the PV effect (the photon hypothesis). In 1949 the Americans Shockley, Bardeen and Brattain discovered the transistor and clarified the physics of the p and n junctions in doped semiconductors materials. The first solar cell with an efficiency of about 6% was developed and later in 1956 a silicon solar cell was made with an efficiency of 10%.

The rapid development of space exploration opened up excellent opportunities for solar cell application. In 1958, 108 solar cells were sent into space for trials for the first time. Serial production begun soon afterwards, albeit in small numbers. In 1970, annual production of solar cells for space applications totalled 500 m2. Earth-bound use of solar cells was given a boost during the 73/74 oil crisis, and this has since led to the launch of numerous research and development projects. The most important aim here has been to reduce the cost of PV plants.

Solar cells and photovoltaic plants have since become a common part of everyday life. Their application spectrum is broadening all the time and ranges from small - scale applications in pocket calculators and watches to large electricity - generating plants with outputs in the kW and MW ranges

Biofuel Test Specifications

EN 14214 for Bio-Auto Fuels
EN 14213 for Bio-Heating Fuels
ASTM D6751-01 for Biodiesel (B100)

What is Biofuel?

Fuel made from renewable natural processes including biodiesel such as FAME, FAEE, biogas, bioethanol and biobutanol.

Biofuel Blends

Biodiesel blends are designated BXX, where XX is the volume percent of biodiesel extender that has been blended with conventional diesel base fuel. For example, B20 which is a common blend for fleets and buses contains 20% biodiesel extender and 80% base diesel fuel. Pure biodiesel extender l is also referred to as B100.

Advantages of Biofuel