Solarthermal consultancy

Here, you can find answers on questions concerning thermal solar energy - say plants that produce heat.

Solar plants for ... 

You can send messages and questions to .

The consultancy is independent of OEM's and for family-sized plants free of charge!
Questions for big-sized plants will be answered in 24 hours with a rough design and an economical analysis.

All mentioned (green) examples were mounted under direct supervision of the author.

Worthy plants for every family:

All systems have a 10-year warranty on the certified (black-chrome- or TiNOx/sunselect-) collectors, complete with isolated water tank, control and security components, pump and mounting material !

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Solar plants for heating and hot water

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Solar air conditioning

Adsorption-type air conditioning

Used within air conditioning or cooling plants working on the vaporisation principle, solar systems can save a lot of energy - most during the hot months. They can pre-heat the fresh air and dry the adsorbens.
In these systems either solar-air and solar water collectors can be used. The latter are often asked for as (vacuum) tubes - but the more economical solution in most cases are flat plate collector (1/2 price @ 75 % power compared to tubes).
For air heating or drying the solar air heating plant is directly flown through, while water-based systems heat the fresh air via an water-air exchanger.

To see the costs - 2 examples:

1. VEBA (energy distributor), Bochum: to give 50 MWh/a of solar energy for air conditioning, 88 m² of flat plate collectors were mounted at specific system costs of about € 600 per m² collector area.

2. City works Remscheid: for the 80 kW (cooling power) air condition and solar hot water plant of a business building 120 m² of flat plate collectors werew mounted at system costs of about € 570 per squaremeter. During winter the solar plant is able to deliver energy for the buildings heating system.
 

Absorptions-type air conditioning

These systems may work econimical in the future. Now you need for a 15 kW cooling plant 25 kW of solarthermal power.

The needed temperatures are above 80 °C - vacuum tubes could possibly be worth mounting.

Very important for a good solar performance in any of these applications are low as possible forward temperatures of about 70 tro 85 °C for the cooling system !

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Solar air heating plants

Especially for buildings, using air conditioning, these plants are most advisable. They convert solar heat directly into warm air (without the use of additional exchangers as would be needed in water-based systems).
So these systems are especially suited for low-energy housings, restaurants (example: hostel "Kettenkasten" in Warnemünde), hotels, storage halls and other.

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Desalination of salt water

Since short - thanks to an EU-project - a flat-plate-type of collector (SODESA) is available, that can resist to 90 °C agressive salt-water of the oceans, using a glas absorber ! It has an output like other flat plate collecotrs at 80 °C: 53 ... 39 %. All tests in real applications where succesfull !

This is the simple means for fresh water producing plants in southern countries - please look for details !

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Bigger solarthermal plants

Thanks to wide-spread practical experiences today bigger solarthermal plants can be installed without problems concerning design and operation.

Principially there are different solutions:

1) All loads are served by one solar plant via one main heat exchanger

(examples: District Clinic Wolgast; Senior Citizen Carecenter Berlin - Prenzlauer Berg; ; Senior Citizen Carecenter Berlin - Prenzlauer Berg; Hotel "Seenot" Groß-Köris; Hotel "Luise" Erlangen; Zero-Heat-Need houses in Berlin-Spandau and Berlin-Neukölln; Garden workers hostel Berlin)

2) All loads get their heat via different heat exchangers (perhaps combined with a local heating network), whereas

2.a) to every load there is also a smaller solar plant installed (example: Solarhouses Berlin-Hirschgarten) or
2.b) a bigger solar plant distributes heat to loacal heating network (example: Technical University Magdeburg)

The heat storage is done by main water or earth tanks - or as in 2.b) in some decentral tanks and perhaps in the local heating network itself.

Besides the above mentioned subsidies there a some for pilot projects as well:

* starting at € 30.000 of investment costs, the Deutsche Bundesumweltstiftung gives subsidies and subsidiesed loans or
* starting at a daily hot water need of  7 m³/d @ 60 °C the German Solarthermie-2000 programme (TP 2 and 3) gives up to 30 - 40 % as subsidies.

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