1. Graphical Overview of a Solar Thermal System Thermoelectric Converter Sun Available Heat Electronic- Control - Unit

2. General Design of a Solar Thermal System Collektor Main Pump T2 T1 ECU  T) Electronic Control Unit Electronic Thermometer Storage-Tank

3. Solar Thermal Model Collektor Pump T2 T1 ECU  T) Electronic Control Unit Electronic Thermometer Storage-Tank

4. Solar Thermal Model Collector with Thermo-Tubes Thermal-Solar-System-Controller Storage Tank (Thermo-Flask) Pump Special thanks are going to Wellner Haustechnik, Bad Kreuznach, www.wellner- haustechnik.de, contributing the Thermotubes Collector Modelwww.wellner- haustechnik.de Panel-Sensor Storage Tank Sensor

5. Thermoflask – Tubes How evacuated tube collectors work Thermos flasks can keep coffee and tea hot for hours because there is a vacuum insulated intermediate layer between the double vessel walls. With the two concentric glass tubes, evacuated tubes also form a hermetically sealed space that is vacuum insulated. In addition to this, the outer surface of the inner tube is coated with a highly efficient, environmentally friendly absorber coating. This converts incident sunlight almost completely into heat and radiates almost no heat. The inner tube becomes hot while the outer enclosing tube remains cold.

6. Solar Thermal System - Controller

7. Flow-Chart Sensor Check and Heat-Control Constant DELTA_T = 10 Restart Program Read SerialNumber Sensor T1 (b7) Copy SN Sensor T1 (b1 = b7) Read SerialNumber Sensor T2 (b7) b1=SN_T1 AND b7=SN_T2 ? Yes No „Sensor error“ Constant SN_T1 = 120 Constant SN_T2 = 15 Read T1, T2 Show „T1 [°C], T2= [°C ]“ Yes No T2 > T1? ΔT = T2 – T1 ΔT > DELTA_T No Yes „Pump ON“ „Pump OFF“ „Heat Control OFF“ Sensor-Check Heat - Control

8. Program Pump-Control ;----------------------------------- constants --------------------------------------------------- ; symbol SN_T1 = 15 ; SerialNumber Sensor 1 (DALLAS 18B20) symbol SN_T2 = 120; SerialNumber Sensor 2 (DALLAS 18B20) symbol DELTA_T = 8; pump switching temperature difference ; (betweeen solarpanel and storage tank) ; ; -------------------------------- main program -------------------------------------------------- ; init:low 0:high 5 : high 6; Pump OFF (port 0), Sensor-LED's OFF (port 5,6) gosub message ; displays starting initialization gosub init0 ; checking the temperature sensors ; main: gosub lcd1; status message readowsn 6; reading the serial number of T1 b1 = b7; caching b7 of the serial number readowsn 7; reading the serial number of T2 b2 = b7; caching not absolutely required but more systematically if b2 = SN_T2 AND b1 = SN_T1 then; sensors connected ? readtemp 6,b1 ; reading the value T1 (requires about 700 ms) readtemp 7,b2 ; reading the value T2 (requires about 700 ms) gosub lcd2 ; displays the sensor values on the LCD device if b2 >= b1 then ; in this case, the difference b2-b2 is greater 10 b3 = b2-b1 ; calculating delta T if b3 > DELTA_T then; delta T > DELTA_T-degrees: makes pump working ? high 0 ; pump ON gosub lcd3; message pump ON else ; if not, do this: low 0; pump OFF gosub lcd4; message pump OFF endif else gosub lcd10 ; if T2 < T1 then message: “heat control = 0ff” endif else goto init; if one ore both sensors are failing endif goto main end