Concept of Energy Supply

Content

(a click to the sub-title leads to the article section)

1. Frame Conditions
2. Energy Requirements
3. Mission and Goals of the Energy Concept
4. Actions and Solutions
5. • Reduction of Energy Consumption
     
   • Procedure with Realization of the Energy Concept
     
   • Components of the Energy Concept
     
   • Mechanism of the Energy Supply System
     
6. Capital Expenditure
   
7. Block Diagram

1. Frame Conditions

• Open alpine association hut of category I, new building, low energy house, special wooden construction
  
• 31 beds; 60 mattresses; 90 seats for dining in 2 rooms
  
• about 4000 accomodation-guests per year; 10.000 day-visistors
  
• open from may until november, through new years eve, and on easter (sum about 204 days)
  
• material transport on a forrest-road (11km), further via ropeway (max. 150kg netto, abt. 250m height)
  
• way-connections to Bad Tölz, Benediktbeuern, Jachenau, Lenggries, Kochel, Walchensee
  
• from the end of the forrest-road access to the hut only by feed on a winding path
  

2. Energy Requirements

Based on the operation of the old hut we have known the experienced data of the "direct" energy consumers, f.i. ropeway operation, water pump, lighting system, cooking and washing. heating was mostly in the area of the hutkeeper with the woodstove of the kitchen (it was also used to produce a little amount of hot water for the kitchen and personnel). The two tiled stoves in the dayroom (the only heating sources of the old hut) had been used not often and not sufficiently. For cooking also liquid gas was used.

The "indirect" energy consumption of the hut in the environment had been about 1700 liters of fuel ( f.i. for the daily one, mostly two transports of personnel from Benediktbeuern to the base station of the ropeway, the daily supply rides of the hutkeeper for fresh food, the weekly supply rides for the delivery of drinks - cooled and in bottles).
Hypothesis: 23 km forrest road and 500m height per ride.
The direct and indirect energy requirement of the old hut were used as a base for the planning of a new ecological overall concept of the new hut and also for a new energy concept.
The daily energy requirements has been 40 kWh electrically and 90 kWh thermically.

3. Mission and Goals of the Energy Concept

• Arguments of an optimum economy and minimum capital expenditure must not get highest priority although economy and ecology should be estimated equal.
• Highest possible reduction of the overall emissions from the operation of the hut during summer and winter, ( supply rides, personnel rides, noise, exhaust fumes, waste water)
• Exact regard of a lawfulness Operation of the hut
• Full comfort of the hut and a sufficient offer of accomodation, food and drinks by intelligent solutions
• Temporary heating through the opening period when temerature is low, weather is bad, at night and when from september on the hut lies in the shadow of the northern wall
• Sufficient cooling of the depots of fresh food (safe against vermin) and sale of drinks primarily based on big containers
• Block-heating-generator, capable of automated starting, with ecologically beneficial fuel, independant of personnel
• 100% exploitation of the motor-heat for the thermal energy requirement of the hut; no emergency cooling at normal operation
• Low budget operation, also during the hut-closing at wintertime
• Low service requirements by robust, simple individual devices of the energy supply
• Safe possibilities for replacement of individual devices at the end of lifetime
• Reliable redundancy of the devices

4. Actions and Solutions

During longlasting model-calculations specialists have together experienced the theoretically best way of solutions. Because of the additionally necessary requirements the overall energy requirements rarely can be reduced, but will be shifted more to the direct energy requirements. The produced energy will be optimally used with the latest state of the art.

The usable power for the hut has been doubled to times before. The pollution could be reduced to 30 percent compared to the installations before (in spite of increasing the power!).

Destruction of environment by transports of dangerous goods will be avoided.
The success of the new energy concept will be fully reached first after all included people have changed their working procedures and loved habits, which mostly were aimed to economy, to the goals of a ecologically beneficial hut operation.

4.1 Reduction of Energy Consumption

Based on the actual conditions, carefully was checked which energy consumer could be avoided because alternative possibilities exist. With the operation concept of the Tutzinger Hütte the result shows the following picture:

Avoidable Consumer of electric current

Device	Remark
Coffee percolator	Hotel infusion device with cooked water from the gas stove
Microwave	With fresh food and corresponding menue not necessary
washer, dryer, iron pressing	Light sleeping bag mandatory; rest laundry ecologically beneficial finished down in the valley
Electric refrigerators	Gas driven refrigerators because gas directly and low priced available
Electric heating	Underfloor heating driven by BHKW and wood stoves in the side building or self-supplier-room
Electric cooker	Gas stove
Electric boiler	Hot water from warm water container; cooked water from gas stove
Dish washer with heating	Hot water from warm-water-container which is fed by the block-heating-generator (BHKW)

Necessary Consumer of electric current

Device	Consumption	Remark
Ropeway	1 to 4 kWh three phase current	about 4 rides daily
Drinking water pump	2 x 0.4 kWh three phase current
Degermination	0,72 kWh / day
Refrigeration engineering	3 x 0,7 kW three phase current	1 of 3 alternating, 14 hours daily
Heating/Warmwater	0,3 kW	steady power
Dedector 110 V DC	3,85 kWh at 35 A	during loading phase, Rest for consumer
3 Phase inverse rectifier, light, telephone converter, smoke alarm, rescue guard, emergency illumination	0,3 kW	base consumption
Vacuum cleaner	0,9 kWh
Dung water pump	2 kWh Drehstrom	1 x yearly at season end
Ventilator (kitchen), small kitchen devices	0,3 - 0,5 kW	when necessary at intense activity 2 hours
Hotwater dishwasher	0.3 kW three phase current	at intense activity ca. 2 hours per day

4.2 Procedure with the draw-up of the energy concept

• Together with the hutkeeper an operation concept for the hut was developed. Daily returning activities are organized in a time table with optimized course of the work so that saving of energy and other ecological aspects are especially considered.
  
  
• All data for planning based on
• • experienced values
  • the changed operation data and
  • the recommendations of the producers
  • had been carefully estimated and considered in dimensioning for the
    overall energy concept with sufficient reserves.
    
    
• With all used devices the operation was discussed in details and and the preconditions of the producer were fulfilled
  
  
• Use of simple commercial industrial devices with service and spareparts supply from the near areas. Easy maintenance, ruggedness and simplicity of the modules instead of high efficiency based on electronics are preferred. If possible electronics was avoided.
  
  
• Planning of equal distribution of the consumers to the 3 phases; destination of priorities based on importance; operation of the generator if possible under full power.
  
  
• Precaution measures for the circuits that none "undesired" consumers could be switched to the net.
  
  
• Reception, documentation and evaluation of all important consumers by counters for time and power in the individual cables.
  
  
• For most important functions spare systems are available ( emergency generator, tiled stove, spare detector, gas-heating-device, 3 stoves for wood or coal, 1 cooker for bottle-gas)
• All installations were done by special firms which also got the missions for professionel yearly maintenance
  
  

4.3 Components of the Energy Concept

base station ropeway
gas tank and gase hose cognizable

• Primary energy/gas supply; Propan liquid gas (LPG), 6400 Liter gastank at the base station (1100 m), Refill by regular tank car via forrest road, hut supply via gas-pipe`` DN 20, NP 100, length abt. 600 meter and height abt.250 m, fixing by steelrope on ropeway supporter, prepressure steering 500 - 700 mbar, endpressure steering at the hut for kitchen and BHKW
  
• Block-heating-generator (BHKW) from firm EAW in Westenfeld, 230 / 400 V three phase current, Synchrongenerator, power abt. 7,5 kVA electrical and 18 kW thermal, Ford 4 cylinder ottomotor with vacuum operated control; for low noise fixed on dam-felt, noise 60 dBA, operation with propangas (max. 50 min. 30 mB), warmth exchanger with condensate trap/ -outflow, 24 V generator for starting battery (automated starting) and regulation-tension, additional power supply, potentialfree trouble report , Stamford three phase current synchrongenerator, condensate pump, 70 mm plastic waste gas pipe
  
• warmth store (abt. 500 kW) 2 layer store tank a 3800 Liter store 100% of thermal energy of the electric current production for alternating use during operation of the hut
  
• industrial batteries OPZS 48Volt DC, 1200 Ah load, for the storing of redundant electric energy (for later use).
  

4.4 Mechanism of the Energy Supply System

• The newly installed system has 3 bidirectional invers rectifier at a 48V71200Ah battery block (accumulators). They are such synchronized to build a 3-phases current net at the hut. 4.5 kWp are permanently possible. Based on a certain level the block heating generator or/and the diesel generator will be added to the system.
• The inverse rectifier are such tuned that the block heating generator will be operated with best efficiency. If more energy is neccessary as the block heating generator can deliver, the inverse rectifier will add energy from the battery block. Is the energy demand less then the battery block will be loaded.
• All components can also be manually operated by the hut warden. The components are switched and wired so that each can supply the hut independantly from others.
• All components are industry standard, not special devices. A photovoltaic device on the huts roof supports the block heating generator. It is most valuable in wintertime. Its power is sufficient to maintain the battery block without the necessity of operating the block heating generator.
  
  

5. Capital Expenditure

Only for a part of the necessary activities frame-contracts could be fixed. Individual contracts were made f.i. for brickwork for the gas pipe ( base for the gas tank, ropefixing, a.s.o.), shifting of the switchboards, increasing of the control ingeneering, service works and some smaller additions. Especially proplematic was to keep in order the parallel operation of the supply engineering (ropeway, drinking water, electric power) without break.

6. Block Diagram of the Energy Supply

Draft: Ingenieurbüro Dipl.-Ing. Phys. Michael Berger, Garmisch-Partenkirchen
Drawing: Ulf Schreglmann