The daily needs of drinking water for the staff could be estimated at V4=80 litres/day. For producing the necessary drinking water a solar experimental still from the West University in Timisoara could be used, [7]. The still is supplying roughly V5=4l water per day. The solar energy converted into heat and used for water evacuation at the temperature of 540C is Q3=mAev (Aev is a latent heat of evaporation; at t=540C we have Aev=2.372 MJ/kg and Q3=9.5MJ/m2*day). The drinking water could be obtained by 5 solar stills, each with an area of 4m2. In the collecting ponds of water there is a layer of finely crushed rock of marble for water mineralization. The solar stills are installed either on the ground, or on the building porch.

Indoor illumination

The light has to be distributed equally in the lair and the illumination level, E is in the range from 5 to 60 lx. The electrical energy used by the light bulbs is from 9 to 16 kJ/m2*hour. Fluorescent lamps can give the same light as a 40W bulb; such a lamp could cover an area of 5m2. Taking into account that the total surface of the lair is of 500m2, 100 fluorescent lamps would be necessary to cover this surface. The total installed power could be 100*8W=800W (maximum value to be considered would be 1kW), [8] ,[9], [10]. The average time estimated for the daily illumination of the lair is of 4h. The average daily energy consumption could be estimated as: 100 lamps * 8W *4h/day = 3.2 kWh/day.

If we choose Siemens PV modules (12 Vdc, 53Wp), the total number of such units to be used for the lair illumination is 18.

For sizing the storage batteries, we would consider: an autonomy of 2 days, battery voltage 24Vdc, discharging coefficient Kd=0.3. The capacity of the batteries would be Cb=3200Wh/day * 2 days/ 24 Vdc * 0.3=888Ah.

The selected inverter would have the following characteristics: 24Vdc/220Vc. a, 1.2K, efficiency 0.85%.

The charge controller will have the following characteristics: 24Vdc, 40A.