The Elaboration of Energy Efficient Solar
Greenhouse
Taysaeva Valentina, Centre of solar energy (Buryat State Academy
of Agricultural)
Russia
Summary of technical characteristics:
- The size of the greenhouse of 100 square meter are optimized
at max solar radiation during the heating period from 15.02 to
15.11 (240 days) for the latitude 52.3 degree; the inclination
angle of the light transparent cover to the horizon is 60 degree;
the sun rise 30 degree. The maximum geometrical index Imin = 1,78.
- Heat supply (heating and hot water supply) is provided with:
Hybrid solar system (HSS) on the base of solar collectors (SC)
water-air, area - 12 square meter in the southern wall of a greenhouse;
Passive solar system (PSS) combined with the northern wall made
of hollow blocks 0,2 m wide and filled in with HAE of porous material.
Heat accumulating floor with HAE of porous material 15 cubic meter,
inside the floor there are perforated pipes of 35 sm in diameter
to supply hot air from HSS and PSS.
- The heating amount -66228 kWh/h for 6500 degree-days of heating
period.
- Heat balance of solar greenhouse (kWh/h) + 25301,4: (heat deficit
- 20483,9; heat excess + 45785,3).
Technical and economic characteristics:
- Combination of fencing construction (floor, walls, ceiling) with
heat accumulators will save up to 40 % of construction materials;.
- Optimization of geometrical sizes of a greenhouse elements provides
maximum supply of solar energy during heating period allowing to
use a greenhouse as a spring and autumn one (without heating) from
March to October.
- The use of the mirror screen - warmer will make it possible
to decrease heat losses of a greenhouse up to 15% and will supply
additional inflow of solar radiation by 20%.The use of HSS and
PSS without accumulating may provide up to 60% of heat amount
(39737 kWh).
- Seasonal accumulation of excess heat (45785,3 kWh) directly
in fencing increases the contribution of the passive system by
20%.
- The annual economic effect will be 2000 RUR. per 1 m2 of protected
soil at the price for heat in the districts of the Republic of
Buryatia ranging from 703 to 2843,5 RUR/Gcal and 1000-1512 RUR/m2
with the electrical heating at the price 0,07$/ kWh
- Recoupment period - 4-5 years.
Heat energy cost, RUR/m2 - 150 (compared to traditional energy
supplier - 550, solar green house -analogue - 270).
