THE ECONOMIC EVALUATION OF ENERGY REDUCTION AND SUBSTITUTION TECHNIQUES

Ir. D. Meijaard
Consumption of fuel in heating glasshouses is price-dependent. At the moment the consumption tends to increase. As a result of technical innovations there is a structural increase in the consumption of electricity.

The economic evaluation of energy saving and substitution techniques is from the nature of the economic indicators a risky affair. The evaluating is done from the point of view of the entrepreneur. Criteria are the profitability of the investment, the pay-out period, the sum of investment per m2 glass and the managerial aspect of alterations in the conditions of growing the crops.

Reduction techniques with low investment costs as thermal screens and computer together with the low energy prices are now used for an improvement of the conditions of growing. They are available and contribute at present also to the saving of energy. The extent of their use is dependent on the price of the energy. Saving techniques with a substantial light reduction have no future not even in the south.

The prospect for total energy are favourable in the light of structural developments and economic price relations. The degree of penetration will depend on the policy of the traditional suppliers of electricity.

The best chances for district heating lie in the application of water of a high temperature with a withdrawal of heat larger than normal (Delta T). The price of the water has to be fixed on the number of m3, not on the amount of heat that is withdrawn. In that case the saving in costs will be at a maximum for the grower.

There is generally little room to pay for the supplied water. The costs, therefore, of generating and transporting the warm water may not be high. The prospects of techniques with substantial costs for generating heat as e.g. geothermic heat are therefore not intensively followed up.

The prospects for the heatpump depend on technical developments. The same is true for the windmills.

Meijaard, Ir. D. (1989). THE ECONOMIC EVALUATION OF ENERGY REDUCTION AND SUBSTITUTION TECHNIQUES. Acta Hortic. 245, 520-529
DOI: 10.17660/ActaHortic.1989.245.71
https://doi.org/10.17660/ActaHortic.1989.245.71

Acta Horticulturae