Articles
FARM-ECONOMIC ASPECTS OF LOW TEMPERATURE ENERGY FOR HEATING IN THE DUTCH GLASSHOUSE-INDUSTRY
Most growers produce heat by gasboilers.
The use of water with a high temperature of 90 °C at the most in 51 mm steel pipes is characteristic.
Alternative heat sources like district heating, waste heat and heat pump involve the use of water with a lower temperature.
This is called low temperature energy.
To be able to use low temperature energy the heating system must be changed as a new way of heating has to be developed.
A change of the heating system leads to higher costs.
These higher costs have to be compared with the benefit in costs when using water of a lower temperature.
Farm-economic calculations have been made of the break-even points (b.e.p.). The b.e.p. is the price at which there is no difference in costs between the use of low temperature and high temperature water.
It is defined as the price of 1 m3 natural gas equivalent (n.g.e.). Only the costs of durable production means and fuel have been taken into consideration.
The calculations have been made for a range of water-temperatures, different heating systems and various situations in practice.
Low temperature energy is of a lower value to growers than high temperature energy.
If low temperature energy makes it necessary to install a quicker heat releasing system the price of the low temperature energy must be cheaper accordingly.
The same is true for the next situations; a condenser is used, the heat intensity is lower, a higher heating capacity will be necessary, CO2-enrichment will be applied and the new heating system cause light reduction.