Environmental Engineering Reference
In-Depth Information
age is twice as high. The insulation standard of a building has considerably more
infl uence on the rate of solar coverage than these two elements. Optimal insulation
options should be considered when there is an interest in increasing the amount of
solar coverage as a way of contributing towards climate protection.
From Thinking about a Solar Thermal System on the Roof to
Installing a System
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Determine orientation and angle of roof.
Is the roof suitable in terms of orientation and tilt angle?
Recommendation: a minimum of 95% according to Figure 5.15.
Does the roof have too much shade?
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Decide whether only water for domestic use should be heated or whether solar
heating or cooling support is also desired.
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Implement outline design following rule of thumb.
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Possibly implement detailed design by hand or using simulation tools.
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Apply for appropriate approvals for listed buildings.
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Request quotations.
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Have professional company provide additional details for design.
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Apply for subsidies or low - interest loans.
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Award contract for the work.
6.5 Economics
Depending on type and design, between 200 and 350 euros per square metre should
be estimated for fl at-plate collectors and between 400 and 600 euros per square
metre for vacuum-tube collectors in Central Europe. A 300-litre heat storage cylin-
der costs around 700 to 1100 euros. Installing a solar thermal system can be espe-
cially cost-effective in new buildings or when an existing hot water storage cylinder
is old and has to be replaced anyway. The costs for a solar thermal system fall within
a wide range. A system purely for domestic hot water with four square-metre fl at-
plate collectors and a 300-litre hot water storage cylinder can be acquired for as
little as 2000 euros, not including installation. The average cost of a European
system for a four-person household excluding installation is between 3000 and 3400
euros; a system including installation is around 5000 euros. Depending on the size
of the collector, the cost of a system that provides support heating can be double or
even higher. Government grants are sometimes available to help cover the costs.
Even if the investment costs for a solar thermal system are known, getting a handle
on the economics is diffi cult compared to photovoltaics. The output of a photo-
voltaic system can be tracked accurately through an electricity meter and the state-
