investment can be calculated. The economic value of the total energy savings is presented in Table 16,
where the cost of 1 kWh heating is set at 0,9 DKK and of 1 kWh of electricity is 2,2 DKK. The total economic
savings is thus calculated to be 446.317 Euro per year. The simple payback time is then calculated to be 12
years.
mentioned above. The sensitivity of the bottom line result to these uncertainties are therefore briefly
investigated. For the investments the uncertainty lied with additional energy investments in the new
buildings. If this investments is doubled the simple payback time changes to 13.2 years. For the energy
savings the uncertainty mainly lies with the difficulty in establishing the energy consumptions had the
energy investments not been made. The savings were calculated based on design calculations. It is
generally observed that the actual energy consumption is higher than the consumptions based on design
calculations. This is the case both before and after energy renovation and for houses built according to the
standard BR requirements and to low-energy standards. If, for example, the actual consumptions are 50%
higher than the design values, this would also influence with the same percentage on the obtained energy
savings, which in this case would be 50% higher. The electricity production is guaranteed, so it is adjusted
for this purpose. In this case the simple payback time would be 8,8 years. Based on this admittedly simple
sensitivity analysis it is fair to say that the simple payback time will lie in the interval between 9 and 13
years.
446.317