2.1. The Danish Building Regulation

New energy regulations, within the Danish Building Regulations from 2006, have been tightened with 25-30 % for new buildings compared with the prior Building Regulations from 1995. With the new energy regulations the energy frame will always have to be calculated for new buildings and includes energy for heating, hot water, cooling, ventilation and lighting. When the energy frame is calculated, electricity consumption is multiplied by 2.5 to compensate for the inefficiency of the power production. Energy production from on-site energy sources are subtracted from the calculated energy frame with the same factors: 2.5 for electricity and 1 for the other energy sources. This makes energy production from on-site PV-cells more profitable per kWh in regards to the energy frame compared to e. g. solar heating.

2.2. Barriers

One of the barriers in implementing PV-systems in buildings is the lack of experience among tradesmen and the cost of the PV-panels. The development of the PV-window is based on overcoming these barriers to make it easier to integrate the PV-window in buildings and to reduce the installation costs and hence make it more attractive to use PV-technology in buildings.