One of the possibility to increase the use of photovoltaic power sources is to utilize solar cell panels as anti-noise barriers along the highways. Since anti-noise barriers amount to about 20% of the cost of building the highway roads, the cost of solar energy obtained in this way would be much lower than that from other commercial solar sources .
Two projects are currently in pilot phase at two different sections of the highway under construction in Slovenia. The first project is based on the use of highway noise barriers equipped with photovoltaics and piezomaterials for energy production. Technical documentation for the test field at the Krska vas – Obrezje highway in the length of 100 m has been prepared. In this case the noise barrier will be equipped with photovoltaics and piezomaterials. This project is aimed to demonstrate how much energy can be obtained from the noise barrier while the noise protection is improved. The noise barrier device will serve as a self organized energy device where on one hand the energy is obtained from photovoltaics and piezomaterials, and on the other hand the device also needs energy for absorption of high frequency acoustic noise emissions. The goal will be to satisfy these energy needs with only part of the produced energy, so that the energy balance of the device is positive.
Another similar project is designed for a windy area of the Razdrto-Vipava highway in the initial length of 500 m with a possible extension to 8 km. Here the noise barrier will also serve as a wind barrier. Also in this case the energy balance will be studied. Due to high wind loads the wind represents an additional source of energy, which will improve the energy balance of the device.
Suggested energy strategies for Slovenia and Croatia are summarised as follows:
1. Increase GDP/capita maintaining energy consumption per capita constant or at most keeping GDP/capita growth twice as large as the energy consumption/capita growth.
2. Increase the fraction of solar, geothermal, biomass and small hydro energy in 2010 to be 50% larger than it is in 2004.
3. Maintain and develop nuclear science and nuclear technology skills so that strategies to reduce nuclear waste problems can be implemented.
4. Change the pattern of energy consumption by emphasising renewable energy sources and reducing fossil fuel.
5. Increase R&D support and R&D activity to provide opportunities for major breakthroughs and to assure incremental improvements in energy technologies, in particular renewable technologies.
The negative environmental impact of energy use in Slovenia and Croatia has been analyzed. The analysis leads to a pragmatic policy to keep all energy options open allowing each one to seek its role in a competitive and economical energy mix. Discussed changes in the consumption patterns represent an important option for reducing negative impacts and are therefore a vital component of a successful strategy for sustainable development. The fastest way to change the consumption patterns is the implementation of green tax reform, where external costs of the environmental damage are also included into the consumer price. This would however significantly increase the price of fossil fuel energy, and is thus only acceptable, if a global agreement is reached. A proper combination of green tax reform and research can thus lead to new energy consumption patterns which are both environmentally sustainable and economically viable. Here environmental sustainability aims to reduce the fossil fuel use well beyond the proposed Kyoto targets in order to stabilize the global climate, and increased support for energy research is expected to decrease the price of clean energy so that it becomes competitive with the fossil fuels. If only a small fraction of external environmental costs were spent on research, clean and renewable energy technologies would become cheaper, new energy sources like fusion and energy producing bacteria closer, and radioactive waste storage safer.