Ing. Jiří Bím

The energy sector, especially in Europe passes a very hard period. Russia’s unprovoked aggression against Ukraine just exposed a large degree of de-pendence on fossil resources from Russia. The greatest dependency is in the natural gas sector, but also in the oil, coal, or nuclear products sectors. In re-action, European Union release new proceedings called RePowerEU to get rid of dependence on Russia and other hostile countries and achieve climate neutrality by 2050. Renewable energy sources have a key role in this energy transition, typically because of no operational commodities, or simply safe-ly obtainable commodities for the operation of these resources. Agrivolta-ics as part of the whole photovoltaic sector are in many countries tested in pilot projects and definitions are slowly implementing into national poli-cies. Different countries are trying to implement agrivoltaics in their policy in different ways, and several pilot installations are helping each govern-ment to understand the technology. Agrivoltaics has many forms and types. It can be combined with permanent cultures like berries, apple farms or conventional agriculture. After many years of testing agrivoltaics around the world, the biggest barrier is the legislative and permitting process. This paper highlights key barriers to agrivoltaic systems and describes ways how to unlock them.

The fertility of farmed land in the Czech Republic is generally deteriorating. Farmers are increasingly struggling on their land blocks with deteriorating soil conditions. This is caused by many factors, such as inappropriate crop composition and rotation, the use of fertilizers or the effect of erosion, both wind and water. Government Regulation 48/2017 Coll. has been in force for more than a year, ordering farmers to grow one type of crop on a block of land with a maximum area of ​​30 ha. There are three ways of dividing large blocks of land. The first is crop rotation, the second is the creation of a 110 m wide belt of secondary crops, the third option is the creation of a 22 m wide protective anti-erosion belt. The last option makes it possible to maximize the production of the selected crop, and above all, a grassy protective belt prevents erosion the best. To maximize the use of the given area, the farmer can place photovoltaic panels on the protective strip, especially vertically. The panels are ideally oriented east-west, if a southern orientation is needed, the structure can be adjusted and the panels oriented to the south. For vertical installation, we use bifacial panels that are capable of generating electricity from both sides. This combination brings many direct and indirect benefits. The main benefit of placing photovoltaic panels on the protective strip is the shadow created, which, especially in the hot summer months, will keep the grass protective strip in good condition, prevent rapid evaporation of water, and the protective strip will be able to fulfill its function. Photovoltaic panels also produce clean electricity that the farmer can sell or use. The electricity produced can cover own consumption or the energy can be used, for example, for irrigation pumps or charging of agricultural equipment. The use of produced electricity will always depend on the distance and size of the protective belt from the place of energy use. In order for this solution to be economically competitive, the use of the produced electricity is an important variable. In the future, we must count on the further use of clean excess energy, for example for the production of methane or green hydrogen. The synergy between agriculture and clean energy production is in line with Europe's current drive towards decarbonisation in 2050.

The aim of the article is to present the results regarding a comprehensive evaluation of the efficiency of Cannabis cultivation with an emphasis on the economic evaluation of the use of residual biomass either for direct energy use or for biochar production. The results of field experiments conducted in the Czech Republic showed great variability and adaptability of six tested varieties, out of which 'Fedora' and 'CS' were selected for further evaluation for energy and biochar production due to favourable yields of stem biomass (5.5 – 8.5 t DM/ha). Biochar produced from hemp biomass revealed texture properties which corresponded to quality commercial sorbents and met the limits related to the use in a variety of applications, e.g. soil amendment or water treatment. The economic analysis showed the advantage of residual biomass exploitation for the production of biochar, resp. for energy use as a by–product of the primary production of bioactive substances from Cannabis plants. The cost of obtaining 1 GJ of heat in the fuel is between 4.1 and 5 EUR, while another economic effect relates to the income from the sale of flowers for the extraction of bioactive substances. Concerning the conditions of the Czech Republic, the cost of biochar production from hemp biomass ranges, assuming the pyrolysis technology with the capacity 250 kg of raw biomass per hour, from 452 to 667 EUR/t (without excess heat utilization), and from 381 to 596 EUR/t (with excess heat utilization).