"Es gibt nichts Gutes, außer man tut es" - Arbeit an der Verständlichkeit von Gesetzestexten in der Schweizerischen Bundeskanzlei

In recent years, some attempts have been made to establish guidelines for the drafting of statutory texts. None of these, however, have been very successful. Still, the need for such guidelines is felt. Over the last 25 years, the language sections of the Swiss Federal Chancellery (Sprachendienste der Schweizerischen Bundeskanzlei) have worked with optimising statutory texts. The article presents some of the principles, on which the work of the language sections is based, and underlines the importance of creating necessary institutional structures for optimising such texts. For optimisation can only be successful if language specialists are seriously involved in the whole drafting process

Small unit compound modules : a new approach for light weight PV modules

A new concept for light weight solar modules is presented in this paper. The main difference to the common module type is the replacement of the frame at the laminates fringe by a lattice-like structure at the rear or at the rear and front side. Due to the smaller distances between the mechanical supporting elements the stiffness of the laminate itself can be reduced to a minimum, enabling the use of thin glass or alternative materials like for example polymer foils

Record-light weight c-Si modules based on the small unit compound approach : mechanical load tests and general results

The “small unit compound” (SUC) concept allows the preparation of very light weight c-Si solar laminates utilizing thin glass or plastic materials. A main difference to the common module type is the replacement of the frame at the laminates fringe by a lattice-like structure at the rear or at the rear and front side. Due to the small distances between the mechanical supporting elements which prevent the dishing of the laminate, the stiffness of the laminate itself can be reduced to a minimum. This enables the use of thin glass or alternative materials such as polymer foils. In this paper we present results of mechanical tests with such modules and discuss general results concerning the module lay-out. The paper has a focus on glass/glass and glass/backsheet laminates with glass thicknesses of 0.8, 1.1, 1.6 and 2 mm. A 60 cell glass/backsheet module 0.8 mm front glass with a weight of as low as 6.3 kg (without junction box and cables) has been fabricated. According to our knowledge this is the lowest weight for 60-cell c-Si modules with front glass ever reported. First hail resistance tests show that these modules may surpass the IEC 61215 norm. Only slightly lower weights are possible if alternative materials are used instead of glass for the front side cover

On Digital Sustainability and Digital Public Goods

Several 2022 reports from government and academic organisations contain the key message that sustainable development can be achieved using digital technologies. The report ‹Digital Reset› (Digitalization for Sustainability, 2022) calls for using digital technologies to reduce greenhouse gas emissions and resource waste in the agriculture, mobility, industry, and energy sectors. The researchers see digitalisation as a means to an end for sustainable transformation. Similarly, the report by the Coalition for Digital Environmental Sustainability (CODES, 2022), presents an action plan that includes impact initiatives to «achieve a sustainable planet in the digital age». The EU argues that digital technologies must play a key role in achieving climate neutrality in the EU by 2050 (Muench et al., 2022). The authors call for a ‹twin transition›, managing digital and green transitions simultaneously so that they reinforce each other

PV installations based on vertically mounted bifacial modules evaluation of energy yield and shading effects

Bifacial solar modules promise an increased energy yield, compared to systems with standard, monofacial panels, and also offer new opportunities with regard to the installation. One particular approach is the vertical mounting of PV modules, which is reported to be an effective measure to avoid soiling or dust deposition and is an option to obtain a broadened energy generation profile. In spite of the general interest in this type of installation, the amount of published data is very limited, especially with regard to arrays, for which pronounced shading effects can be expected. In this work we present an analysis of the energy yield and the respective losses for arrays of vertically mounted bifacial solar modules with varied installation conditions

Performance analysis of vertically mounted bifacial PV modules on green roof system

A combination of PV and green roof is an ideal fusion in terms of ecology. The green roof improves the water retention in the city, whereas the PV system produces electric power at the place where it is consumed. Flat tilted modules in south or east west direction on green roofs generally require intensive maintenance to prevent them from being shaded by plants and often cover the roof area to a large extent. Because of the space requirement conflict between PV on the roof and green roofs, it is essential to combine these two systems in a smart way. Vertically mounted bifacial modules can be an option to combine PV and green roof and to also allow a cost-effective maintenance. In this paper we report about the layout and the performance of a corresponding system, subdivided into two groups with differing albedo. Custom made bifacial modules with 20 cells were produced to reduce the wind load and to improve the general appearance. This 9.09 kWp bifacial plant achieved a specific yield of 942 kWh/kWp in one year (11.08.2017 to 10.08.2018). High quality DC power measurement systems are installed to monitor two modules in each bifacial test field and a reference south-facing module. This allows an energy yield comparison between the vertical bifacial test system with east-west orientation and the monofacial south-facing reference over four months of outdoor measurements. The use of plants with good reflective properties, which are also well suited two the ambient conditions on flat roofs, resulted in a yield increase of 17 % compared to a standard green roof planting. The vertically installed bifacial modules obtained an almost identical specific yield (-1.4 %) compared to a stand-alone monofacial southfacing reference module. Due to the increased yield in the mornings and afternoons, the vertical bifacial modules can achieve higher self-consumption depending on the load profile

Energy yield prediction of a bifacial PV system with a miniaturized test array

Because of the sensitivity on multiple additional factors, compared to monofacial standard installations, the simulation and prediction of a bifacial PV arrays yield is by far more complicated and less reliable. Accordingly, the determination of optimized installation conditions is considerably less straightforward for bifacial installations. Due to the pronounced dependencies also the assignability of otherwise applied installation conditions to similar systems is limited. Because of the low accuracy of the traditional approaches to predict the bifacial system output the use of a miniaturized test rig might be an interesting option. Provided that the results can be assigned to measurements at real systems it can be used as a cheap and flexible testing device. Miniaturized devices could be used in long-term trials for yield measurements at specific locations, to identify optimum installation conditions or to validate simulation algorithms. Running several test rigs with different configurations in parallel would enable a direct comparison. The small size of a miniaturized rig also allows a fast change of the set-up, which is an interesting feature to test the respective impact at otherwise almost unchanged conditions in short-term tests. In this paper we report on a test device which is a miniaturized (1:12) replica of an existing PV array with commercial bifacial modules. The measurement data of both systems are compared in order to investigate if there is a clear assignability. A unique feature of the large test field, a permanent and automated variation of the tilt angle, is also transferred to the miniaturized version. Accordingly, the whole tilt angle range is tested and potential tilt angle dependent effects are revealed. Based on the obtained data we give an estimation of the error in the prediction accuracy and discuss options for possible improvements

Warum digitaler und nachhaltiger Wandel gleichzeitig stattfinden muss

Regierungen und akademische Organisationen sind sich sicher, dass eine nachhaltige Entwicklung mit digitaler Technologien erreicht werden kann. Auch die EU argumentiert, dass Technologie eine Schlüsselrolle bei der Erreichung der Klimaneutralität in der EU bis 2050 spielen müssen (Muench et al., 2022). Unserer Autor*innen fordern einen «doppelten Übergang», d. h. die gleichzeitige Bewältigung des digitalen und des grünen Wandels, so dass sie sich gegenseitig verstärken

Photovoltaic systems with vertically mounted bifacial PV modules in combination with green roofs

Dependent on the specific conditions flat roofs can be well suited for the installation of large photovoltaic systems in urban areas. For urban designers also other aspects, such as the insulation of buildings, cooling, air purification and water retention play an important role besides the ecological energy generation. The combination of photovoltaics and roof greening can therefore be an interesting fusion. It combines the advantages of a green roof with the local electrical energy production at the place of consumption. However, using a conventional photovoltaic system with tilted modules in south or east-west direction on a green roof causes problems, as typical low tilt angels and high ground coverage rates result in an almost complete coverage of the roof surface. Plants, growing in between the covered areas provoke undesirable shading of the collector surface. Only a frequent maintenance procedure, complicated by dense PV system layouts, can avoid a reduction of the energy yield in the course of time. Vertically mounted specially designed bifacial modules are an option to realize photovoltaic power generation in combination with a functional green roof at low maintenance costs. In this paper, we report on the layout and the energy yield of a corresponding system. Custom-made bifacial modules with 20 cells were produced and vertically installed in landscape orientation. The narrow layout of the modules lowers the wind load and reduces the visibility. The enhanced power in the morning and evening of vertically east-west installed modules can additionally lead to higher self-consumptions rates. Despite having some shading and undergrounds with albedo factors of less than 0.2, the bifacial installation with a rated power of 9.09 kWp achieved a specific yield of the 942 kWh/kWp in one year (11.08.2017–10.08.2018). This is close to typical values of 1000 kWh/kWp achieved for south-facing PV systems in the same region. The impact of the greening on the albedo and the system performance is investigated in more detail with two smaller sub-systems. The energy yields of the two bifacial sub-systems are compared to a monofacial, south-facing reference module. The use of silver-leaved plants in this system resulted in higher albedo values and a more resilient roof greening