Most of us consider solar energy to be a green technology, something that can help us reduce carbon emissions from our energy system, since there are no direct emissions from photovoltaic (PV) modules in operation. However, considering the life cycle of the modules, some of the various manufacturing steps of making mono- or multi crystalline silicon solar cells and fitting them in a PV module require quite a lot of energy. The energy use in the manufacturing process is the main factor contributing to the climate impact of PV modules, and depending on the electricity mix used, there is a substantial difference in the carbon efficiency of solar modules. PV modules with materials sourced from low carbon production facilities can have a much lower carbon footprint than the industry average. There are also significant differences between different technologies where multi crystalline solar cells are less energy-intensive to produce than monocrystalline, and thin film solar cells are less energy-intensive than both types of silicon-based solar cells.
In short: not all PV modules are created equal when it comes to carbon footprint. And by promoting the most carbon efficient PV modules, we can make a green technology even more green.
So, how to choose the most climate efficient option as a building owner looking to invest in PV? It is not easy to find information on the climate impact of the PV modules and the local PV supplier usually cannot account for the whole supply chain of their products. Even though the products are “made in” an EU country, this only refers to the final assembly. China is dominating many of the early manufacturing steps, especially the ultra-thin silicon wafers, a necessary building block of PV modules.
Climate Efficient Solar Energy, a project run by the Greater Stockholm Energy Agency, aims to address these issues.
Together with RISE (Research Institute of Sweden) and HBV (a central purchasing body of public housing companies), the project partnership has developed a procurement criterion to be used in public and private tenders of PV installations which will make the green technology of PV even greener by valuing climate impact in public procurement.
By developing and testing the criterion and putting together a guide for climate-optimised management of PV systems, we want to increase the knowledge of market players about the environmental impact of the overall system. This helps the players see the whole picture with a life cycle perspective which also takes into account the production and management of obsolete solar cells.
Partnering with real estate and housing companies, the project will try out a new way of tender evaluation where the climate impact of PV modules is calculated and weighed into the price. The first tenders with this new way of accounting for climate impact of PV modules will be tested and evaluated in the spring of 2022.
- Publication date
- 8 May 2023