Investment is crucial if we are to achieve our shared climate goals. However, there is a growing understanding that the technologies and resources needed to implement the energy transition are not yet available on a sufficient scale and within the desired time frame. Waking up to the price tag of the energy transition and the slow emergence of new markets for renewable energy products also challenges companies' abilities to realise their goals through investments. Regulatory environment volatility, uncertainty in the investment environment, and geopolitical instability add to the challenge of realising our climate goals.
At St1 we have continued to implement our own energy transition roadmap, achieving excellent progress thus far. The roadmap is committed to our key value chains and focus areas, and its viability will require healthy cash flow and strong partners.
The largest green field investment in the history of St1, our Gothenburg Biorefinery, was completed last year and is now producing renewable fuels, with a strong focus on sustainable aviation fuels (SAF). To support production, we have built our own value chain in highly competitive feedstock sourcing.
We see biogas as an important and rapid means of leveraging the circular economy to reduce CO2 emissions. Last year, we continued our strong investment program in biogas production, liquefaction, and distribution networks in Finland, Sweden and Norway. We carried out our projects throughout our own company and with our strong partners. As the most visible achievement, we completed the construction of a new biogas processing and liquefaction refinery in Borås, Sweden. Within a few years, we aim to be the leading company in the entire liquefied biogas value chain in our Nordic home market.
Our 1,855 MW wind and solar development portfolio took firm steps forward. We announced our first solar park investment in Gothenburg, Sweden. Meanwhile, the roll-out of a new high-capacity electric charging network in our retail network is advancing at full speed in Norway, Finland and Sweden.
Despite the challenges in accelerating the energy transition, we continue the development of our ambitious Power-to-X projects. The emergence of profitable markets for synthetic fuels takes time, and their breakthrough is yet to come.
Our net sales in 2023 were EUR 8.2 billion, which was EUR 2.3 billion less than in the previous year. The decrease in net sales was due to the development of world market prices of oil products during the year and the maintenance shutdown at the Gothenburg oil refinery. The country-specific distribution of net sales remained very similar to previous years, with 23% of net sales coming from Finland, 51% from Sweden, 25% from Norway and 1% from the United Kingdom.
Operating profit was EUR 185.6 million, which was nearly EUR 100 million less than in the previous year. Profit after taxes was 146.7 million euros, compared to 235.4 million euros in the previous year. The refining margin was lower than the exceptionally high level of the previous year, but still good. The margin was also affected by the spring maintenance shutdown at the refinery. Stock and valuation items also had a negative impact on the result. The result of the biogas business turned positive overall.
Cash flow from operating activities was EUR 361.8 million. Investments totalled EUR 241.1 million. The largest of these were the biorefinery construction in Gothenburg and the plant's maintenance shutdown, which is scheduled to take place every four years. In addition, investments were made in a biogas processing and liquefaction plant in Borås, Sweden. Last year, St1's renewable energy investments amounted to a robust EUR 111 million, representing 46% of the total investments of the year. In addition to the refinery maintenance shutdown, 54% of the investments were directed to the Nordic retail and logistics network and information systems.
The Group's equity stood at EUR 1,377.2 million at the end of the financial year, and the equity ratio strengthened to 55.7.
St1 Nordic committed to the UN Global Compact in 2020. Since then, its ten core principles concerning human rights, working life, the environment, and the fight against corruption have inspired our sustainability work and given it a solid backbone upon which we can build more transparent and sustainable business operations.
In 2023, our sustainability work continued to strengthen our compliance and due diligence processes, which support securing proof-of-sustainability certification for our feedstock and products. The focus was on our HVO, biogas and wind projects, which are strategic areas for our energy transition.
In 2023. we published our first Due Diligence statement that was prepared in accordance with the 2015 UK Modern Slavery Act and the Norwegian Transparency Act.
Our strategy execution comes alive through our dedicated employees. We balance organisational agility with a strong focus on psychological safety and transparent communication. To further empower our employees to thrive, we have strengthened our leadership and talent management. Our Culture for Growth provides us all with a solid foundation to grow with the company. We measure its success frequently and evaluate the results together with action points throughout the organisation.
A strong focus on Health, Safety, Security and Environment (HSSE) performance is of high importance to all our operations. The success of our work is measured especially in exceptional circumstances, such as last year's refinery shutdown for inspection and maintenance, where 1,000 external constructors in addition to our own 250 employees worked side-by-side in the area for several weeks. Due to simultaneous biorefinery construction going on, on peak days, the number of external contractors on site reached 2,000. Relative to that, our HSSE work is moving in the right direction, but there is still work to do to reach a truly world-class level.
After a good year of results, the future outlook for the business in accordance with our chosen strategy looks solid, and we will continue to implement our energy transition with a strong balance sheet.
I would like to thank all our employees for their commitment to our common goals and team spirit. I also wish to thank all our partners and customers for your trust and cooperation.
