What is the expected growth of the number of strategic convenience sites in 2021 
ss in the last 12 months, more than doubling the number of retail sites in growth markets, growing the number of strategic convenience sites to more than 1,900, delivering a record $1.3 billion of convenience gross margin and increasing the number of electric charge points to more than 10,000. Taken together, this gives us confidence in our growth plans to 2025 and beyond.
Looking to 2021, you should expect another strong year of strategic progress. We will continue to expand in growth markets, rolling out Jio-BP branded stations in India with 5,500 stations expected in this market by 2025. We plan to increase investment in our Castrol brand to drive growth and value, and further expand our 28,000 strong network of branded independent workshops. We expect to grow our margin from convenience and electrification, supported by a planned further expansion of around 10% in our network of strategic convenience sites and the continued roll-out of ultra-fast charge points across our retail sites in the U.K. and Germany. And we will evolve and personalize our customers' experience by further enhancing our digital and loyalty offers. Finally, as Murray mentioned, we plan to provide enhanced disclosures in early March. This will allow you to better understand why we think these businesses are so valuable.
Moving finally to low carbon electricity and energy, we are very clear about where we can add value here and we have four focus areas, low carbon electricity, integrated gas, bioenergy and hydrogen and CCUS. Since unveiling our strategy, you've raised some questions about low carbon electricity, in particular, whether we can meet both our volume and our returns objectives. So today, I'm going to focus on three questions that we've heard. The chart here shows BP's projects, pipeline, and hopper on a net basis.
So, question one, will we really put value over volume? The answer is emphatically, yes. Capital discipline is central to our growth agenda. We are clear that value creation will come from the quality of the opportunities that we mature through our hopper into our development pipeline and we will only pursue opportunities that we believe can generate disciplined project returns of at least 8% to 10%. Let me give you an example. In the second half of 2020, our teams evaluated an option to acquire a pipeline of solar assets in the United States. This opportunity had real scale and could have significantly added to our existing pipeline. But despite making into the final few bidders, we withdrew because the purchase price did not underpin our returns expectations. In the fourth quarter alone, we took the decision not to advance over 12 gigawatts of opportunities.
Question two, are there projects available that meet our returns hurdles? Absolutely. At the end of 2020, we had developed a total of 3.3 gigawatts net. This includes projects in our strategic joint venture, Lightsource BP, which has developed around 30 projects to FID with weighted average expected returns in the range of 8% to 10%. And with our U.S. offshore wind joint venture, we reached a major milestone with the announcement of the power offtake agreements. These significantly de-risk the projects, reducing cycle time, and creating certainty over future revenues early in the investment cycle. This means, we are even more optimistic about the value opportunity than when we entered the agreement in September.
Question three, can you find enough projects to meet your volume objective? We're making great progress. On top of the 3.3 gigawatts I've just described, we have a strong pipeline of around 11 gigawatts of options being developed. We have projects in our pipeline across nine countries. Our developed assets plus pipeline grew by around 90% in 2020 and we have a hopper of a further 20 gigawatts of active opportunities under evaluation.
In addition, the formation of our strategic partnership with Equinor has completed and I believe has a great future, leveraging the capability and experience of both companies. As I said earlier, the partnership intends to develop 4
ss in the last 12 months, more than doubling the number of retail sites in growth markets, growing the number of strategic convenience sites to more than 1,900, delivering a record $1.3 billion of convenience gross margin and increasing the number of electric charge points to more than 10,000. Taken together, this gives us confidence in our growth plans to 2025 and beyond.
Looking to 2021, you should expect another strong year of strategic progress. We will continue to expand in growth markets, rolling out Jio-BP branded stations in India with 5,500 stations expected in this market by 2025. We plan to increase investment in our Castrol brand to drive growth and value, and further expand our 28,000 strong network of branded independent workshops. We expect to grow our margin from convenience and electrification, supported by a planned further expansion of around 10% in our network of strategic convenience sites and the continued roll-out of ultra-fast charge points across our retail sites in the U.K. and Germany. And we will evolve and personalize our customers' experience by further enhancing our digital and loyalty offers. Finally, as Murray mentioned, we plan to provide enhanced disclosures in early March. This will allow you to better understand why we think these businesses are so valuable.
Moving finally to low carbon electricity and energy, we are very clear about where we can add value here and we have four focus areas, low carbon electricity, integrated gas, bioenergy and hydrogen and CCUS. Since unveiling our strategy, you've raised some questions about low carbon electricity, in particular, whether we can meet both our volume and our returns objectives. So today, I'm going to focus on three questions that we've heard. The chart here shows BP's projects, pipeline, and hopper on a net basis.
 So, question one, will we really put value over volume? The answer is emphatically, yes. Capital discipline is central to our growth agenda. We are clear that value creation will come from the quality of the opportunities that we mature through our hopper into our development pipeline and we will only pursue opportunities that we believe can generate disciplined project returns of at least 8% to 10%. Let me give you an example. In the second half of 2020, our teams evaluated an option to acquire a pipeline of solar assets in the United States. This opportunity had real scale and could have significantly added to our existing pipeline. But despite making into the final few bidders, we withdrew because the purchase price did not underpin our returns expectations. In the fourth quarter alone, we took the decision not to advance over 12 gigawatts of opportunities.
Question two, are there projects available that meet our returns hurdles? Absolutely. At the end of 2020, we had developed a total of 3.3 gigawatts net. This includes projects in our strategic joint venture, Lightsource BP, which has developed around 30 projects to FID with weighted average expected returns in the range of 8% to 10%. And with our U.S. offshore wind joint venture, we reached a major milestone with the announcement of the power offtake agreements. These significantly de-risk the projects, reducing cycle time, and creating certainty over future revenues early in the investment cycle. This means, we are even more optimistic about the value opportunity than when we entered the agreement in September.
Question three, can you find enough projects to meet your volume objective? We're making great progress. On top of the 3.3 gigawatts I've just described, we have a strong pipeline of around 11 gigawatts of options being developed. We have projects in our pipeline across nine countries. Our developed assets plus pipeline grew by around 90% in 2020 and we have a hopper of a further 20 gigawatts of active opportunities under evaluation.
In addition, the formation of our strategic partnership with Equinor has completed and I believe has a great future, leveraging the capability and experience of both companies. As I said earlier, the partnership intends to develop 4