Welcome. Thank you for joining us today at our virtual STS Primary event. We look forward to sharing an inside view to our incredible Sustainable Technology Solutions segment, but first I would like to cover some important disclosures. This discussion includes forward-looking statements reflecting KBR's views about future events and their potential impact on performance, as outlined on the slide. These matters involve risks and uncertainties that could cause actual results to differ significantly from these forward-looking statements, as discussed in our most recent Form 10-K available on our website. This discussion also includes non-GAAP financial measures that the company believes to be useful metrics for investors. A reconciliation of these non-GAAP measures to the nearest GAAP measure is available in our most recent press release and earnings presentation posted on kbr.com. It is my pleasure to now hand over to Stuart Bradie, our President and Chief Executive Officer.
Thank you, Jamie, and welcome. Today we're going to exclusively focus on our Sustainable Technology Solutions segment, or STS. Our objective is to present in more detail why we believe STS is indeed unique and gives shareholders the opportunity to invest in an IP-based enabler of the energy trilemma. Now, as you're aware, KBR actually reimagined our whole energy-facing business in 2020, with a clear sustainability focus, placing technology and domain expertise at the heart of our offering while leveraging our global presence, digital skills, and significant installed base. Now, the results have been exceptional and well above our initial target of doubling EBITDA by the end of 2025. Today we're going to articulate the why and the how, and we're going to explain the market drivers that have enabled our growth, have delivered our outpacing margin enhancement, and our impressive cash performance.
Now, these market forces and, frankly, societal drivers are indeed enduring, and our resultant bookings will demonstrate the non-cyclical attributes of this business. Now, make no mistake, sustainable technology is a long-cycle business, especially when one takes a portfolio approach combined with a globally significant installed base. Now, we will also break down our margin composition, and we'll show you in more detail the geographic mix and how this is growing in countries and regions where we have significant strategic advantage and presence. We'll explain and show our key customers and why traditional and new market entrants really have us excited for the future, and why what we offer, combined with trusted delivery excellence, results in continued repeat business.
So, in short, we believe the value of STS is very much underappreciated in our stock price, especially as the relative percentage of KBR's Adjusted EBITDA is made up with an increasing contribution from STS. This is largely due to the unique value proposition, which, of course, we recognize we needed to explain more concisely, which is what today is all about. Now, to kick us off, our marketing and comms folks produced what we think's a quite cool video that helps describe in a fairly simplistic way what we do and, of course, thus, how we make our money.
For over a century, clients have relied on KBR's deep domain expertise to solve and bring to life their most challenging energy, chemical, and industrial projects. With the end in mind, we lead clients to define and optimize their opportunities from what is feasible through execution, startup, and beyond, providing full end-to-end risk identification and mitigation. Using our proprietary project requirements, systems, and approaches, we leverage our smart digital tools for scope definition, cost, schedule, safety and design, and sustainability measures to aid client investment optionality. When a project is born, clients license the process technology that drives the chemistry, which converts raw materials into valuable products, using KBR's Sustainable Technology IP portfolio, spanning sustainable aviation fuel, hydrogen, ammonia, waste plastics recycling, olefins, and much more. Our technology IP includes the right to use and purchase our proprietary equipment and catalysts needed to produce the desired products.
Once client achievement of final investment decision, KBR provides detailed design solutions utilizing digital engineering with automated workflows to maximize speed to market of the design deliverables, equipment and material selection and quantities into the supply chain and construction phase. KBR integrates with the supply chain and construction process through KBR Digital Procurement System, IPMS, maximizing the automation of the data flow. KBR provides construction management services, which include oversight of project scope, budget, and timelines. During the last stages of construction, KBR delivers digital monitoring, predictive analytics, maintenance, and training solutions that optimize assets and increase reliability across the client's operational cycle. When clients choose KBR, they get a partner for life, and a class by itself is the only company with the breadth of expertise to effectively and safely deliver, maintain, upgrade, and revamp facilities across the energy and chemical spectrum. At KBR, we deliver.
Hopefully, that was helpful and should give context to what we do. I'm going to build on that a bit, which takes us nicely onto slide 7. This slide depicts clearly how we think of our business and, actually, how we go to market. In the center circle, at the heart of what we do, is our portfolio of IP, knowledge, proprietary data, and know-how. Now, this includes technologies, and we've discussed these many times before, like plastics recycling, sustainable aviation fuel, olefins, ROSE, ammonia, ammonia cracking more recently, etc. Now, it also includes our deep domain knowledge and know-how on things like next-gen LNG, decarbonization of energy security, digital engineering, remote monitoring, and our proprietary integrated project management systems and tools. Now, our customers, they come to KBR because of our specialist knowledge, IP, and capability.
But they also come because we augment that and augment our offering with specialist services that really help our customers realize their objectives, from concept into feasibility, delivering value with decarbonization by increasing energy efficiency or reducing emissions, or improving predictability and speed to market via digital optimization and techniques like modelisation. Now, speed to market is actually a critical success factor for our customers today. There's a natural synergy between sustainable technologies into sustainable solutions that delivers unique value. Perhaps the easiest way to think about this is that KBR operationalizes IP or concepts, delivering high-performing functional assets to meet our customers' objectives. Now, as we'll show you in a moment, STS is a truly, truly global business. We have been very, very deliberate to ensure we maintain our low-risk business model everywhere we operate.
We avoid commoditized, low-margin services, including direct hire construction, and, of course, we completely avoid lump-sum EPC. We do, however, have value-add roles across the asset lifecycle. So now onto slide 8 for more details on the lifecycle. Now, as you saw in the video, the lifecycle has four phases. So here is a different, I guess, a more graphical view of those four phases. Now, we fit in all four with both technologies and solutions. And I think we're uniquely offering end-to-end solutions. Now, 75%-80% is in CapEx, and 20%-25% is in OpEx-related spend from our customers. Now, the OpEx spend keeps us really close to our customers via a significant installed base, which also helps with intimacy as our customers look to modernize or expand or decarbonize their existing assets. And, of course, this whole process starts over again.
Probably easy if I give you a simple, real-life example, and hopefully this will bring this to life a little bit easier. I think most of you know of our investment in plastics recycling. The technology is called Hydro-PRT. We acquired the global rights to sell this technology. In acquiring this technology, our technical experts identified areas to enhance the circularity and the efficiency of the offering by capturing and recycling the steam and heat. Now, this not only made the solution more efficient but ensured the whole process was indeed sustainable. We then utilized our digital engineering understanding to modelise the solution, and this improved predictability. It actually improved cost and, importantly, speed to market. But this also widened the proprietary equipment wallet for KBR and allowed us to exploit our supply chain management expertise.
If required, we can then assist the customer through project execution, supervising and using project management skills and tools to manage the constructor. We can then assist with commissioning the system, training operators, and can, of course, apply digital monitoring and maintenance capability throughout the OpEx lifecycle. So how does KBR and our shareholders realize value? We, of course, sell the proprietary technology as a license to operate. Now, we only sell this with the associated proprietary equipment and engineering, which, again, is value to KBR. And then, if required or wanted, we can sell the project management and commissioning assistance, and that's sold as reimbursable high-value services. The remote monitoring system is sold as a software license, and any follow-on technical services are typically rate-based.
If the customer then wishes sometime in the future to expand the facility, we can then add another module, and that whole process repeats. I will now turn to slide nine to demonstrate at a very high level how this works at scale. Jay will explain the energy trilemma and how KBR is an enabler in exciting and enduring markets in a moment. But if we simplistically take the Mura Hydro-PRT example and then apply the same go-to-market fundamentals, we have 80+ protected technologies, which, as you will appreciate, have very high barriers to entry. Now, we've strategically added to this portfolio over time, all with a very strong focus on sustainability. We've also enhanced our existing technology and our know-how, think next-gen LNG and sustainable services solutions offering to ensure there are decarbonization attributes to all that we offer.
Now, this is a unique and a substantial suite of offerings. Today, we operate in 38 countries, so truly, truly global, with a highly motivated and technically skilled sales team, and that's very important. Now, this team is absolutely world-class. This global presence and strength of relationships and understanding allows us to position for both global and local market trends and nuances. Our continued presence and delivery excellence has resulted in deep, long-lasting, and trusted customer relationships. Now, reputation in this business is absolutely everything. We're very well known for developing, adding value, and commercializing new technologies, making KBR the go-to company to help early adopters and technology developers. That all sounds great, but with that backdrop and, of course, the story, we should be delivering strong margins, and that's exactly what we do.
We delivered over 20% to 0% in 2023 with terrific cash performance and excellent bookings, giving future earnings visibility, which takes me nicely onto slide 10. Here are some key financial highlights. Now, you've seen some of this before. In 2023, adjusted EBITDA was $336 million, which was a terrific performance. Our CAGRs were well ahead of pace, as you know, but really impressive. However, the key takeaway is that STS's adjusted EBITDA was heavily, heavily impacted by repeat business, over 65%, which I believe really demonstrates the strength of our relationships and our delivery value-add focus: 65%. Our book-to-bill was also very strong throughout the year, well above 1%, as we discussed during our Q4 earnings. We close with a backlog of circa $5 billion. Now, Jay will show you in a moment how this gives a great line of sight to future earnings.
Now, you can see on the slide, our EBITDA mix is a good balance between technologies and solutions and on contract type. The 5% fixed price is actually services with defined scope and level of effort. This gives a bit more detail on how our low-risk business model is in practice. In short, this is a high-growth, high-margin, low-capital-intensive business. Our geographic presence, our customer focus, our product portfolio, and access to both CapEx and OpEx funding ensure that we mitigate cycles. Unique, a word we used earlier, I think, is very fitting. With attributes shown on this slide, STS, we believe, is very much undervalued. Now onto slide 11. Now, in no particular order, we have plotted who many believe are our peers. On the left, you have typical services players and EPC players.
Next, you have EPC companies who have some technology, and they often try to leverage that technology to win larger EPC, often lump-sum EPC, contracts. Then on the bottom right, you have technology peers. Now, some have made progress from a sustainability perspective, others less so. Most of these, however, are privately held or contained within much larger conglomerates. So we believe that KBR is indeed unique. In 2020, we repositioned our business to deliver sustainable solutions. And as I stated earlier, we exited commoditized services and high-risk activities like lump-sum EPC. And as I have explained, we add value by deploying industry-leading and differentiated IP, know-how, and digital solutions that are intrinsically linked to high-end sustainable solutions that really improve speed to market, reduce carbon footprint, and increase efficiency for our customers all across the world. Now, the resultant significant value-add to our shareholders is clear.
We are the only publicly listed company with a clear sustainability focus that delivers IP, digital solutions, and sustainable services at scale. Are we peerless? Perhaps from an intrinsic value perspective, but our top-quartile growth, low-risk business model, and double-digit margins really set us apart. Now, certainly, from a multiple perspective, this is a business that is clearly undervalued given these attributes. Onto slide 12. Now, we've talked quite a bit about margin, so we thought it would be helpful to give a breakdown of the relative contribution and realize margin for the component parts. Now, the titles line up with what I presented with the circles earlier. Now, the numbers are pretty self-evident, with sustainable technologies delivering circa 25% EBITDA margins and making up about 40%-55% of the overall STS EBITDA mix.
Now, this includes license sales, which are typically very high-margin, sort of near 100%, and the associated know-how and proprietary equipment. And then the sustainable solutions piece delivers about 15% EBITDA margins and makes up the remaining 45%-60% of overall STS EBITDA. So in total, this results in delivering circa 20% margins, as you've seen. Now, as we sell or add more technologies and know-how and digital solutions to the portfolio, the level of proprietary equipment and services around the circle also grows. Now, I guess this would indicate that the mix over time could favor services. However, in that case, we would realize economies of scale across the sustainable services portfolio due to a relatively low fixed overhead. And as such, we actually expect overall margins over the medium term to be pretty constant.
I will now hand over to Jay, who'll give you more detail on what has been driving our growth and why we believe the outlook is very, very bright. Jay. Thank you, Stuart. Onto slide 14. The energy trilemma is the global challenge to reliably meet the growing consumption of energy while balancing the need for affordability and sustainability. These three dimensions, more energy, cleaner energy, and affordable energy, are often seen as opposing challenges, but achieving balance is vital for providing the people of the world an affordable quality of life while achieving net-zero goals. Demand for energy is growing across the world. As populations grow and more economies are developing, which brings a higher per capita consumption of energy. The Southern Hemisphere economies seek greater mobility and consumption of goods, all derived from energy products, while Northern Hemisphere economies are maintaining demand.
If this increased demand is not offset by innovative new technologies, capabilities, and energy efficiency elsewhere, then global energy consumption will continue to grow year on year. It is worth noting that over 70% of the energy we use today is from single-source energy sources of fossil fuels, with the top three sources of energy all being hydrocarbon-based: oil, then followed by coal and natural gas. The Russia and Ukraine situation has amplified the interconnectivity of the energy supply and its flow down into food security and national security. KBR is at the forefront of the energy trilemma by providing innovative solutions in energy security as well as new low-carbon energy to meet this additional demand and gradually displacing existing fossil fuels in the energy mix.
KBR has the global presence, working with the integrated energy companies and the national oil companies in the Eastern and Southern Hemispheres across the energy trilemma. The energy trilemma has highlighted KBR's competitive advantages, which include a large installed base, relevant experience, delivering scale and complexity, and clients that have the trust and confidence to source our works to KBR. Our proprietary sustainability offerings are built on our differentiated IP and domain expertise. We deliver best-in-class OpEx and CapEx performance with digital solutions for true end-to-end solutions. We also deliver in the most commercially ready markets, such as green or blue ammonia, waste plastic, circularity, sustainable plastic, and sustainable aviation fuel, and more. The know-how KBR brings our clients not only makes the energy transition more affordable but cleaner through delivering these solutions to market quicker and safer, with our first-to-market leadership resulting in impactful positive changes to the environment.
Onto Slide 15. As shared during our earnings call, STS' diversified portfolio accelerates our growth through the power of "and." Because of this, KBR is able to deliver in both traditional grey energy vectors and new blue/all-green energy vectors, and at world scale with the leading national oil companies and international energy companies, and with the first-of-a-kind scaled energy system of tomorrow and in any region of the globe, regardless of where they are in their journey to addressing the energy trilemma. Looking at the traditional vectors, the areas of continued growth, supporting security, and affordability are reaching gigascale in vectors where KBR's longstanding experience is without equal.
While within the new energy vectors, KBR is scaling and deploying solutions to address the most current and necessary challenges in the energy transition, such as sustainable aviation fuel, chemical recycling of waste plastics, as well as blue and green hydrogen and ammonia. KBR's leadership position across these markets reinforces its trusted position with clients, regardless of shape, size, or location. Onto slide 16. This is another key dimension of why KBR is the unique player in the market and equally important to where we make our money. The energy trilemma is global, and so is our presence, giving a wide canvas for STS to provide innovative and affordable solutions. Our playground is the globe, and our presence adapts to fit the spend and the market trends. The challenges vary across the globe, both regionally and temporarily, so we offer our solutions where there is appetite.
Our offer in Iraq is better quality of life for the Iraqi people by capturing the flared gas for use in power plants rather than increasing greenhouse gas emissions. Our offer in Saudi is to expand self-sufficiency through replacing firing oil in power plants with cleaner natural gas and converting oil into more recyclable chemicals. Our world-leading technology in ammonia continues to provide the bulk of fertilizers across the globe, supporting humanitarian aims. No matter how big or small the project is, no matter where it sits across the energy trilemma, no matter which geography it is in, KBR is ready to deliver the investment as long as it fits our strategy, our focus, and our discipline. As we have confirmed previously, this does not include lump-sum turnkey, commoditized offerings, or direct construction. Our risk profile is conservative, with a focus on the bottom line.
With the global demand growing, so is our book of business. Every region has shown growth over the years presented, with the exception of Asia, which was flat due to geopolitics. In summary, we are well-positioned in high-growth geographies with double-digit outlooks at revenue and EBITDA. Now onto slide 17. We work in a trusted partnership with major blue-chip customers and developers across the globe. The size of the bubble shows our top customers in 2023, and the circle denotes relative scale in adjusted EBITDA. With over 65% of our work coming in from repeated customers, it's proof of the trust and confidence that our customers and partners put in KBR. With ADNOC, we are their number one project management consultant and integrator, where we are currently managing over $100 billion of projects with about 700 people dedicated to this successful program.
With Shell, we are working on their Pathfinder project to provide low-cost energy solutions. With BP, we work in Iraq in energy security projects and in the U.K., where we are their integrated project management team for blue and green solutions. With Aramco, we are executing engineering, design, and project management for projects that are over $100 billion in value related to sustainability and diverse the product slate. With Stange in Nigeria, we are providing our world-leading technology in ammonia. With LyondellBasell, we are working in circularity. With Woodside, in liquid hydrogen and LNG. With DuPont, we are a major player in executing all the engineering projects and support along their journey in transforming from a specialty chemical company to specialty material company. With Energy Transfer, we are working in olefins and LNG, and with Seatrium, we are working on offshore production.
Hopefully, what I just shared demonstrates our long-term, sticky relationship with a broad range of mega-customers across the globe, across the energy trilemma. Onto slide 18. Our IP and technology is the crown jewel for STS. Here is our 14-year history showing the tremendous growth in commercializing externally and internally developed technologies. We have grown from 10 technologies to 80+ technologies in less than 15 years. In 2023, we have commercialized nine new technologies, and every single one is ESG-focused. Our technologies are all globally relevant, and they play in providing innovative and affordable solutions to resolve the challenges in the energy trilemma. These technologies are all diverse, mitigate the risk of regional instability and market cyclicity. Through partnerships and alliances over the last year, KBR has obtained: Acetica, technology for the production of acetic acid, which combines methanol with syngas utilization of CO2.
KCAP, KBR's carbon capture solution, is an innovative rotating packed bed design that replaces large distillation towers with an electrified solution, particularly relevant for retrofitting CO2 capture into operating and logistically limited existing assets. PureSAF, KBR's industry-leading sustainable aviation fuel solutions, alongside our partner Swedish Biofuels. With numerous paid studies underway, KBR is expecting accelerated market uptake, similar to the pace of our Hydro-PRT offering. Purifier , for those clients who are looking for ammonia technology-based around autothermal reforming to meet local conditions, KBR has partnered with Topsoe to integrate their leading ATR into KBR's leading ammonia technology. Internally, KBR has developed H2ACT, which stands for Hydrogen-2 Ammonia Cracking Technology, the only ammonia cracking solution that has been licensed at commercial scale. SCOREKlean, a near-zero CO2 footprint ethylene technology based on KBR's core technology and its best-in-class yields. PureLi, purification of extracted lithium intermediates into battery-grade lithium.
H2K, blue hydrogen based on KBR's industry-leading blue ammonia designs. PureM, green methanol technology, which is uniquely a CO2 usage technology that furthers the circularity of CO2 in reusable products. Onto slide 19. For our profit-source trajectory, we play across the three horizons, which have significant and long-term visibility. This is our book of business and our pipeline for opportunities. The colors represented in Adjusted EBITDA: the dark blue is profit expected to come from framework master service agreements in place today. The yellow is profit coming from long-term projects that last 2-5 years. The light blue is profit expected to come from short-term projects less than 2 years. The remaining is new business and is included in our pipeline. 2024 is off to a great start, with more than 85% of work secured in our book of business to meet the annual guidance.
We have work underway now, which even extends beyond 2025. We are a bit of tailwind in the market across the energy trilemma. Having sticky customers who have the trust and confidence in KBR ensures this business is resilient and not cyclical. Onto slide 20. The current STS business represents a highly de-risked, low-capital-intense, high-cash-generative, know-how-led solution provider across the lifecycle of a project. In sustainable technologies, the fees paid are unit price and predominantly paid in advance. Our equipment, modules, and catalysts are manufactured through back-to-back structure contracts with a narrow range of trusted vendors who fabricate these critical pieces of equipment to KBR's design standards. Therefore, the risk profile of the technologies PSL is very low-risk. Sustainable solutions have been de-risked through our exit of direct construction work as well as lump-sum turnkey type contracting.
Our consulting and engineering services offerings are sold with profit and overhead built into time and material type reimbursable formats, all of which are extremely low-risk. As we have continued to remind, we have a highly de-risked suite of services led by the detailed engineering master services agreement type work and program management presenting very low-risk profiles to KBR. I'll now pass it back to Stuart to wrap it up.
So onto slide 21, key takeaways. So let me leave you with just a few key thoughts. STS is unique. It is very well-positioned for continued growth and margin performance. The market outlook, our IP portfolio and sustainable services attributes, trusted customer focus, and global presence mitigate volatility and cycle risk. Backlog has been increased by winning the right work to give visibility of future earnings, with strong underlying book of business over the medium term, which Jay presented earlier. And as I said earlier, STS's Adjusted EBITDA contribution was circa 40%, 40% of KBR. And this segment is now at scale to be considered a highly meaningful part of KBR, a highly meaningful part that up until today has been underappreciated. And hopefully today we went a long way to address this. So thank you for listening. And no doubt we'll be talking in a little while. Thank you.
Bye.