NET Power: gas-fired power with inherent CO2 capture?

NET Power Technology Review

NET Power has developed a breakthrough power generation technology, combusting natural gas and pure oxygen in an atmosphere of pure CO2. Thus the combustion products are a pure mix of CO2 and H2O. The CO2 can easily be sequestered, yielding CO2 intensity of 0.04-0.08 kg/kWh, 98-99% below the current US power grid. Costs are 6-8c/kWh. This NET Power technology review presents our conclusions from patents.

NET Power was founded in 2010, is headquartered in Durham NC, has >30 employees, and has developed an efficient, gas-fired power generation technology with “in-built CCS”.

Specifically, the reactor produces a pure stream of H2O and CO2, which can easily be dehydrated, then a portion of the CO2 can be siphoned off for disposal, while the remainder is re-circulated, as the working fluid in the thermodynamic cycle.

In 2022, Rice Acquisition Corp II agreed to combine with NET Power, at an EV of $1.5bn, with $235M of commitments from the Rice family, Occidental Petroleum and others.

NET Power aims to generate reliable electricity from natural gas and capture the emissions. CO2 intensity is stated at 0.04-0.08 kg/kWh, comparable to utility-scale solar, and 98-99% below the current US power grid at 0.4 kg/kWh.

We first looked at NET Power in a research note in 2019, exploring how next-generation combustion technologies could facilitate easier capture of CO2 (note here).

Levelized costs of power generation are estimated in a range of 6-8c/kWh, assuming $3.5/mcf hub gas prices (and by extension, $4.5-5.5/mcf input gas prices), in our model of NET Power’s oxy-combustion process linked here. The usual caveats apply that levelized cost calculations can be materially lower, or higher, in different contexts.

How does the technology work? The technology is a modified and heavily recuperated super-critical CO2 Brayton cycle. As helpful background reading, we would recommend to start with our overview of thermodynamics, and our overview of super-critical CO2.

The patents give some helpful details on pressures, temperatures, heat exchange, Cp/Cv ratios, and innovations to maximize efficiency; including recuperating waste heat from the air separation plant (which produces the pure O2 for the combustion process) back into the CO2 stream. Details are in the data-file.

What challenges for super-critical CO2 Brayton Cycles? There are six core challenges with super-critical CO2 Brayton cycles. They are outlined in the data-file, along with our assessment of how NET Power addresses the challenges, based on its patents.

Can we de-risk Net Power’s technology? Our NET Power technology review shows over ten years of progress, refining the design of efficient power generation cycles using CO2 as the working fluid. The patents show a moat around several aspects of the technology.

Goldwind: frequency response from wind turbines?

Goldwind frequency response

Goldwind is one of the largest wind turbine manufacturers in the world, having delivered over 50,000 turbines by early-2023. The company was founded in 1998, headquartered in Beijing, it has 11,000 employees, and shares are publicly listed.

The wind industry is increasingly aiming to mimic the inertia and frequency response of synchronous power generators. Goldwind has published some interesting case studies, boosting power by 6-10%, within 1-2 seconds, for 5-6 seconds. Hence this data-file reviews Goldwind frequency response patents to look for an edge?

Synchronous power generators have ‘inertia’. If the grid suddenly becomes short of power, due to a large new load switching on, or a large power source disconnecting, then all of these synchronized machines will slow down very slightly, and in unison. Harvesting their rotational energy provides more power to the grid. But it also lowers the ‘frequency’ of the grid. At least for a few seconds, until firing rates can be ramped up. Generally, the larger the synchronous power generators, the higher their ‘inertia’, the more power that can be drawn out as they slow down, and the less grid frequency will drop per unit of incremental power. This is all crucial to the functioning of a modern power grid.

Wind turbines do not inherently provide any inertia or frequency response. Interestingly, they have about the same amount of angular momentum as conventional power generators, as they spin. But it is not synchronized with the grid. A wind turbine spins at 15-20 revolutions per minute, whereas a typical grid at 50 Hz (or 60 Hz in the US) is completing 50 full AC cycles per second.

An increasing goal for the wind industry is to ‘mimic’ some of the inertia and frequency responses of synchronous generators. Recently, Goldwind has published interesting case studies at wind farms, e.g., in Australia, boosting power by 6-10%, within 1-2 seconds, for 5-6 seconds (chart below).

The goal of this patent screen is to evaluate whether Goldwind’s frequency response algorithms give it an edge over other wind turbine manufacturers. We were unable to de-risk this idea from reviewing the patents, for the reasons explained in the data-file.

There are three key challenges for implementing frequency responses, as a form of ‘synthetic inertia’ and wind power plants, which are also borne out by the patent analysis. It takes time to implement the response (certainly longer than a battery, capacitor bank or conventional generator). Second, it is challenging to coordinate the responses of dozens of turbines, each with a different operating state. Third, there is always a danger that the wind drops at the precise moment you want to implement your frequency response, due to natural wind volatility.

Goldwind frequency response? Goldwind discusses possible solutions to each of these challenges in its patents. The bright spot is that we think many of the solutions are software-side, which will lower their implementation cost, and not pull too hard on already-bottlenecked power electronics. However, as usual, we find it harder to de-risk algorithm-heavy patents.

Jetti Resources: copper leaching breakthrough?

Jetti resources technology review

Jetti Resources has developed a breakthrough technology to recover copper from low-grade sulfide ores, by leaching with sulphuric acid, thiocarbonyls, ferric iron (III) sulphates and oxidizing bacteria. The patents lock up the technology, presenting some of the most detailed experimental data of any patent library that has crossed our screen. But what are the costs of copper production, what CO2 intensity and what technical challenges remain?

Jetti Resources was founded in 2014, it is headquartered in Boulder, Colorado, and employs c50 people. It aims to “unlock, vast stranded copper resources” via a breakthrough technology. This matters as our roadmap to net zero sees global copper demand rising 3x by 2050.

The company has raised $100M via a Series D financing round in October-2022, valuing Jetti at $2.5bn. Its technology is being used in two commercial deployments, including Capstone Copper’s Pinto Valley Mine in Arizona.

The technology extracts copper from low-grade sulfides, which make up 70% of the world’s copper resources, worth $20trn, such as chalcopyrite, the most common copper mineral ore.

However, these challenging ores are currently stranded. The copper cannot be leached out using sulphuric acid and then electrowon; as a passivation layer forms on the surface of sulfide ores. And the financial and environmental costs of transporting these ores to Asian smelters are also high.

We have reviewed Jetti Resources’ technology. Its patent library is concentrated, with two particularly clear patents, containing some of the most detailed experimental data that has crossed our screens in all of our patent reviews (the chart below shows how thiourea, and other reagents, enhances copper recovery). We can partly de-risk the technology based on our patent review. It does seem like a technical breakthrough.

Some variants in the patents also show a complementary benefit combining thiocarbonyls with carbon black, which raises the intriguing possibility of providing an offtake for the carbon black coming out of turquoise hydrogen plants.

There are four major challenges to explore, based on our Jetti Resources technology review. They include thiocarbonyl pricing (and resultant copper pricing), thiocarbonyl quantities needed (i.e., kg of thiourea per kg of copper recovery), environmental credentials and the need for co-reagents. There could be variants of the process that are as expensive and CO2-intensive as conventional copper smelting. Data are tabulated and discussed in the data-file.

Tigercat: forestry and timber innovations?

Tigercat patent review

Tigercat is a private company, founded in 1992, headquartered in Ontario, Canada, with c2,000 employees. The company produces specialized machinery for forestry, logging, materials processing and off-road equipment. Our Tigercat patent review has found a moat around reliable, easy-to-maintain, mobile and efficient forestry equipment.

In the modern forestry industry, we think a crew of 1 x feller buncher, 1 x skidder and 1 x loader can harvest 250 tons of timber per day, with a fuel economy of 1.2 gals/ton of wood. This kind of productivity is up at least 150x from pre-industrial forestry.

We wonder whether there is increasing opportunity for companies in the forestry supply chains, as themes such as sustainable timber (e.g., cross-laminated timber), sustainable forestry, reforestation, sustainable packaging and biochar gain traction in the energy transition.

A key challenge for the industry is that off road machines are subject to higher stress levels, and forestry machines are subject to even higher stress levels. Key components subject to very severe operating loads are axles, wheel spindles, drivetrain components and pump drive gearboxes.

Overall, our Tigercat patent review finds an array of specific, intelligible and focused patents, improving the reliability, maintainability, mobility and fuel economy of forestry equipment.

This is especially applicable for harvesting equipment, such as feller-bunchers, mulching equipment, and novel areas that may matter in the energy transition such as site preparation, re-planting and biochar production. These are all focus areas in the patents.

We have profiled the CO2 credentials of different wood uses as part of our ongoing forestry research.

Agilyx: plastic recycling breakthrough?

Review of Agilyx's plastic recycling technology

This data-file is a review of Agilyx’s plastic recycling technology, after assessing the company’s patents on our usual framework. We conclude that Agilyx has developed a novel and data-driven process, to remove challenging contaminants from feedstocks. Although it may involve higher complexity, higher reagent opex, and some challenges cannot entirely be de-risked from the patents.

Agilyx is a public company listed on the Oslo Euronext Growth, headquartered in Oslo, Norway, with presence in New Hampshire, Oregon, Switzerland and Denmark. The company has 90 employees at YE21.

Its commercial model is to license IP for categorizing thousands of different types of post-consumer plastics (on a royalty basis per kg), license its conversion technology for subsequent pre-processing and pyrolysis of those waste plastics, and also to sell patented equipment.

Agilyx’s long-term mission is to help increase the world’s share of 300MTpa of recycled plastic waste from 10% to 90%. Along the way, its goal is to be the “fastest growing and most profitable plastic recycling technology company”. The synthetic crude oil thereby created is envisaged to be lower carbon than conventional crude oil or virgin feedstock.

As its moat, Agilyx states “we are the only company in the market to offer an integrated solution for chemical recycling and feedstock management… [including] a proprietary technology for identifying, managing and pre-processing [plastic] waste” then breaking it down into synthetic crude oil using a pyrolysis process.

This data-file is a review of Agilyx’s plastic recycling technology. Based on its patents, we infer that Agilyx has developed an intriguing and novel approach to plastic recycling. We think it uses a large database to identify likely hetero-atom contaminants in mixed plastic waste, tailors alkali amendments to those contaminants prior to the pyrolysis stage, pyrolyses the mixture, quenches cracked gaseous hydrocarbons from the reactor, then polishes the depolymerized hydrocarbons by passing them through caustic process solutions that remove impurities. This is explained in the data-file.

However, we cannot entirely de-risk the technology based on the patents, while there are also some challenges from the patent library, including around operating conditions, complexity and operating costs. We have been following the next-gen plastic recycling theme since 2019. There is extremely exciting potential for plastic pyrolysis, but mixed progress to-date, including in 2022. Further and broader details are found in our plastic research.

Sentient Energy: smart grid breakthrough?

Technology review for Sentient Energy

This data-file is a technology review for Sentient Energy, assessing innovations in smart grids. Its technology can achieve energy savings via a combination of “Conservation Voltage Reduction” and “Volt-VAR optimization at the grid edge”. This also helps to integrate more solar and EV charging into power grids. We will explain the technology below and in the data-file.

Sentient Energy is as an “intelligent sensing platform for grid utilities”, helping power utilities to identify and remediate grid issues. It has “the largest mesh network line sensor deployments in North America”. It is a private company. It was founded in 2009, headquartered in Frisco, TX and employs around 150 people. Its products are used by over 25 of North America’s largest utilities, and have helped reduced outage time by 20%, patrol costs by 60% and clocked up 1bn+ intelligent sensor hours in the field.

Volt-VAR optimization at the grid edge is the focus in about one-third of Sentient’s patents, and the focus in our technology review. So what does this mean?

Why does Volt-VAR optimization matter? Imagine a group of houses, all connected to a single grid loop. Nominally, all of them “draw power at 120 Volts”. But in practice, voltage falls off slightly, as you get further from the sub-station (look at the green dots in the chart below). This is because the inevitable creation of electro-magnetic fields “consumes reactive power” (VARs). Park this thought for now.

Sometimes the grid is strained, power prices are very high, and there is a risk of load-shedding. In times like this, it is common for a utility to save energy via “Conservation Voltage Reduction”. If you remember that Power = Voltage x Current, then clearly you can save power by lowering the voltage at the sub-station by 1-5%. It might take a little bit longer for the kettle to boil. But basically nothing is going to break.

What limits Conservation Voltage Reduction is that there is a minimum acceptable voltage. No customer should see their voltage fall below this level. And thus in our image below, we can only lower the voltage at the sub-station by 4 Volts before the ‘pink dots’ below, which tend to be customers furthest from the sub-station, hit the lower limit. But most of the time, a utility is simply guessing here. It has data about the sub-station, which it owns and operates. But it may have hardly any data at all about what is happening downstream of the sub-station.

Technology review for Sentient Energy

Enter “Volt-VAR optimization at the grid edge”. The idea is to place dozens of smart optimization devices around the grid. They can detect the voltage in real time, and they can “inject reactive power” to boost voltage at the critical places where voltage is becoming unacceptably low. There have been several studies and over 10,000 deployments of these devices to date. They can typically increase the power savings during Conservation Voltage Reduction by 2-3x. I.e., during times when power grids are under-supplied, total energy savings of 3-5% can safely be achieved, by safely lowering the sub-station voltage, almost imperceptibly for customers.

This also helps smooth the volatility of solar. One study has shown a 72% reduction in voltage volatility from installing a swarm of grid-edge optimization devices. In turn, this kind of improvement in a grid’s ability to tolerate voltage fluctuations can unlock something like 45% more solar hosting capacity. If smart inverters and dynamic voltage controllers are employed together, than the solar hosting capability can be improved by 60%.

Related research, which may be helpful in explaining the terminology in this short note includes our overview of how power grids work, overview of reactive power compensation, long-distance power transmission, transformers and how hot temperatures strain power grids. We think optimization of the power grid is going to be a $1trn pa opportunity in the energy transition.

In conclusion, our technology review for Sentient Energy finds 3-5% energy savings and great solar penetration can be achieved using smart energy systems. Our assessment on Sentient Energy’s technology, the moat in its patents, and further data-points gleaned from its white papers can be found in the data-file below.

Powin: grid-scale battery breakthrough?

Powin technology review

Powin commercializes energy storage solutions. Its hardware and software are branded as ‘Powin Stack’ and ‘Stack OS’. Hence we have used our usual patent framework to conduct a Powin technology review.

Powin — Company and Patent Review

Powin is privately owned. Its roots go back to 1989. It is based in Portland, Oregon. And it has c300 employees at the time of writing. By 2022, the company has delivered 2.5 GWH of storage projects.

Our Powin technology review finds a moat around specific process improvements for the installation and operation of grid-scale batteries. These are described in the data-file.

Overall, the patent library scores well on our patent framework. The patent library is robust enough to deter simple copy-catting. Although there may also be some controversy around the differentiation of some patent claims. (Differentiation is always a question mark for companies in these kinds of supply chains).

Advantages of Powin’s battery systems are their modularity, streamlined installation and software. A guideline is 200 MWH-AC of storage per acre. This is 30% more compact than other solutions. The total time to procure a Centipede system, of inter-connected Powin battery modules, is c50% less than stick-built solutions.

Our patent review found that half of Powin’s IP is software-side. This includes smart features allowing operators to control the way batteries are balanced. The technology also tracks whether batteries are still covered within warranty, on systems envisaged to have a 20-year life.

Context for grid-scale batteries

Grid-scale batteries are growing increasingly important, especially in regions with high renewables penetrations, to backstop the short-term volatility of solar and short-term volatility of wind.

The chart below captures 30 deployments of Powin battery systems. They range from 1 – 90 MW. These deployments have been growing more frequent, and larger.

Interestingly, some recent solar projects have elected to construct 0.2 – 1.0 MW of battery capacity per MW of solar capacity.

Powin technology review

Our full conclusions on Powin’s patents and technology, and the data behind charts, are spelled out in the data-file…

X Energy: nuclear fuel breakthrough?

X-Energy technology review

X-Energy Technology Review. X-Energy is a private, next-generation nuclear company, founded in 2009, headquartered in Maryland, USA with c300-employees at the time of writing. Its reactor design is a high-temperature, gas-cooled reactor (HTGR), commercializing 80MWe of electricity from c200MWth of heat.

Progress and economics. A $2.4bn advanced demonstration project is being progressed in Washington State, for start-up in 2027, half of which will be funded by the DOE (the other main recipient is TerraPower). Ultimately, levelized costs of 6c/kWh are targeted (these are very competitive levelized costs).

X-Energy’s key innovation is using an inherently safe TRISO fuel. TRISO fuel comprises ‘TRI-structural ISO-tropic fuel” particles. Each of these particles is around 0.85mm wide, and contains a 15.5% enriched uranium core (HALEU), surrounded by a porous layer of graphite, then three further containment layers of dense carbon and ceramic, to make the particle “the most robust nuclear fuel on Earth”. It cannot melt or melt down. This enables a simplified reactor design, using 220,000 x 60mm ‘fuel pebbles’, each containing around 19,000 TRISO fuel particles.

What stands out about X Energy’s patents is that they are substantively all focused on manufacturing its TRISO fuel, and they score very highly on our usual patent framework. Specifically, our work reviews a concentrated library of patents focused on manufacturing TRISO particles from gels of enriched uranium oxides, which are then coated with protective layers, using chemical vapor deposition. Many of the patents specify precise reagents and reaction conditions, backed up with experimental data and detailed design drawings. Hence our X-Energy technology review suggests a moat around the core IP.

Prysmian: power cable technology breakthroughs?

Prysmian power cable technology

Prysmian is a public company, with history going back to 1879, and €12bn of revenues in 2021. It is headquartered in Milan, with 29,000 employees, operating 108 cabling solutions plants in 50 countries. But can we find a Prysmian power cable technology ‘moat’, or de-risk future project delivery by reviewing Prysmian’s recent patents?

We are increasingly excited by an up-cycle in power transmission, associated with the build-out of renewables. To this end, 75% of Prysmian’s business is energy (50% is power-infrastructure, 22% is industrial and network solutions, 13% project work, 12% telecoms). The company has inter-connected 35 large wind farms in the past decade and run 30 inter-connectors.

After reviewing recent patent filings, we conclude that Prysmian has developed a partial moat across multiple, incremental improvements and specializations in cabling solutions, and its R&D has likely also lowered future installation risks on lump-sum turnkey contracts.

Large power cables are challenging, because current flows generate heat via the Joule effect. Power cables must not heat up above 90C, or it can cause safety issues and damage to materials. Another challenge for cables is water-proofing, especially in deep water, as any water that penetrates the cable could flash to steam, cause damage, and corrode the conducting metals. Another challenge is installing cables without damaging them, in non-accessible spaces or deep water, which is achieved by wrapping metallic armor around the cables, although this increases weight. A 400kV cable can weigh 40kg/meter.

Against this backdrop, Prysmian scores well on our usual patent assessment framework, with specific, clear, intelligible and manufacturing-focused patent filings; and many interesting technical disclosures around its optical and power cabling solutions: from real-simplified testing while installing ultra-deepwater HVDCs to cooling EV fast-charging cables. Full details on Prysmian power cable technology are in the data-file.

Nostromo: thermal energy storage breakthrough?

Nostromo technology review

Nostromo technology review. Nostromo is a public company, founded in 2016, with c40 employees in Israel and California. Website here. It is commercializing a thermal energy storage system, which integrates with AC, to store coolness (e.g., during peak wind/solar generation), then re-release the coolness at ‘peakload’, (e.g., in mid-late afternoon, or after sunset).

The flagship product is called ‘IceBrick’, a modular, water-based energy storage cell, which can be retro-fitted onto most commercial buildings in about 4-6 months. It claims 86-92% round-trip energy efficiency, 94% depth of discharge over 4-hours and <1% degradation over 20-years.

We have reviewed the company’s patents on our usual patent framework. Nostromo’s patent library is concentrated, but it scores highly on our framework, as it lays out specific challenges that have hampered other designs, very specific details on how Nostromo’s system improves efficiency and consistency, and the patent library is also easy-to-understand, focused and considers deployments.

The technology is an exciting alternative and complement to lithium ion batteries for energy storage, or more specifically demand shifting. It may be particularly well-suited to commercial buildings in hot climates, where AC can comprise 50% of peakload power generation, per our note here. The main challenge is system costs, explored in the data-file and compared with lithium cells and lithium battery storage. Finally, we think there may be other applications of phase change materials that do not simply accomplish energy storage, but also reductions in total energy consumption (note here).

Full details of our Nostromo technology review can be downloaded in our data-file below.

Further conclusions are linked in the recent article sent out to our distribution list, here.

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