Solar surface: silver thrifting?

Silver intensity in the solar industry

Ramping new energies is creating bottlenecks in materials. But how much can material use be thrifted away? This 13-page note is a case study of silver intensity in the solar industry, which halved in the past decade, and could halve again. Conclusions matter for solar companies, silver markets, other bottlenecks.

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 here.

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.

Silicon carbide: faster switching?

Silicon carbide power electronics

Silicon carbide power electronics will jolt the energy transition forwards, displacing silicon, and improving the efficiency of most new energies by 1-10 pp. Hence we wonder if this disruptor will surprise to the upside, quintupling by 2027. This 12-page note reviews the technology, advantages, challenges, and who benefits?

Thermodynamics: Carnot, Rankine, Brayton & beyond?

Thermodynamic cycles

Engines convert heat into work. They are governed by thermodynamics. This note is not a 1,000 page textbook. The goal is to explain different heat engines, simply, in 13-pages, covering what we think decision makers in the energy transition should know. The theory underpins the appeal of electrification, ultra-efficient gas turbines, CHPs, nuclear HTGRs and new super-critical CO2 power cycles.

Decarbonized gas: ship LNG out, take CO2 back?

Transport CO2 in LNG carriers

This note explores an option to decarbonize global LNG: (i) capture the CO2 from combusting natural gas (ii) liquefy it, including heat exchange with the LNG regas stream, then (iii) send the liquid CO2 back for disposal in the return journey of the LNG tanker. There are some logistical headaches, but no technical show-stoppers. Abatement cost is c$100/ton.

Global energy: ten themes for 2023?

Predictions for global energy in 2023

This 14-page note lays out our top ten predictions for global energy in 2023. Brace yourself for volatility, a recession due to energy shortages, and deepening bottlenecks on accelerating new energies? However, the biggest change for 2023 is that an energy super-cycle is now gradually coming into view.

Decarbonizing global energy: the route to net zero?

Roadmap to Net Zero

This 17-page report revisits our roadmap for the world to reach ‘net zero’ by 2050, after integrating over 1,000 pieces of research from 2019 through 2022. Our updated roadmap includes large upgrades for renewables and energy efficiency; less reliance on new energies breakthroughs; but most of all, simple, pragmatic progress is needed as bottlenecks and shortages loom.

Nature based solutions: CO2 removals in 2022?

Market for nature based carbon offsets

Is the nascent market for nature-based carbon offsets working? We appraised five projects in 2022, and contributed $7,700 to capture 440 tons of CO2, which is 20x our own CO2 footprint. This 11-page note presents our top five conclusions. Today’s market lacks depth and efficiency. High-quality credits are most bottlenecked. Prices rise further in 2023. A new wave of projects is emerging?

Electrification: the rings of power?

Electrification in the energy transition

Electrification is the largest, most overlooked, most misunderstood part of the energy transition. Hence this 10-page note aims to explain the upside, simply and clearly. Electricity rises from 40% of total useful energy today to 60% by 2050. Within the next decade, this adds $2trn to the enterprise value of capital goods companies in power grids and power electronics.

CO2 offsets: Pachama’s AI platform?

Pachama CO2 offset review

Pachama is a nature-based technology company, which has raised $79M, to create a portal where buyers can choose “from rigorously vetted forest restoration and conservation projects”, which in turn are tracked using proprietary AI. This data-file is a Pachama CO2 offset review. We have assessed the portfolio, some challenges and our own experiences, via our usual framework for assessing nature-based CO2 removals.


As of November-2022, the majority of projects available on Pachama’s portal are avoided emissions projects. These are excellent conservation projects, accredited by VERRA, protecting vulnerable eco-systems, and achieving some of the highest biodiversity scores of any projects that have crossed our screens.

However, it remains debatable whether these projects can be considered to be “offsetting CO2”. CO2 credits are not being awarded for pulling additional CO2 out of the sky and storing it in a natural eco-system, as per other CO2 removal projects that we have assessed.

Rather, CO2 offsets are being issued relative to a hypothetical scenario where a protected forest is deforested at a rate of 1-2% per year (varies by project) over the next 20-70 years (chart below).

We think that over time, Pachama would like to seed new forests, and more incremental projects on its platform, but for now there is limited depth in the nature-based CO2 market, and most of the certified CO2 offset projects are REDD (conservation) projects.

In one of the largest CO2 offset projects in the Pachama portfolio today, CO2 offsets are issued relative to a scenario whether a carbon-dense, 26-000 year old peatland is drained and thus caused to release c500MT of CO2. Blue carbon eco-systems can store a lot of carbon, over 1,000 tons/hectare, possibly over 2,000 tons/hectare. But 500MT is a truly enormous number. It is equivalent to the direct annual emissions of the entire global fertilizer industry per our CO2 breakdown. This raises some question marks.

It gets a bit philosophical, but in our view, carbon “offsetting” should be about cancelling out the net impacts of emitting +X tons of unavoidable CO2 into the atmosphere by pulling out -X tons of CO2 from the atmosphere and sequestering it over the long-term. Not by avoiding a further +X tons of emissions. (Morally, you cannot atone for a murder by enumerating the list of people you have not murdered !!).

We want to support conservation of nature, and high-quality organizations in nature-based solutions; and so we allocated $700 to offset 40 tons of CO2 from the Pachama portfolio at the current price of $17.6/ton. However, our overall experience was somewhat disappointing: per the Pachama website, we thought we were buying from “Pachama’s global portfolio of high-quality forest projects” (screenshot above). But after making the purchase, all of our purchase ended up allocated to the single, large peat conservation project, described above.

Further details on our Pachama CO2 offset review are in the data-file. We have also appraised other CO2 removal projects using the same framework.

Copyright: Thunder Said Energy, 2019-2023.