Transformers: rise of the beasts?

A transformer is needed to step the voltage up or down at every inter-connection point in the grid. Hence this 14-page note explores how renewables and EVs will expand future transformer markets. The main challenge is that the need for smaller, simpler units may exacerbate margin pressure in an already competitive industry. So who is best-placed?


It is sometimes said that ‘electrification is the future’ or that the 21st century energy system will primarily be about ‘moving electrons’. So how do you actually “move electrons”? The physics of power distribution and transformers are explained on pages 2-6.

What is changing in the energy transition is that renewables and EV chargers are being added to the grid. Each inter-connection likely requires a transformer. The market impacts are quantified on pages 7-10.

What costs and consequences? We break down the cost of transformers on pages 11-12, with upside for specific raw materials. Recent raw material inflation has already increased transformer costs c12% in 2021. Deploying more renewables will create mild inflation in transformer costs (in c/kWh) for downstream power consumers.

Who benefits? The commercial landscape is explored on pages 13-14, including a screen of leading companies that manufacture transformers. The market is competitive. Hence we focus on who might be better-placed.

Shifting demand: can renewables reach 50% of grids?

25% of the power grid could realistically become ‘flexible’, shifting its demand across days, even weeks. This is the lowest cost and most thermodynamically efficient route to fit more wind and solar into power grids. We are upgrading our renewables ceilings from 40% to 50%. This 22-page note outlines the growing opportunity in demand shifting.


Renewables would struggle to reach 50% penetration of today’s grids, due to their volatility. Pages 2-7 quantify the challenges, which include capacity payments for non-renewable back-ups, negative power pricing >20% of the time, >10% curtailment and 30% marginal cost re-inflation for new projects.

But a greater share of renewables would help decarbonization. This objective is explained on page 8, showing the relative costs and CO2-intensities of electricity technologies.

Renewable electricity storage is not the solution. It is costly and thermodynamically inefficient, which actually dilutes the impact of renewables. Costs and efficiency losses are quantified for batteries and for hydrogen on pages 9-11.

Demand shifting is a vastly superior solution. Pages 12-17 outline half-a-dozen demand-shifting opportunities that have been profiled in our research to-date. Companies in the smart energy supply chain are also noted and screened.

What impacts? We model that up to 25% of the grid can ultimately be demand-flexible, while this can help accommodate an additional 10pp share for renewables in the grid, before extreme volatility begins to bite (see pages 18-19).

Europe leads, and we now assume renewables can reach 50% of its power grid by 2050, with follow-through consequences for our gas and power models (page 20).

Our global renewables forecasts are not upgraded, as the bottleneck on a global basis is simply annual capacity additions, which must treble between 2020 and 2050, in our roadmap to ‘net zero’. (pages 21-22).

Vertical greenhouses: what future in the transition?

Vertical greenhouses achieve 10-400x greater yields per acre than field-growing, by stacking layers of plants indoors, and illuminating each layer with LEDs. Economics are exciting. CO2 intensity varies. But it can be carbon-negative in principle. This 17-page case study illustrates how supply chains are localizing and more renewables can be integrated into grids.


The first rationale for vertical greenhouses is to grow food closer to the consumer, which can save 0.6kg of trucking CO2 per kg of food. Eliminating freight is much simpler than decarbonizing freight (pages 2-4).

The second rationale for vertical greenhouses is that they are 10-400x more productive per unit of land, hence they can free up farmland for reforestation projects that absorb CO2 from the atmosphere (pages 5-6).

The third rationale for vertical greenhouses is that their LED lighting demands are flexible, which means they can absorb excess wind and solar, in grids that are increasingly laden with renewables. They are much more economical at achieving this feat than batteries or hydrogen electrolysers (pages 7-10).

The overall CO2 intensity of vertical greenhouses depends on the underlying grid’s CO2 intensity, but the process can in principle become carbon negative (pages 11-13).

The economics are exciting. We model 10% IRRs selling fresh produce at competitive prices, with upside to 30% IRRs if fresher produce earns a premium or operations can be powered with low-cost renewables when the grid is over-saturated (pages 14-15).

Leading companies in vertical greenhouses and in their supply chain are discussed on pages 16-17.

Prevailing wind: new opportunities in grid volatility?

UK wind power has almost trebled since 2016. But its output is volatile, now varying between 0-50% of the total grid. Hence this 14-page note assesses the volatility, using granular, hour-by-hour data from 2020. EV charging and smart energy systems screen as the best new opportunities. Gas-fired backups also remain crucial to ensure grid stability. The outlook for grid-scale batteries has actually worsened. Finally, downside risks are quantified for future realized wind power prices.


This rise of renewables in the UK power grid is profiled on page 2, showing how wind has displaced coal and gas to-date.

But wind is volatile, as is shown on page 3, thus the hourly volatility within the UK grid is 2.5x higher than in 2016.

Power prices have debatably increased due to the scale-up of wind, as shown on page 4.

But price volatility measures are mixed, as presented on pages 5-6. We conclude that the latest data actually challenge the case for grid-scale batteries and green hydrogen.

Downside volatility has increased most, as is quantified on pages 7-8, finding a vast acceleration in negative power pricing, particularly in 2020.

The best opportunities are therefore in absorbing excess wind power. EV charging and smart energy systems are shown to be best-placed to benefit, on pages 9-10.

Upside volatility in power prices has not increased yet, but it will do, if gas plants shutter. The challenge is presented on pages 11-13, including comparisons with Californian solar.

Future power prices realized by wind assets are also likely to be lower than the average power prices across the UK grid, as is quantified on page 14. This may be a risk for unsubsidized wind projects, or when contracts for difference have expired.

Geothermal energy: what future in the transition?

Drilling wells and lifting fluids to the surface are core skills in the oil and gas industry. Hence could geothermal be a natural fit in the energy transition? This 17-page note finds next-generation geothermal economics can be very competitive, both for power and heat. Pilot projects are accelerating and new companies are forming. But the greatest challenge is execution, which may give a natural advantage to incumbent oil and gas companies.


The development of the geothermal industry to-date is summarized on pages 2-4. We also explain the rationale for geothermal in the energy transition.

The costs of a geothermal projects can be disaggregated across wells (page 5), pumping (page 6-7) and power turbines (pages 8-9). We draw out rules of thumb, to help you understand the energy economics.

The greatest challenge is geological complexity, as argued on page 10. It is crucial to find the best rocks and mitigate execution risks.

Base case economics? Our estimates of marginal costs are presented for traditional geothermal power (page 11), next-generation deep geothermal electricity (page 12) and using geothermal heat directly (page 13).

Leading companies are profiled on pages 14-16, after tabulating 8,000 patents. We also reviewed incumbent suppliers, novel pilots, and earlier-stage companies.

We conclude that geothermal energy is a natural fit for incumbent oil and gas companies to diversify into renewables, and arguably a much better fit than wind and solar (page 17).

Biomass and BECCS: what future in the transition?

20% of Europe’s renewable electricity currently comes from biomass, mainly wood pellets, burned in facilities such as Drax’s 2.6GW Yorkshire plant. But what are the economics and prospects for biomass power as the energy transition evolves? This 18-page analysis leaves us cautious.


Arguments in favor of biomass are outlined on pages 2-3, using the carbon cycle to show how biomass could be considered zero-carbon in principle.

Examples of biomass power plants are described on pages 4-5, focusing upon Drax and RWE, and drawing upon data from 340 woody biomass facilities in US power.

The economics of producing biomass pellets are presented on pages 6-7, including a detailed description, capex breakdown, and critique of input assumptions.

The economics of burning biomass pellets to generate electricity are presented on pages 8-9, again with a detailed description and critique of input assumptions.

The economics of capturing and disposing of the CO2 are presented on pages 10-12, allowing us to build up a full end-to-end abatement cost for BECCS.

Energy economics are disaggregated on pages 13-14, in order to derive a measure of energy return on energy invested (EROEI) and CO2 intensity (in kg/kWh). Surprisingly, we find the EROEI for BECCS to be negative.

Is it sustainable? We answer this question on 15-17, arguing that biomass energy and BEECS, properly considered, both have a higher CO2 intensity than gas.

Conclusions and implications are presented on pages 18, including bridges for the total CO2 intensity of biomass and BECCS.

Decarbonized power: how much wind and solar fit the optimal grid?

What should future power grids look like? Our 24-page note optimizes cost, resiliency and CO2, using a Monte Carlo model. Renewables should not surpass 45-50%. By this point, over 70% of new wind and solar will fail to dispatch, while incentive prices will have trebled. Batteries help little. They raise power prices by a further 2-5x to accommodate just 3-15% more renewables. The lowest-cost, zero-carbon power grid, we find, comprises c25% renewables, c25% nuclear and c50% decarbonized gas, with an incentive price of 9c/kWh.


Pages 2-4 illustrate the volatility of wind and solar generation at today’s grid penetration, providing rules of thumb around intermittency.

Pages 5-6 illustrate the strange consequences once renewables surpass 25% of the grid, including curtailment, negative power pricing and financing difficulties.

Pages 7-9 quantify and explain how much curtailment will take place in a typical grid as renewables scale from 25% to 40%, 50% and 60% of gross generation, using a Monte Carlo approach. The model shows when and why curtailment is occurring.

Pages 10-20 quantify and explain the costs of batteries, to backstop renewables as they scale from 25%, to 40%, 50% and 60% of the grid, while avoiding curtailment. Real world conditions are not conducive to competitive battery economics.

Pages 21-23 quantify the residual reliance on natural gas. Amazingly, even our most aggressive battery scenarios only permit 10% of gas-power capacity to be shuttered. Low-utilization gas is costly. High-utilization gas is less costly. And the economics of decarbonized gas are superior to any renewables plus batteries combination.

Page 24 concludes that natural gas will emerge as the ‘best battery’ to backstop renewables, estimating the most likely shares in an optimal power mix.