A new optimistic Nature paper from the LUT University in Finland looks to a key role being played by renewables for rapid transitioning of the power sector across states in India. Progress has been uneven at times, but LUT says that a renewables-based power system by 2050 could be ‘lower in cost than the current coal dominated system’ and have ‘zero greenhouse gas emissions’ while providing ‘reliable electricity to around 1.7 billion people’.
Electricity generation would be based on solar PV, wind energy, and hydropower, while batteries and multi-fuel reciprocating internal combustion engines based on synthetic fuels provide the required flexibility to the power system. This transition, it says, would ‘address multiple imperatives: affordability, accessibility, and sustainability without compromising economic growth’.
Solar PV capacity increases in all the states during the transition, and from 2030 onwards, PV has a steady average annual growth rate of 35% across the states of India, as PV supported by batteries dominate the installed capacities, reaching almost 3000 GW by 2050. By contrast, annual growth in wind capacities slows down during this period, due to the better cost competitiveness of solar PV, which is the main source of electricity generation, with a share of about 77% in the total installed capacity across India in 2050. Total wind capacity in the country by 2050 is about 410 GW (19%), while hydro is only 3%. Nuclear drops off to just 0.4% by 2050. There is still then some vestiges of coal and gas use in the power sector in some locations, but in most places they have been squeezed to marginal levels.
The variable renewables that replace them will have to been balanced, and to do that the scenario has the installed electricity storage capacity increasing from about 22 TWh in 2030 to around 95 TWh by 2050. The LUT team says that ‘utility-scale and prosumer batteries contribute to a major share of the electricity storage output, with more than 98% by 2050, due to their low cost and high round trip efficiency, as diurnal storage requirements increase considerably by 2050’. But green power-to-gas (P2G) synthetic hydrogen and methane is also used for longer term storage. The team say that ‘in a power-to-gas process, renewable electricity is used to capture carbon dioxide (CO2) from the air using direct air capture units and in the process of electrolysis, separating hydrogen (H2) from water. In the next step, these two gases are combined in a methanation process to produce synthetic methane (e-methane). The low capex of gas storage results in large capacities being installed during the transition, but only contributes to the vital seasonal storage through the transition.’
DAC
LUT is clearly keen on P2G plus Direct Air Capture and Utilisation for synfuel production, as opposed to zero carbon P2G hydrogen production. The merits of the various types of carbon capture are debatable. Making synfuel from captured CO2 and green hydrogen via ‘DACU’ may add flexibility, but, arguably, it also adds costs, and carbon is put back into the air when the synfuel is burnt. Direct Air Capture and Storage avoids that, but then you have to invest in storage and you don’t produce a fuel. You just take CO2 out of the atmosphere- but at least you don’t put it back.
Some say that while natural carbon sequestration by plant, soil and trees may be helpful, artificial carbon removal is not worth the effort, but there is an ongoing debate over the pros and cons of DACU versus DACS, with some claiming merit for each, but with DACS sometimes being favoured as lower carbon. For their part, some members of LUT, in another paper, have pushed for the use of DACU and so called e-fuels and e-chemicals in ‘hard to decarbonise’ industry. Indeed, LUT look to there being growing global demand for carbon dioxide. Can that really be done in a low or even carbon neutral way? LUT seems to think so, and, in the context of their Indian paper, they have electrolysers playing a key role, including for synfuel production, with 407 GW installed by 2050. A huge expansion…
This Indian scenario is just for the power sector. In addition, of course, there would be heat and transport needs to meet, with LUT assuming that electricity would be a mainstay, although synfuels may also be important. But as the team conclude, one thing is clear, ‘as the share of renewables increases across the different states, storage technologies, especially batteries and the transmission grid provide much needed flexibility during the transition, without increasing the total cost of the system. The system’s LCOE decreases from 71 €/MWh in 2020 to 38 €/MWh by 2050’. That’s very impressive. Let’s hope it is also realistic!
East and West
China, with now over 1000 GW of renewables capacity in place, has clearly opened a pathway to renewables, which others in the region, like India, may follow. India certainly has the potential. But so do other parts of the region. For example, IRENA says that the ten-member Association of Southeast Asian Nations (ASEAN) can also accelerate ahead and meet its growing energy demand with renewables, while cutting 75% of energy-related CO2 emissions by 2050, and saving $160bn in energy costs.
One way or another, the East could be going green…but then so could the whole world, and go beyond 90%, according to a new paper from the US National Renewable Energy Labs/Department of Energy. It’s focused on the problem of getting the ‘last 10%’ of carbon out of the global power system. There’s still some way to go before we need to do that in practice, and they note that some pathways rely ‘on a wide range of emerging technologies to meet a small fraction of demand’. But they look for candidates at all of the non-fossil options, including yet more renewables, fossil-free hydrogen, nuclear and carbon capture, as well also multi-day demand-side resources.
Exploring how it might be done, they compare ‘economic factors associated with the low-utilization condition and discuss unique challenges of each option to inform the complex assessments needed to identify a portfolio that could achieve carbon-free electricity’. It may be a bit premature to specify all the details, but it is helpful, in general terms, to see if we can reach 100% non-carbon globally, as LUT has tried to do for India, as well as it, and EWG, has also attempted to do for most other countries. Certainly they think it is possible, though whether it will actually happen around the world remains to be seen- with, in key areas, things going a bit slower at present, due in part to the gas price shocks. Even so, the prospect for the future do look promising.
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