Pieces — Renewables FAQ
Renewables FAQ
Is battery technology good enough yet? What are the limits on cost and capacity?
Making renewables the mainstay of the system runs straight into questions about batteries: is the technology there yet, and are cost and capacity constrained? In 2025 the cost of four-hour storage fell to a record US$78/MWh, and annual deployment passed 100 GW worldwide for the first time. Long-duration storage, over days and seasons, remains a frontier. This piece sets out the technology trends from lithium-ion to sodium-ion, the dividing line between short and long duration, and the market design problems in Japan — separating what is in practical use from what is still to be developed.
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Renewables FAQ
Why do some countries push renewables while others do not?
Why does the pace of renewable deployment differ so widely between countries? Wind and solar are the core of the system in Germany and Denmark, while the transition stalls in Japan, South Korea and the fossil fuel producers. Leaving aside vague explanations about leadership or national character, this piece uses data from the IEA, IRENA and Ember to compare countries along five axes: resource endowment and fossil dependence, the predictability of policy, market structure and incumbents, social acceptance and local participation, and integration with finance and industrial policy.
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Renewables FAQ
Does raising the share of renewables actually work as climate policy?
Does expanding renewables really cut emissions? This piece answers with international data and life-cycle assessment: emissions intensity in the power sector has fallen sharply wherever the renewable share has risen, and even counting manufacturing, solar and wind emit a twentieth to an eightieth of coal. But the power sector is only about a third of emissions, so renewables have to move together with electrifying transport, buildings and industry. Renewables work — on conditions, and those conditions are the real argument.
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Renewables FAQ
From an energy security standpoint, how risky is importing renewable equipment?
Japanese energy security debates often hold that renewables leave the country dangerously dependent on China. It is true that solar panels, turbines, lithium batteries and mineral refining are concentrated there. But Japan's primary energy self-sufficiency is 12.6%, the lowest in the OECD, and fossil fuel imports run to ¥30 trillion a year — a far larger exposure. This piece compares dependence on Middle Eastern and Russian fossil fuels with a China-weighted renewable supply chain, and frames the shift as one from a continuous dependence on fuel to a one-off dependence on equipment and minerals.
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Renewables FAQ
Doesn't manufacturing wind turbines emit CO₂ and consume rare earths?
Wind power is often accused of emitting so much CO₂ in manufacturing, and consuming so many rare earths, that it defeats its own purpose. Read the international data carefully and life-cycle emissions come to a seventieth to a ninetieth of coal's, onshore and offshore alike, with energy payback around a year. The real issues lie elsewhere: neodymium magnets in direct-drive turbines, China's grip on rare earth supply, and what happens to blades at the end of their lives. This piece brings the LCA figures, the bill of materials, the mineral supply chain, blade recycling and Japanese policy together in one view.
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Renewables FAQ
Doesn't manufacturing solar panels emit CO₂ and consume rare metals?
Solar is often criticised over the CO₂ of manufacturing and the consumption of rare metals. The latest life-cycle analyses show modern crystalline silicon panels repaying the energy of their manufacture in one to three years and emitting a twentieth to a fortieth of what coal does. This piece works through energy payback time and what panels are actually made of — silicon, glass, aluminium, copper, silver — separates the image of scarce metals from the reality, and sets out the issues that genuinely deserve attention: the concentration of manufacturing in China, human rights, and the state of recycling.
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Renewables FAQ
Does electrotech really create jobs, or does it destroy the ones we have?
Do renewables, batteries, EVs and heat pumps create work, or take it away from coal plants and the car industry? Using the latest figures from IRENA, the IEA and others, alongside Japan's industrial structure, this piece looks at how many jobs are lost, where the new ones appear and in what numbers — and at what a just transition requires from policy.
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Renewables FAQ
Can renewables supply all our energy with today's technology?
Is a 100% renewable society really a fantasy? Several countries and regions already run their electricity systems on renewables alone, and international bodies keep publishing scenarios in which heat, transport and industry as well as power are almost entirely renewable by 2050. This piece separates primary from final energy, works through the options in electricity, heat, transport and industry, covers green hydrogen and synthetic fuels, and sets out Japan's potential and the institutional constraints — asking what is genuinely possible today and where the real bottleneck lies.
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Renewables FAQ
Don't large solar farms destroy forests and landscapes?
Are large solar farms really eating Japan's forests and its scenery? Disputes at Hokuto, Ito, Kirigamine and the Atami debris flow have fixed an image of renewables as deforestation and disaster risk — yet the statistics show that conversion of forest to solar covers a tiny fraction of the country. This piece sets the data against the record, looks at the weaknesses of the old FIT design and of siting governance, at the environmental assessment, fill regulation and promotion-zone rules introduced since, at Japan's rooftop, car park, agrivoltaic and floating potential, and at the nature-positive siting principles now taking shape internationally.
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Renewables FAQ
Solar and wind depend on the weather. How can supply be kept stable?
“Solar and wind are at the mercy of the weather, so surely large amounts of them mean more blackouts.” The doubt persists — yet Germany, Denmark, South Australia and others run their grids reliably with variable renewables at 30–60% of supply. What makes that possible is flexibility: batteries, pumped hydro and hydrogen; demand response and virtual power plants; flexible operation of thermal and nuclear plants; and stronger interregional links. This piece works through the mechanisms, the Japanese constraints that are institutional rather than physical, and the way forward.
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Renewables FAQ
Isn't renewable energy too expensive up front? Can the investment be recovered?
“Renewables cost too much up front to ever pay back.” That picture is already out of date. IRENA's latest data makes solar and onshore wind the cheapest new generation in the world, and in Japan residential solar typically pays back in seven to ten years and commercial self-consumption in five to eight. This piece works through the international trend in levelised cost, payback periods in Japan, the PPA models that remove the up-front investment altogether, the collapse in battery costs, and how to handle the risk of curtailment — and asks which side, renewables or fossil fuels, now carries the greater risk of never paying back.
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