Context and Chronology

Ember offers an alternative accounting approach that measures delivered services — useful energy — instead of raw primary fuels. The report documents large conversion losses in today’s energy system and shows how counting outcomes rather than stocks reduces projected primary supply needs when end‑use electrification scales. In 2023 about 380 exajoules of primary energy did not become useful work; on average primary inputs were 75 GJ per person versus 26 GJ of useful energy.

Ember quantifies an efficiency gap that favours electricity: delivered electricity converts to useful services at roughly 68%, while molecular fuels through the combustion chain average about 29%. Electrified technologies — heat pumps and electric motors — multiply the productive value per unit of clean generation (heat pump thermal output commonly cited in the report corresponds to a 300–400% effective gain in useful thermal service per unit of electricity). That arithmetic lowers the system‑level requirement for new primary molecules if policy and investment prioritise end‑use electrification.

The report also places this metric change in historical perspective. A widely used 2008 primer that treated primary energy as the central accounting unit helped shape a decade and more of modelling and policy, but several of its baseline assumptions now bias decision‑making. Rapid learning and scale‑up in solar, wind and lithium‑ion batteries since then have reduced the cost and operational limits that once made renewables seem marginal; multi‑hour storage, hybrid renewables+storage parks, cross‑border interconnection, seasonal thermal storage and district heat networks further lower peak and capacity needs and shrink the case for synthetic fuels in many contexts.

Practical implications follow across markets. Financial investors and utilities that evaluate projects on primary‑fuel assumptions face higher impairment risk for thermal generators, hydrogen pipelines and other molecule‑centric infrastructure if demand is overstated. The report and supplementary perspectives warn that pipelines and hydrogen assets can become stranded where commercial offtake is weak — a policy and fiscal risk if regulators allow network expansion without contract‑backed demand. Conversely, manufacturers of heat pumps, EVs, inverters, and grid services gain an outsized commercial advantage as their products deliver more useful energy per unit of final energy.

For policymakers the prescription is twofold: (1) adopt useful‑energy metrics to align targets and subsidies with services delivered rather than fuels shipped; (2) treat large molecule infrastructure as optionality that requires firm, contract‑backed customer commitments and decision gates. Shifting public support toward grid reinforcement, faster interconnection, storage, and end‑use electrification yields lower‑cost emissions reductions in many institutional contexts. Finally, matching technology choices and policy instruments to governance and finance structures explains why decentralized, modular pathways succeed in some places and centrally planned assets remain appropriate in others.