Dear International Energy Ministers attending the IEA Global Conference on Energy Efficiency in Denmark this week (June 7-9, 2022),
Well done and thank you: for targeting the single most effective action for reducing world carbon emissions: Energy Efficiency.
By improving energy efficiency you will:
* Directly reduce carbon emissions from your country’s economy;
* Reduce the amount of renewable electricity generation needed to decarbonize your country, thereby speeding-up your energy transition;
* Reduce your consumption of gas and the resulting fugitive methane and combustion CO2 emissions.
* Improve your country’s energy security by reducing your need to import energy;
* Improve your country’s economy: Improving energy-efficiency will directly improve your country’s economic efficiency and the financial headroom available for you to generate tax revenue from energy users.
So backing energy efficiency is a win-win-win-win-win move. Well done and thank you!
But there is one problem. Many of you are also jumping on the hydrogen bandwagon, and you talk about how your country is going to become a “world leader in hydrogen” (Dozens of countries around the world have announced this… just Google it!)
Do you know that one of the worst things you can do for energy efficiency is to electrolyze water to make green hydrogen? It converts ‘Thermodynamic Work’ (electricity) into ‘Thermodynamic Heat’ (hydrogen) and instantly throws away at least half of the energy value.
Two interesting consequences of this are:
* it takes about 3 times more electricity to run a hydrogen-powered truck than to run an electric truck and
* it takes 6 times more electricity to heat a house with hydrogen than to heat the same house with a heat pump.
Six (6) times!.. that is A LOT MORE ENERGY… 500% more! That means you need 6 times as many wind turbines or solar panels: to generate the electricity to heat your country’s building stock using green hydrogen, than if you use heat pumps.
The reason is that the hydrogen processes are fundamentally inefficient and waste valuable energy as low-grade heat. Someone has to pay for that wasted energy, and I am afraid that it will end up being your economy… For example, you will have to subsidize the price of hydrogen to make heating and trucking affordable.
So, you can see that inappropriate use of hydrogen is almost the worst thing you can do for energy efficiency.
Please think about this when you are sitting around the table with your colleagues in Denmark this week discussing energy efficiency.
May I give you one piece of advice about how to achieve energy efficiency?
Use your Thermodynamic Work’ (electricity) directly. Don’t waste more than half of its value by first converting it into ‘Thermodynamic Heat’ (hydrogen). Electrify everything you can (eg trucks and heating) and only use hydrogen when absolutely necessary (eg to make fertilizer).
Good luck with your meeting.
David Cebon
