Our journey of analysis and scientifically-informed thought-experiments starts here, because…

…the renewable energy revolution is underway: we are building ever more installations for producing „clean“ energy: photovoltaic (solar) panel arrays, wind turbines, hydroelectric, to name the principal players.

But in energy storage technology we are lagging far behind…

But we must also store energy in order to provide constant supplies and capture excess: that will reduce the installations to a minimum. This is important in order to minimize their environmental impact. In sensible and flexible storage we are lagging very far behind. In 2020 in the UK alone, around 3.6 TWh (terawatt hours) of renewable energy went to waste because it could not be stored: that’s enough to power around 1,000,000 households for one year — and, interestingly, more than double the amount of renewable electricity generation in China. In 2022, California alone squandered 1.9 TWh of renewable energy for lack of storage.

Alarming amounts of renewable energy are wasted globally, trend rising…

Globally we may well be talking about more than 200 TWh wasted renewable electricity generation each year. In many parts of the world, this would power almost 0.3 billion households for one year: they have much lower per capita consumption compared with the US or Europe, for example. This is electricity that is — in extreme cases — led to earth („dumped“) because the grid can’t handle it, or „switched off“ at source, e.g. feathering wind turbine blades to prevent the rotors turning, or switching off the „inverters“ of solar panels.

Alarmingly, as the capacity of renewable energy grows, many places are having to curtail this energy even more: it simply can’t be used in a timely way or stored. Wasted renewable energy that therefore doesn’t replace fossil energy is connected with an unnecessary CO2 emission. This also has costs, both environmental and financial. We could already be ramping up the synthesis of renewable fuel using this energy. And we could use very simple and cheap — existing — infrastructures to do so.

No energy storage medium gives us back all that we put in: We lose much, even via battery storage…

A „problem“ with this idea might have occurred to you: yes, we can fairly accurately estimate the amount of „lost“ energy. But if we were able to store it, and then re-use it, we definitely wouldn’t get the same amount of energy out as we put in. Indeed, that’s unavoidable with any system involving energy conversions. Imagine we converted excess electricity into stored methane and then used it to drive gas-powered power plants. How much energy would we „lose“? We have, say, 50% efficiency of electricity conversion to methane, and then 65% efficiency of re-conversion to electricity (gas-powered electricity generation can be relatively very efficient). Multiplied, these give only 33% efficiency.

Surprisingly to many, this is very similar to a battery-based storage solution (analysis published in The Decarbonization Delusion). The battery solution doesn’t reach higher efficiencies because of the following: one has to take into account the energy needed to create the battery, and that is very large. Furthermore, there are significant energy losses in charging and discharging; and also for supplying cooling facilities for the heat that the battery generates. A gas-fired power plant can easily last for 30 years; but most information sources converge on 10 years for battery-based energy storage at present.

Gas-powered electricity generation: The most efficient balance from carbon compounds

For a synthetic gas energy storage/re-generation system, the burden of material is small compared with batteries. And most of the gas-based system is very easy to recycle. Battery recycling is very energy-intensive, produces significant toxic collateral, and is not nearly as complete. The environmental dangers of a megabattery storage economy are already evident in the massive mineral mining associated with it: indeed, this impact would be much greater than that of the synthetic fuel storage system.

In sunny summers we could, with synthetic fuels, store massive amounts of energy for cloudy winters, when we need much more than the regenerative capacity can supply. To attempt such a plan with batteries would require unimaginable quantities of battery material. Additionally, because of the lower energy density of batteries, we would need extremely large installations.

Striking good compromises between practicability, losses and environmental sustainability…

We must distribute energy in convenient forms for the end-point users; and we must have mobile energy forms for transportation. All of this must be done with the same environmental consciousness as the energy generation. Yes, we will never be able to store and use the currently wasted renewable electricity to more than a certain percentage of its nominal value: all storage and re-mobilization of energy involves losses. Some technologies produce more losses than others. But we must see all in the context of full-chain/life-cycle analyses in the long term: we must focus on environmental impact (not just efficiency) as the major determinant.

This website is all about how I think that we can do all of this, largely by using insights from the biology that has enabled life to exist sustainably on Earth for more than 3.5 billion years.

Further reading:

> World Economic Forum on the energy storage challenge
> Worldwide renewable energy wastage because of lack of suitable energy storage
> Progress in renewable electricity generation in China

Copyright Andrew Moore 2024