Truly renewable and sustainable energy production needs to be sustainable all through the value-chain, from the mining and mineral extraction (such as lithium for batteries, the processing of base materials like the metals and plastics, the manufacturing of components, the installation, the energy storage, and the eventual disposal/recycle/re-purpose after life. This is the cradle-to-cradle solution we ultimately should be working towards.

The concept of “cradle-to-cradle” was developed by US-based architect William McDonough. Learn more:

There is a huge problem with renewable energy storage, especially seasonal storage with big fluctuations in energy consumed. The options considered up till now include massive investment in infrastructure that produces much more than 20 times the power of an average day to meet the needs of peak periods or supplying a large number of batteries (that can only store energy for a certain amount of time—weeks, at most). Because peak demand happens only a few times each year, none of these sound feasible. And underground thermal-energy storage is also too expensive to implement on a large scale.

Electrochaea provides а sustainable solution to energy storage that largely sticks to the cradle-to-cradle concept, mentioned above. This solution allows for renewable energy to be stored indefinitely and transported without losses. The pilot project was implemented in a Copenhagen waste treatment plant operated by Biofos.

The Technology

The Copenhagen plant already has a process for producing renewable energy out of wastewater that is being treated in the plant:

  • organic matter is allowed to settled to the bottom of large, open tanks
  • sludge, rich in carbon-containing molecules, is transferred to a sealed bioreactor
  • microbes filtered from local soil are added that work to produce methane
  • the facility takes the methane and then burns it in a biomass power plant

Yet, the process is not absolutely clean. Some chemical degradation takes place that creates carbon dioxide.

Electrochaea gets help from microbial life called archaea to convert the carbon dioxide released in the bioreactor into methane.

  • The wastewater-treatment plant sends a mixture of carbon dioxide and methane.
  • Meanwhile, two shipping container-sized electrolyzers use renewable electricity to split water into hydrogen and oxygen.
  • The oxygen is sent off into the atmosphere, and the hydrogen to the Electrochaea bioreactor.
  • In the time the mixture of gases travels from the bottom of the bioreactor to its top, 99 out of every 100 molecules of carbon dioxide and hydrogen are converted into methane, water, and heat.

The end product is “renewable methane” or “biomethane”. It is produced from non-fossil-fuel sources and without any fossil-fuel power! This methane can be used to run boilers in homes, power plants, cars. It can easily be stored and, unlike hydrogen, there is already infrastructure to support it.

The Limitations

Electrochaea’s solution depends on access to CO2.

Learn more about this amazing project here.

Batteries can’t solve the world’s biggest energy-storage problem. One startup has a solution.

Copenhagen, Denmark Sometimes, there can be too much of a good thing. Every so often, from California to Germany, there’s news of “negative electricity prices,” a peculiar side effect of global efforts to generate clean energy. Solar farms and wind turbines produce varying amounts of power based on the vagaries of the weather.

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