3 February 2023  | Israel’s renewable percentage of total energy production 9%

Green Hydrogen energy storage source for off-grid applications

Article written by Eitan Mike Miller
Eitan’s major field of interest is off-grid solar systems design, along with water filtration & extraction, he worked in Siemens CSP (formally Solel), and Israel Water Authority. | Mike@off-grid.tech

What is ‘green Hydrogen energy’?

Hydrogen energy is another way of storing electrical energy for long-term use as a hydrogen fuel cell, like chemical battery solutions or fossil fuels but with a more advanced ecological approach.

Non-CO₂-emitting Hydrogen electricity poses an alternative for batteries and fossil fuels as means of energy when no renewable energy exists.

This green Hydrogen can be generated by solar panels or other renewable energy sources and used on-demand to provide adequate, reliable energy that would otherwise be lost or reduced owing to electrical losses or a lack of available energy storage capabilities.

Hydrogen energy can be used to power DC motors, AC-DC inverters, turbines, power plants, hydrogen cell engines, hydrogen cars ‘FCEV’ (using a hydrogen fuel cell stack with or without batteries) for industrial and off-grid applications.

Green Hydrogen advantages:

The advantages of hydrogen storage-based electricity over traditional chemical or mechanical-based energy storage technologies include their ability to provide vast volumes of clean and very dense energy without the complication of space, maintenance, and money that conventional high-capacity energy storage demands.

Additionally, it is ‘greener’ and more robust in the maintenance cost, environmental impact, and storage requirements (it can be placed underground in sealed containers).

On the other hand, traditional energy storage is poor and ineffective; Battery production consumes rare, vital minerals, alongside to ample physical space it requires; also, there’s a constant deterioration in performance over time and has a short service life, with expensive recycling operations.

In the case of renewable energy sources, ‘Green Hydrogen’ might be used as energy storage to buffer electrical gaps when high demand is needed, but renewable energy sources aren’t sufficient for the loads (night for solar, summer for wind turbines), or as a backup for micro-grid power plants that experience grid-tied shutdowns or poor supply.

  • The potential thermal energy of the Hydrogen energy lasts significantly longer than standard industrial Batteries.
  • It may be utilized (‘discharged’) at a higher rating and capacity (discharge rate or ‘depth of discharge’-in chemical Batteries terms).
  • Green Hydrogen can be stored in sealed or inflated containers and cylinders above or underground.
  • Hydrogen fuel cells are a more power-dense source than fossil fuels and acid batteries, which can only use a portion of the potential energy per unit within.

How does ‘green Hydrogen’ work?

In the electrolysis process, water separated [‘H2O’] into its bare atoms, Hydrogen & Oxygen, by a 2 / 1 to Hydrogen ratio.

An Electrolyzer’s initiated WAelectrolysis process applies an electrical charge to Cathode and Anode with a special membrane (that filters the movement of O2).

In this process, Hydrogen is used negative charge, and Oxygen is positively charged.

The process results in pure Hydrogen gas, whereas the Oxygen by-product is released into the atmosphere or captured for another use.

The amount of Hydrogen production is diverse by the power applied to the relative volume of water, its conductivity level, and the current passing through it.

The device processes this separation stage called ‘water electrolyzing.’

General facts:

Hydrogen is a highly flammable gas only with above 4% oxygen within it.

It can be stored and transported in gas or liquid form, and be used for energy production without a further process with a fuel cell engine or the most gas turbines.

  • Green Hydrogen – made by renewable energy source by water electrolosis (Alkaline Electrolyser, Proton exchange membrane, Solid Oxide Electrolyser).
  • Grey Hydrogen – Natural Gas converted to steam methane reforming (SMR), CO2 emmited to the atmosphere.
  • Blue Hydrogen – Natural Gas converted to steam methane reforming (SMR), CO2 captured and reusend for the industies (food, heavy industriey, etc)
  • Brown Hydrogen – Methane or Coal converted to steam methane reforming (SMR), CO2 emmited to the atmosphere without filtration.

Green Hydrogen Applications

  • Micro-grid farms and residence power supply in conjunction with solar and wind power
  • Hydrogen fuel stations for engines used H2 fuel stack in forklifts, golf carts, boats, and agricultural drones are along FCEV.
  • Energy buffer to existing battery stack storage for midday usage or seasonal balancing.
  • Long-period emergency power storage or used during low renewable energy production in the winter.
  • Micro-grid farms and residence backup to the grid-tie system, whereas power outages occur frequently or if a constant power supply is required.
  • Although no grid connection is available, there are Villages of infrastructures, and renewable energy sources exist.
  • Turbines, agriculture machinery, and Liquid gas engines (might get converted to H2 fuel cell engines).

Green Hydrogen Advantages

  • 100% clean energy without greenhouse emissions
  • Can be made to a small residence or industrials application
  • Long service life up to 30 years
  • Self-dependent power source without any cost
  • Simple maintenance
  • High reliability and safety
  • Fill the cells may thank few minutes while charge lead-acid batteries might last few hours
  • Can operate safely in extreme weather (for instance, can’t operate in cold near-freezing weather without prewarm the inter cells)
  • The Hydrogen can last a long time in storage without power reduction
  • The source material (water) is widely available in nature, not vital, and rare minerals are necessary for the operation.
  • The system components don’t emit greenhouse gases.
  • Hydrogen is a fuel twice dense as traditional fusil fuel. Also, it might compress like LPG in round steel cylinders.

Green hydrogen Disadvantages

  • The majority of scenarios probably require DIY projects because there are almost no public-domain shelf products; most products are industrial scale or experimental; however, some companies, such as Testa’s Power Wall, offer Hydrogen power banks to small to medium-sized clients.
  • The worldwide Legislation on Hydrogen production or use hasn’t been settled yet, so the legality of use must question, and local legal advice is pre-requirement.
  • If used in the transportation-the deployment of Hydrogen for transportation in fuel stations is at an early stage where only some countries have that option, and the distance between them is far.
  • Therefore, it requires high safety standards, resulting in a high migration or entry points cost.
  • Hydrogen storage and production knowledge are Still developed by start-ups and traditional oil companies’ innovation centers, so this technology hasn’t matured yet.
  • Transportation of liquid or pure Gas Hydrogen is usually expensive and complicated.
  • We might need a Hydrogen compressor for the hydrogen tank
  • High cost of PEM (based on precious minerals such as Platinum, Iridium, Gold)
  • Lack of standardizations worldwide.
  • The initial investment in construction or integration onto an existing micro-grid system is excessively costly.
  • In 2022, there will be almost non-mass production electrolyzers, so they must be built by hand from various individual components.