This portal page aggregates news, information, companies, products, services
and business opportunities relevant to renewable energy storage.
One of the greatest challenges in utilising renewable energy (including
wind) is managing the balance between supply and demand – the wind does
not always blow and direct sunlight is not always available. Traditionally,
excess electricity is stored in batteries, but batteries have a finite storage capacity. Combining renewable
energy with and
hydrogen storage technology, enables much greater volumes of energy
to be stored as
hydrogen. This hydrogen can then used in a fuel cell or internal combustion
engine to generate electricity. A similar configuration can also be used
to provide an onsite supply of hydrogen for
Electrolysis in general has the advantage over batteries of enabling separation of the storage medium from energy harvest and generation. Batteries have to be sized for peak load needs, while electrolyzers can be sized for average load, since storage is not coupled. Combined with the higher energy density of hydrogen vs. typical battery materials, the energy density is substantially higher, reducing cost. Rechargeable batteries also require substantial controls in order to avoid overcharge and other unsafe conditions. PEM-based water electrolyzers in particular have advantages over both batteries and other competing electrolysis technologies in operational safety and energy density. Alkaline-based electrolyzers do not scale down well to smaller sizes because of the KOH that has to be managed in the system. An alkaline unit therefore takes up 2-4 times the physical footprint of a PEM unit with the same generation capacity of 65 kg H2/day. Alkaline electrolyzers also require a prolonged start-up and shut-down period which cannot be circumvented; alkaline electrolyzers cannot tolerate turn down below 50% capacity due to excessive cross cell diffusion and resultant hazardous gas mixtures. In contrast, PEM electrolyzers have excellent load-following capability.
There are a number of
solutions for renewable energy storage worldwide and there are a number
opportunities and products for companies looking for renewable on site