A review of more than 60 studies (plus m4ore than 65 studies on P2G) on power and energy models based on simulation and optimization was done. Based on these, for power systems with up to 95% renewables, the electricity storage size is found to be below 1.5% of the annual demand (in energy terms). While for 100% renewables energy systems (power, heat, mobility), it can remain below 6% of the annual energy demand. Combination of sectors and diverting the electricity to another sector can play a large role in reducing the storage size. From the potential alternatives to satisfy this demand, pumped hydro storage (PHS) global potential is not enough and new technologies with a higher energy density are needed. Hydrogen, with more than 250 times the energy density of PHS is a potential option to satisfy the storage need. However, changes needed in infrastructure to deal with high hydrogen content and the suitability of salt caverns for its storage can pose limitations for this technology. Power to Gas (P2G) arises as possible alternative overcoming both the facilities and the energy density issues. The global storage requirement would represent only 2% of the global annual natural gas production or 10% of the gas storage facilities (in energy equivalent). The more options considered to deal with intermittent sources, the lower the storage requirement will be. Therefore, future studies aiming to quantify storage needs should focus on the entire energy system including technology vectors (e.g. Power to Heat, Liquid, Gas, Chemicals) to avoid overestimating the amount of storage needed.

/pdf/a-review-at-the-role-of-storage-in-energy-systems-with-a-3pe9h4h281.pdf

A review at the role of storage in energy systems with a focus on Power to Gas and long-term storage

A technique is described for the measurement of the residual stress tensor averaged over a specified volume within a component. The method involves measurement of small changes in lattice spacing using high resolution neutron diffraction. The stress is inferred from these measurements of the strain, and the theory of the relationship between the two quantities is described, including the effects of crystalline anisotropy. The various types of high resolution neutron diffractometer suitable for the work are described. Experimental results validating the method are given for a simple bent bar of mild steel of known strain, a plastically strained mild steel bar, and a mild steel tube of known torsional strain. Examples of the method in practical use are given by a cracked fatigue test specimen, a double-V test weld and a weld joining a tube to a plate. A more detailed example is the anisotropic response of a polycrystalline sample under elastic and plastic strain; this is illustrated by measurements...

Neutron diffraction methods for the study of residual stress fields

Friction stir welding (FSW), a highly efficient solid-state joining technique, has been termed as “green” technology due to its energy efficiency and environment friendliness. It is an enabling technology for joining metallic materials, in particular lightweight high-strength aluminum and magnesium alloys which were classified as unweldable by traditional fusion welding. It is thus considered to be the most significant development in the area of material joining over the past two decades. Friction stir processing (FSP) was later developed based on the basic principles of FSW. FSP has been proven to be an effective and versatile metal-working technique for modifying and fabricating metallic materials. FSW/FSP of aluminum alloys has prompted considerable scientific and technological interest since it has a potential for revolutionizing the manufacturing process in the aerospace, defense, marine, automotive, and railway industries. To promote widespread applications of FSW/FSP technology and ensure t...

Recent Advances in Friction Stir Welding/Processing of Aluminum Alloys: Microstructural Evolution and Mechanical Properties

Friction stir lap joining aluminum and magnesium alloys

Effect of welding processes and conditions on the microstructure, mechanical properties and corrosion resistance of duplex stainless steel weldments—A review

A preliminary investigation has been carried out into the application of friction stir welding for joining a magnesium alloy to an aluminium alloy. The work has shown that liquation during the welding process can lead to the formation of a brittle intermetallic at the joint interface. This intermetallic has a microstructure composed of a divorced lamellar eutectic containing Al12Mg17 and magnesium. The formation of this microstructure and its influence on mechanical properties are discussed in terms of solidification theory.

V. Linton

Papers

Friction stir welding of magnesium alloy AZ31B to aluminium alloy 5083

Influence of time on residual stresses in friction stir welds in agehardenable 7xxx aluminium alloys

Failure of a super duplex stainless steel reaction vessel

Alternative carriers for remote renewable energy sources using existing CNG infrastructure

Microstructural and mechanical factors influencing high pH stress corrosion cracking susceptibility of low carbon line pipe steel