A Critical Review of Power Take-Off Wave Energy Technology Leading to the Conceptual Design of a Novel Wave-Plus-Photon Energy Harvester for Island/Coastal Communities’ Energy Needs

Abstract

As the global interest in renewable energy generation continues, the need to develop new and innovative solutions is being explored every day throughout the world by researchers and innovators. Hybrid renewable energy innovations are gaining progressive interest not only because of the threat of climate change but also due to the technological advancements seen in renewables. Ocean waves have immense potential as a renewable energy source, and related technologies have advanced continuously over the past few decades. In response, this paper extensively studies wave energy converters (WECs) based on the power take-off (PTO) technique, and presents a novel hybrid wave-plus-photon energy (HWPE) harvester called Wavevoltaics, based on wave and solar energy capture systems for coastal communities’ power needs, in line with decarbonization measures. The HWPE harvester uses a simple rack-and-pinion mechanism in combination with solar cell technology to convert the wave energy into usable electrical energy in a water column structural design. This novel HWPE device can be used to provide power for lighting and gadgets for coastal communities that rely heavily on fossil fuels for their lighting and electrical needs. Later in the paper, the challenges faced in hybrid wave energy development are presented.

A review of friction stir welding parameters, process and application fields

“…FSW process applied with different pin geometries, tool rotational speed and traverse speeds. 167.95 MPa ultimate tensile strength and 92 RHN maximum microhardness value obtained [13].…”

“…al. [13] investigated mechanical properties of AA6061T6 and AA6351T6 plates joined by friction stir welding. They used vertical milling machine for FSW and 5 mm thickness Al plates.…”

Ocean Wave Energy Converters: Analysis, Modeling, and Simulation. Some case studies

“…Thus, the power of the waves fluctuates with different time constants. In deep water, the harvested average wave power can be obtained using linear potential wave theory [10],…”

“…64𝜋 2 𝐻 𝑚0 2 𝑇 𝐸 (10) where, P is the wave power per unit length of wave crest (W/m), ρ is the density of sea water (ρ = 1025kg/m 3 ), g is the acceleration due to gravity (g = 9.81m/s 2 ), H m0 is the significant wave height (m), and T E is the average power period in the wave (s). The significant wave heights in the simulations can be chosen according to the equal energy transport theorem [14] [15], 𝐻 𝑚0 = 2√2𝐻 𝑚 (11) where "H m " is the amplitude of the regular wave with equal energy.…”

“…Likewise, other authors [9] introduce some WECs with multiple degrees of freedom, describing their operation. Other authors propose floating platforms technologies as an effective solution for harvesting wave energy [10]. Another drawback is the incorporation of marine energy into the power-grid.…”