HE & S L.L.C.

Tech

Technology Overview

Drake Passage, Southern Ocean | Photo Credit: Jack Pan

Drake Passage, Southern Ocean | Photo Credit: Jack Pan

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In order to appreciably slow the accelerating rate of climate change, a top priority is reducing the current rate of greenhouse gas emissions from fossil fuel consumption. In recent decades, there has been a gradual, but monumental, effort to transition to a sustainable energy infrastructure. However, each type of renewable energy has its disadvantages. Namely, these issues are related to their intermittency in energy output and their relatively low efficiency in energy conversion to electricity. An emerging solution is to combine a renewable energy source with energy storage (e.g. solar or wind with electric batteries). Nevertheless, batteries also have some fundamental flaws that are often overlooked. Metals used in batteries are finite and non-renewable, and the practicality of the battery recycling program is still under debate. The case for solar and battery combination has been extremely polarized in recent years, but it is evident that our energy future depends on multiple forms of renewable energy, supplemented with suitable storage methods.

Our company proposes to leverage oceanic waves as an energy source to produce compressed air as a means of energy storage. While wave energy is abundant and largely continuous, it has the disadvantage of losing efficiency to the grid, therefore its output range cannot meet massive demands. On the other hand, although compressed air has a competitive energy density and advantageous mobility, it has not been popularized in use; this is due to two issues: 1) The current leading method to compress air uses electricity to power a compressor, which substantially increases the cost, and 2) There is no effective method to deal with the heat waste generated from air compression on a large scale. Our mechanical system can overcome these issues. This mechanical system can synchronously use the motions of oceanic waves to continuously and cost-effectively produce compressed air, while being cooled by the ocean, which will serve as a massive heat sink. Thus, our device will be capable of overcoming the existing obstacles to harness and store oceanic wave energy in a seamless process.

Currently, we focus on constructing this modular mechanical system for local electricity generation and energy storage on marine buoys. We aim to connect this device to the grid in the future.


We may not have even invented the best device yet.
— Robert Thresher, Research Fellow at the National Renewable Energy Laboratory

A conservative estimate of total incident wave energy is 2,110 terawatt-hour/year in the U.S., while California Energy Commission reports that San Diego’s cumulative annual electricity consumption in 2015 was 19,781 gigawatt-hour/year (including both residential and non-residential consumptions). Hence, the entire San Diego County can be powered exclusively by wave energy even if less than 1% of the total wave energy in the U.S. is utilized. Techno-economic analysis, according to 2006 estimates of existing technologies, estimated cost for electricity generated from wave energy is approximately 10 — 30 cents/kWh, and this cost is projected to decline to approximately 5 — 6 cents/kWh in the coming decade. At the latter price range, the cost of wave energy is highly competitive with the current solar and wind technologies. However, further developments are required to achieve this competitive price range. The present development of wave technologies is equivalent to that of solar and wind in the 1980 – 1990’s, while the U.S. is about 5 – 15 years behind our European counterparts. As the movement for transitioning to a renewable energy infrastructure continues, and as the bluetech industry continues to thrive, it is conceivable that there will be a massive vacuum in the U.S. wave energy market.

While the potential market for wave energy and compressed air energy storage is massive, the exact figure remains nebulous due to the lack of historic data. However, as per American Recovery and Reinvestment Act of 2009, a federal funding of $3.1 billion was granted to state energy programs for supporting energy-efficient and renewable energy technologies. The U.S. wave and tidal energy market will witness attractive growth prospects. The projected growth is attributed to the increasing investment in exploration of natural resources. For instance, in 2013, the Department of Energy announced $16 million for 17 projects to efficiently capture tidal and wave energy.

Patent Pending | Copyright 2017