Ocean thermal energy conversion uses the ocean thermal gradient between cooler deep and warmer shallow or surface seawaters to run a heat engine and produce useful work in the form of electricity. OTEC can operate with a high capacity factor and so can operate in base load mode; the denser cold water masses, formed by ocean surface water interaction with cold atmosphere in quite specific areas of the North Atlantic and the Southern Ocean, sink into the deep sea basins and spread in entire deep ocean by the thermohaline circulation. Upwelling of cold water from the deep ocean is replenished by the downwelling of cold surface sea water. Among ocean energy sources, OTEC is one of the continuously available renewable energy resources that could contribute to base-load power supply; the resource potential for OTEC is considered to be much larger than for other ocean energy forms. Up to 88,000 TWh/yr of power could be generated from OTEC without affecting the ocean’s thermal structure. Systems may be either open-cycle.
Closed-cycle OTEC uses working fluids that are thought of as refrigerants such as ammonia or R-134a. These fluids have low boiling points, are therefore suitable for powering the system’s generator to generate electricity; the most used heat cycle for OTEC to date is the Rankine cycle, using a low-pressure turbine. Open-cycle engines use vapor from the seawater itself as the working fluid. OTEC can supply quantities of cold water as a by-product; this can be used for air conditioning and refrigeration and the nutrient-rich deep ocean water can feed biological technologies. Another by-product is fresh water distilled from the sea. OTEC theory was first developed in the 1880s and the first bench size demonstration model was constructed in 1926; the world's only operating OTEC plant is in Japan, overseen by Saga University. Attempts to develop and refine OTEC technology started in the 1880s. In 1881, Jacques Arsene d'Arsonval, a French physicist, proposed tapping the thermal energy of the ocean. D'Arsonval's student, Georges Claude, built the first OTEC plant, in Matanzas, Cuba in 1930.
The system generated 22 kW of electricity with a low-pressure turbine. The plant was destroyed in a storm. In 1935, Claude constructed a plant aboard a 10,000-ton cargo vessel moored off the coast of Brazil. Weather and waves destroyed it before it could generate net power.. In 1956, French scientists designed a 3 MW plant for Ivory Coast; the plant was never completed, because new finds of large amounts of cheap petroleum made it uneconomical. In 1962, J. Hilbert Anderson and James H. Anderson, Jr. focused on increasing component efficiency. They patented their new "closed cycle" design in 1967; this design improved upon the original closed-cycle Rankine system, included this in an outline for a plant that would produce power at lower cost than oil or coal. At the time, their research garnered little attention since coal and nuclear were considered the future of energy. Japan is a major contributor to the development of OTEC technology. Beginning in 1970 the Tokyo Electric Power Company built and deployed a 100 kW closed-cycle OTEC plant on the island of Nauru.
The plant became operational on 14 October 1981. This set a world record for power output from an OTEC system where the power was sent to a real power grid. 1981 saw a major development in OTEC technology when Russian engineer, Dr. Alexander Kalina, used a mixture of ammonia and water to produce electricity; this new ammonia-water mixture improved the efficiency of the power cycle. In 1994 Saga University designed and constructed a 4.5 kW plant for the purpose of testing a newly invented Uehara cycle named after its inventor Haruo Uehara. This cycle included absorption and extraction processes that allow this system to outperform the Kalina cycle by 1-2%; the Institute of Ocean Energy, Saga University, is the leader in OTEC power plant research and focuses on many of the technology's secondary benefits. The 1970s saw an uptick in OTEC research and development during the post 1973 Arab-Israeli War, which caused oil prices to triple; the U. S. federal government poured $260 million into OTEC research after President Carter signed a law that committed the US to a production goal of 10,000 MW of electricity from OTEC systems by 1999.
In 1974, The U. S. established the Natural Energy Laboratory of Hawaii Authority at Keahole Point on the Kona coast of Hawaii. Hawaii is the best US OTEC location, due to its warm surface water, access to deep cold water, high electricity costs; the laboratory has become a leading test facility for OTEC technology. In the same year, Lockheed received a grant from the U. S. National Science Foundation to study OTEC; this led to an effort by Lockheed, the US Navy, Makai Ocean Engineering, Dillingham Construction, other firms to build the world's first and only net-power producing OTEC plant, dubbed "Mini-OTEC" For three months in 1979, a small amount of electricity was generated. A Europpean initiative EUROCEAN - a funded joint venture of 9 European companies active in offshore engineering - was active in promoting OTEC from 1979 to 1983. A large scale offshore facility was studied. A 100 kW land based installation was studied combining land based OTEC with Desalination and Aquaculture nicknamed ODA.
This was based on the results from a small scale aquaculture facility at the island of St Croix that used a deepwater supply line to feed
The Charles R. Jonas Federal Building known as the United States Post Office and Courthouse, is an historic structure located at 401 West Trade Street, in Charlotte, North Carolina, which has served at various times as a courthouse of the United States District Court for the Western District of North Carolina, a United States post office. Designed by the Office of the Supervising Architect under James A. Wetmore, it was completed in 1915; the Charles R. Jonas Federal Building is located on a site important to the history of Charlotte, is one of the few historic structures remaining in the Central Business District; the first branch of the U. S. Mint had been built on the northeast section of the site in 1836, in 1891, a Post Office facility was built on the southwest portion of the site; the space between the two buildings was converted to a park/plaza. In 1913 the Mint functions were discontinued and the 1891 post office building was torn down. In 1915 the first portion of what would become the Charles R. Jonas Federal Building, a new Post Office, was built on the site of the older one.
In 1934 an addition to the original Post Office was completed on the site of the Mint. The addition tripled the size of the original and changed the orientation of the main facade and entry of the building to West Trade Street at the southeast; the site of the Federal building has been used for U. S. government buildings. That use continues today as the site of the Jonas Federal Building where the 1915-1934 building remains a symbol of the Federal presence in Charlotte, it is, in fact, the busiest statutory location for holding Federal Court in the Western District of North Carolina. Although the settlement of Charlotte dates from the colonial period, it is much a symbol of the "new South", it has become one of marketing centers. As a result of this, the Central Business District is now given over to commercial enterprises housed in new buildings. Therefore, in addition to representing the Federal government in Charlotte, the Charles R. Jonas Federal Building is one of the few historic structures remaining in the Central Business District.
The building is a two-story Neoclassical limestone structure. The main elevation faces West Trade Street, it features a full-length colonnade, with a projecting central temple-front pavilion. On either side of the central pavilion are colonnades divided into eight bays. Massive, monolithic Corinthian columns support an entablature with denticulated cornice; each of the three entry doors has an elaborate limestone surround featuring fluted engaged pilasters which support a decorative cornice. There are two secondary entrances with decorative limestone surrounds set within the flanking colonnades; the southeast elevation is the main elevation of the original 1915 building and features two entries, one at either end. The entry doors are set within projecting corner pavilions; the decorative door surrounds feature fluted engaged pilasters. Flanking each entry door are original bronze wall-mounted lanterns; the central pavilion of the elevation is expressed as nine bays delineated by engaged Corinthian pilasters.
The denticulated cornice and unembellished frieze are present on the southeast and northeast. The northwest elevation reflects the design of the southeast elevation though there are no main entry doors here; the central portion of the facade is divided into nine bays delineated by engaged pilasters. Due to the slope of the site, basement windows are above grade on this elevation; the southwest elevation features a distinctive original copper-clad loading dock. Significant interior spaces include the ceremonial courtroom on the second floor; the L-shaped lobby, once a Post Office sales area, retains its original marble floors, pilasters, light fixtures and ornamental plaster ceiling. The 1930s courtroom carved door surround. An effort has been made to retain original woodwork in the second floor office spaces; this article incorporates public domain material from websites or documents of the General Services Administration
Ligado Networks is an American satellite communications company. The company was known as LightSquared. After restructuring, emerging from bankruptcy and modifying its network plan, the new company, Ligado Networks, launched in 2016, it operates the SkyTerra 1 satellite. Ligado Networks is based in Virginia; the company is governed by a seven-member board of directors with Ivan Seidenberg as Chairman and Doug Smith as president and CEO. Fortress Investment Group, LLC, Centerbridge Partners LP and JPMorgan Chase & Co. own controlling stakes in Ligado Networks. Ligado Networks has 40 MHz of spectrum licenses in the nationwide block of 1500 MHz to 1700 MHz spectrum in the L-Band. With it, the company is developing a satellite-terrestrial network to support the emerging 5G market and Internet of Things applications; the company reached a cooperation agreement in 2007 with Inmarsat, a British satellite telecommunications company, that rearranged the L-Band spectrum so the company could use a larger, contiguous stretch of spectrum.
Potential interference issues at the time prevented LightSquared from deploying the network. In 2010, the company acquired licenses to mid-band spectrum. LightSquared's plans, which did not come to fruition, were to use the spectrum to create a 4G wireless mobile network covering North America. Ligado Networks originated in 1988 with the company American Mobile Satellite Corporation, as Mobile Satellite Ventures after a merger between Motient Corporation and TMI Communications; the company operated two geostationary satellites covering the North American market: MSAT-2, licensed in the United States, launched in 1995. Mobile Satellite Ventures changed its name to SkyTerra Communications in 2008. LightSquared emerged from SkyTerra after Philip Falcone's Harbinger Capital Partners acquired SkyTerra in March 2010; the company received about $2.9 billion in assets from Harbinger and affiliates, as well as more than $2.3 billion in debt and equity financing. LightSquared sought to develop a 4G LTE wireless broadband network using spectrum in the L-Band.
The company launched its SkyTerra 1 satellite from Baikonur Cosmodrome in Kazakhstan on November 14, 2010. At its launch, the satellite contained the largest commercial reflector antenna put into service. SkyTerra 1 replaced MSAT-1 and MSAT-2 as most of the data from the company's MSAT satellites relocated to SkyTerra 1; the spectrum the company controls was set aside for satellite communications only. That changed in 2004 when the FCC granted approval for the company to augment its satellite network with cellphone towers on land. In January 2011, the FCC approved a conditional waiver to allow the company to use its spectrum for land-based-only LTE communications if the company resolved GPS interference; the GPS industry and military claimed the company's use of its spectrum would interfere with their communications. In February 2012, the FCC proposed to suspend indefinitely the ATC authorization due to the interference issues with satellite services. Three months LightSquared filed for chapter 11 bankruptcy.
On December 7, 2015, the company emerged from bankruptcy as a new company under the control of Centerbridge Partners, Fortress Investment Group and JPMorgan Chase & Co.. In December 2015, the company reached settlements with GPS companies Garmin Ltd. Deere & Co. and Trimble Navigation Ltd. to establish how the company and GPS companies can coexist. The company announced its new name, Ligado Networks, on February 10, 2016. On March 1, 2001, Ligado Networks' predecessor, Mobile Satellite Ventures applied to the FCC to use a "combination of spot-beam satellites and terrestrial base stations."In 2011, LightSquared's plan for standalone-terrestrial broadband services met resistance over potential interference issues with GPS systems. In a January 12, 2011, letter to the FCC, National Telecommunications and Information Administration chief Lawrence Strickling said that LightSquared's hybrid mobile broadband services raise "significant interference concerns" and that several federal agencies wanted the FCC to defer action on LightSquared until the concerns were addressed.
On January 20, 2011, GPS industry representatives sent a letter to the FCC, sharing a study by Garmin International that said "widespread, severe GPS jamming will occur" if LightSquared's plans were approved. The study used simulated LightSquared transmitters. Testing showed that LightSquared's proposed ground-based transmissions could "overpower" the fainter GPS signals from space-based satellites. With the band close to those GPS signals, "GPS devices could pick up the stronger LightSquared signals and become overloaded or saturated". On January 26, 2011, The Federal Communications Commission granted a conditional waiver that allowed LightSquared and its wholesale customers to offer terrestrial-only devices rather than having to incorporate both satellite and terrestrial services; the waiver was conditioned on resolving concerns about interference to GPS. Companies that provide global positioning systems, in addition to the United States Air Force, the operator of the GPS system, opposed the FCC waiver, saying that more time was needed to resolve concerns that LightSquared's service might interfere with their satellite-based offerings.
LightSquared promised to work with GPS providers and give the FCC monthly updates on a resolution to interference concerns. On April 5, 2011, with respect to concerns raised by the U. S. GPS Industry Council and NTIA about LightSquared’s proposed operations, the FCC stated that LightS