Wednesday, December 18, 2013

Solar Startup Could Make At-Home Renewable Energy Purchases Easily

An online marketplace will let U.S. homeowners to evaluate selections for going solar as easily as they can compare prices for airline tickets for the first time this December.

Geostellar is a startup backed by power producer NRG Energy Inc. It is in quest of becoming the Expedia or Orbitz of the solar industry. The said solar industry is a one-stop shop where consumers can not compare the benefits of leasing solar panels versus buying them outright alone but eventually sign up to install a system.

On the site,, Solar players together with NRG, No. 1 U.S. installer SolarCity Corp, Boston-based solar loan provider Admirals Bank, manufacturer and financier Conergy, East Coast installer Roof Diagnostics and Connecticut’s Clean Energy Finance and Investment Authority will feature their products.

Geostellar looks forward to its platform will let installers and financiers to lower the price of getting hold of new customers. It is a main objective in the ferociously competitive rooftop solar industry. Solar companies are centered on cutting prices therefore they will be able deliver on their promise to save customers money on power bills by converting to solar.

Geostellar will make money by claiming a portion of a system’s total installed price – between 10 and 20 percent, Chief Executive David Levine said.

According to Levine, Geostellar, which was founded in 2010, got its start by selling data to solar companies that showed the solar energy potential of individual rooftops. Its early customers included solar financing companies SunRun, Sungevity and others.

It increased to $14 million from NRG, Flash Forward Ventures, satellite imagery company GeoEye (now owned by DigitalGlobe Inc), and the state of Maryland’s venture capital fund, in May 2012
Levine had tried to convince his customers to use Washington-based Geostellar’s data to build a website where consumers can comparison shop for solar. He resolved to use those funds to build it himself.
“We went back to those customers and said instead of us giving you data and you doing the marketing, we want to be your customer acquisition engine,” Levine said in an interview.

To build 3D representations of neighborhoods and their rooftops, Geostellar makes use of satellite data. It is a simulation that moves the sun across the sky then facilitates the company calculates how much sun a rooftop gets at any specific time of the year. A key factor of this occurrence is in determining whether going solar makes financial sense. The website then layers on the value of government incentives in addition to local utility rates to provide customers a full view of what it would charge them to sign up for a solar installation.

Visitors to Geostellar’s website or its mobile app called Solar Mojo can then compare and contrast the costs and benefits of a solar lease, a lending plan or a cash purchase, depending on the market. Lastly, they can sign up for what they want with the click of a button.

Wednesday, November 13, 2013

Zero-emission cars on roads by 2025: Eight US states pledge to get 3.3m zero-emission

On Thursday, the governors of eight states pledged to get 3.3m zero-emission vehicles on roadways by 2025 in an effort to curb greenhouse gas pollution. In the eight states includes California and New York

To sign a memorandum of understanding, representatives from all eight states were to assemble in Sacramento. This would raise infrastructure and make other alternations to help increase market share for electric cars, hydrogen fuel-cell electric vehicles and plug-in hybrids. The expectations are in 2015, there should be more than 200,000 zero emissions vehicles on the road.

“This agreement is a major step forward to reducing the emissions that are causing our climate to change and unleashing the extreme weather that we are experiencing with increased frequency,” New York Governor Andrew M Cuomo said in a statement.

The other states such as Massachusetts, Maryland, Oregon, Connecticut, Rhode Island and Vermont are also involve in the agreement. All in all the eight states represent about 23 percent of the US auto market.

Every state has already separately agreed to policies to entail a percentage of new vehicles sold to be zero emission by 2025. California’s authorization alone of 15.4% calls for a total of 1.5m zero-emission vehicles to be on the state’s roads by that time.

It’s a precipitous curve. Today in California, plug-in-hybrids and electric vehicles make up less than 2% of the auto market.

First, the states will institute a taskforce to contribute ideas that will help inflate the network of charging and fueling stations necessary to make electric and hydrogen-fueled vehicles more striking to consumers, all under terms of the memorandum.

“The idea is to broaden the pool of people talking about this and working their way through the challenges that come up in setting up this kind of infrastructure, and growing this kind of a market,” said Dave Clegern, a spokesman for California’s Air Resources Board, which regulates auto emissions.

Now, there are 16 zero-emission vehicles from eight manufacturers on the market; nine that run on batteries alone, two hydrogen fuel cell cars and five plug-in hybrid models, which can run on battery alone or gasoline.

Officials say that every automaker will have a zero-emission model by 2015.

According to car dealers, who are under pressure to help meet these 2025 goals, getting fueling infrastructure like charging stations in place quickly is the only way to get average consumers used to a new product that requires new driving habits.

“We think that is going to be necessary for some of the range anxiety and other acceptance barriers that need to be broken down,” said Brian Maas, president of the California New Car Dealers Association.

“The cars are coming – they’re here already – but if you don’t have a place to charge them, there’s not going to be the level of consumer acceptance.”

Governors signing the memorandum all addressed the cooperative exertion as a way to hurriedly resolve the foreseeable problems that occur when making such far-reaching adjustments in people’s everyday lives.

Furthermore some observe future economic benefits from the switch to new vehicles.

Massachusetts Governor Deval Patrick said more electric vehicles are key to his state’s efforts grow the region’s economy.

“Diversifying transportation fuels and providing drivers with options will help reduce vulnerability to price swings in imported oil that hurt consumers and our economy,” Patrick said in a statement.

Wednesday, July 17, 2013

Renewable Energy Sources Used For Boiler Electricity Room Production in Middle East and North Africa

The Middle East & North Africa (MENA) region belongs to the few areas in the world where investment in renewable energy appears to be overcoming the global economic crisis. Fresh investment in renewable energy in the region amounted to USD 2.9 billion in 2012, up by about 40% from that of 2011 and a 6.5-times growth from 2004.

The region’s growth in the renewable energy sector posted increased confidence among investors from 2009 to 2012, exhibited primarily by the entry of some of the largest international energy corporations into the solar energy market, including, in particular, national and global oil and gas companies.

Solar energy has gained the top average annual growth in the region’s power generation production.

Wind ranks second with average annual growth of 27%, about five times over that of fossil fuels, while retaining the lead in total installed capacity among non-hydro renewables.

Based on absolute values, hydroelectric power still holds the chief renewable energy source for power generation in MENA at present.

The percentage share of renewable energy climbed to 3.3%, up by 0.4% percentage points within the same period. Although this may appear like a negligible gain, it should be emphasized that renewable power generation garnered shares against traditional power sources despite a marked increase in demand for electricity, which makes this growth truly significant.

Friday, July 5, 2013

Energy savings by operations

Fleet management, logistics and incentives

5.23 Reductions in scheduled speed (i.e., accepting longer voyage periods) will enhance efficiency although it will result in more ships being required. Nevertheless, there is a trade-off between freight rates and fuel cost: with lower freight rates and higher fuel prices, it may be more advantageous to reduce speed.

Generally speaking, efficiency improves when we concentrate cargoes in larger ships as much as possible. Obviously, larger ships that are not fully loaded are not efficient when they do sail. Smaller ships, on the other hand, end up having higher net energy efficiency for being able to fill their cargo hold to capacity and having access to more ports and cargo types, [7].

Voyage optimization

5.29 Voyage optimization can be achieved by:

.1 choosing optimal routes to avoid adverse weather and current conditions will minimize energy consumption (weather routeing);

.3 ballast optimization – preventing unnecessary ballast use. Attaining optimal ballast may sometimes be difficult since it also affects the safety and comfort of the crew; and

.4 trim optimization – determining and operating at the proper trim.

5.31 Weather routeing can bring substantial savings for ships on particular navigational courses. Certain types of weather routeing systems, performance monitoring systems and technical support systems and other procedures can be used to help attain optimal voyage performance.

Energy management

There are certain cargoes, such as special crude oils, bitumen, heavy fuel oils, etc., that need heating.

The heat required may partly be provided by producing steam or using exhaust heat. However, in many instances an extra steam boiler is required to supply enough steam. Steam from exhaust gas is usually sufficient to heat the heavy fuel oil used on most vessels; in port, however, steam from an auxiliary boiler may be required.

5.35 It is often feasible to decrease energy use on board by achieving more conscious and optimal operation of ship systems. Examples of measures to under taken include:

.1 avoiding unnecessary use of energy;

.2 avoiding parallel running of electrical generators;

.3 optimizing steam plants (tankers);

.4 optimizing the fuel clarifier/separator;

.5 optimizing HVAC operation on board;

.6 cleaning heat exchangers and the economiser; and

.7 detecting and repairing leakages in boilers and compressed-air systems, etc.

A lot of savings may be achieved by upgrading automation and process control, for example, automatic temperature control, flow control (automatic speed control of pumps and fans) and automatic lights. The potential for attaining energy-savings using energy-management measures is hard to determine, since that depends on the ship’s previous operational efficiency and on the contribution of auxiliary power use in the overall energy scheme. A 10% savings on auxiliary power may be a practical target for many vessels. This amounts to about 1 to 2% of the total fuel consumption, depending on actual conditions.

5.37 Optimal maintenance and tuning up of main engines.

5.38 Maintaining a clean hull and propeller is vital in achieving fuel efficiency.

Selecting more effective hull coatings.

16. Reducing navigational for ships is often seen as a “quick win” in terms of reducing carbon emissions from vessels.

Recent studies reveal that many abatement technologies are available, and cost-effective, such as:

-          Slide valves reduce NO2 on slow-speed engines by 20%, very inexpensive, fit easily and are cost-effective.

-          In-engine controls could reduce new engine NO2 by 30%.

-          Selective Catalytic Reduction cuts NO2 by 90%.

-          Water Injection/Humid Air Motor cuts NO2 by 50%/75%.

-          Scrubbing by sea-water cuts SO2 by 75%.

Thursday, July 4, 2013

Housing Corp. Switches From Fuel Oil to Natural Gas, Saves $2.8m

Climate Change & Environmental Services (CCES) managed the construction management and environmental permitting for a major boiler modernization project for a large apartment complex in New York City that has reduced emissions and saved the complex over $2.8 million in fuel costs compared to the previous 12-month period.

East River Housing (ERH) Corporation operates a boiler house providing heat and hot water to a number of apartment buildings with over 2,700 units plus a shopping center. It had been combusting over 2 million gallons of No. 6 fuel oil annually. The housing corporation decided to modernize the boilers and switch from fuel oil to natural gas.

ERH replaced one aging boiler with a new modern unit and renovated its other two existing boilers, installing new low NOx burners with flue gas recirculation. ERH worked with Con Edison, the local utility, to bring a natural gas line into the boiler house for the fuel switch.

No. 2 diesel oil is to be used as a backup during natural gas interruptions, necessitating the installation of a new tank farm replacing the No. 6 fuel oil tank farm.

CCES carried out construction management to address scheduling and technical issues with the implementation of the installation and testing, as well as all environmental permitting. The physical installations are complete and the plant has operated under natural gas for one full year now.

CCES has assessed the cost savings due to the project. Given natural gas being piped to the facility, removal of No. 6 oil tanks, and use of a modern No. 2 oil tank farm, ERH virtually eliminated the risk of a messy oil spill in the densely populated area. In addition, emissions of pollutants critical in an urban area all markedly dropped because of this project, such as NOx (85%), particulate matter (75%), greenhouse gases (equivalent of removing 4,600 cars from the road), and SO2 (99%). These reductions helped change the permitting status of ERH from major to minor, saving them much in fees and removing several regulatory requirements.

CCES determined that themal efficiency improved by about 18% (fewer therms to create steam). “We are not sure if the thermal efficiency improved because of natural gas being more fluid than No. 6 fuel oil, which is thick and viscous or because of the new equipment. But probably both contributed,” said Marc Karell, principal with CCES.

CCES also calculated cost savings. In the 12 months of natural gas service (May 2012 through April 2013), ERH directly saved over $2.8 million (63%) in fuel costs compared to the previous 12-month period, despite this being a measurably colder winter than the one before. CCES also calculated avoided cost savings (added fuel costs ERH would have had to incur if ERH still combusted No. 6 fuel oil with the old boilers). The avoided cost savings for the 12-month period was conservatively estimated to be over $5.3 million.

The project payback, initially anticipated to be about 4 years, will be under 2.5 years based on direct cost savings.

Asked if switching from fuel oil to natural gas was a viable option for other facilities, Karell said it depends on the availability of natural gas and the cost of extending a natural gas line to the site.

Wednesday, July 3, 2013

Including All the Benefits in Cost-Benefit Analyses of Solar Energy

On the issue of evaluating energy alternatives, biomass boiler policymakers makes a room to commonly conduct cost-benefit anlayses. Which appears almost run-of-the-mill, correct? The difficulty, however, arises when we have to choose the parameters. What costs should we input? Short-term or long-term costs? Should we include externalities? If a particular system has by-products that pollute and endanger life on earth as it is, how greatly should it affect our decisions? These are the vital questions that we need to consider.

So it goes for the benefit side. Do we give weight to the resource as a short-term or long-term energy provider? Do we consider the time of generation, knowing that electric power costs are higher when there is a great demand for it? Do we input other benefits from the grid, for instance, the opportunity to do away with other capital investments in tranmission and distribution systems?

And there are those benefits existing outside of the grid. Should we input into the analyses the value of having cleaner air and reduced morbidity for society at large? What about the impacts of climate change? Economic and employment impacts? And impacts of the use of water?

We believe we should.

For this purpose, we have joined a coalition of similarly-oriented companies (American Lung Association in California, California Center for Sustainable Energy, Asia Pacific Environmental Network, Brightline Defense Project, California Environmental Justice Alliance, California Solar Energy Industries Association, Distributed Energy Consumer Advocates, Environment California Research & Policy Center, Coalition for Clean Air, Environmental Defense Fund, Interstate Renewable Energy Council, Inc., Local Energy Aggreagation Network, Dr. Luis Pacheco,, Sierra Club, Solar Energy Industries Association) in order to petition the California Energy Commission to carry out a study of the societal costs and benefits of the State’s net-energy metering program.

Vote Solar is a non-profit organization striving against the ill-effects of climate change and fostering economic development by introducing solar energy as a primary power source in society.

Tuesday, July 2, 2013

A Room for Alternative Energy Source: Solar Energy Collecting as an Alternative Energy Source

Boiler Efficiency Technology: Compared to solar energy which collects alternative energy at a dependable constant, water evaporates and wind dies down.

A solar panel is made up of an array of black squares called photovoltaic cells which collect energy from the Sun. More and more, solar panels are getting more efficient, and progressively cheaper due to innovative designs which focus the collected sunlight with ever-increasing precision to a singular point.

As the size of the cells decreases, their efficiency increases, making each cell less expensive and more productive to manufacture. In terms of cost, therefore, the price of producing solar-power energy per watt-hour has decreased to $4.00 as of this writing; whereas, 17 years ago, it was almost double that cost.

Generating solar-powered electricity is clearly environment-friendly because of its absolutely zero emissions into the atmosphere while it utilizes one of the most naturally available resources to generate it.

Solar panels are gradually and definitely becoming more practical and popular features on the rooftops of people’s homes, being easy to install as a heating system to provide hot water or electricity.

Photovoltaic cells utilize copper pipes running through a glass-covered collector for heating water which is usually stored in a water tank on the roof. The circulated water is siphoned thermally in and out of the tank, producing hot water.

Even on cloudy or stormy days, photovoltaic cells have become more efficient at collecting enough solar energy. Particularly, Uni-Solar, has developed solar collection arrays for the home that operate efficiently during overcast days, by utilizing a more technologically-advanced system which stores more energy at one time during sunny days than other less-efficient systems.

Another solar power system now available for consumers is the PV System which is connected to a nearby electrical grid. When there is an excess of solar energy being collected by any home, the excess energy is transmitted to the grid for shared use as a means of decreasing the grid’s dependence on hydro-generated electricity.

Connecting to the PV System can help bring down one’s energy costs as compared to a complete solar energy system, while immediately decreasing pollution and removing pressure off the grid system. Several places are establishing centralized solar collection systems for small towns or suburban areas.

Some top corporations have signified their intention to also enter into the use of solar power generation (a clear sign that solar-generated energy has become an economically viable source of alternative energy).
In fact, Google is installing a 1.6-megawatt solar-power generation system on top of its corporate headquarters, while Wal Mart plans to set up its own gigantic 100-megawatt system.

Countries, such as Japan, Switzerland, Germany, Australia and the United States, have been promoting the cause of solar-energy production by granting government subsidies or by providing tax breaks to companies and families who desire to use solar power for generating their heat or electricity.

With the advances in technology being applied for more efficient solar collection materials, more and more private investors will realize the advantages of investing in this “green” system and view solar energy collecting as a wise and productive alternative energy source.

Tuesday, June 11, 2013




Short term:
-          Reduced fuel sulfur level in SO2 Emission Control Areas (SECAs) from 1.5% to 0.5%.
-          Include SO2 /PM related health effects in addition to impacts on air, sea, and land as justification for SECA.
-          Enhance SECA program to high ship-traffic areas in Mediterranean, North Atlantic and Pacific Rim.
-          Regional limits in coastal places, inland channels and at ports.
Medium term:
0.5% sulfur fuel worlwide

Long term:
Synchronization with on-road diesel fuels (500 ppm to 10-15 ppm, in the long-term)
-          International requirements (IMO)

New engines

Short term:
-          NO2 standards 40% percent below present IMO standards (Year 2000 level).
-          PM levels
-          Encourage new technology developments

Medium term:
-          NO2 standards 95% percent below present IMO standards (Year 2000 level)
-          PM levels further cut down
-          Encourage new technology developments

Long term:
Encourage the application of advanced systems, particularly near-zero emission technologies in potential applications.
-          International standards (IMO)

New vessels

Short term:
-          Adopt global requirements for on-land power standardization.
-          All newly-built ships with onshore electricity capability, particularly ferries and cruise ship.

Long term: Promote the utilization of modern ship-design principles for potentially efficient applications
-          Promoting contracting of cleanest carriers.
-          Environmentally sensitive fees and charges.
-          International standards (IMO).

Existing vessels and engines

Short term:
-          Apply emissions operating standards by ship class and engine properties depending on observed retrofit potential.
-          Study viability and potential benefits of programs to promote early vessel retirement and environmentally-viable decommissioning.
-          International levels (IMO)
-          Promoting contracting of cleanest carriers
-          Environmentally sensitive fees and charges.

At port

Short term:
Select strategy that provides benefits for optimum reduction of emissions, based on local fuel availability and environmental application of electricity power generation
-          Onshore electricity
-          Least sulfur on-road fuel and NO2 and PM post-treatment.

Medium term: Market-based approaches to promote low- or non-carbon fuel sources to service onshore electricity for berthed vessels
-          Port authorization needed.
-          Promoting contracting of cleanest carriers.
-          Environmentally sensitive fees and charges.

Short term:
-          Implement inventory of GHG emission and fleet baseline
-          Market-based methods for ships.
-          Implement fuel economy requirements by ship type and engine properties for new vessels.

Medium term:
Implement fuel economy requirements by vessel type and engine class for existing ships.
-          Promoting contracting of cleanest carriers
-          Environmentally sensitive fees and charges.
-          Cap and trade program for maritime industry alone.

-          International requirements (IMO).

Assessment of potential reduction of emissions

Assessment of potential reduction of emissions

Potential for reduction of CO2 emissions
5.76 Several options for efficiency improvements have been considered in earlier paragraphs. The potential for energy saving by combining these steps is very vital.

Nevertheless, costs, lack of incentives and other obstacles block many of them from being implemented. Hence, when assessing the potential savings, we also establish clear assumptions regarding the extent of compromise, effort and extra costs that are needed.

An evaluation of potentials for saving energy using present technology and methods is presented in table 5-2. The values given in this table exhibit the variations in benefits for various ship types and the level of motivation to achieve savings.

5.77 Projected efficiency improvements are presented as scenarios in Chapter 7. The high values presented in table 5-2 relate fairly well to the scenario with the highest improvement in energy consumption, in which net improvements, without the use of low-carbon fuels, range from 58% to 75% in 2050, depending on the type ship. This assumption, including indicators of historical transport efficiency for various ship types, is portrayed in figure 5-1. The historical background for the generation of efficiency data is shown in Chapter 9.

Renewable energy from shore

Renewable energy from shore
5.45 Renewable energy is generated on land using wind generators, hydroelectric plants, geothermal plants, solar-energy plants, etc. Potentially, power from such providers could be harnessed to run ships if a suitable energy carrier was available. However, as long as there is a shortfall of renewable power onshore, there is little prospect for using land-based renewable energy to propel ships. A noteworthy exception is the use of land-generated power while a ship is berthed.
15. Ideally, fuel cells, solar-power, wind kites, etc. are all potential alternative technologies; but they are often seen as auxiliary power sources and not viable replacements for the main propulsion systems on a ship.

14. Other fuel sources may also play a role and bio-fuels can be utilized in operating ships. However, with the amount of fuel used by the maritime industry and the present economic instability, the industry would deem it wise for lawmakers to investigate more clearly the impact of a significant take-up of bio-fuels by such a big consumer as global shipping before arriving at any decisions.
5.2 Present propulsion systems using carbon-based fuels are seen as the only realistic large volume fuel for vessels over the next two decades years and even longer.

Use of natural gas is presently leading in terms of a lower carbon fuel for the short-medium term, either as compressed natural gas (CNG) or liquefied natural gas (LNG). With existing available propulsion equipment, its use could attain around 20% reduction in CO2 emissions in comparison to residual or diesel-oil fuels.
5.3 Ultimately, hydrogen could become a viable source. Sustainable bio-fuel may also have a role to play if enough fuel were provided to shipping. Alternatively, new and radical fuels and/or technologies may play a vital role.

Fuels with lower fuel-cycle CO2 emissions
5.46 Emissions of CO2 can be reduced by using fuels with lesser overall emissions through the full-fuel process (i.e., production, refining, distribution and consumption). The conversion from residual fuels to distillate fuels, implied by the sulphur regulation in the revised MARPOL Annex VI, has already been accepted; hence, there is no point considering the potential benefits and disadvantages of this move on the emission of CO2 now. Other fuel alternatives with bright prospects for cutting the production of CO2 include bio-fuels and natural gas.

5.47 Current-day bio-fuels (also known as “first-generation” bio-fuels) come from sugar, starch, vegetable oil, or animal fats. Many of these fuels can be readily used for ship diesels with no (or minor) alteration of the engine. Bio-fuels can be upgraded (hydrogenated) in a refinery. As such, the end-result is of high-quality and the practical problems mentioned do not apply. This upgrade process requires energy and leads to additional emissions.
5.48 The net benefits on emissions of CO2 vary among many types of bio-fuels. Not all bio-fuels provide a CO2 benefit. Bio-fuels, in fact, have in certain instances led to a 7% to 10% increase in the NO2 emissions.
5.51 In summary, the current potential for cutting COemissions from ships by using bio-fuels is inadequate. This is not only because of technology issues but also of cost, of limited availability and of other factors based on the production of bio-fuels and their use. Moreover, the bio-fuels are significantly more costly today than petroleum fuels.

Liquefied natural gas (LNG)
5.52 Liquefied natural gas is an alternative fuel in the maritime industry. Having a higher hydrogen-to-carbon ratio compared with oil-based fuels, this fuel produces lower specific CO2 emissions (kg of CO2/kg of fuel). Moreover, LNG is a clean fuel since it contains no sulphur; this eliminates the SOx emissions and almost eliminates the emissions of particulate matter.

Furthermore, the NO2 emissions are cut by up to 90% due to decreased peak temperatures in the process of combustion. Unfortunately, LNG use will increase methane (CH4) emissions, thus cutting the net global warming benefit to 15% instead of 25%.
5.54 One of the primary obstacles for LNG use as a fuel for vessels is finding sufficient space for onboard fuel storage. Energy content being held equal, LNG is 1.8-times larger than diesel oil in terms of volume. Nevertheless, the large pressure storage tank needs ample space, and the final volume requirement reaches to three times that of diesel oil.
Shifting from diesel propulsion to LNG propulsion is possible, but LNG is mostly applicable for new ship construction since significant alteration of engines and allocation of addition storage capacity is needed.
5.56 In summary, the current potential for cutting emissions of CO2 from vessels through LNG use is relatively small, since it is generally suited for newly-built ships and because  LNG bunkering choices are limited today.

The cost of LNG is currently substantially lower than the cost of distillate fuels, justifying an economic incentive to shift to LNG.

As to alternative fuels, only LNG is a viable competitor for replacing conventional fuels. The problematic issue of on-vessel storage and containment systems and the land-based infrastructure needed for resupply adversely limits the option for this fuel. The operational distance of ships utilizing LNG is constrained by the fuel storage size and boil-off standards. LNG is seen by industry as more fitted to short sea-navigation than the deep ocean trade. In fact, several ferry routes with dedicated land-based supply infrastructure in Scandinavia presently use LNG as fuel for main propulsion.

The shipping industry is a multi-service industry, and provides many various functions for society.

Nuclear energy is technically viable for sea vessels with many instance of nuclear-powered commercial and military ships. Safety and acceptability issues are, naturally, predominant in this ongoing debate. Nuclear powered ships require a delicate infrastructure and disaster response scheme. Due to common apprehensions among countries, nuclear propulsion will not play an important role in commercial vessels. Nuclear power, though put to effective use in the 1960s, would not be viable commercially or acceptable socially. If it were to be considered at all, it would be more acceptably and efficiently used for synthesizing marine fuels on land.

According to a research that IMO commissioned, technologies could cut fuel use and oil consumption by as much as “30–40%”. However, some of these approaches have been applied by merchants and the fall below their expectations.

Non-conventional technologies presently being evaluated for application, for instance, the sky-sail concept, twin-propeller and the under-hull air cushion give serious prospects.

The kite-system developer believes that the system may cut a ship‘s fuel consumption by an average of 10–35% annually, based on wind power availability. However, new tests have shown  a low passing grade for this system. Within ideal wind conditions, fuel usage can be cut temporarily by up to 50%. (528.pdf)

Emission-reduction technologies
5.57 Although COremoved by chemical conversion from flue gases, it is not deemed viable. Emission-cutting methods are generally applicable to pollutants within exhaust gases, NO2, SO2, PM, CH4 and NMVOC.

Emission-reduction options for NO2
5.58 NO2 emissions from diesel engines can be cut by using certain measures, such as:
- Fuel conversion.
- Modification of the combustion process.
- Modification of the charge air.
- Exhaust gas treatment (selective catalytic reduction, SCR).
5.59 A fuel’s sulphur content and its deposit-producing tendency can affect the possibilities for other emission-cutting technologies, such as exhaust-gas recirculation (EGR) or selective catalytic reduction (SCR). Usage and quality of water are problems met by options utiizing water.
5.61 LNG fuel usage is both a fuel switch and a combustion-process shift.
5.62 Reduction of NO2 by 15-20% from the present levels can be attained with changes in the internal-combustion process. Currently, cutting NO2 emissions to Tier III limits (~80% reduction) can only be reached by using selective catalytic reduction (SCR) post-treatment or LNG and lean, premixed combustion.

Emission-reduction options for SO2
5.65 Exhaust-gas scrubbing systems can be utilized to cut sulphur dioxide (SO2) levels. Two primary principles apply here: open-loop seawater scrubbers and closed-loop scrubbers. Both scrubber systems may also remove PM and reduce amounts of NO2.
Scrubbing of exhaust gases utilizes energy which is calculated in the range of 1-2% of the MCR.
5.66 Removal of SOthrough scrubbing reduces the exhaust gas temperature. On the other option, SCR technology needs high temperatures of exhaust gas and also produces low sulphur and PM content. Combining SCR with scrubbing to remove SO2 does not seem viable.
5.67 Polluting substances coming from the exhaust is carried by the wash-water.

Sulphur oxides react with seawater to produce stable compounds that are generally common in seawater and not considered dangerous to the environment in many places. However, particulates in the exhaust that are eventually disposed into the seawater may harm the environment. The revised IMO Scrubber Guidelines [31] establish limits for the effluent, including limits for Polycyclic Aromatic Hydrocarbons (PAH), pH, nitrates, turbidity and other materials. Port State standards for effluent pollutants will have a substantial impact on the possible use of seawater scrubbers. To achieve these standards, an effluent-treatment system must be installed. Normally, the more SO2 and PM removed by the scrubber from the exhaust, the more pollutants will need to be removed from the effluent.

Emission-reduction options for PM
5.70 Some PM emissions from fuels high in sulphur content can be cut by scrubbing with seawater. The potential reduction of PM levels are said to be from 90% to 20%, depending on the source. With low-sulphur fuels, PM emissions can be cut significantly by optimizing combustion to attain greater oxidation of soot and of PM, reducing the use of lube oil and certain additives in lube oil. Burning emulsions of fuel and water can also reduce PM emissions to a certain level.

Emission-reduction options for CH4 and NMVOC
5.72 Engine-exhausts containing methane (CH4) and non-methane volatile organic compounds (NMVOC) are relatively low. Limited reductions may be attained by optimizing the process of combustion. NMVOC can also be oxidized using a catalyst. These catalysts are commonly used in connection with SCR systems, where they oxidize unused ammonia and removing ammonia emissions.
5.73 CH4 emissions can be cut substantially through meticulous design to prevent crevices. However, a little CH4 emission is inevitable. Using a catalyst, this CH4 can be oxidized, although this is not as straightforward as cutting NMVOC levels. Further research and development are required in this area.
5.74 Emissions of CH4 from gas-powered engines can be practically removed through high-pressure gas injection instead of lean premixed-combustion. This alternative principle is believed to be well suited for big two-stroke engines. The disadvantage, however, is that NO2 emission reduction through direct injection is lower than what can be attained with the lean premixed-combustion option.

Alternatives for reducing HFC emissions and other refrigerants

5.75 Hydrofluorocarbons (HFC) emissions are connection to leaks during the operation and maintenance of refrigeration systems. Technical steps to cut down leaks include designs less affected by corrosion, vibration and other stresses, decreasing the effect of leaks by cutting down the refrigerant charge (i.e., by cooling indirectly) and compartmentalizing the piping design in order to isolate a leakage.