Renewable Energies


Among all renewable resources, wind energy has been proven to be a relatively matured technology and has tremendous potential in commercialization and mass production. Today the major application of wind power is electricity generation from large grid-connected wind farms. With the expansion of the power grid and the reduction of electricity scarce areas, the small-scale wind turbine has now been applied in fields such as city road lighting, mobile communication base stations, offshore aquaculture, and seawater desalination in several countries.

The first project of O’brien Tech in Hong Kong is called “WindCycle”. These kinds of Vertical Axis Wind Turbines can be sited in urban environments, especially for Cities like Hong Kong due to territorial limitations, where traditional wind farms requiring large areas of land or sea to be deployed are not viable options.

This means that WindCycle turbines can be sited wherever winds are generated in the city by moving vehicles or particular building structures that produce an increase in natural wind speed.


To carry out the development of innovative and cost-effective environment technologies in green transportation, renewable energy sources, air pollution control, wastewater treatment, water, and waste recycling.

Green Transport Technology Development – development of new technologies to reduce the fuel consumption and GHG emission in transport

Pollution Control Technology Development – development of advanced air and water pollution control technologies to conform with the increasing tightened government discharge limits

Recycling Technology Development – development of cost-effective technologies in the recycling of materials, chemicals, water, and energy

One of the most important elements of “reindustrialization” is to assist existing industries with adopting smart and clean production, to minimize impacts on the environment. Cleaner production is an investment, not an expense. Reducing the pollution from sources can enhance energy efficiency and bring economic benefits to businesses.


Government and public-sector organizations are facing an exceptional pace of change.

Delivery of public services is undergoing radical change, as governments across the globe are at the peak of upheaval, abandoning former legacy systems in favor of digital solutions.

Modernizing services successfully will require leaders to adopt initiatives that are sustainable and provide lasting legacies. Similarly, for successful adoption to happen, you need to develop the skills required for a digitally enhanced future.


It can be harnessed using a range of ever-evolving technologies such as photovoltaics, solar heating, solar thermal energy, molten salt power plants, and others.

It is an essential source of renewable energy, and its technologies include the use of photovoltaic systems, concentrated solar power, and solar water heating to harness the energy.

The development of affordable, inexhaustible, and clean solar energy technologies will have huge longer-term benefits. It will increase countries’ energy security through reliance on an indigenous, inexhaustible, and mostly import-independent resource, enhance sustainability, reduce pollution and lower the costs of mitigating global warming. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared.


It is the use of falling or fast-running water to produce electricity or to power machines. This is achieved by converting the gravitational potential or kinetic energy of a water source to produce power.

Hydro Power is one of the oldest methods of sustainable energy production. Since ancient times, hydropower from watermills has been used as a renewable energy source for irrigation and the operation of mechanical devices, such as gristmills, textile mills, trip hammers, domestic lifts, and others. 

Hydro Power is now used principally for hydroelectric generation.

Hydro Power is an attractive alternative to fossil fuels as it does not directly produce carbon dioxide or other atmospheric pollutants and it provides a relatively consistent source of power. Nonetheless, it requires a sufficiently energetic source of water, such as a river or elevated lake.


It is an electrochemical cell that converts the chemical energy of fuel like hydrogen and an oxidizing agent like oxygen into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requiring a continuous source of fuel and oxygen (usually from air) to sustain the chemical reaction. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied.


Fuel cells have been used in many applications for primary and backup power for commercial, industrial and residential buildings and in remote or inaccessible areas.

They are also used to power fuel cell vehicles, including automobiles, buses, boats, motorcycles, and submarines.

There are many types of fuel cells, but they all consist of an anode, a cathode, and an electrolyte that allows ions, often positively charged hydrogen ions (protons), to move between the two sides of the fuel cell. At the anode a catalyst causes the fuel to undergo oxidation reactions that generate ions (often positively charged hydrogen ions) and electrons. The ions move from the anode to the cathode through the electrolyte. At the same time, electrons flow from the anode to the cathode through an external circuit, producing direct current electricity. At the cathode, another catalyst causes ions, electrons, and oxygen to react, forming water and possibly other products.

In addition to electricity, fuel cells produce water and heat. The energy efficiency of a fuel cell is generally between 40 and 60%; however, if waste heat is captured in a co-generation scheme, efficiencies of up to 85% can be obtained.


The high temperature and pressure in Earth’s interior cause some rock to melt and solid mantle to behave plastically. Temperatures can reach over 4000 °C.

Geothermal Energy is the term used for the generation of electricity from the earth’s geothermal resources. Although only a very small fraction is currently being profitably exploited.

As a result of government-assisted research and industry experience, the cost of generating geothermal power decreased by 25% over the 1980s and 1990s.  More recent technological advances have dramatically reduced costs and thereby expanded the range and size of the viable resources and in 2021 the U.S. Department of Energy estimates that geothermal energy from a power plant “built today” costs about $0.05/kWh.

Worldwide, 13,900 megawatts  (MW) of geothermal power were available in 2019.

An additional 28 gigawatts of direct geothermal heating capacity is installed for district heating, space heating, spas, industrial processes, desalination, and agricultural applications as of 2010.



It is harnessed by converting energy from tides into useful forms of power, mainly electricity using various methods.

Among sources of renewable energy, tidal energy has traditionally suffered from relatively high cost and limited availability of sites with sufficiently high tidal ranges or flow velocities, thus constricting its total availability. However, many recent technological developments and improvements, both in design (e.g. dynamic tidal power, tidal lagoons) and turbine technology (e.g. new axial turbines, cross-flow turbines), indicate that the total availability of tidal power may be much higher than previously assumed and that economic and environmental costs may be brought down to competitive levels.

Electricity generation from marine technologies increased an estimated 16% in 2018 and an estimated 13% in 2019. Policies promoting R&D are needed to achieve further cost reductions and large-scale development.


Batteries for electric vehicles are characterized by their relatively high power to rate ratio, specific energy, and energy density; smaller, lighter batteries are desirable because they reduce the weight of the vehicle and therefore improve its performance. Compared to liquid fuels, most current battery technologies have much lower specific energy, and this often impacts the maximum all-electric range of the vehicles.

The most common battery type in modern EVs is lithium-ion and lithium-polymer, because of their high energy density compared to their weight.

The amount of electricity (i.e. electric charge) stored in batteries is measured in Amp/h, with the total energy often measured in kW/h.

Lithium-ion batteries can be discharged and recharged daily and at any state of charge.

The battery pack makes up a significant cost of an EV. As of December 2019, the cost of electric-vehicle batteries has fallen 87% since 2010 on a per-kilowatt-hour basis. As of 2018, vehicles with over (400 km) of all-electric range, such as the Tesla Model S, have been commercialized and are now available in numerous vehicle segments.

In terms of operating costs, the price of electricity to run EVs is a small fraction of the cost of fuel for equivalent internal combustion engines, reflecting higher energy efficiency.


With the increasing demand for Electric Vehicles, EV chargers are a piece of equipment that supplies the electric power for charging plug-in electric vehicles (including cars, motorbikes, hybrids, trucks, buses, boats, and others).

Although batteries can only be charged with DC power, most electric vehicles have an onboard AC-to-DC converter that allows them to be plugged into a standard household AC electrical receptacle. Inexpensive low-power public charging stations will also provide AC power, known as “AC charging stations”.

To facilitate higher power charging, which requires much larger AC-to-DC converters, the converter is built into the charging station instead of the vehicle, and the station supplies already-converted DC power directly to the vehicle, bypassing the vehicle’s onboard converter. These are known as “DC charging stations”. Most fully electric car models can accept both AC and DC power.

Charging stations provide connectors that conform to a variety of standards. DC charging stations are commonly equipped with multiple connectors to be able to supply a wide variety of vehicles.

Public charging stations are typically found street-side or at retail shopping centers, government facilities, and other parking areas.


While a significant majority of water vessels are powered by diesel engines, with sail power and gasoline engines also popular, boats powered by electricity have been used for over 120 years. Electric boats were very popular from the 1880s until the 1920s when the internal combustion engine became dominant.

The interest in this potentially renewable marine energy source has been increasing steadily, especially as more efficient solar cells have become available, for the first time making possible motorboats with an infinite range like sailboats.

In public transportation Ferries, the possibility to convert existing boats from diesel to electric engines has become real since modern battery packs allow to allocate enough energy density to support uninterrupted regular transportation.

Being electric engines are not only way more efficient than diesel engines but more important non-pollutant to the air and keeping the waters clean of diesel and oil drained by traditional engines into the waters.


Drones and Electric Aircrafts are powered by electricity from battery packs, almost always via one or more electric motors which drive propellers. Electricity may be supplied by a variety of methods, the most common being batteries and/or solar cells.

Electrically powered aircrafts have been flown at least since the 1970s and were the forerunners of the small unmanned aerial vehicles (UAV) or drones, which in the twenty-first century have become widely used for many purposes.

Between 2015 and 2016, Solar Impulse 2 completed a circumnavigation of the Earth using solar power. More recently, interest in electric passenger aircraft has grown, for both commercial airlines and personal air vehicles.