Renewable Energy in Hong Kong

The Electrical and Mechanical Services Department commissioned a two-stage consultancy study in late 2000 to investigate the feasibility of wider application of renewable energy technologies in Hong Kong. Findings from the Stage 1 Study suggest that the renewable energy technologies that are considered potentially feasible for wide-scale application in Hong Kong are solar power, wind power and energy from waste.

Hong Kong has been using solar energy for over 20 years, albeit in a very small scale and mainly for water heating application. The first solar hot water heating installation was installed in 1980 for a bathhouse in Stanley. There are also a number of solar water heating installations for low-rise houses in some suburban areas and a few for swimming pools. The largest system installed so far in the territory is at the Sheung Shui Slaughter House where the system is used to pre-heat the incoming water in the slaughtering process.

Apart from using solar energy for heating purpose, solar energy was also harnessed locally by photovoltaic systems to generate electrical energy. Since the 1980s solar cells have been employed to power small automatic weather monitoring points in various locations in Hong Kong. In addition to using photovoltaic systems in small and stand-alone applications, a number of Building Integrated Photovoltaic systems in both government and private projects have emerged recently and showcased the successful integration of the photovoltaic system with the electrical systems of the buildings. These projects include Wanchai Tower, EMSD Headquarters at Kai Tak, Science Park and the “Green School” at Ma Wan, etc.

So far Hong Kong only has a few small wind turbines installed. The Hong Kong Observatory has successfully made use of small wind turbines coupled with photovoltaic panels to form hybrid arrays to supply electricity to some of their weather monitoring stations in remote sites.

The utilisation of landfill gas (mainly methane) as an energy source has not been extensive in Hong Kong. At present, most landfill sites use landfill gas as a heating fuel in the landfill’s leachate treatment plant and also as a primary fuel to power generation plants to produce electricity for on-site consumption. One of the landfill sites succeeds in utilizing landfill gas to feed a nearby town gas production plant as process fuel to crack naphtha in the production of town gas.

Social and Economic Concerns

Large-scale renewable energy schemes, however, could cause concerns about the consequence on the surroundings. Large open spaces are generally required for the exploitation of energy either from the sun or wind. Land is scarce in Hong Kong and most available potential renewable energy sites are either located in areas targeted for various urban developments, or in our country park areas where natural and wildlife conservation measures are in place. In addition, the visual and noise impacts of renewable energy installations, although subjective to some extend, can be a major concern to the public.

Furthermore, the development cost of renewable energy at present is still high. Based on the “user-pay” principle, consumers using renewable energy will be required to pay a higher energy price.

Urge for Wider Adoption of Renewable Energy

The urge for wider adoption of renewable energy is emerging as an irreversible worldwide trend. Apart from looking at renewables from the environmental angle, the search for new energy sources as substitutes for fossil fuels is another reason providing the drive.

With a projected world population of 10 billion by the year 2050, the increasing global energy
demand will bring about more rapid depletion of the world’s fossil fuel reserves. The possible tightening of energy supplies in future will inevitably result in higher prices of fuels and electricity.

Renewable energy can reduce the reliance on exhaustible sources of fossil fuel. Developed countries are now making more and more investments on the development of the related technology on renewable energies. We would envisage that when those equipment and systems for harnessing renewable energies are to be produced on a massive scale, the unit price of electricity so generated could be comparable to conventional electricity generated from fossil fuels.

Renewable Energy Explained

In contrast to the fossil fuels, renewable energies, as the name suggests, exist perpetually and in abundant quantity in the environment. They areready to be harnessed, inexhaustible, and more importantly, they are environment-friendly. However, the term “renewable energy” has no official or commonly accepted definition.

As an example, the Renewable Energy Working Party of the International Energy Agency defined renewable energyto mean energy that is derived from natural processes that are replenished constantly.

Typical renewable energy sources are wind, heat & light from the Sun, oceanwave, purposely-growth energy crops, potential energy of running water, geothermal energy, etc. Energy generated from waste is termed as one  kind of renewables in some countries. Others regard it as a waste disposal process rather than a renewable source, since there are pollutants generated as by-products, although modern technology has significantly reduced the pollutant emission to a very low level.

Modern solar thermal technologies capture sunlight and utilise its energy to produce hot water, steam and electricity. Apart from using purposely designed equipment to capture the solar energy, buildings in cold countries can be designed to make the best use of the heat energy from the sun by incorporating appropriate design features such as large south-facing windows and special building materials that absorb and slowly release thesun’s heat for warming the building interior.

Solar photovoltaic technologies, on the other hand, employs photovoltaiccells made from semi-conducting materials such as silicon to produce directcurrent electricity when they are exposed to the sun. In the absence of moving components that are subject to wear and tear, photovoltaic cells canoperate for a very long period without much maintenance commitment. Thesimplest and most common type of photovoltaic cells provides power towatches and calculators, while the more sophisticated “state-of-the-art” photovoltaic systems can generate electricity to supplement local consumption in a building or a designated system, and the excess power caneven be fed to the city electrical grid.

Wind is the movement of air molecules, resulting from variations in airpressure created by difference in solar heating over the earth surface. Wind turbine is a device which captures the kinetic energy of wind to turn agenerator for producing electrical power. Nowadays wind farms employing groups of wind turbines located either on land or on near-shore waters are becoming more and more common to harness the wind energy for mass production of electricity.

Other forms of renewable energy technology like hydroelectric power, wavepower, geothermal energy and energy form vegetation are also gaining increasing popularity in power generation. However the exploitation ofthese forms of renewables is very often dictated by geographical conditions, and thus the extent of their application usually has a wide variation amongst countries.

Municipal solid waste commonly refers to residential and commercial refuse, and takes up the largest percentage of waste generation in industrialized countries. There are three basic processes that are currently used toconvert municipal solid waste into useful heat or electricity, viz, thermal process, biological processes, and landfill gas utilisation. All three methods produce energy from organic materials present in the waste that would otherwise be converted naturally into methane or carbon dioxide; both are undesirable by-products as they are the main constituents of greenhouse gases.

Choose Your Energy Source With a Programmable Charger

The Germans seem to believe, in part anyway, that electro mobility makes sense only if car batteries are charged using electricity from renewable energy sources. But the supply of green electricity is not always adequate. An intelligent charging station can help, by adapting the recharging times to suit energy supply and network capacity.

Germany is rich or getting poor, depending on your view of economics with aims to have one million electric vehicles – powered by energy from renewable sources – on the road by 2020. And, within ten years, the German environment ministry expects “green electricity” to make up 30 percent of all power consumed.

From a math perspective the proposition is it would be possible to achieve CO2-neutral electro mobility. But, in reality, it is a difficult goal to attain. As more and more solar and wind energy is incorporated into the German power grid, the proportion of electricity that cannot be controlled by simply pressing a button is on the increase. In addition, there is a growing risk that the rising number of electric vehicles will trigger extreme surges in demand during rush hour.

They are thinking ahead over there.  This – from a society that not so long ago was busily decommissioning nuclear – but now is looking to build more nuclear stations.  Reality wins one there.

Dominik Noeren of the Fraunhofer Institute for Solar Energy Systems says, “What we need is a smart grid that carries information in addition to power.  The information transport equipment is available now.  Noeren explains the structure of the grid has to change from a push (information feedback) system based on energy demand to a pull (information feedout) system based on production output. In Noeren’s opinion, “electric cars are best equipped to meet this challenge.” Introduced in large numbers, they have the capacity to store a lot of energy. On average, a car is parked for at least 20 hours out of 24. That is more than enough time to recharge them when the wind picks up or the demand for electricity is low.

Fraunhofer Smart Charger Concept Art. .

The Fraunhofer researchers developed a “smart” charging station, a device that enables electric vehicles to recharge when the system load is low and the share of energy from renewable resources is high. In this way, load peaks can be avoided and the contribution of solar and wind power fully exploited. “For us, it is important that end consumers are completely free to decide when they want to recharge. We do not want them to suffer any disadvantages from the controlled recharging of their vehicles’ batteries,” Noeren emphasizes. That’s why he favors electricity rates that adapt to the prevailing situation in the power grid — ones that are more expensive in periods of peak demand and particularly cheap when there is a surfeit of renewable energy.

Noeren is right, most all light and personal transport vehicles sitting still and empty is the vast bulk of the useable lifetime.  That presents an opportunity both to charge, store and discharge.  The amount of energy has a value as well as the speed the amount is delivered.  Add those points to the time of day that energy is drawn and the available renewable supply.  One might be very interested if one charged up on the cheap overnight and discharged to others during the morning rush.  Smart enough information handling and the cost of energy for transport could make much more sense.

The Fraunhofer thinking is the person using the “smart” charging station could then choose between recharging immediately or opting for a cheaper, possibly longer, recharging time. If they go for the second option, all they need to do is enter the time when their vehicle has to be ready to drive again. The charging station takes care of everything else, calculating the costs and controlling the recharging process. Via the display the user can track the progress of recharging and also see the costs incurred and the amount of energy used.

They’re halfway there . . . Now if the utility companies catch on and work out the economics the markets could start some forecasts.

A lot depends on more than the price(s).  There’s a whole lot of politics, investment and return, and operating costs to understand much better before much can happen.  A huge amount of mass storage would help as well.

Yet, it’s a gallant start.   The group showed their prototype charger at the Hannover Messe back in April.


Original post: New Energy and Fuel