Monthly Archives: March 2016

Ecologically Sustainable Rooftop Solar and Waste-to-Energy as Alternatives to Unsustainable Mini-Hydro

Increased demand for energy due to population growth and development is currently a major issue in Sri Lanka. Due to high cost and greenhouse gas emissions, there is an increased effort to get Sri Lanka out of fossil fuels and into renewable energy sector which is commendable. Currently, several renewable energy technologies have shown tremendous potential and the options are growing as more research and technological breakthroughs are made worldwide. Each of these renewable energy technologies have their own advantages and disadvantages based on cost, capacity, location and impact to the environment. Therefore, as Sri Lanka pushes to generate more energy through renewable sources, a thorough comparison of each should be done to promote the best options that are suited for our tropical island nation.

Sustainable Energy Authority and Ministry of Power and Energy in Sri Lanka are currently promoting mini-hydro energy as the top priority, followed by solar, wind and waste to energy as renewable sources of energy. Below is a detailed evaluation of each and recommendations for selecting and promoting “Ecologically Sustainable Renewable Energy”.


1. Solar Power

Solar power generation has come a long-way since its beginnings and currently becoming very competitive form of renewable energy. Solar power can be generated through several methods and the most common and environmentally friendly option is through Photovoltaic (PV) panels. PV panels can be installed in rooftops as well as in solar farms. Solar farms are attractive options for countries with vast open areas of land such as the Middle East, Australia and North America. But for an island nation and a biodiversity hotspot such as Sri Lanka with limited land resources, it is not a viable option. Rooftop solar projects on the other hand reuse existing rooftops of government and private office buildings, factories and residential homes. They do not have any negative ecological impacts, can be easily installed in a relatively short period of time. Excess power from rooftop solar panels can be fed back to the national grid. Rooftop solar projects also offer the benefit of being able to install off grid in rural areas as demonstrated in countries such as Bangladesh1 making rooftop solar projects best suited for Sri Lanka.


2. Waste-to-Energy

Mountains of unhealthy landfills in several major cities such as Colombo, Kandy, Galle and Ratnapura are already causing major environmental and health issues to the surrounding community. However, the technology is already available to address the solid waste issues while generating electricity to the national grid. “Plasma Gasification” is one of the most suitable as it breaks down solid waste into the basic elements with no harmful gases released in the process.

Plasma gasification can be used to convert carbon-containing materials to synthesis gas that can be used to generate power and other useful products, such as transportation fuels. Plasma gasification provides a number of key benefits:

* It unlocks the greatest amount of energy from waste

* Feedstocks can be mixed, such as municipal solid waste, biomass, hazardous waste, and auto shredder waste

* It does not generate methane, a potent greenhouse gas

* It is not incineration and therefore doesn’t produce leachable bottom ash or fly ash

* It reduces the need for landfilling of waste

* It produces syngas, which can be combusted in a gas turbine or reciprocating to produce electricity or further processed into chemicals, fertilizers, or transportation fuels-thereby reducing the need for virgin materials to produce these products

WPC - Gasification Process Diagram - Key Enabling Technology_2.jpg

Well established International companies that have successfully implemented waste to energy projects overseas have submitted their proposals to Urban Development Authority (UDA) as of July 2015. These proposals indicate the waste to energy projects will be on build-own-operate basis (i.e. no cost to the Government) with the only requirements being a steady supply of waste, power purchase agreement at the Gazetted Rs. 26.1 kWh and suitable land. Unfortunately, the proposals are yet to be approved by the relevant authorities even though both solid waste and energy are two of the major issues facing the country.


3. Wind Power

Wind power generation is another renewable energy source gaining popularity. While both onshore and offshore options are available for wind power generation, offshore wind power is more suited for Sri Lanka due to limited land availability but having a large Exclusive Economic Zone (EEZ) in the Indian Ocean. However, wind power generation does come with a few ecologically negative effects. Recent studies have shown that due to the blade turbines in wind farms, millions of birds get killed each year. To address this issue, bladeless turbines4 have been developed and introduced to the market. Selecting locations that are not used as bird migratory routes is also another option to reduce the ecological damage caused by wind power generation.


4. Mini-Hydro Power

Power generation through mini-hydro technology involves building a weir to block the natural water flow of a waterfall, stream or river and diverting the water through a penstock to a forebay tank and eventually to the powerhouse. A turbine in the powerhouse generates the electricity. The capacity of most of the mini-hydro projects in Sri Lanka ranges from 0.3 MW to 3 MW with the average less than 1 MW. Due to the abundance of waterfalls and streams in the wet zone Rainforest habitat in Sri Lanka as well as incentives provided by the Government, mini-hydro projects have become very popular at the expense of the surrounding sensitive environment.

While the actual generation of power through this process does not generate greenhouse gases and therefore considered environmentally friendly, the ecological effects of mini-hydro projects indirectly contributes to climate change due to deforestation. The ecological impact is very high due to long stretches of streams that go dry (e.g. 6.5 km stretch of stream in Anda Dola, Dellawa Rainforest). Further ecological damage is done due to construction of new access roads, powerhouse, penstock, forebay and workers quarters construction within or in buffer zones of rainforests. With Sri Lanka named as a biodiversity hotspot and majority of endemic species habitat located in the sites selected for mini-hydro projects, the recent explosion of mini-hydro projects have created an ecological disaster.

Along many small streams in catchment areas, developers try to achieve the required power by using flow rates even less than 1 cubic meter per second which is the mandatory flow rate for mini-hydro projects. To achieve their desired energy output in streams with low flow rates, height between the weir and power-house need to be increased. This is achieved by increasing the length of the penstock which adversely affect considerable length of the stream. Once construction is completed, that part of the stream go dry even during a small period with no rain.




Renewable Energy Ecologically Sustainable Potential Capacity
Rooftop Solar Power Yes Very High (1+ GW)
Waste to Energy Yes Medium (~200 MW)
Wind Power (Bladeless Turbines) Yes High (Up to 1 GW)
Mini-Hydro Power No Medium (~400 MW)

While mini-hydro projects are given top priority as sustainable energy in Sri Lanka, it is the least ecologically sustainable energy source. Due to lack of national policy and poor site selection, mini-hydro projects so far has caused massive destruction to protected forest reserves and world heritage rainforests. Further, it is most susceptible for changes in weather patterns on short periods of time as streams and waterfalls increasingly go dry regularly due to rapid deforestation in Sri Lanka.

Considering ecological sustainability and total potential capacity, “rooftop solar power” comes as the clear winner. Many countries in Europe and Asia are currently giving priority to rooftop solar projects, with France passing legislation to require all new buildings in commercial zones have either plants or solar panels11. Other countries such as U.S.A provides tax incentives for residential and commercial rooftop solar projects. In Sri Lanka, the 1 MW rooftop solar installation at MAS factory in Thulhiriya generates more power than many approved mini-hydro projects that have been constructed in ecologically sensitive areas such as Koskulana in Sinharaja and Anda Dola in Dellawa Rainforest.

In addition to giving priority to “rooftop solar” projects through incentives, the Government authorities should be requested to evaluate and approve the stalled process of Waste-to-Energy projects. Everyday the submitted proposals at UDA are collecting dust, the residents near the mounting garbage dumps are facing severe health hazards and the threat of garbage dumping within protected forest reserves increases. Waste-to-Energy projects which solve solid waste issue while generating power to the national grid should therefore be promoted as a national priority.

Rooftop Solar Power, Waste to Energy and Wind Power are sources of ecologically sustainable energy that can provide uninterrupted power regardless of drought conditions or catastrophes such as radiation and oil leaks that plague the traditional sources of energy such as hydropower, nuclear and coal power.

Sri Lanka has the capacity to easily meet the national energy demand through ecologically sustainable energy sources without sacrificing its natural resources such as waterfalls, streams and rivers for ecologically destructive mini-hydro projects. The destruction of these ecologically rich sites also negatively affect the surrounding communities and eco-tourism, which in turn result in loss of foreign exchange and employment opportunities. If the current trend of mini-hydro projects continue, Sri Lanka will suffer from irreversible damage done to the natural ecosystem for generations to come.

Rainforest Protectors of Sri Lanka




1. Off grid solar power

2. MAS unveils country’s largest rooftop solar plant in fabric park

3. HNB invests in solar power to reduce carbon footprint

4. The Future of Wind Turbines? No Blades

5. Athwelthota mini hydro power plant

Rupavahini News 8pm, Sunday, March 6, 2016

‘Freshwater fish species are threatened due to the construction of a dam at Athwelthota. The impact from the dam to the ecosystem is considerably negative. According to environmentalists, owing to the proposed hydro power plant, the Athwelthota Palan Ganga ecosystem in the Kalutara District is directly at risk of environmental damage. The Athwelthota Palan Ganga river, which beautifies the Baduraliya village of the Kalutara district by flowing through the area, commences from Sinharaja as a tributary of Kukuleganga. Between the villages of Athwelthota and Molapitiya, the tributary can be seen cascading down a height of about 5 metres, creating a scenic waterfall – this is the ‘Peelithuda’, or ‘Athwelthota’, fall. The base of the fall hosts about 18 species of endemic freshwater fish. A mini hydro power plant has been proposed at the site of the fall, threatening this valuable biodiversity. The power plant, which will include a dam across Palan Ganga to create 1.5MW of power at the cost of LKR35m, has received approval from the Forest Conservation Department of Sri Lanka. Under the project, the dam will be built above the waterfall, creating a reservoir and a power plant building. An extremely weak environmental assessment report, such as the one created in connection with this project, receiving approval is extremely disappointing, as per environmentalists. According to environmentalist Janaka Vithanage of the Centre for Environmental Justice, the fish species ‘Hal mal dandiya’ is found only at Athwelthota Fall. According to him, the fall hosts about 35 species of freshwater fish; any artificial change in the water level will disrupt the life cycle of the fish species that breed here. Moreover, he says when a dam is built across the water the resulting sedimentation will change their habitat and drive them to extinction.

Villagers here are also extremely displeased with the hydro power project, given that it will irreparably alter this site which is a popular scenic attraction for local and foreign tourists. On one occasion, the Additional Provincial Secretary had stated that the villagers had been notified of the project. Commenting on this, however, the former Gramasevaka of Athwelthota, Mr. Padmasiri Pelawatte, commented that only officials at the higher echelons of administration were aware of the project and that the villagers had been unaware. The provincial council had recently erected a notice board at the waterfall informing visitors that the Athwelthota Fall is dangerous and that it had been the site of several drownings. However, villagers who regularly visit the fall to bathe in its cool waters are of the opinion that the disappearance of the waterfall would be an

unspeakable loss. Environmentalists opine that false reports written by certain officials looking for quick money are the causes of the type of environmental destruction that is threatening in this situation. The fact that the Forest Conservation Department passed this report and approved the project under the recommendation of the Central Environmental Authority is cause for great disappointment, according to environmentalists. Environmentalist Janaka Vithanage commented further that “if you go on to the Web, you can see advertisements for mini hydro power plants in Sri Lanka that have been constructed and put on sale. This is currently the most profitable business in Sri Lanka. This fall is right now facing the dry season, and there is only enough water to accommodate the breeding of the fish; there is not enough water to produce much energy. Development trends have changed. About 200km of river bed have dried up due to hydro power projects in the country”. Following comments by environmentalists, NARA has requested to produce a report on the fish species at the Fall and the Central Environmental Authority has also sought an exhaustive report from the University of Kelaniya on the situation. The question now is whether the intention behind these projects in the expansion of the country’s power-generation network or the filling up of private coffers.

6. Public protest by villagers in Ratnapura over mini-hydro project

7. Incidents of mini-hydro projects under construction causes inconveniences to locals

8. Learning Vallibel lessons the hard way

9. Mini-Hydros Clean energy comes at a high cost to nature

10. Illegal Hydro Power Project in Sri Pada

11. France decrees new rooftops must be covered in plants or solar panels