Clean, practical solutions to Sri Lanka's energy crisis - I

We have shown that solar power, the least polluting form of energy after hydro-power, has a high potential in Sri Lanka for FIRM electric power and to meet the expected power shortage. However, solar energy is not the only option available to Sri Lanka. In a continuation of this article, we address the enormous potential for biomass energy, and also show how it can be used to re-vitalize ailing agricultural sectors like coconut, rubber etc.

By Chandre Dharmawardana-May 6, 2019, 8:05 am 

Minister of Power and Energy Ravi Karunanayake is reported to have taken the initiative to contact French and Canadian agencies over Sri Lanka's grave energy crisis. The Minister has even explored awarding a Turkish company a tender to provide electricity from two power-ships. A sense of desperation is clear from reports that the Ceylon Electricity Board (CEB) officials offered alms to the Sri Maha Bodhi and appealed the gods to cause rains and fill the hydro-electricity reservoirs! Some rain has come, and the Easter bombings have intervened. And yet, the power crisis continues.

The CEB should have turned to the Sun God and solar energy sooner, but even now it is claimed that solar energy cannot provide "firm power" (continuous power). CEB planners have also ignored energy generation from the vast biomass available in Sri Lanka, considering it to be small potatoes. Given these assumptions, the CEB planners concluded correctly that a combination of hydro-power and large installations of coal-power is the optimal answer to Sri Lanka's energy needs. Such large-scale approaches to power need long-range planning and a FIRM commitment to the plans till completion.

While coal power is one of the most polluting types of energy, Sri Lanka is already ringed in the north by dozens of Tamil-Nadu coal plants. Sri Lanka's largest contribution to noxious fumes comes from burning over 60,000 barrels of diesel, motor and other fossil fuels a day. Even so, Sri Lanka's per capita emissions are a tenth of most western countries, and well managed coal-power plants can be run with a much reduced threat to the environment. So, contrary to the claims of the so-called "environmental lobby", the pollution from the proposed coal plants is arguably irrelevant to the total picture, as cleaner and AFFORDABLE alternatives were unavailable. This was the basis of the CEB long-ranged plan.

The Rajapaksa government adhered to the CEB plans and delivered continuous power from 2005 to 2014, electrified the whole country, and brought down tariffs by 25% when the Lakvijaya coal-power plant opened in Norochcholai – a name derived from "Horagolla", ironically evoking a salubrious clump of "Hora" trees! Unfortunately, Lakvijaya bears stark testimony to the CEB's incapacity to meet even minimal environmental standards, and in endangering the health of the local people. Hence the cancellation of the proposed coal powered plant in Sampura (located in the ancient "Somapura" historic area, see https://dh-web.org/place.names/) before it became another horror story is fortunate for Sri Lanka.

In the following we point out that fossil power is NOT NEEDED and that there are inexpensive non-polluting options that can be implemented RAPIDLY, unlike commissioning thermal or hydro-electric installations. Sri Lanka spent some $5 billion per year a few years ago, and still spends nearly $3 billion per year at current lower oil prices. However, the country can be largely FREE of such a burden.

Here we show how solar energy can give firm power WITHOUT batteries or alternators. We show how whole agricultural sectors that are now ailing can be re-booted inexpensively to become vibrant bio-energy sectors, while vitalizing them. The potential is vast enough to meet Sri Lanka's needs for decades to come, and even to sell to the Indian continent using a cable link, breaking the isolation of Sri Lanka's power grid.

Floating Solar Arrays

In 2009, just after the end of the Eelam war, Prof. Epasinghe (a Presidential adviser) and I met the then President Mahinda Rajapaksa, and discussed this very question of future power needs. I was given the opportunity to address some officials of the Presidential Secretariat and show a film on solar energy. One of my proposals was the possibility of using floating solar arrays positioned in reservoirs, with the power generated STORED AS WATER in the reservoir itself, instead of in batteries.

Power is stored by pumping the water back into reservoir, or just saving the equivalent amount of water that otherwise flow into a turbine, if the reservoir is equipped with generators. The resulting power is rendered when needed by the turbines as firm alternating current. Those were new ideas at the time. The talk can be accessed even today at: (https:/dh-web.org/place.names/posts/dev-tech.ppt).

Of course, solar panels were quite expensive in 2009, but our projections showed solar panels to become competitive soon. When the Rajapaksa government raised the price of electric power on May Day in 2013, I hailed it as a great step forward in making an equitable playing field for solar (see my article in Island, May 7th 2013). Other proposals suitable for Sri Lanka that I made included energy from biomass, and a call for electric trains instead of motor ways. Unfortunately, suggestions by scientists are rarely accepted by politicians.

So I was happy that a 100 MW floating solar array will be launched on the Maduru Oya reservoir, a decade after my suggestion. However, the proposal is still technically less satisfactory than my proposal, which needed no batteries to store the electricity and no alternators. If, say 200-250 hectare of the Randenigala reservoir were covered by solar panels, some 200 MW may be produced per hour when the sun shines. The solar power so produced can be fed into the grid and, assuming a head of 100 meters, some 800 cubic meters per hour can be saved IN THE RESERVOIR, for use after sunset. No batteries are needed! The cost, even inclusive of the floater, is incredibly low since the installation amortizes over a life of about 20 years.

The saving is much more, as emphasized in my talk in 2009. Some 35% of the water in a reservoir is lost by evaporation in a tropical climate. If 25% of the reservoir is covered, the solar panels shield the water from the sun's heat during the day and from the wind, both day and night. Assuming 400GWh of annual power generation at Randenigala, a potential 120GWh is "lost" to evaporation. The mere presence of the solar panels saves 30 GWh of power! Applying that to all the suitable reservoirs, the floating arrays save some 300GWh per year -equal to one Laxapana - by just being there!

The presence of solar panels discourages the growth of algae in the water. The environmental advantages compensate the disadvantages as long as we do not exceed 25% coverage. The panels should be distributed in an environmentally optimal manner. While floating panels are more expensive than fixed land panels, it avoids tricky negotiations for renting roofs of consumers. No clearance of land is needed for floating arrays. However, given some six million homes in Sri Lanka, most without roof-top solar panels, the claim that solar energy is not a viable option for Sri Lanka is false.

However, solar energy is not the only option available to Sri Lanka. In a continuation of this article, we address the potential for biomass and also shows how it can be used to re-vitalize ailing agricultural sectors like coconut and rubber.

We have shown that solar power, the least polluting form of energy after hydro-power, has a high potential in Sri Lanka for FIRM electric power and to meet the expected power shortage. However, solar energy is not the only option available to Sri Lanka. In a continuation of this article, we address the enormous potential for biomass energy, and also show how it can be used to re-vitalize ailing agricultural sectors like coconut, rubber etc.

(To be continued.)

[The Author was a past-Professor of Chemistry and a Vice-Chancellor of the SJP University in the 1970s. He is currently a Professor of Physics in Canada.]