Clean energy without foreign exchange

[This article is dedicated to the late Dr. Janaka Ratnasiri who tirelessly worked hard to make the country move away from fossil fuels.]

According to a news report published in The Island (17 July 2021), the CEB Engineers Union had stated that the government’s target for increasing to 70% the electricity from renewable energy to the national grid is not practical. Apparently, even if it were practical, the CEB does not have computerised infrastructure for managing the variable switching-in and switching-out, needed for integrating “non-firm” energy sources like wind and solar into the grid.

The CEB can say, if we only had that “excess capacity” then blackouts wouldn’t happen! But this is irrelevant, given Dr. Siyambalapitiya’s admission (The Island 19-08-20) that “the system” cannot even handle a 0.5% power fluctuation from “unmonitored” sources like “solar and wind”.

Engineer S. Kumarawadu, the President of the CEB Engineers Union, claims that transmission lines have to be upgraded to meet targets. That should have been a part of the long-term plan anyway. One hopes that the CEB union is more reliable than the GMOA, where Dr. Padeniya has been making statements from cloud cuckooland itself (see https://www.youtube.com/watch?v=rGe6ld2q1vs).

The views of the CEB Engineers Union are very relevant to the country’s energy planning. However, it also has gross vested interests. What the power sector in Sri Lanka does NOT have, is an independent Research and Development (R&D) arm, similar to the Tea Research Institute, Coconut Research Institute, etc., available for agriculture. It is the vital research done by the rice research institutes in developing high-yielding seeds that kept up with the population explosion and fed the country. They faced political bulls running amok in the agricultural china shop, advocating a return to traditional seeds, traditional manure, and the use of occult practices like “kem”, while advocating getting rid of “all chemicals”.

As they are not guided by an R&D arm, the engineer managers choose conventional turn-key solutions that they know of. The CEB is an “unthinking beast” that does not run research projects or pilot plants and patent new ideas. Its “Long Term Generation Planning” (LTGP) Branch makes a no-brainer expansion plan every year.

The CEB’s LTGP 2015-2034 is still excessively tied to fossil fuels. This is not surprising, as it does not have the capacity to integrate new technologies, or even run a proper simulation of its own system, its power failures and blackouts. It has gone to Canadian, European or Japanese organisations to do simulations that should have been “in house” jobs. Its “research” is at best a tender board tango done with wheeler-dealing politicians. The CEB ends up blaming politicians who canceled “well-laid” LTG plans, while the politicians blame an uncooperative “CEB mafia”!

Consider the claim (see The Island, 17th July) that supplying 70% of the needed power using renewable sources is not practical. This is contradicted by other information sourced to the CEB itself. A news report (23-12-2019, The Island) claimed that when there were heavy rains, 70% of the power needed came from hydroelectricity. Similarly, on 10th August 2020 the CEB reported that over 50% of the power came from hydro as there had been adequate rains.

Some 40 GWh is needed at present. Hydroelectricity provides about 20 GWh of this, while coal provides some 18 GWh. As mentioned above when there is sufficient rain, 70% of the needed electricity comes from hydro! That is, some 28 GWh can be harvested if the water levels are preserved over the two monsoons. So, this increased the the hydro-electric output by some 40%. This figure is consistent with high hydro-electric outputs in the rainy seasons.

When the reservoirs are full, the evaporation is also extreme. King Parakramabahu wanted to use every drop of water reaching the ocean but did not consider evaporation. In my writings during the past two decades, I have pointed out the need to stop the over 30-40% evaporation losses happening day and night, due to the wind and the prevailing heat. These worsen with global warming. During heavy rains the water spills over and gets wasted. Additional storage to save spill water by restructuring reservoir dams, and using locally made floats to cover parts of the surface to cut evaporation can boost the hydro-electricity output over 30-40%.

So far, just by protecting the water from evaporation and spillage, we gain perhaps a 30% boost in hydro-power without using any solar panels. Floats can be added WITHOUT foreign exchange. If solar panels and wind turbines are added around these reservoirs, even more energy is harvested. Do your own calculations to see what you get! For answers, see my earlier articles, e.g., The Island of 15.07.2020, or 31-08-20: https://island.lk/sri-lankas-power-supply-blackouts-and-how-to-prevent-them/). Hence you don’t need any fossil fuel in the end.

Evaporation control will become extremely acute with increased global warming. Otherwise, even the 20GWh currently supplied by Hydro will dwindle down due to extended droughts. However, once the systems are set up to prevent evaporation, the gained 30-40% increase in hydroelectricity is produced by a gain in head water in the reservoir. NO STORAGE BATTERIES ARE NEEDED. This is “firm energy” and remains compatible with the utterly outdated grid stabilization schemes still used by the CEB.

So, preventing evaporation will rapidly increase the island’s power capacity by, say, 30% . Given some 22 major hydroelectric reservoirs with a surface area of about 1000 ha each, if 50% of the surface be covered using floats, 11,000 ha (110 sq km) are protected. It can be shown that the environmental impact is positive. The water quality is improved due to reduced algae growth. The annual hydro-power of about 6000 GWh will rise to 8000 GWh when evaporation is cut. This is the cheapest and cleanest possible electricity!

Typically, sunlight can annually produce about 100-200 GWh per sq. km (100 ha) under Sri Lanka’s conditions. If solar panels are also placed on the floaters deployed to cut evaporation, then 1000-2000 GWh per annum of solar energy can be harvested, with no hassle or delays in acquiring land rights. Any excess daytime energy can be saved by retaining the corresponding amount of hydro-head in the reservoirs, without sending the reservoir water down into the turbines. That is, solar electricity has been stored without batteries and converted to firm power!

Furthermore, evaporation shields, equipped with solar panels are a one-time capital investment, and there is no need for continued importation of LNG, coal or oil as envisaged in the conventional expansion plan of the CEB that takes no account of global warming. The type of costly infrastructure development needed for LNG is not needed for the simple approach of cutting down evaporation, as the first conservation step that will boost Sri Lanka’s clean power capacity. And yet, in the LTGP 2020-2039, the CEB has only paid lip service to government policy on fuel diversification by adding LNG-based generating capacity, whereas LNG is an expensive fossil fuel that should have been avoided! Why is LNG energy being falsely referred to as “clean energy” in CEB documents?

However, unconventional solutions should NOT be implemented without running pilot projects. Such projects must be run by a yet to be established Power Research Institute, which should have been established at least in the days of the accelerated Mahaweli project. A first floating solar project has been proposed near the Parliament, on the Diyawanna Lake. But this is largely a no-brainer as the Diyawanna lake is not connected to a turbine, and no gain in evaporation is achieved. No natural mechanism of energy storage, as saved water is available and one has to resort to batteries.

Some unconventional solutions that have been proposed (without any trials or pilot projects) include the use of urban garbage as an energy source, while ignoring the now well established biomass approaches that use fast-growing Giricidia or Castor to produce dendro energy. Several 10MW dendro plants already exist, and establishing 20 more within the next 2-3 years, to add 200MWs of capacity is straightforward.

Attempts to use urban garbage in settings similar to Sri Lanka, e.g., India, has led to failure in actual operations. Only a total of 138 MW has been installed in India by 2019 although its garbage output is massive. The extreme wetness of the garbage, inadequate separation of wet garbage from dry garbage, and the difficulties of plant operation for methane production, incineration and pyrolysis, and disposal of toxic ash have become serious problems. This is, in my view, an unsuitable approach for Sri Lanka, although suitable for a research and development (R&D) pilot project, since Colombo alone produces 2-5 thousand tons of urban garbage per day. Sri Lanka should develop dendro power while leaving “garbage to energy” conversion as an R&D project.

CHANDRE DHARMAWARDANA

Canada