Sri Lanka power system debate – Renewable energy potential underestimated

Friday, 8 June 2018 00:00 -     - {{hitsCtrl.values.hits}}

By Mayura Botejue

Visionary goals have been expressed in recent reports on harnessing renewable energy (RE) in Sri Lanka. The ADB and UNDP issued a report titled ‘100% Electricity Generation through Renewable Energy by 2050,’ while the Ministry of Power and Energy report was titled ‘Sri Lanka Energy Sector Development Plan for a Knowledge-based Economy 2015-2025’. The latter featured a lofty pronouncement by the Minister Champika Ranawaka that stated: “We have set an ambitious goal of 100% energy self-sufficiency by 2030.”

The island is blessed with hydro, wind and solar resources with existence of synergy between intermittent renewables (wind, solar) and hydropower. While costs of wind and solar plant continue to drop, advances in battery storage technology, smart meters and the trend towards distributed generation holds great promise over the decades to come. Thus, RE dominance in the national electricity generation mix can be attained economically as long as policies favour this outcome. 

Meanwhile the debate is taking place on the proposed power system mix of the CEB Long-Term Generation Expansion Plan (LTGEP).

The CEB Engineers’ Union claims that the LTGEP is well-balanced with a generation mix of LNG, coal, hydro, wind, solar, etc., while the PUCSL has proposed that all future thermal power plants be based on Liquid Natural Gas (LNG) fuel.

The CEBEU believe that if the PUCL plan is implemented, the nation will depend largely on a single fuel for thermal power generation resulting in a detrimental impact on the energy security of the country.

The debate is complicated with arguments about costs of the various plant, fuel types used and the environmental impact of using coal.

The CEB plan reflects a change from past preference for a conventional power system configuration (base load coal with hydro power for grid regulation and storage) to the currently proposed system of a balanced portfolio of power plant options that feature thermal plant (firm) and renewable energy (RE) based plants such as wind and solar (intermittent). The plan is a step in the right direction. 

Large-scale integration of RE-based plant is starting to happen. If the trend is to continue towards RE dominance over the coming decades, the type and operational characteristics of fossil fuel plants commissioned during the transition phase must be judged on how they influence the rate at which RE plants are integrated to the electricity supply network. Excess ‘must operate’ thermal capacity could delay the increased harnessing of wind and solar even though their cost of energy was low.

Transition towards 

RE dominance 

With the existing power system featuring a mix of coal, oil, hydro and diesel power plant, the large-scale integration of wind and solar presents new challenges to the power system planner.

In order to project forward from the present state towards a RE-dominant power system, it may be best to consider the hypothetical case of a 100% RE-based power system decades ahead.

On the basis of current technological trends and project activities taking place in the developed world, one could assume that a Sri Lanka specific 100% RE power system would feature the following elements:

  • Electricity considered a commodity with buying and selling through the network;
  • Time of day metering (semi-hourly with smart meters and batteries in use);
  • Wind, solar and hydro dominant;
  • Advanced forecasting of wind and solar energy yield;
  • Hydro power plant catchment enhancement (reforestation to increase “soak and trickle” effect - form of storage via delayed release); 
  • Utility scale battery storage;
  • Roof top solar PV with battery storage (residential, commercial, industrial) with smart meters driving demand side management programs;
  • Smart offices, factories and homes with efficient electrical machinery and appliances;
  • National utility unbundled with distributed generation;
  • Mini/micro grids;
  • Rural electric cooperatives (bio mass, solar PV); 
  • Wheeling of “green” power to businesses that seek favorable credentials for export products and/or marketing credentials;
  • National authority with generation planning and HV electric transmission system operational responsibility; and,
  • National authority for regulatory oversight.

The preparation of a LTGEP generation expansion plan over the transition phase to arrive at the above state seamlessly and economically will be a complex task with rate of capacity additions, type of plant and managing the intermittency the challenges that need to be addressed.

Type of fossil 

fuelled plant

If analysis shows that additional fossil fuel plants are required, what type of plant should be utilised?

Coal is firm, but inflexible and does not make a good marriage with intermittent wind and solar power. Local environmental issues are prevalent (ground waste, emissions and acid rain affect).

LNG is firm, flexible and has added advantage of a clean source of supply for industrial heating and piped supply to commercial, industrial and residential facilities. Additional benefit over the long term (10 - 20 years) if gas is extracted from the Gulf of Mannar.

Diesel is firm and flexible with fast-track development, small scale infrastructure, low EPC cost, but high operating cost (fuel). Diesel plants can be placed at strategic port locations such as Galle, Hambantota, Trincomalee and Kankesanthurai.

Leaving economics aside, Sri Lanka is perfect for operating a hybrid power system. With the existing power plants in place (thermal + hydro), a program to increase power generation capacity by aggressively pursuing development of wind, solar, diesel plants and battery systems is technically feasible today (diesels and batteries will address intermittency). 

With cost of wind and solar power plants and battery systems on a downward trend and their energy performance improving, the economics for implementing this option will look promising a few years ahead with the maximised RE harnessing option yielding the added benefit of creating skilled employment opportunities throughout the country.

Those having doubts about the tremendous promise of RE should follow activities taking place in the world today. 

For example, in coal-rich Australia, a recent news item reported that a 1,300 MW combined wind, solar and batteries project will beat coal power on price and reliability. The reader may Google “CWP 1,300 MW wind solar and batteries project” for details.

The fossil fuel dependent State of Hawaii is pursuing a Clean Energy Initiative to cut out the dependence on oil and coal by setting a goal to achieve 100% clean energy by 2045. Wind, solar, batteries and smart devices will play a major part in helping to attain this goal. The reader may Google; “Hawaii Clean Energy Initiative” for details.

In light of the above, why is the power system expansion debate so much focused on the coal and/or LNG option? Since LNG and coal plant developments require major infrastructure investment, does it make sense to pursue both options for the sake of energy security? Both expose the nation to fuel price and currency risk.

Leaving aside the issue of “power politics”, is the desire for additional “base load” plant due to the conservative mindset of the national power system planners? Are they concerned about the risk of integrating a large quantum of unregulated capacity? Is it also because the very same technocrats, university academics and concerned citizens (stake holders) lack familiarity with large-scale integration of RE plant for power generation? 

Power sector technocrats are proceeding on the basis of knowledge and capabilities of a conventional approach while technological disruption – resulting from rapid advances on multiple fronts - is having a major influence on the integration of RE to the electric grid.

Seek foreign assistance 

It will be best if the Government approached the international development and climate change mitigation institutions to request high level expertise on technical and commercial matters to address the challenge of integrating a large quantum of RE for electric supply over the coming decades. 

The priority areas where assistance should be solicited are; a) resource assessments and setting up a geographic information system (GIS) for zoning land suitable for wind, solar and biomass, b) educating technocrats on state of the art RE technology and its evolution in the coming decades, c) advanced programs for system simulation to study effects of large scale RE integration, d) economic and commercial aspects that cover project development, electricity pricing, unbundling the electric supply network, skills development, etc. and, e) policies for accelerating RE project development via private sector investments.

If the former Power and Energy Minister Champika Ranawaka’s vision of an energy an empowered nation and a knowledge-based economy is to be realised, an accelerated program for harnessing RE will be an essential pillar of that vision. 

(The writer is Senior Consultant at DNV GL Energy and engaged in wind and solar power project development activities in the South Asian region. He counts over 25 years of project experience gained in an international environment and is a renewable energy advocate and an environmental activist. The writer can be reached at: [email protected].)