Brightening the Pearl in the Indian Ocean with hybrid renewables

By Amila Withanaarachchi 

The electricity powering and the lights of your house were generated just moments ago. The way things stands today, the electricity demand must be in constant balance with the electricity supply. In other words, for some reason, if the existing power plants fail to generate and transmit electricity to us, the resulting vacuum needs to be immediately filled with a backup energy source. However, historical incidents such as the failure of Norochcholai coal power plant claim that not only such fossil fuel options fail to respond quickly, but are unreliable and unsecure as well. 

However, as per the latest reports, approximately 53% of country’s electricity demand is catered through fossil-based energy sources such as coal and oil sources, despite the serious issues associated with coal and other thermal power plants; and the balance energy demand is catered through renewable energy options such as hydro, wind, and solar energy sources. Then, the question is, “If fossil fuel energy sources are unpredictable, unsustainable, and unsecure, why can’t we totally rely on renewable energy?” 

Well, while renewable has more benefits compared to coal and other oil power plants, the instability and inability to store such energy solutions are one of the key obstacles to the sector’s development. 

While this could be the most frequently heard excuse we hear today, in this article I intend to challenge such views and argue that the renewable could be the solution for us in the coming decade. We are not thinking about this in the right way. Our thinking about renewable energy is outdated with the reality where the renewable energy market, policies, investments, and technologies at present and where they are heading in the future.   

Hybrid projects – A promising opportunity for developing economies 

The traditional belief around renewable energy systems claims that the variability of wind and solar power in a grid (i.e., inconstant wind flow and solar radiation resulted in generating instable electricity) cannot be balanced with the existing technology. 

Some time ago, the scientists and engineers were only concerned about the potentiality of pairing renewable energy sources such as wind or solar projects with storage. Enhanced battery storages and pumped-storage hydroelectricity are such solutions on which we were more concerned. But such resolutions are still in preliminary stages and need more research and development to reach the commercial stage. Does that mean we have to live with the current limitations and wait more and more years to make our renewable energy fantasy a reality? 

Not anymore! There is a simple but highly reliable solution; we call it hybrid energy power solutions.    

Hybrid energy power

Due to the technology advancement, several innovative hybrid renewable energy solutions are developing in the global context. For example, solar could be easily combined to a site that already has a wind farm, or floating solar could be paired to a hydroelectric reservoir. 

In many parts of the world, solar thermal has already been paired with geothermal to increase the temperature of the steam driving a turbine, and so has biomass. Tidal stream just offshore could also be paired with the wind just onshore. However, in a majority of these cases, wind and the solar combination is the most popular hybrid renewable solution, where wind energy being the dominant energy source while solar panels were assigned a secondary role in the power generation process.

Current installed capacities of the 

hybrid solutions

As of Bloomberg Energy Finance 2017 report, during the year 2017, some 20 renewable energy hybrid projects of a combined 10MW or more had been built or are being developed around the world. Thus, by the end of the year 2017, the total installed capacity of the hybrid energy resources was accounted for 5.6GW. Among the leading countries with renewable energy hybrid projects so far built or announced worldwide is China, followed by Australia, India, Morocco, and the United States.   

Suitability to Sri Lanka

Most novel renewable energy solutions such as solar and wind are less efficient compared to traditional renewable energy solutions such as hydro and fossil fuel energy sources. For example, the average capacity factor (i.e., the ratio of actual output against the potential output) of solar PV is 10-25%, and in the onshore wind, this is approximately 20-35%. Higher initial investments along with such productivity limitations are some of the main barriers to the sector’s development. 

Another important concern associated with wind and solar technologies is that it’s associated inconstancy. In other words, the varying solar radiation and the wind flow in a given point of time fail to generate a consistent power supply to the grid. 

Adjoining two or more power generation technologies at the same site is one way to enhance the efficacy of renewable energy and improve its competitiveness. Apart from such benefits, combined power solution can deliver a more consistent supply of power to the grid. In addition to such technical advantages, hybrid solutions can also bring many benefits to Sri Lankan power sector due to the country’s geographic standpoint and environmental conditions.

In many parts of the world, hybrid wind and solar projects are becoming more common due to the natural synergies of the sun and wind. In coastal areas of Sri Lanka, wind speeds pick up at night and drop off in the day when solar radiation is more plentiful. Seasonal variations in the island can also support co-location of these two energy sources. For example, during the two monsoon periods (southwest monsoon and northeast monsoon), combining wind and solar resources can strengthen a plant’s overall generation profile to better match grid needs.

One of the critical obstacles many renewable power developers have to face is the higher capital expenditure associated with power generating equipment and infrastructure. However, if we are to compare the investment capital an investor has to bear in developing two separate power plants, hybrid renewable energy power projects may also offer the opportunities to ease capital expenditure per unit of installed capacity. In most cases, irrespective of the two technologies investors intend to combine, almost everything from the substation to the transmission line, grid connection, transformers, cabling, and monitoring systems can be shared between two or more technologies.

While these technical infrastructures are typical for most energy plants, sharing such facilities can, in turn, reduce cost and improve project competitiveness. Also, at the development stage, investing in such a hybrid project also allows developers to streamline development costs and environmental approvals. Sharing the cost of operation, maintenance equipment, and onsite staff could be advantageous. In some cases, a single workforce can function for cleaning, security, and system monitoring.

Paving the way 

for a green future 

Today Sri Lanka spends a significant share of the country’s import expenditure on fossil fuels to meet the energy requirements. As a developing nation, the country’s demand for electricity is escalating at a continuous phase. Thus it is essential for Sri Lanka to secure its energy future by focusing on the development and adoption of indigenous, renewable sources of energy to meet this growing demand.

From the several renewable energy options we have (hydro, wind, solar, biomass, geothermal, and wave energy), pragmatically, most commercially viable options are limited to hydro, wind, and solar energy sources. However, in the current context, we have already tapped into most of the viable hydropower options. Further, along with country’s planned developments, the available land and resources available to meet country’s energy requirements are gradually declining. 

Within this context, while our small island is running out of usable lands for power generation, hybrid renewable energy power solutions can produce more electricity from each hectare of land. This is a vital and urgent issue concerning our current situation as a victim of the climate change and global warming. 

Also, Sri Lanka is among the 43 countries of the Climate Vulnerable Forum that agreed to make their electricity generation 100% renewable as rapidly as possible, and by the year 2050 at the latest. Hence, when formulating strategic energy mix for the country, the proposed hybrid renewable energy solutions should be a definite choice that we should seriously consider, because, at the end of the day, the choices we make today will be the future for the generations to come.  

[The writer, MPhil (Kelaniya), M.Sc. (La Trobe, Australia), B.Sc. (Kelaniya), CIMA, SLIIT (Diploma) is a lecturer at the University of Newcastle, Australia. While working as lecturer and course coordinator for the Business undergraduates at the faculty of Business & Law he is also perusing a Ph.D. (Management) at the same university. Mr. Withnaarachchi is also a staff member at the Department of Industrial Management, University of Kelaniya. He can be reached via [email protected].]