Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, biomass tides, and geothermal heat, which are renewable (naturally replenished).
About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.8% and are growing very rapidly. The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables.
Energy in water can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy.
There are many forms of water energy
Wind power is power generated by the wind. Airflows can be used to run wind turbines. Modern wind turbines range from around 600 kW to 5 MW of rated power, although turbines with rated output of 1.5–3 MW have become the most common for commercial use; the power output of a turbine is a function of the cube of the wind speed, so as wind speed increases, power output increases dramatically. Areas where winds are stronger and more constant, such as offshore and high altitude sites, are preferred locations for wind farms. Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favourable sites.
Solar energy is the energy derived from the sun through the form of solar radiation. Solar powered electrical generation relies on photovoltaics and heat engines. A partial list of other solar applications includes space heating and cooling through solar architecture, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes.
Biomass (plant material) is a renewable energy source because the energy it contains comes from the sun. Through the process of photosynthesis, plants capture sun’s energy. When the plants are burnt, they release sun’s energy contained in them. In this way, biomass functions as a sort of natural battery for storing solar energy.
Ceylon Electricity Board is the pioneer of implementing Renewable Power Generation in Sri Lanka. CEB's Renewable Power Generation dates back to 1969, the inception of CEB, with Hydro Power Technology and it managed to generate Power entirely from Hydro Power to the whole country in the initial era. Later, CEB took the initiative to open business opportunities to private investors by allowing Mini-Hydro Power Plants to get synchronized to the Power Grid.
While CEB's primary focus on renewable energy was on major Hydro, CEB researched for other renewable resources in parallel as harnessing major Hydro potential was gradually reaching the ultimatum. As a result, CEB introduced Wind and Solar Power Generation taking another gigantic step towards a Carbon Neutral Sri Lanka.
Along with the varying Government policies from 2017 and with the latest target given to achieve at least 70% of the energy generation via Renewable Energy sources, Ceylon Electricity board has grabbed the opportunity to accelerate the generation of Solar Power despite numerous technical limitations.
Solar Power Generation is the main form of renewable energy source that indicates the highest growth during the last few years. CEB has classified the Solar potential identified in the country in to following categories of development and are implemented through several configurations appropriately.
1. Ground Mounted Solar
a. Large and Medium scale Solar parks (10-100 MW)
b. Scattered small scale Solar projects (1-10 MW)
c. Scattered small scale Solar projects in LV Network
2. Rooftop Solar (Net Metering, Net Accounting, Net Plus)
3. Floating Solar
Annual electrical energy produced from Solar has risen nearly 46% in past two decades as illustrated in figure below. Total capacity of commercial Solar Power Plants by end of 2020 was 67 MW and nearly 347 MW of Solar roof tops were also connected by end of 2020. Scattered developments of small-scale Solar Power Plants have been already initiated and feasibility studies were initiated to develop Solar Power Plants in park concept.
'Cost of Solar Power Generation technology is becoming increasingly competitive and a steady and strong growth is expected to continue for both rooftop and ground mounted applications in commercial scale. Along with these initiatives, CEB Engineers are faced with new challenges in grid connection owing to the technical limitations in the Power Network to cater the rapid increase of Solar Power projects and synchronizing the new Power generation projects with the existing Power network that has maintained constant synchronization over the past decades. To promote Rooftop Solar Power Generation, “Energy Banking Facility”, commonly known as the “Net Energy Metering Facility” was introduced for electricity consumers. However, commercialization of Power Generation provides room for low-cost, low-quality products that will disturb the entire Power network of the country. CEB Engineers are aggressively working on resolving such dynamics to enable Solar Power Generation retain a dominant share as planned in the 20 year long term Generation Plan (https://ceb.lk/front_img/img_reports/1636539187LTGEP_2022-2041_Web_compressed.pdf ).