Although hybrid wind, solar, and water systems have been extensively developed, there has recently been a lot of interest in the possibility of balancing unstable PV power generation by using hydro sources in order to increase system reliability. We will introduce the solar-hydro hybrid power plant to you in this article.
Floating Solar Power
In this context, floating solar photovoltaics (FPV) is emerging as a supplement to traditional solar power on buildings and ground-mounted as well as an intriguing solution for hydropower developers.
Simple in its conception is: using conventional solar panels installed on floating structures such as floats, pontoons, or membranes, while the whole system is firmly anchored and connected to the electrical connection onshore.
Even though it is still a niche market, the industry is expanding quickly (+122% since 2015), getting more developed, and getting cheaper every day.
The benefits of floating solar power are:
- it saves land surface, reducing land pressure on settlements or agricultural areas (locations with high levels of conflicting interests) and decreasing land acquisition costs;
- it is quite easy to deploy which limits site preparation and civil works;
- the solar panels installed on water benefit from a higher cooling effect, leading to lower temperature losses thus improving yields;
- covering water surfaces limit evaporation, saving more water for hydropower or irrigation uses; and
- to a certain degree, covering water surfaces can also limit algae growth, thus improving water quality for freshwater supply.
Developing floating solar power must, of course, be done with some caution, particularly in light of potentially negative social and environmental effects, such as those on fisheries and aquatic flora and fauna.
Strong anchoring and mooring are required in extreme conditions as they could be difficult. The design must take into account factors such as wind, waves, changing water levels, ice, floating objects, corrosion, ultraviolet light, etc.
It’s possible that maintenance is more challenging than on land: equipment longevity on ever-moving floating structures needs to be monitored, electrical protection on the water can be tricky, and access for personnel may not be so easy.
More Electricity, More Money
In the past, flat, open spaces have made it simpler to build ground-mounted solar parks. It is theoretically quite difficult for both energy sources to be located in the same place because hydropower needs steeper terrain for water to flow.
However, the possibility of deploying large-scale solar power close to active hydropower projects is greatly expanded by floating solar power.
By sharing some of the existing resources, such as the electrical infrastructure and existing transmission lines to move the power, more energy can be generated at the same location, generating more revenue.
Furthermore, hydropower operators are battling ever-tougher restrictions: providing flexibility to power systems, but also coping with more demanding water management.
Projects for hydropower frequently serve multiple purposes: managing drinking water, water supply to the industry, irrigation, and recreational activities.
Conflicts may arise regarding reservoir operation as a result of dealing with multiple stakeholders, which increases complexity.
To address the issues with both energy sources, a hybrid power plant that runs both the hydro and solar components at once can be used.
While solar power contributes to water conservation over the long to medium term by offering seasonal and daily flexibility, hydropower makes up for unstable solar power production through its quickly adjustable output.
The operator can then increase electricity sales and negotiate higher prices with a power output that is even more stable and dispatchable.
Collocation Is Fine, Hybrid Is Best
China currently has the best hybrid example (that isn’t floating): Having been in use since 2014 is the Longyangxia power plant. In this context, the term “hybrid” refers to a system in which solar and hydropower are interconnected.
Various research institutions have been examining the project’s complementary operations, scheduling, and optimization since the early stages of its development.
Unfortunately, despite evidence of the advantages offered by such hybrid plants, it appears that the industry has so far failed to replicate the implementation of projects of this kind.
Water + Sun = The Way Forward
The complex local and national regulations and policy frameworks, as well as the perceived technical complexity of hybrid operations, are directly responsible for the slow development to this point.
Aside from that, until recently, very different industries developed, built, and ran hydropower and solar power facilities.
Due to the need to locate large areas with few competing interests and close proximity to the grid, solar companies are now searching for opportunities on water, creating new opportunities for floating solar power technology.
The autumn of 2020 saw the release of a number of intriguing mergers and acquisitions news stories.
The acquisition of SN Power, a developer of hydropower plants currently owned by the Norwegian investment fund for developing nations, NORFUND, was announced by Scatec Solar, a developer, and operator of solar power plants across emerging markets.
Additionally, the venerable Norwegian hydropower company Statkraft announced the expansion of its solar power capacity through the acquisition of Solarcentury, a significant player in the European solar market with headquarters in the UK.
The development of hybrid projects is anticipated as a result of the current trend toward international multi-source renewable energy actors.
The potential for the world is enormous. According to a Lappeenranta University of Technology study, floating solar power on reservoirs around the world could generate an additional 6,270 TWh of electricity each year (with only 25% of the surface covered).
In Norway, hydropower generates about 40 times as much electricity each year as this.
Are hydro-connected floating solar power plants a part of the solution to both the integration of more variable renewable energy and the modernization of older renewable assets? Most likely, it increases flexibility, allowing for further integration of renewables.
It also adds capacity. The output of these hybrid plants is greater than the simple sum of the two energy sources, to put it simply: one + one does not equal two, but three.
Hybrid Hydro-Floating Solar Power Plant
The development of a sizable hybrid hydro and floating solar power plant at an undisclosed location in West Africa is the goal of a research project that the Norwegian government has decided to support with NOK79 million ($9.1 million).
The project is being led by renewable energy developer Scatec, which is based in Norway.
The 510 MW Lower Kaleköy hydroelectric unit in eastern Turkey was upgraded by Cengiz Holding to include an 80 MW solar power plant, converting it into a hybrid power plant.
The government-backed 1 GW project in Karapnar is still under construction, making the photovoltaic component the biggest complete facility of its kind in the nation.
Near the 88-meter-high Lower Kaleköy dam in the Bingöl province, 200,000 solar panels have been installed on the banks of the Murat River. In just six months, Cengiz Holding completed the installation and connection of the 80 MW photovoltaic units.
When the solar facility was added, Lower Kaleköy, also known as Aşa Kaleköy, ranked as the sixth-largest private system of its kind.
It is the first hybrid power plant in Turkey and the second largest in the world, according to Ahmet Cengiz, president of Cengiz Holding Energy Group.