| Renewables integration
In their paper published in Nature Sustainability, Yubin Jin et al state there is huge potential for floating solar projects on reservoirs, although additional studies will be needed to assess the long-term consequences of such large systems. Based on multiple reservoir databases and a realistic climate driven photovoltaic system simulation, the authors say that the practical potential electricity generation for such systems with a 30% coverage on 114,555 global reservoirs is estimated at 9343+TWHyr-1
. The proximity of most
reservoirs to population centres and the potential to develop dedicated local power systems also means that more than 6200 communities and/or cities in 124 countries could be self-sufficient with local floating solar plants, while reduced annual evaporation could conserve 106
+km3 of water. Statkraft is one company heeding the call to develop
more floating solar, and recently started commercial operations at the Banja Floating Solar Plant in Albania. Located at the Banja reservoir where Statkraft is operating its 72MW hydropower plant, this innovative R&D project has an installed capacity of 2MWp and planned annual generation of approx. 2.6 GWh. The plant is comprised of four individual floating units, each with a surface area of approximately 4000m2
operating and balancing trade-offs in complex water–energy–food–ecosystem (WEFE) resource systems, by introducing a novel artificial intelligence- assisted, multi-objective design framework that was demonstrated on a national-scale case study for Ghana in West Africa. The proposed framework has two components: an
and
equipped with more than 1500 solar panels. Developed by Norwegian company Ocean Sun and implemented with Albanian company, Doko, in addition to generating renewable energy, the project shall also serve as a learning base to properly assess the potential benefits of this technology. “The completion of the implementation phase of this
R&D project marks another achievement for Statkraft in Albania. This project has been implemented in close cooperation with the Albanian authorities. With our Banja and Moglice hydropower plants in Albania we are the largest private investor in renewable energy in the country and are currently looking into further optimising these renewable assets,” said Statkraft’s Country Head in Albania, Rigela Gegprifti. Albania has one of the highest shares of renewable
energy in Southeast Europe and hydropower represents around 95% of its installed power capacity. In addition, Albania has some of Europe’s highest number of sunshine hours per year, presenting significant potential for the development of solar power and a good fit with existing hydropower capacity.
Multisector consideration New research has warned that unless consideration
is given to multisector performance, the use of hydropower to counterbalance the temporal variability of intermittent renewables and integrate them into the gird, has the potential to affect aquatic ecosystems and increase cross-sectoral water conflicts. An artificial intelligence-assisted multisector design framework has been used in Ghana to show how hydropower’s flexibility alone could enable expanding intermittent renewables by 38%, but would also increase sub-daily Volta River flow variability by up to 22 times compared to historical baseload hydropower operations. This would damage river ecosystems and reduce agricultural sector revenues by US$169 million per year. Research by Gonzalez et al in Nature Sustainability aims to support decision-makers in designing,
integrated river basin and power system simulator and a multi-objective artificial intelligence-based optimised design process. It helps analysts and stakeholders to identify power system designs and hydropower operations that minimise adverse environmental impacts and intersectoral conflicts when addressing the challenge of integrating intermittent renewables. A diversified investment strategy identified using
the proposed framework, including intermittent renewables, bioenergy, transmission lines and strategic hydropower re-operation could reduce sub-daily flow variability and enhance agricultural performance while meeting future national energy goals. The tool supports national climate planning instruments such as nationally determined contributions (NDCs) by steering towards diversified and efficient power systems and highlighting their sectoral and emission trade-offs and synergies. Gonzalez et al say that their study shows multisector conflicts can be aggravated unless a diversified set of power system infrastructure investments with appropriate management are put in place. Their results encourage planners to consider the negative impacts on water, food and ecosystems and encourage investment in power systems that balance multisector performance while reducing CO2 emissions.
Imbalanced The difficulties involved with integrating intermittent
renewables into electricity grids is being experienced by India, where concern is growing that the country could be facing the risk of night time power cuts this summer. Rapid expansion of solar power, which has witnessed a four-fold growth over the past five years, has addressed surging energy demands during the daytime but delays in developing additional hydropower and coal-fired capacity may lead to widespread power outages out of daylight hours. A recent Reuters news report describes the situation as being “a little stressed” and that non-solar hours in April are expected to be 1.7% lower than peak power demands, while peak hydro availability will be 18% lower than April last year when output had been boosted by favourable weather conditions.
Above: Developers of floating solar projects have been encouraged to collaborate with hydropower generators to deploy more schemes on reservoirs
References
Designing diversified renewable energy systems to balance multisector performance by Jose M. Gonzalez, James E. Tomlinson, Eduardo A. Martínez Ceseña, Mohammed Basheer, Emmanuel Obuobie, Philip T. Padi, Salifu Addo, Rasheed Baisie, Mikiyas Etichia, Anthony Hurford, Andrea Bottacin-Busolin, John Matthews, James Dalton, D. Mark Smith, Justin Sheffield, Mathaios Panteli & Julien J. Harou. Nature Sustainability January 2023
https://doi.org/10.1038/ s41893-022-01033-0
https://store.frost.com/ technological-advancements- in-floating-solar-technologies. html
www.reuters.com/world/ india/dark-summer-nights- india-faces-high-risks- power-cuts-after-years-coal- hydro-2023-03-08/
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