Kenya\u2019s\nLake Turkana wind plant, which curtails power generation during nighttime when\nthe country\u2019s demand is low, could direct the surplus to electrify pumps for recycling\nhydroelectric dam water.<\/p>\n\n\n\n
The\n310MW wind farm in northern Kenya, which records highest wind speeds from\nevening, has to shut down several turbines at night when the country\u2019s\nconsumption drops by nearly half. Kenya is yet to evolve into a 24-hour working\neconomy, hence when the night falls, activity drastically slows down.<\/p>\n\n\n\n
For shutting down several turbines on reduced demand, Lake\nTurkana wind investors are paid a curtailment fee by retailer Kenya Power for\nthe deemed energy. Payments for curtailed generation surged by $180 million\n(Sh18 billion) to Sh70.8 billion last year. This left Kenya Power with a\nskeleton net profit of Sh262 million in the last financial year, a 92 percent slump,\nits worst performance in over a decade.<\/p>\n\n\n\n
But this grim picture could be turned around.<\/p>\n\n\n\n
Experts suggest that the nighttime surplus wind power could be\nused for hydropower recycling, with the economy benefiting from the clean\nenergy even at night. <\/p>\n\n\n\n
That\u2019s\nbesides future plans to sell excess nighttime generation to neighbouring\neconomies upon completion of the ongoing interconnecting transmission lines\nwith Uganda, Tanzania and Ethiopia.<\/p>\n\n\n\n
Hydropower\nrecycling, also known as pumped hydropower storage (PHS) or water battery\ntechnology is where electric pumps are installed at a hydropower dam to pump\ndownstream water uphill back to the dam. The pumped storage technology ensures\nsteady generation of cheap hydropower throughout the year even during prolonged\nbouts of drought.<\/p>\n\n\n\n
It\u2019s\na standard global practice for the pumping to happen at nighttime when\nelectricity demand is low.<\/p>\n\n\n\n
\u201cDuring\nperiods of low demand, especially nighttime, renewable energy such as wind is\nused to pump water uphill. When demand increases, water from the upper\nreservoir runs downhill through the turbines to produce electricity,\u201d says\nInternational Hydropower Association (IHA).<\/p>\n\n\n\n
\u201cPumped\nstorage combined with variable renewable energy can provide reliable, dispatchable\nand low carbon electricity to domestic and industrial consumers,\u201d it adds.<\/p>\n\n\n\n
In\nKenya\u2019s context, the surplus nighttime Turkana wind power could be used to pump\ndam water to elevation and stored for release and generation during daytime,\nand during peak demand. <\/p>\n\n\n\n
Government-owned\npower producer KenGen plans to install the pumped storage technology at its key\nhydro dams. It\u2019s not yet clear whether the Nairobi bourse-listed company will\ntap the Turkana surplus wind to power the pumps.<\/p>\n\n\n\n
The\n310MW Turkana wind farm is the largest in Africa, enough to light up to one\nmillion Kenyan households and started operating in September 2018.<\/p>\n\n\n\n
The\nwind park is currently electronically synchronised with hydroelectric plants. <\/p>\n\n\n\n
Hydros\nserve as Kenya\u2019s spinning reserve \u2013 stabilising the national grid by balancing\nout fluctuations in wind and solar power. This is despite the fact that hydroelectric\ndams are vulnerable to drought, a situation that hydropower recycling could help\nstabilise should Kenya adopt it.<\/p>\n\n\n\n
Hydropower is Kenya\u2019s cheapest electricity source at an average\nof $0.05 (Sh5) per unit, while Turkana wind costs \u20ac0.0853 (Sh9) per kWh \u2013 in the same range as Kenya\u2019s geothermal.<\/p>\n\n\n\n
The\nInternational Hydropower Association (IHA) reckons that pumped storage\nhydropower will help turbocharge the world\u2019s transition to green energy, away\nfrom polluting fossil fuels.<\/p>\n\n\n\n
\u201cPumped\nstorage succeeds in balancing the variable nature of wind and solar by\nproviding reliable energy in bulk and on demand for sustained periods,\u201d the\nassociation says.<\/p>\n\n\n\n
\u201cAs\nvariable renewable energy sources continue to displace dispatchable fossil\ngeneration, power system flexibility becomes a crucial tool to prevent both\ninterruptions to end users and extreme levels of price volatility,\u201d it adds.<\/p>\n\n\n\n
The\nhydropower agency says that a lack of flexibility can reduce the resilience of\npower systems or lead to significant losses of clean electricity via curtailments.\nAs variable renewable energy continues to grow and, in some systems, begins to\ndisplace conventional generators, system operators are faced with the challenge\nto effectively manage increasing uncertainty and variability.<\/p>\n\n\n\n
Flexibility\nhere refers to a power system\u2019s capability to maintain uninterrupted service\nwhen encountering often large and rapid swings in supply or demand.<\/p>\n\n\n\n
Flexibility\nin electricity systems can be provided by four main pillars:<\/p>\n\n\n\n
\u2022\nFlexible power supply – such as gas turbines and hydropower that are capable of\nrapid start-ups and dispatching adjustable output; <\/p>\n\n\n\n
\u2022\nFlexible power demand – where consumers are incentivised to adjust their demand\naccording to system requirements such as demand-side response; <\/p>\n\n\n\n
\u2022\nInterconnections to adjacent power systems – essentially expanding the area\nover which supply and demand can be balanced, while linking distant flexible\ngenerators; and <\/p>\n\n\n\n
\u2022\nEnergy storage – to balance supply and demand.<\/p>\n\n\n\n
These\nflexibility tools can protect the security of the electricity grid by ensuring\nthat demand is always met. <\/p>\n\n\n\n
The International Hydropower Association (IHA) estimates that the total energy stored within the world\u2019s pumped hydropower storage projects to be about 9,000-gigawatt hours (GWh). <\/p>\n\n\n\n