Coal unit retirements addressed by Montana lawmakers

Zambia Mining Electricity Tariff Agreement signals a shift to a 9.33 cents/kWh flat rate for mining companies, as Zesco and the ERB steer power pricing talks, with backdating, copper output, and tariffs in focus.

Key Points

A policy to set a 9.33 cents/kWh flat rate for mines, with Zesco backdating terms still under negotiation.

✅ 9.33 cents/kWh flat tariff accepted by most mining houses

✅ Talks involve Zesco, ERB, First Quantum, Glencore, Vale, Vedanta

✅ Backdating to January remains under negotiation

Zambia is close to reaching an agreement with mining companies over its plans to increase electricity prices, in line with recent increases in Hong Kong seen elsewhere, Finance Minister Felix Mutati reports.

The government last month proposed introducing a flat tariff of 9.30 U.S. cents/kilowatt hour (kWh) backdated to January for mining companies, instead of individually negotiated rates that have averaged 6 U.S. cents/kWh, a structure echoing Manitoba's planned 2.5% yearly hikes over three years, but mining companies opposed the plan.

A team headed by the minister of energy was due to hold talks with mining companies this week, including First Quantum Minerals,.

"We have concluded with all the mining houses except for one. They have accepted our proposal to actually pay 9.33 cents/kwh," Mutati told Reuters in a move comparable to BC Hydro's 3.75% rate plan over two years.

However, an agreement has not yet been reached on backdating the higher tariffs to January as proposed by power firm Zesco Ltd, a point comparable to issues outlined in Nunavut's electricity price hike analysis, he said.

"It is part of the negotiations but ideally that is what the government is considering," Mutati said.

Other mining companies operating in Zambia, Africa's No. 2 copper producer, include Glencore of Switzerland, Brazil's Vale and London-listed Vedanta Resources .

Last week Zambia's Energy Regulation Board (ERB) approved a 75 percent increase in the price of electricity for retail customers, whereas utilities such as BC Hydro's $2 per month proposal in Canada have pursued more gradual adjustments. (Reporting by Chris Mfula; Editing by James Macharia and Susan Fenton)

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Grid Inertia and Stability underpin synchronous generation, frequency control, and voltage resilience, with virtual inertia, fast governor response, and hydro ramping mitigating oscillations when gas turbines or large generators trip or interconnectors fail.

Key Points

Grid inertia and stability show how synchronous assets resist frequency swings and damp oscillations in AC grids.

✅ Synchronous machines and loads collectively stiffen system frequency.

✅ Fast governor, hydro ramps, and virtual inertia arrest deviations.

✅ Excess inertia is costly; smart controls can replace part of it.

The discussion on inertia and synchronous generation is rather confused. Inertia is necessary because it provides stability to the grid. “Strength” and “stiffness” are terms that are used to show that lots of rotating inertia is “good’ or even essential to a stable grid. Because it was free it is often assumed that the system needs as much generator inertia as it always had, though some argue for keeping electricity options open to manage reliability during transition.

But inertia is just one way to supply stability and it can be argued that beyond more than a certain minimum level, generator inertia is an expensive and anachronistic way of providing stability.

Stability is required to protect timing circuits, minimise mechanical loads on motors and generators caused by changing speed, prevent overheating of inductive loads like AC motors and most of all to prevent voltage/frequency oscillations after fast changes in load or generation e.g. from a loss of a connection or generator or even start-up of all the hot water services at 10PM.

Inertia is one simple way of providing stability because the rotating mass of the generators absorbs or disburses energy by small changes in speed.

While the inertia of turbines is large, it is only useful as a store of energy if you can use it.  Most of the energy stored in a rotating turbo-generator is unavailable because the energy is 1/2Jω2 where ω is the angular velocity and J the rotary inertia. As the angular velocity is only supposed to vary by 0.15Hz in 50Hz you can only use 0.6% (49.85/50)2 of the inertia in the system to stabilise the load. Even if a 1Hz short term deviation is allowed it is still only 4% of the system inertia.

The key to stability is not so much the inertia itself but the synchronous nature of an AC system which locks all the turbines and loads together at the same frequency, thus inertia is not just that of one generator but all the synchronous generators, the capacitance of the transmission and distribution network and even all the AC motors and loads on the load side. These later contributors are still there, even if some of the generation is no longer synchronous, and recent low-carbon electricity lessons emphasize system-level coordination.

The downside of inertia is that once it is given up it must be replaced. So, if system frequency falls by 1Hz, to recover the frequency a large fraction of the output response from the remaining generators is used just to spin all the generators and loads back up to speed rather than just supply lost power to the grid. In the best case, it will prolong the frequency disturbance. In worst case the extended frequency deviation will trigger protection circuits and more widespread faults.

In a conventional system inertia provides the first 0.1-10 seconds of load disturbance response and it was free. A steam plant is quite good for the next 3-6 seconds after a disturbance because there is a quantity of steam in the steam chest which can be released quickly.

If the lost generation stays off line steam is then limited because it has slow ramping after that first steam dump. Hydro comes up after 20-150 seconds but has excellent stability and very fast ramps, especially in pumped storage hydro configurations where response is rapid. The combination of inertia of water in the penstock and rotary inertia of the generator gives very stable ramping and for large scale power changes, hydro seems to offer the best combination of ramp rate and stability.

Gas turbines respond quite well after 8-30 seconds, then ramp quickly if they don’t stall or oscillate which they are prone to do at low loads. It is clear that “the straw that broke the camel’s back” in the SA blackout was the failure of gas turbine generators at the Quarantine station to respond properly to rapidly increasing demand, a contrast to California shutdowns that raised questions about grid management practices.

However, even if inertia is seen as desirable at the plant level, gas turbine plants have no more inertia per MW than wind and many of them are operated slaved to the largest generator(s) because it is simpler and more efficient, and recent moves like new Ontario gas plants aim to boost capacity.

But if the key large generator(s) are for some reason isolated from the grid, the gas turbines will sag under the increased load and they will have limited mechanism or perhaps, if they are already at full load, even capacity, to respond. So, within fractions of a second their frequency will start to fall just as quickly as a group of wind turbines.

Even if governor response is fast, maximum stable ramp rates are around 5-10% per minute usually starting at less than that (they tend to have S shaped response curves) Gas turbines have another weakness which means that their inertia is of less value to the grid.

If frequency falls the compressors slow down reducing compression ratio and thus power so even more so more of the governor response is needed just to compensate for reduced air flow.

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Ohio gas-fired generation accelerates as combined-cycle plants join PJM Interconnection, challenging FirstEnergy's Davis-Besse baseload in Lucas County with 869-955 MW capacity and lower costs than nuclear, this summer and a new 2020 project.

Key Points

Ohio gas-fired generation is new combined-cycle capacity for PJM, adding 955 MW and competing with nuclear baseload.

✅ 955 MW Lucas County plant approved by Ohio Power Siting Board

✅ 869 MW Oregon Clean Energy Center entered service this summer

✅ PJM says reliability unaffected without FirstEnergy nuclear

Nuclear generators already struggling in Ohio will face even more competition from almost 900 MW of gas-fired generation that came online this summer, amid concerns over a growing supply gap in some regions, and another 950 MW plant now in the works.

Both plants will connect to the PJM Integration market, according to the Toledo Blade, and will generate more power than FirstEnergy's nearby Davis-Besse nuclear plant overall.

The Clean Energy Future–Oregon project will cost an estimated $900 million to construct, and is expected to begin operation in 2020. The project was initially approved more than four years ago.

Nuclear plants in Ohio have pressed for subsidies to remain in operation, as their emissions-free power is being pushed off the grid by cheaper natural gas, reflecting a broader debate over the future of struggling nuclear plants across the U.S. In May, FirstEnergy CEO Chuck Jones told the Ohio Senate Public Utilities Committee that its Davis-Besse and Perry nuclear plants are unlikely to successfully compete with low cost gas-fired generation in the wholesale power market.

Proponents of supporting baseload generation like coal and nuclear have pointed to their contributions to the reliability and resiliency of the power system, and some jurisdictions are considering new large-scale nuclear to meet those goals. But FirstEnergy's Ohio nuclear plants are not necessary for system reliability, according to Craig Glazer, vice president of federal government policy at PJM Interconnection and the former chairman of the Public Utilities Commission of Ohio.

The Ohio Power Siting Board last week authorized Clean Energy Future-Oregon LLC to construct a 955 MW gas-fired, combined-cycle power plant in Lucas County.

The plant will be located on a 30-acre parcel of land in Oregon, Ohio, and will interconnect to the regional electric transmission grid via nearby 138 and 345 kV transmission lines.

The project is being developed by CME Energy, which this summer also brought online the Oregon Clean Energy Center, an 869 MW gas-fired power plant at a nearby location, while governments elsewhere weigh new gas plants to boost electricity production.

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Summerside Plant Asbestos Removal enables a heating system upgrade to electric furnaces with heat storage bricks, maximizing wind energy use and lowering peak loads; contractor tenders closed, work starts May 1.

Key Points

A city effort to remove asbestos so an electric furnace heating upgrade with wind energy heat storage can proceed.

✅ Four electric furnaces with heat storage bricks

✅ Maximizes wind energy, lowers peak load and diesel use

✅ Work starts May 1; about three weeks; no service disruptions

The City of Summerside is in the process of removing hazardous asbestos at the Summerside Electric Power Plant building in order to clear the way for replacement of the heating system.

The city is hiring a contractor to do the work and tenders for the project closed Thursday afternoon. 

The heating system is being replaced with four new electric furnaces, which are Heat for Less Now products. The products help maximize wind energy by using bricks to store heat created from wind energy for use during peak demand times, similar to using more electricity for heat initiatives advocated in the N.W.T.

"This program's working so well we wanted to continue with that in the power plant," said Rob Steele, electrical operations supervisor with the City of Summerside. 

Time to replace system

The new system will heat the whole building, as other utilities evaluate options like geothermal power plants to meet targets. 

"Having more of these units with heat storage already placed in them can lower the peak load of Summerside which therefore will help keep our diesel engines from running, aligning with power grid operation changes being considered in Nova Scotia," said Steele. 

Steele said the existing system is beyond life its expectancy and maintenance is getting costly so it's time to replace it, amid calls to reduce biomass electricity in generation portfolios. 

"And unfortunately in 1960 and 1963 asbestos was used on the elbow sections of the piping insulation and of course that must be removed for us to proceed," said Steele.  

Steele said the city doesn't know how much the project will cost yet as the tenders just closed Thursday afternoon. He said the city plans to announce the cost along with the successful bidder who will do the asbestos removal April 6. 

The city said there won't be any interruption of power or services during the upgrades, even as major facilities like the Bruce nuclear reactor undergo refurbishment elsewhere. Work is expected to start May 1 and take about three weeks to finish. 

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Sendou Coal Plant Compliance Review examines AfDB oversight in Senegal's Bargny, addressing environmental and social safeguards, public consultation, resettlement concerns, air pollution, coastal erosion, SENELEC grid impacts, and CES implementation of ESAP.

Key Points

An AfDB review assessing environmental, social, and consultation compliance at Senegal's Sendou coal plant in Bargny.

✅ Independent experts to investigate community complaints.

✅ Focus on air pollution, coastal erosion, livelihoods, resettlement.

✅ Actions by SENELEC and CES under a social action plan.

 The Board of Directors of the African Development Bank Group approved the eligibility assessment for compliance review of the Bank-financed 125-MW Sendou coal-fired power plant project in the village of Bargny Minam in Senegal, which at 125 MW contrasts with Quebec's 1,000 MW authorizations for industrial projects.

Independent experts will carry out further investigations to clarify issues raised by two groups of residents from the community of Bargny.

Both groups raised questions over government policy and the National Code of the Environment, and the potential vulnerability of communities and a heritage site to air pollution, coastal erosion and the disruption of livelihoods. The groups expressed concern over the level of public consultation which had taken place around the project, and over the Bank's environmental, social and human rights standards. In particular, they feared that no resettlement plan had been prepared to mitigate any potential negative social impacts of the project.

“Having received these complaints, which it takes extremely seriously, the Bank has decided to further investigate them,” said Pierre Guislain, Vice-President for Private Sector, Infrastructure and Industrialization at the AfDB.

“At the outset of the project, the Bank carried out in-depth due diligence, and registered many of these important elements in its environmental and social action plan for the project – a plan which is now being carried out by the company managing the project, Compagnie d'Electricité du Sénégal (CES).”

Guislain confirmed that the Bank will continue to follow up on issues raised, including concerns over the potential of disrupted livelihoods for women and other seasonal and temporary workers who dry and package fish, and at complaints over land plots that may have been reclaimed by Government without compensation.

“We last reported to the Board in September 2016 and hope to do so again towards the second semester of 2017. The Bank takes its social and environmental responsibility extremely seriously,” he said.

Working in close collaboration with the Bank, SENELEC and the Project Company CES proactively undertook several actions since the month of July 2016 to significantly enhance the Project surrounding communities' social benefits and living conditions during both the construction and operation phases. A social action plan, part of a tripartite agreement between SENELEC, CES and the Bargny municipality signed in March 2017, was set up alongside an implementation and follow up committee representative of the local population.

The project was approved by the Board in 2009 at a cost of €206 million, far below the overruns at the Kemper power plant in Mississippi, which the Bank co-finances with the Banque Ouest Africaine de Développement (BOAD), the Nederlandse Financierings-Maatschappij voor Ontwikkelingslanden N.V. (FMO), and Compagnie Bancaire de l'Afrique de l'Ouest (CBAO). AfDB's financing comprises a senior loan of €55 million, and a supplementary loan of €5 million.

The project is being developed on a “build, own, and operate” basis and aims to supply up to 40% of Senegal's electricity. Senegal currently generates 80% of its electricity from diesel-fueled power. The Government of Senegal has developed a strategy for diversifying and increasing domestic power generation capacity, similar to efforts where Cape Town builds its own power plants and buys additional electricity, with a combination of conventional thermal base load and renewable energy. Sendou is the first coal-fired plant in Senegal.

The coal will be imported via sea and unloaded at Dakar harbour, from where it will be transported by truck to the coal storage site on the plant. The project aims at producing at least 925 GWh of electricity a year. The power, alongside supply from a Turkish LNG powership operating in Senegal, will be delivered to the national interconnected grid system of SENELEC, Senegal's public electricity utility company.

The project includes the development, design, procurement, construction, operation and maintenance of the 22-hectare site. Power production can be expanded to 250 MW through a second phase project, for which project preparation has not yet started. The project will also build a 1.6-km 225 kV transmission line, reflecting regional investment in grid hardware such as a new electricity poles plant in South Sudan, and associated switchyard to connect the plant to SENELEC.

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Leningrad II VVER-1200 Reactor Vessel assembly completed in Sosnovy Bor, with Rosenergoatom preparing for first criticality, hydraulic tests, and physical startup checks of neutron physics, control systems, and passive heat removal safety.

Key Points

Core vessel for Leningrad II Unit 1, completed, sealed, and prepared for hydraulic tests ahead of first criticality.

✅ Hydraulic tests to verify circuit integrity and equipment density

✅ Physical tests to refine neutron-physics of initial fuel loading

✅ Passive heat removal system testing completed; fuel loading began

Rosenergoatom has completed the assembly of the reactor vessel for unit 1 of the Leningrad Phase II nuclear power plant, which is in Sosnovy Bor in western Russia, even as it develops power lines to reactivate the Zaporizhzhia plant in a separate project. The nuclear power plant operator subsidiary of state nuclear corporation Rosatom said yesterday the VVER-1200 is now being prepared for first criticality this month.

Alexander Belyaev, chief engineer of Leningrad NPP, said in the company statement, noting industry-wide nuclear project milestones this year: "The reactor is fully assembled, sealed and ready for hydraulic tests of the first and second circuits, during which we will once again check the equipment of the reactor installation, and finally confirm its density. After that, it will be possible to start the reactor at the minimum controlled power level."

Belyaev said this preparatory phase "envisages a whole series of physical tests that will make it possible to refine the neutron-physical characteristics of the first fuel loading of the nuclear reactor, as well as prove the reliability of the entire control and safety system (in line with the US NRC's final safety evaluation for the NuScale SMR) of the reactor installation".

The existing Leningrad plant site has four operating RMBK-1000 units, while Leningrad II will have four VVER-1200 units, as projects like the Georgia nuclear expansion continue to take shape globally. Testing of the passive heat removal system of unit 1 of Leningrad II was completed in late August and fuel loading began in December, while a new U.S. reactor startup underscored the broader resurgence.

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