One of TVA's primary responsibilities is to plan for and provide an adequate, reliable supply of electricity to meet the needs of the 8.7 million people and more than 650,000 businesses and industries that depend on TVA electricity.
The region's economy continues to grow, and the demand for TVA electricity in the next decade is expected to continue to grow at its current rate of almost 2 percent a year. Since 1994, peak demand on the TVA system has grown about 10,000 megawatts, an amount equal to the power needed to serve the region's five largest cities — Memphis, Nashville, Knoxville, Chattanooga and Huntsville.
This fall, TVA began work to complete Unit 2 at Watts Bar Nuclear Plant by 2013, which will add about 1,200 megawatts to the system. TVA also committed $20 million in the 2008 budget to develop an energy-efficiency plan. The plan will outline TVA programs to reduce growth in power use by 1,200 megawatts by 2013 and identify programs to further reduce the growth in power demand over the next decade.
Even with these reductions and additional generation from Watts Bar, the region's growth in power demand will require another generating unit as large as the Watts Bar unit by 2017.
To meet this growth, TVA can build new plants or buy power from other utilities or independent suppliers. The increasing volatility of the energy market makes reliance on other suppliers a less attractive option for meeting long-term needs, because it would cost our customers significantly more, even if we can get the energy when we need it.
Currently, nuclear and fossil fuels are the only economically viable options for generating large amounts of electricity needed to serve growing communities. Renewable energy technologies are evolving, but have not reached the point where they can supplant the large generating resources needed to reliably sustain the electricity demands of today's society.
At the end of October, TVA and 12 other members of a consortium of electric utilities and nuclear suppliers took the first step toward the possible construction and operation of two advanced commercial nuclear power reactors at the Bellefonte site in north Alabama.
At this point, no decision has been made on whether to build the two generating units. The application offers a cost-effective way to preserve the nuclear power option while evaluating other alternatives. The Nuclear Regulatory Commission will take four years to review and decide whether a construction and operating license should be granted.
TVA will be working with its utility and industrial customers to develop programs that lead to more cost-effective use of our existing generating resources. It will take all the options — renewable energy, energy efficiency and new generation — to meet our future energy needs, and TVA is committed to working with our stakeholders to make sure we can continue to reliably supply the electricity needed to preserve the quality of life and to enable economic development across the Tennessee Valley.
Maryland Renewable Energy Violations highlight RPS compliance gaps as facilities selling renewable energy certificates, including waste-to-energy, biomass, and paper mills, face emissions and permit issues, prompting PSC and Attorney General scrutiny of environmental standards.
Key Points
Alleged RPS noncompliance by REC-eligible plants, prompting PSC review and potential decertification under Maryland law.
✅ Complaint targets waste-to-energy, biomass plants, and paper mills
✅ Facilities risk loss of REC certification for environmental violations
✅ PSC may investigate nonreporting; AG reviewing evidence
Many facilities that supply Maryland with renewable energy have exceeded pollution limits or otherwise broken environmental rules, violating a state law, according to a complaint sent by environmental groups to state energy and law enforcement officials.
Maryland law says that any company that contributes to a state renewable energy goal — half the state’s energy portfolio must come from renewable sources by 2030 — must “substantially comply” with rules on air and water quality and waste management. The complaint says more than two dozen power generators, including paper mills and trash incinerators, have records of formal or informal enforcement actions by environmental authorities.
For years, environmental groups have criticized Maryland policy that counts power plants that produce planet-warming carbon dioxide and health-threatening pollution as “renewable” energy generation, and similar tensions have emerged in California’s reliance on fossil fuels despite ambitious targets, but lawmakers concerned about protecting industrial jobs have resisted reforms. The renewable label qualifies the companies for subsidies drawn from energy bills across the state.
In a complaint filed this week, the groups asked the attorney general and Public Service Commission to step in.
“We’re subsidizing companies to produce dirty energy, but we’re also using ratepayer money to support companies that in many instances are paying environmental fines or just flouting the law,” said Timothy Whitehouse, executive director of Public Employees for Environmental Responsibility. “There’s no one to hold them to account in Maryland.”
A spokeswoman for Attorney General Brian Frosh said his office would review the complaint, which was signed by Whitehouse and Mike Ewall, executive director of the Energy Justice Network.
Public Service Commission officials said the facilities must notify them if found out of compliance with environmental rules, while at the federal level FERC action on aggregated DERs is shaping market participation, and the commission can then revoke certification under the state renewable energy program. In a statement, commission officials said they would launch an investigation if any facility had failed to notify them of any environmental violations, and encouraged anyone with evidence of such a transgression to file a complaint.
Companies named in the document accused the groups of painting an inaccurate picture.
“This complaint is based on misleading arguments designed to halt waste-to-energy practices that have clear environmental benefits recognized by the global scientific community,” said Jim Connolly, vice president of environment, health and safety for Wheelabrator, which owns a Baltimore trash incinerator.
Maryland launched its renewable energy program in 2004, diversifying the state’s energy portfolio with more environmentally friendly sources of power, even as regional debates over a Maine-Québec transmission line highlight cross-border impacts. Under the program, separate from the electricity they generate and sell to the grid, renewable power facilities can sell what are known as renewable energy certificates. Utilities such as Baltimore Gas and Electric Co. are required to buy a growing number of the certificates each year, essentially subsidizing the renewable energy facilities with money from ratepayer bills.
A dozen types of power generation qualify to sell the certificates: Solar, wind, geothermal and hydroelectric plants, as well as “biomass” facilities that burn wood and other organic matter, waste-to-energy plants that burn household trash and paper mills that burn a byproduct known as black liquor.
The complaint focuses on waste incinerators, biomass plants and paper mills, all of which environmental groups have cast as counter to the renewable energy program’s environmental goals, even as ACORE criticized a coal and nuclear subsidy proposal in federal proceedings.
“By subsidizing these corporations, Maryland is diverting the hard-earned income of Maryland ratepayers to wealthy corporations with poor environmental compliance records and undermining the state’s transition to clean renewable energy,” Whitehouse and Ewall wrote.
For example, they note that the Wheelabrator plant in Southwest Baltimore has been fined for exceeding mercury limits in the past. That occurred in 2011, when the plant settled with state regulators for violations in 2010 and 2009.
Connolly said there is “no question” the facility complies with Maryland’s renewable energy law.
Incinerators in Montgomery County and in Fairfax County, Virginia, that are owned by Covanta and sell the energy certificates in Maryland have been cited for accidental fires inside both facilities. The Maryland incinerator violated emissions rules in 2014, the same year that New Jersey forbade the Virginia facility from selling energy certificates into that state’s renewable energy program over concerns it wasn’t following ash testing regulations.
James Regan, a spokesman for Covanta, said both facilities “have excellent compliance records and they operate well below their permitted limits.” He said the Virginia facility is complying with ash testing requirements, and that both facilities emit far lower levels of pollutants such as particulate matter than vehicles do.
“It’s clear to us there’s a lot of misleading and wrong information in this document," Regan said.
The Environmental Protection Agency endorsed waste-to-energy facilities under former President Barack Obama because, while burning household trash emits carbon dioxide, scientists said that still had a smaller impact on global warming than sending trash to landfills, even as industry groups have backed the EPA in a legal challenge to the ACE rule as regulatory approaches shifted.
Environmentalists and community groups say the facilities still are harmful because they emit high levels of pollutants such as mercury, nitrogen oxides and lead. The concerns prompted Baltimore City Council to pass an ordinance in February that tightened emissions limits on the Wheelabrator facility, even as the new EPA pollution limits for coal and gas plants are being proposed, so dramatically that the company said it would no longer be able to operate once the rules go into effect in 2022.
The complaint does not mention the century-old Luke paper mill in Western Maryland that long faced criticism for its participation in the renewable energy program, but which owner Verso Co. closed this year.
It does say several of paper company WestRock’s mills in North Carolina and Virginia have faced both formal and informal EPA enforcement actions for violation of the Clean Water Act, including evolving EPA wastewater limits for power plants and other facilities, and the Clean Air Act. A WestRock spokesperson could not be reached for comment.
The complaint also says a large biomass facility in South Boston, Virginia, owned by the Northern Virginia Electric Cooperative has a record of noncompliance with the Clean Air Act over three years.
John Rainey, the plant’s operations director, said it “experienced some small exceedances to its permit limits,” but that it addressed the issues with Virginia environmental officials and has installed new technology.
All those plants have sold credits in Maryland.
Whitehouse said the environmental groups’ goal is to clean up Maryland’s renewable energy program. They did not file a lawsuit because he said there was no clear cause of action to take the state to court, but said he hopes the complaint nonetheless spurs action.
“It’s not acceptable in a clean energy program that we’re subsidizing some of the most dirty sources of energy,” he said. “Those sources aren’t even in compliance with the law, and no one seems to care.”
Japan Offshore Wind Investment signals Japanese utilities entering UK offshore wind, as J-Power and Kansai Electric buy into Innogy's Triton Knoll, leveraging North Sea expertise, 9.5MW turbines, and 15-year fixed-rate contracts.
Key Points
Japanese utilities buying UK offshore wind stakes to import expertise, as J-Power and Kansai join Innogy's Triton Knoll.
✅ $900M deal: J-Power 25%, Kansai Electric ~16% in Innogy unit
✅ Triton Knoll: 860MW, up to 90 9.5MW turbines, 15-year fixed PPA
✅ Goal: Transfer North Sea expertise to develop Japan offshore wind
Two of Japan's biggest power companies will buy around 40% of a German-owned developer of offshore wind farms in the U.K., seeking to learn from Britain's lead in this sector, as highlighted by a UK offshore wind milestone this week, and bring the know-how back home.
Tokyo-based Electric Power Development, better known as J-Power, will join Osaka regional utility Kansai Electric Power in investing in a unit of Germany's Innogy.
The deal, estimated to be worth around $900 million, will give J-Power a 25% stake and Kansai Electric a roughly 16% share. It will mark the first investment in an offshore wind project by Japanese power companies, as other markets shift strategies, with Poland backing wind over nuclear signaling broader momentum.
Innogy plans to start up the 860-megawatt Triton Knoll offshore wind project -- one of the biggest of its kind in the world -- in the North Sea in 2021. The vast installation will have up to 90 9.5MW turbines and sell its output to local utilities under a 15-year fixed-rate contract.
J-Power, which supplies mainly fossil-fuel-based electricity to Japanese regional utilities, will set up a subsidiary backed by the government-run Development Bank of Japan to participate in the Innogy project. Engineers will study firsthand construction and maintenance methods.
While land-based wind turbines are proliferating worldwide, offshore wind farms have progressed mainly in Europe, though U.S. offshore wind competitiveness is improving in key markets. Installed capacity totaled more than 18,000MW at the end of 2017, which at maximum capacity can produce as much power as 18 nuclear reactors.
Japan has hardly any offshore wind farms in commercial operation, and has little in the way of engineering know-how in this field or infrastructure for linking such installations to the land power grid, with a recent Japan grid blackout analysis underscoring these challenges. But there are plans for a total of 4,000MW of offshore wind power capacity, including projects under feasibility studies.
J-Power set up a renewable energy division in June to look for opportunities to expand into wind and geothermal energy in Japan, and efforts like a Japan hydrogen energy system are emerging to support decarbonization. Kansai Electric also seeks know-how for increasing its reliance on renewable energy, even as it hurries to restart idled nuclear reactors.
They are not the only Japanese investors is in this field. In Asia, trading house Marubeni will invest in a Taiwanese venture with plans for a 600MW offshore wind farm.
UK Nuclear Energy Ten Point Plan outlines support for large reactors, SMRs, and AMRs, funding Sizewell C, hydrogen production, and industrial heat to reach net zero, decarbonize transport and heating, and expand clean electricity capacity.
Key Points
A UK plan backing large, small, and advanced reactors to drive net zero via clean power, hydrogen, and industrial heat.
✅ Funds large plants (e.g., Sizewell C) under value-for-money models
✅ Invests in SMRs for factory-built, modular, lower-cost deployment
✅ Backs AMRs for high-temperature heat, hydrogen, and industry
The UK government has just announced its “Ten Point Plan for a Green Industrial Revolution”, in which it lays out a vision for the future of energy, transport and nature in the UK. As researchers into nuclear energy, my colleagues and I were pleased to see the plan is rather favourable to new nuclear power.
It follows the advice from the UK’s Nuclear Innovation and Research Advisory Board, pledging to pursue large power plants based on current technology, and following that up with financial support for two further waves of reactor technology (“small” and “advanced” modular reactors).
This support is an important part of the plan to reach net-zero emissions by 2050, as in the years to come nuclear power will be crucial to decarbonising not just the electricity supply but the whole of society.
This chart helps illustrate the extent of the challenge faced:
Electricity generation is only responsible for a small percentage of UK emissions. William Bodel. Data: UK Climate Change Committee
Efforts to reduce emissions have so far only partially decarbonised the electricity generation sector. Reaching net zero will require immense effort to also decarbonise heating, transport, as well as shipping and aviation. The plan proposes investment in hydrogen production and electric vehicles to address these three areas – which will require, as advocates of nuclear beyond electricity argue, a lot more energy generation.
Nuclear is well-placed to provide a proportion of this energy. Reaching net zero will be a huge challenge, and industry leaders warn it may be unachievable without nuclear energy. So here’s what the announcement means for the three “waves” of nuclear power.
Who will pay for it? But first a word on financing. To understand the strategy, it is important to realise that the reason there has been so little new activity in the UK’s nuclear sector since the 1990s is due to difficulty in financing. Nuclear plants are cheap to fuel and operate and last for a long time. In theory, this offsets the enormous upfront capital cost, and results in competitively priced electricity overall.
But ever since the electricity sector was privatised, governments have been averse to spending public money on power plants. This, combined with resulting higher borrowing costs and cheaper alternatives (gas power), has meant that in practice nuclear has been sidelined for two decades. While climate change offers an opportunity for a revival, these financial concerns remain.
Large nuclear Hinkley Point C is a large nuclear station currently under construction in Somerset, England. The project is well-advanced, with its first reactor installed and due to come online in the middle of this decade. While the plant will provide around 7% of current UK electricity demand, its agreed electricity price is relatively expensive.
Under construction: Hinkley Point C. Ben Birchall/PA
The government’s new plan states: “We are pursuing large-scale new nuclear projects, subject to value-for-money.” This is likely a reference to the proposed Sizewell C in Suffolk, on which a final decision is expected soon. Sizewell C would be a copy of the Hinkley plant – building follow-up identical reactors achieves capital cost reductions, and setbacks at Hinkley Point C have sharpened delivery focus as an alternative funding model will likely be implemented to reduce financing costs.
Other potential nuclear sites such as Wylfa and Moorside (shelved in 2018 and 2019 respectively for financial reasons) are also not mentioned, their futures presumably also covered by the “subject to value-for-money” clause.
Small nuclear The next generation of nuclear technology, with various designs under development worldwide are smaller, cheaper, safer Small Modular Reactors (SMRs), such as the Rolls Royce “UK SMR”.
Reactors small enough to be manufactured in factories and delivered as modules can be assembled on site in much shorter times than larger designs, which in contrast are constructed mostly on site. In so doing, the capital costs per unit (and therefore borrowing costs) could be significantly lower than current new-builds.
The plan states “up to £215 million” will be made available for SMRs, Phase 2 of which will begin next year, with anticipated delivery of units around a decade from now.
Advanced nuclear The third proposed wave of nuclear will be the Advanced Modular Reactors (AMRs). These are truly innovative technologies, with a wide range of benefits over present designs and, like the small reactors, they are modular to keep prices down.
Crucially, advanced reactors operate at much higher temperatures – some promise in excess of 750°C compared to around 300°C in current reactors. This is important as that heat can be used in industrial processes which require high temperatures, such as ceramics, which they currently get through electrical heating or by directly burning fossil fuels. If those ceramics factories could instead use heat from AMRs placed nearby, it would reduce CO₂ emissions from industry (see chart above).
High temperatures can also be used to generate hydrogen, which the government’s plan recognises has the potential to replace natural gas in heating and eventually also in pioneering zero-emission vehicles, ships and aircraft. Most hydrogen is produced from natural gas, with the downside of generating CO₂ in the process. A carbon-free alternative involves splitting water using electricity (electrolysis), though this is rather inefficient. More efficient methods which require high temperatures are yet to achieve commercialisation, however if realised, this would make high temperature nuclear particularly useful.
The government is committing “up to £170 million” for AMR research, and specifies a target for a demonstrator plant by the early 2030s. The most promising candidate is likely a High Temperature Gas-cooled Reactor which is possible, if ambitious, over this timescale. The Chinese currently lead the way with this technology, and their version of this reactor concept is expected soon.
In summary, the plan is welcome news for the nuclear sector, even as Europe loses nuclear capacity across the continent. While it lacks some specifics, these may be detailed in the government’s upcoming Energy White Paper. The advice to government has been acknowledged, and the sums of money mentioned throughout are significant enough to really get started on the necessary research and development.
Achieving net zero is a vast undertaking, and recognising that nuclear can make a substantial contribution if properly supported is an important step towards hitting that target.
BC Hydro Clean Power Call 2024 seeks utility-scale renewable energy, including wind and solar, to meet rising electricity demand, advance clean goals, expand grid, and support Indigenous participation through competitive procurement and equity opportunities.
Key Points
BC Hydro's 2024 bid to add zero-emission wind and solar to meet rising demand and support Indigenous equity.
✅ Competitive procurement for utility-scale wind and solar
✅ Targets 3,000 GWh new greenfield by fiscal 2029
✅ Encourages Indigenous ownership and equity stakes
The Government of British Columbia (the Government or Province) has announced that BC Hydro would be moving forward with a call for new sources of 100 percent clean, renewable emission-free electricity, notably including wind and solar, even as nuclear power remains a divisive option among residents. The call, expected to launch in spring 2024, is BC Hydro's first call for power in 15 years and will seek power from larger scale projects.
Over the past decade, British Columbia has experienced a growing economy and population as well as a move by the housing, business and transportation sectors towards electrification, with industrial demand from LNG facilities also influencing load growth. As the Government highlighted in their recent announcement, the number of registered light-duty electric vehicles in British Columbia increased from 5,000 in 2016 to more than 100,000 in 2023. Zero-emission vehicles represented 18.1 percent of new light-duty passenger vehicles sold in British Columbia in 2022, the highest percentage for any province or territory.
Ultimately, the Province now expects electricity demand in British Columbia to increase by 15 percent by 2030. BC Hydro elaborated on the growing need for electricity in their recent Signposts Update to the British Columbia Utilities Commission (BCUC), and noted additions such as new generating stations coming online to support capacity. BC Hydro implemented its Signposts Update process to monitor whether the "Near-term actions" established in its 2021 Integrated Resource Plan continue to be appropriate and align with the changing circumstances in electricity demand. Those actions outline how BC Hydro will meet the electricity needs of its customers over the next 20 years. The original Near-term actions focused on demand-side management and not incremental electricity production.
In its Update, BC Hydro emphasized that increased use of electricity and decreased supply, along with episodes of importing out-of-province fossil power during tight periods, has advanced the forecast of the province's need for additional renewable energy by three years. Accordingly, BC Hydro has updated its 2021 Integrated Resource Plan to, among other things:
accelerate the timing of several Near-term actions on energy efficiency, demand response, industrial load curtailment, electricity purchase agreement renewals and utility-scale batteries; and
add new Near-term actions for BC Hydro to acquire an additional 3,000 GWh per year of new clean, renewable energy from greenfield facilities in the province able to achieve commercial operation as early as fiscal 2029, as well as approximately 700 GWh per year of new clean, renewable energy from existing facilities prior to fiscal 2029.
The Province's predictions align with Canada Energy Regulator's (CER) "Canada's Energy Future 2023" flagship report (Report) released on June 20, 2023. The Report, which looks at Canadians' possible energy futures, includes two long-term scenarios modelled on Canada reaching net-zero by 2050. Under either scenario, the electricity sector is predicted to serve as the cornerstone of the net-zero energy system, with examples such as Hydro-Quebec's decarbonization strategy illustrating this shift as it transforms and expands to accommodate increasing electricity use.
Key Details of the Call
Though not finalized, the call for power will be a competitive process, with the exact details to be designed by BC Hydro and the Province, incorporating input from the recently-formed BC Hydro Task Force made up of Indigenous communities, industry and stakeholders. This is a shift from previous calls for power, which operated as a continuous-intake program with a standing offer at a fixed rate, after projects like the Siwash Creek project were left in limbo.
Drawing on advice from Indigenous and external energy experts, the Province seeks to advance Indigenous ownership and equity interest opportunities in the electricity sector, potentially with minimum requirements for Indigenous participation in new projects to be a condition of the competitive process. The Province has also committed $140 million to the B.C. Indigenous Clean Energy Initiative (BCICEI) to support Indigenous-led power projects and their ability to respond to future electricity demand, facilitating their ability to compete in the call for power, despite their smaller size.
BC Hydro expects to initiate the call in spring 2024, with the goal of acquiring new sources of electricity as early as 2028, even as clean electricity affordability features prominently in Ontario's election discourse.
Boeing 787 More-Electric Architecture replaces pneumatics with bleedless pressurization, VFSG starter-generators, electric brakes, and heated wing anti-ice, leveraging APU, RAT, batteries, and airport ground power for efficient, redundant electrical power distribution.
Key Points
An integrated, bleedless electrical system powering start, pressurization, brakes, and anti-ice via VFSGs, APU and RAT.
✅ VFSGs start engines, then generate 235Vac variable-frequency power
✅ Bleedless pressurization, electric anti-ice improve fuel efficiency
✅ Electric brakes cut hydraulic weight and simplify maintenance
The 787 Dreamliner is different to most commercial aircraft flying the skies today. On the surface it may seem pretty similar to the likes of the 777 and A350, but get under the skin and it’s a whole different aircraft.
When Boeing designed the 787, in order to make it as fuel efficient as possible, it had to completely shake up the way some of the normal aircraft systems operated. Traditionally, systems such as the pressurization, engine start and wing anti-ice were powered by pneumatics. The wheel brakes were powered by the hydraulics. These essential systems required a lot of physical architecture and with that comes weight and maintenance. This got engineers thinking.
What if the brakes didn’t need the hydraulics? What if the engines could be started without the pneumatic system? What if the pressurisation system didn’t need bleed air from the engines? Imagine if all these systems could be powered electrically… so that’s what they did.
Power sources
The 787 uses a lot of electricity. Therefore, to keep up with the demand, it has a number of sources of power, much as grid operators track supply on the GB energy dashboard to balance loads. Depending on whether the aircraft is on the ground with its engines off or in the air with both engines running, different combinations of the power sources are used.
Engine starter/generators
The main source of power comes from four 235Vac variable frequency engine starter/generators (VFSGs). There are two of these in each engine. These function as electrically powered starter motors for the engine start, and once the engine is running, then act as engine driven generators.
The generators in the left engine are designated as L1 and L2, the two in the right engine are R1 and R2. They are connected to their respective engine gearbox to generate electrical power directly proportional to the engine speed. With the engines running, the generators provide electrical power to all the aircraft systems.
APU starter/generators
In the tail of most commercial aircraft sits a small engine, the Auxiliary Power Unit (APU). While this does not provide any power for aircraft propulsion, it does provide electrics for when the engines are not running.
The APU of the 787 has the same generators as each of the engines — two 235Vac VFSGs, designated L and R. They act as starter motors to get the APU going and once running, then act as generators. The power generated is once again directly proportional to the APU speed.
The APU not only provides power to the aircraft on the ground when the engines are switched off, but it can also provide power in flight should there be a problem with one of the engine generators.
Battery power
The aircraft has one main battery and one APU battery. The latter is quite basic, providing power to start the APU and for some of the external aircraft lighting.
The main battery is there to power the aircraft up when everything has been switched off and also in cases of extreme electrical failure in flight, and in the grid context, alternatives such as gravity power storage are being explored for long-duration resilience. It provides power to start the APU, acts as a back-up for the brakes and also feeds the captain’s flight instruments until the Ram Air Turbine deploys.
Ram air turbine (RAT) generator
When you need this, you’re really not having a great day. The RAT is a small propeller which automatically drops out of the underside of the aircraft in the event of a double engine failure (or when all three hydraulics system pressures are low). It can also be deployed manually by pressing a switch in the flight deck.
Once deployed into the airflow, the RAT spins up and turns the RAT generator. This provides enough electrical power to operate the captain’s flight instruments and other essentials items for communication, navigation and flight controls.
External power
Using the APU on the ground for electrics is fine, but they do tend to be quite noisy. Not great for airports wishing to keep their noise footprint down. To enable aircraft to be powered without the APU, most big airports will have a ground power system drawing from national grids, including output from facilities such as Barakah Unit 1 as part of the mix. Large cables from the airport power supply connect 115Vac to the aircraft and allow pilots to shut down the APU. This not only keeps the noise down but also saves on the fuel which the APU would use.
The 787 has three external power inputs — two at the front and one at the rear. The forward system is used to power systems required for ground operations such as lighting, cargo door operation and some cabin systems. If only one forward power source is connected, only very limited functions will be available.
The aft external power is only used when the ground power is required for engine start.
Circuit breakers
Most flight decks you visit will have the back wall covered in circuit breakers — CBs. If there is a problem with a system, the circuit breaker may “pop” to preserve the aircraft electrical system. If a particular system is not working, part of the engineers procedure may require them to pull and “collar” a CB — placing a small ring around the CB to stop it from being pushed back in. However, on the 787 there are no physical circuit breakers. You’ve guessed it, they’re electric.
Within the Multi Function Display screen is the Circuit Breaker Indication and Control (CBIC). From here, engineers and pilots are able to access all the “CBs” which would normally be on the back wall of the flight deck. If an operational procedure requires it, engineers are able to electrically pull and collar a CB giving the same result as a conventional CB.
Not only does this mean that the there are no physical CBs which may need replacing, it also creates space behind the flight deck which can be utilised for the galley area and cabin.
A normal flight
While it’s useful to have all these systems, they are never all used at the same time, and, as the power sector’s COVID-19 mitigation strategies showed, resilience planning matters across operations. Depending on the stage of the flight, different power sources will be used, sometimes in conjunction with others, to supply the required power.
On the ground
When we arrive at the aircraft, more often than not the aircraft is plugged into the external power with the APU off. Electricity is the blood of the 787 and it doesn’t like to be without a good supply constantly pumping through its system, and, as seen in NYC electric rhythms during COVID-19, demand patterns can shift quickly. Ground staff will connect two forward external power sources, as this enables us to operate the maximum number of systems as we prepare the aircraft for departure.
Whilst connected to the external source, there is not enough power to run the air conditioning system. As a result, whilst the APU is off, air conditioning is provided by Preconditioned Air (PCA) units on the ground. These connect to the aircraft by a pipe and pump cool air into the cabin to keep the temperature at a comfortable level.
APU start
As we near departure time, we need to start making some changes to the configuration of the electrical system. Before we can push back , the external power needs to be disconnected — the airports don’t take too kindly to us taking their cables with us — and since that supply ultimately comes from the grid, projects like the Bruce Power upgrade increase available capacity during peaks, but we need to generate our own power before we start the engines so to do this, we use the APU.
The APU, like any engine, takes a little time to start up, around 90 seconds or so. If you remember from before, the external power only supplies 115Vac whereas the two VFSGs in the APU each provide 235Vac. As a result, as soon as the APU is running, it automatically takes over the running of the electrical systems. The ground staff are then clear to disconnect the ground power.
If you read my article on how the 787 is pressurised, you’ll know that it’s powered by the electrical system. As soon as the APU is supplying the electricity, there is enough power to run the aircraft air conditioning. The PCA can then be removed.
Engine start
Once all doors and hatches are closed, external cables and pipes have been removed and the APU is running, we’re ready to push back from the gate and start our engines. Both engines are normally started at the same time, unless the outside air temperature is below 5°C.
On other aircraft types, the engines require high pressure air from the APU to turn the starter in the engine. This requires a lot of power from the APU and is also quite noisy. On the 787, the engine start is entirely electrical.
Power is drawn from the APU and feeds the VFSGs in the engines. If you remember from earlier, these fist act as starter motors. The starter motor starts the turn the turbines in the middle of the engine. These in turn start to turn the forward stages of the engine. Once there is enough airflow through the engine, and the fuel is igniting, there is enough energy to continue running itself.
After start
Once the engine is running, the VFSGs stop acting as starter motors and revert to acting as generators. As these generators are the preferred power source, they automatically take over the running of the electrical systems from the APU, which can then be switched off. The aircraft is now in the desired configuration for flight, with the 4 VFSGs in both engines providing all the power the aircraft needs.
As the aircraft moves away towards the runway, another electrically powered system is used — the brakes. On other aircraft types, the brakes are powered by the hydraulics system. This requires extra pipe work and the associated weight that goes with that. Hydraulically powered brake units can also be time consuming to replace.
By having electric brakes, the 787 is able to reduce the weight of the hydraulics system and it also makes it easier to change brake units. “Plug in and play” brakes are far quicker to change, keeping maintenance costs down and reducing flight delays.
In-flight
Another system which is powered electrically on the 787 is the anti-ice system. As aircraft fly though clouds in cold temperatures, ice can build up along the leading edge of the wing. As this reduces the efficiency of the the wing, we need to get rid of this.
Other aircraft types use hot air from the engines to melt it. On the 787, we have electrically powered pads along the leading edge which heat up to melt the ice.
Not only does this keep more power in the engines, but it also reduces the drag created as the hot air leaves the structure of the wing. A double win for fuel savings.
Once on the ground at the destination, it’s time to start thinking about the electrical configuration again. As we make our way to the gate, we start the APU in preparation for the engine shut down. However, because the engine generators have a high priority than the APU generators, the APU does not automatically take over. Instead, an indication on the EICAS shows APU RUNNING, to inform us that the APU is ready to take the electrical load.
Shutdown
With the park brake set, it’s time to shut the engines down. A final check that the APU is indeed running is made before moving the engine control switches to shut off. Plunging the cabin into darkness isn’t a smooth move. As the engines are shut down, the APU automatically takes over the power supply for the aircraft. Once the ground staff have connected the external power, we then have the option to also shut down the APU.
However, before doing this, we consider the cabin environment. If there is no PCA available and it’s hot outside, without the APU the cabin temperature will rise pretty quickly. In situations like this we’ll wait until all the passengers are off the aircraft until we shut down the APU.
Once on external power, the full flight cycle is complete. The aircraft can now be cleaned and catered, ready for the next crew to take over.
Bottom line
Electricity is a fundamental part of operating the 787. Even when there are no passengers on board, some power is required to keep the systems running, ready for the arrival of the next crew. As we prepare the aircraft for departure and start the engines, various methods of powering the aircraft are used.
The aircraft has six electrical generators, of which only four are used in normal flights. Should one fail, there are back-ups available. Should these back-ups fail, there are back-ups for the back-ups in the form of the battery. Should this back-up fail, there is yet another layer of contingency in the form of the RAT. A highly unlikely event.
The 787 was built around improving efficiency and lowering carbon emissions whilst ensuring unrivalled levels safety, and, in the wider energy landscape, perspectives like nuclear beyond electricity highlight complementary paths to decarbonization — a mission it’s able to achieve on hundreds of flights every single day.
Solar Plus Storage is accelerating across utilities and microgrids, pairing rooftop solar with lithium-ion batteries to enhance grid resilience, reduce peak costs, prevent blackouts, and leverage tax credits amid falling prices and decarbonization goals.
Key Points
Solar Plus Storage combines solar generation with batteries to shift load, boost reliability, and cut energy costs.
✅ Cuts peak demand charges and enhances blackout resilience
✅ Falling battery and solar costs drive nationwide utility adoption
✅ Enables microgrids and grid services like frequency regulation
Todd Karin was prepared when California’s largest utility shut off power to millions of people to avoid the risk of wildfires last month. He’s got rooftop solar panels connected to a single Tesla Powerwall in his rural home near Fairfield, California. “We had backup power the whole time,” Karin says. “We ran the fridge and watched movies.”
Californians worried about an insecure energy future are increasingly looking to this kind of solution. Karin, a 31-year-old postdoctoral fellow at Lawrence Berkeley National Laboratory, spent just under $4,000 for his battery by taking advantage of tax credits. He's also saving money by discharging the battery on weekday evenings, when energy is more expensive during peak demand periods. He expects to save around $1,500 over the 10 years the battery is under warranty.
The economics don’t yet work for every household, but the green-power combo of solar panels plus batteries is popping up on a much bigger scale in some unexpected places. Owners of a rice processing plant in Arkansas are building a system to generate 26 megawatts of solar power and store another 40 MW. The plant will cut its power bill by a third, and owners say they will pass the savings to local rice growers. New York’s JFK Airport is installing solar plus storage to reduce its power load by 10 percent, while Pittsburgh International Airport is building a 20-MW solar and natural gas microgrid to keep it independent from the local utility. Officials at both airports are worried about recent power shutdowns due to weather and overload-related blackouts.
And residents of the tiny northern Missouri town of Green City (pop. 608) are getting 2.5 MW of solar plus four hours of battery storage from the state’s public utility next year. The solar power won’t go directly to townspeople, but instead will back up the town’s substation, reducing the risk of a potential shutdown. It’s part of a $68 million project to improve the reliability of remote substations far from electric generating stations.
“It’s a pretty big deal for us,” says Chad Raley, who manages technology and renewables at Ameren, a Missouri utility that is building three rural solar-plus-storage projects to better manage the flow of electricity across the local grid. “It gives us so much flexibility with renewable generation. We can’t control the sun or clouds or wind, but we can have battery storage.”
The first solar-plus-storage installations started about a decade ago on a small scale in sunny states like California, Hawaii, and Arizona. Now they’re spreading across the country, driven by falling prices of both solar panels and lithium-ion batteries the size of a shipping container imported from both China and South Korea, with wind, solar, and batteries making up most of the utility-scale pipeline nationwide. These countries have ramped up production efficiencies and lowered labor costs, leaving many US manufacturers in the dust. In fact, the price of building a comparable solar-plus-storage generating facility is now cheaper than operating a coal-fired power plant, industry officials say. In certain circumstances, the cost is equal to some natural gas plants.
“This is not just a California, New York, Massachusetts thing,” says Kelly Speakes-Backman, CEO of the Energy Storage Association, an industry group in Washington. She says more than 30 states have renewable storage on the grid. Utilities have proposed and states have approved 7 gigawatts to be installed by 2030, and most new storage will be paired with solar across the US.
Speakes-Backman estimates the unit cost of electricity produced from a solar-plus-storage system will drop 10 to 15 percent each year through 2024, supporting record growth in solar and storage investments. “If you have the option of putting out a polluting or non-polluting generating source at the same price, what are you going to pick?” says Speakes-Backman.
She notes that PJM, a large Mid-Atlantic wholesale grid operator, announced it will deploy battery storage to help smooth out fluctuating power from two wind farms it operates. “When the grid fluctuates, storage can react to it quickly and can level out the supply,” she says. In the Midwest, grid-level battery storage is also being used to absorb extra wind power. Batteries hold onto the wind and put it back onto the grid when people need it.
While the solar-plus-storage trend isn’t yet putting a huge dent in our fossil fuel use, according to Paul Denholm, an energy analyst at the National Renewable Energy Laboratory in Golden, Colorado, it is a good beginning and has the side effect of cutting air pollution. By 2021, solar and other renewable energy sources will overtake coal as a source of energy, and the US is moving toward 30% electricity from wind and solar, according to a new report by the Institute for Energy Economics and Financial Analysis, a nonprofit think tank based in Cleveland.
That’s a glimmer of hope in a somewhat dreary week of news on carbon emissions. A new United Nations report released this week finds that the planet is on track to warm by 3.9 degrees Celsius (7 Fahrenheit) by 2100 unless drastic cuts are made by phasing out gas-powered cars, eliminating new coal-fired power plants, and changing how we grow and manage land, and scientists are working to improve solar and wind power to limit climate change as well.
Energy-related greenhouse gas emissions in the US rose 2.7 percent in 2018 after several years of decline. The Trump administration has rolled back climate policies from the Obama years, including withdrawing from the Paris climate accords.
There may be hope from green power initiatives outside the Beltway, though, and from federal proposals like a tenfold increase in US solar that could remake the electricity system. Arizona plans to boost solar-plus-storage from today’s 6 MW to a whopping 850 MW by 2025, more than the entire capacity of large-scale batteries in the US today. And some folks might be cheering the closing of the West’s biggest coal-fired power plant, the 2.25-gigawatt Navajo Generating Station, in Arizona, which had spewed soot and carbon dioxide over the region for 45 years until last week. The closure might help the planet and clear the hazy smog over the Grand Canyon.
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