Utilities warming to ice-storage AC systems

By Toronto Star


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Mountain Equipment Co-Op's newest store, which opened last November in Burlington, is without question the greenest of them all.

A white roof keeps it cooler in the summer. Rooftop windows let in natural sunlight and sensors turn on what lights there are only when needed. Special parking is reserved for customers who drive hybrid-electric and other super-efficient vehicles. Rain is collected from its rooftop and used as grey water for toilets and outside watering.

Atop the roof sit two massive solar arrays consisting of dozens of parabolic mirrors that concentrate the sunlight to generate both electricity and heat for hot-water production. Each array is attached to a motorized tracker, which follows the sun throughout the day to maximize the amount of energy collected.

All said, the building's design makes it 68-per-cent more energy efficient than comparable retail properties, an achievement that has earned it Leadership in Energy and Environmental Design (LEED) certification, with a gold rating.

But there's more. To achieve such high energy-efficiency, the building also cools itself using massive blocks of ice instead of energy-hungry air conditioners. At the back of the building sit four Ice Bear systems, looking like oversized refrigerators knocked on their sides, developed by Santa Clara, Calif.-based Ice Energy Inc.

The concept behind the Ice Bear is quite simple: at night, when electricity is plentiful, a condensing unit pumps refrigerant through copper coils equally distributed through the body of the water-filled unit, which is heavily insulated. The coils freeze the 1,800 litres of water in the unit and then automatically shut off.

During the day, when power demands peak and electricity is more expensive, the system is reversed and the ice is used to cool air that is circulated through a building's ventilation system. The biggest energy draw that's really used at this point is 300 watts to run a ventilation fan. That's the equivalent of having three incandescent light bulbs on.

Each Ice Bear system, when water is completely frozen, can supply the same amount of cooling as a conventional five-tonne rooftop air conditioning system for about six hours – that is, until all the ice melts. It then takes a good 10 or 11 hours to refreeze the water in preparation for the next day.

Now, like most emerging clean technologies, the clear environmental benefits don't necessarily translate into economic benefits. James Alden, the chief operating officer of Toronto-based Summerhill Group, an environmental consultancy that's helping the Ice Bear concept gain traction in Canada, will be the first to tell you that the system is at least double the cost of traditional rooftop air conditioners.

"You're not going to sell this to a customer strictly on a payback perspective, with the exception of companies aiming for LEED certification," like Mountain Equipment Co-Op, he said.

On the other hand, Alden said the system makes sense for utilities looking to eliminate daytime spikes in electricity demand by shifting consumption to periods of low demand – that is, overnight. This can make economic sense on a system-wide scale because it delays the need to build so-called "peaker" power plants and can ease congestion on the grid, possibly deferring costly transmission and distribution upgrades.

He envisions a major utility or group of utilities strategically deploying enough Ice Bear systems to retailers and other commercial buildings throughout the province to shift 30 megawatts of peak-time demand to low-peak periods. The units would be owned by the utilities and could be remotely controlled through a smart grid.

Hydro One, Powerstream, Toronto Hydro, and a number of other utilities have already visited Mountain Equipment Co-Op to learn about the system. "All the large utilities are interested," Alden said, pointing out that under the new Green Energy Act local electric utilities can now do these kinds of projects more freely.

Now, they just have to get creative.

You may remember an Ontario-born company called Tamarack Lake Electric Boat Co., which has developed a solar-hybrid pontoon boat. The company is in the process of moving to New York State and has rebranded itself Buffalo Solar Boats. Seems incentives south of the border were better than those offered – or not offered – here.

But don't fret, as another local has come out with an all-electric solar boat, this one called the Humber Foton. Made by Toronto-based Humber Boat Ltd. (www.humberboats.ca), the Foton is more like a slow-moving fishing boat. A six horsepower electric motor with custom solar panels on the front costs $8,895. The two horsepower model is $7,895.

Don't expect a speedboat. The top model only goes up to 10 km/h for about 1.5 hours before needing a recharge. But if you're on a quiet lake and aren't in a hurry, it may fit the bill.

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California Legislators Prepare Vote to Crack Down on Utility Spending

California Utility Spending Bill scrutinizes how ratepayer funds are used by utilities, targeting lobbying, advertising, wildfire prevention cost pass-throughs, and CPUC oversight to curb high electricity bills and increase accountability and transparency statewide.

 

Key Points

Legislation restricting utilities from using ratepayer money for lobbying and ads, with stronger CPUC oversight.

✅ Bans ratepayer-funded lobbying and political advertising

✅ Expands prohibited utility communications and influence spending

✅ Aims to curb bills, boost transparency, and CPUC accountability

 

California's legislators are about to vote on a bill that would impose stricter regulations on how utility companies spend the money they collect from ratepayers. This legislation directly responds to the growing discontent among Californians who are already grappling with high electricity bills, as Californians ask why electricity prices are soaring amid wildfire prevention efforts.

Consumer rights groups have been vehemently critical of how utilities have been allocating customer funds, amid growing calls for regulatory action from state officials. They allege that a substantial portion of this money is being funnelled into lobbying efforts and advertising campaigns that yield no direct benefits for the customers themselves.

The proposed bill would significantly broaden the definition of what constitutes prohibited advertising and political influence activities on the part of utility companies, separate from income-based fixed electricity charges proposals that affect rate design. This would effectively restrict the ways in which utilities can utilize customer funds for such purposes.

While consumer advocacy groups have favored the legislation, it has drawn opposition from utility companies and some labor unions, as lawmakers weigh overturning income-based utility charges in parallel debates. Opponents contend that it would hinder utilities' ability to communicate effectively with their customers and advocate for their interests. Additionally, they express concerns that the bill could result in job losses within the utility sector.

The vote on the bill is expected to take place on Monday. The outcome of the vote is uncertain, but it is sure to be a closely watched development for Californians struggling with the burden of high electricity bills, with many wondering about major changes to their electric bills in the near term.

 

California's Electricity Rates: A Burden for Residents

A recent report by the California Public Utilities Commission (CPUC) revealed that the average Californian household spends a significantly higher amount on electricity compared to the national average. This disparity in electricity rates can be attributed to a number of factors, including the financial costs associated with wildfire prevention measures, investments in renewable energy infrastructure, and maintenance of aging electrical grids, even as the state considers revamping electricity rates to clean the grid.

 

Examples of Utility Company Spending that Raise Concerns

Consumer rights groups have specifically highlighted instances where utility companies have used customer money to fund lavish executive compensation packages, sponsor professional sports teams, and finance political campaigns. They argue that these expenditures do not provide any tangible benefits to ratepayers and should not be funded through customer bills.

 

The Need for Accountability and Prioritization

Proponents of the bill believe that the legislation is necessary to ensure that utility companies are held accountable for how they spend customer funds. They believe that the stricter regulations would compel utilities to prioritize investments that directly improve the quality and reliability of electricity services for Californians, alongside discussions of income-based flat-fee utility bills that could reshape rate structures.

The impending vote on the bill underscores the ongoing tension between the need for reliable electricity services and the desire to keep utility rates affordable for Californians. The outcome of the vote is likely to have a significant impact on how utility companies operate in the state and how much Californians pay for their electricity.

 

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EDP Plans to Reject $10.9 Billion-China Three Gorges Bid

EDP Takeover Bid Rejection signals pushback on China Three Gorges' acquisition bid, as investors, shareholders, and analysts cite low premium, valuation concerns, and strategic renewables assets across Portugal, the US, Brazil, and Europe utilities.

 

Key Points

EDP's board views China Three Gorges' 3.26 euro per share offer as too low, citing valuation and renewables exposure.

✅ Bid premium 4.8% above close seen as inadequate.

✅ Stock surged above offer; market expects higher price.

✅ Advisors UBS and Morgan Stanley guiding EDP.

 

EDP-Energias de Portugal SA is poised to reject a 9.1 billion euro ($10.9 billion) takeover offer from China Three Gorges Corp. on the grounds that it undervalues Portugal’s biggest energy company, according to people with knowledge of the matter.

The board of EDP, which may meet as early as this week, views the current bid of 3.26 euros a share as too low as it indicates a premium of 4.8 percent over Friday’s close, said the people, asking not to be identified because the discussions are private. EDP is also working with advisers including UBS Group AG and Morgan Stanley on the potential deal, they said.

Representatives for EDP, UBS and Morgan Stanley declined to comment. Representatives for Three Gorges didn’t immediately respond to requests for comment.

#google#

Shares of EDP surged the most in a decade to above the bid level on Monday, signaling that investors expect the Chinese utility, which is its biggest investor, to sweeten the offer to gain full control. For Three Gorges, which spent two decades building a hydro-power plant spanning China’s Yangtze River, the deal would bolster its efforts to expand abroad and give it deeper access to markets in Europe, the U.S. and Brazil.

China’s biggest renewable-energy developer already is the largest shareholder of EDP with a 23 percent stake and now is seeking more than 50 percent. While the government in Lisbon has indicated it’s comfortable with the Chinese offer, EDF electricity price deal illustrates policy dynamics in the region and it holds out little incentive for shareholders to tender their stock.

 

Stock Jumps

Shares of EDP rose 9.3 percent to 3.40 euros in Lisbon on Monday, even as rolling back European electricity prices remains challenging, after earlier jumping by the most since October 2008.

“We believe the price offered is too low for China Three Gorges to achieve full control of a vehicle that provides, among other things, a strategic footprint into U.S. renewables,” Javier Garrido, an analyst at JPMorgan Chase & Co., said in a note. “We expect management and minorities to claim a higher price.”

The offer adds to a wave of investments China has made overseas, both to earn a yield on its cash and to gain expertise in industries ranging from energy to telecommunications and transport. Concern about those deals has been mounting in the U.S. regulatory arena recently. European Union governments have been divided in their response, with Portugal among those most supportive of inward investment.

“China Three Gorges is an ambitious company, with expansion already in international hydro, Chinese onshore wind and floating solar, and European offshore wind,” said Angus McCrone, a senior analyst at Bloomberg New Energy Finance in London. “It may have to do better on bid price than the 5 percent premium so far offered for EDP.”

 

Fortum’s Troubles

The low premium offered by Three Gorges echoes the struggle Fortum Oyj had in winning over investors in its bid for Uniper SE last year, while North American deals such as Hydro One’s Avista bid faced customer backlash as well, highlighting parallels. The Finnish utility offered 8 billion euros to buy out the remainder of Uniper in September, immediately sending shares of the German power generator above the offer prices. At least for now, Fortum has settled for a 47 percent stake it bought in Uniper from EON SE, and most other shareholders decided to keep their stake.

The EDP transaction would advance a wave of consolidation among Europe’s leading utilities, which are acquiring assets and development skills in renewables as governments across the region crack down on pollution. EDP is one of Europe’s leading developers of renewable energy, building mainly wind farms and hydro plants, and has expanded in markets including Brazil and the U.S. electrification market.

 

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Germany’s renewable energy dreams derailed by cheap Russian gas, electricity grid expansion woes

Germany Energy Transition faces offshore wind expansion, grid bottlenecks, and North-South transmission delays, while Nord Stream 2 boosts Russian gas reliance and lignite coal persists amid a nuclear phaseout and rising re-dispatch costs.

 

Key Points

Germanys shift to renewables faces grid delays, boosting gas via Nord Stream 2 and extending lignite coal use.

✅ Offshore wind grows, but grid congestion curtails turbines.

✅ Nord Stream 2 expands Russian gas supply to German industry.

✅ Lignite coal persists, raising emissions amid nuclear exit.

 

On a blazing hot August day on Germany’s Baltic Sea coast, a few hundred tourists skip the beach to visit the “Fascination Offshore Wind” exhibition, held in the port of Mukran at the Arkona wind park. They stand facing the sea, gawking at white fiberglass blades, which at 250 feet are longer than the wingspan of a 747 aircraft. Those blades, they’re told, will soon be spinning atop 60 wind-turbine towers bolted to concrete pilings driven deep into the seabed 20 miles offshore. By early 2019, Arkona is expected to generate 385 megawatts, enough electricity to power 400,000 homes.

“We really would like to give the public an idea of what we are going to do here,” says Silke Steen, a manager at Arkona. “To let them say, ‘Wow, impressive!’”

Had the tourists turned their backs to the sea and faced inland, they would have taken in an equally monumental sight, though this one isn’t on the day’s agenda: giant steel pipes coated in gray concrete, stacked five high and laid out in long rows on a stretch of dirt. The port manager tells me that the rows of 40-foot-long, 4-foot-thick pipes are so big that they can be seen from outer space. They are destined for the Nord Stream 2 pipeline, a colossus that, when completed next year, will extend nearly 800 miles from Russia to Germany, bringing twice the amount of gas that a current pipeline carries.

The two projects, whose cargo yards are within a few hundred feet of each other, provide a contrast between Germany’s dream of renewable energy and the political realities of cheap Russian gas. In 2010, Germany announced an ambitious goal of generating 80 percent of its electricity from renewable sources by 2050. In 2011, it doubled down on the commitment by deciding to shut down every last nuclear power plant in the country by 2022, as part of a broader coal and nuclear phaseout strategy embraced by policymakers. The German government has paid more than $600 billion to citizens and companies that generate solar and wind power. As a result, the generating capacity from renewable sources has soared: In 2017, a third of the nation’s electricity came from wind, solar, hydropower and biogas, up from 3.6 percent in 1990.

But Germany’s lofty vision has run into a gritty reality: Replacing fossil fuels and nuclear power in one of the largest industrial nations in the world is politically more difficult and expensive than planners thought. It has forced Germany to put the brakes on its ambitious renewables program, ramp up its investments in fossil fuels, amid a renewed nuclear option debate over climate strategy, and, to some extent, put its leadership role in the fight against climate change on hold.

The trouble lies with Germany’s electricity grid. Solar and wind power call for more complex and expensive distribution networks than conventional large power plants do. “What the Germans were good at was getting new technology into the market, like wind and solar power,” said Arne Jungjohann, author of Energy Democracy: Germany’s ENERGIEWENDE to Renewables. To achieve its goals, “Germany needs to overhaul its whole grid.”

 

The North-South Conundrum

The boom in wind power has created an unanticipated mismatch between supply and demand. Big wind turbines, especially offshore plants such as Arkona, produce powerful, concentrated gusts of energy. That’s good when the factory that needs that energy is nearby and the wind kicks up during working hours. It’s another matter when factories are hundreds of miles away. In Germany, wind farms tend to be located in the blustery north. Many of the nation’s big factories lie in the south, which also happens to be where most of the country’s nuclear plants are being mothballed.

Getting that power from north to south is problematic. On windy days, northern wind farms generate too much energy for the grid to handle. Power lines get overloaded. To cope, grid operators ask wind farms to disconnect their turbines from the grid—those elegant blades that tourists so admired sit idle. To ensure a supply of power, operators employ backup generators at great expense. These so-called re-dispatching costs ran to 1.4 billion euros ($1.6 billion) last year.

The solution is to build more power transmission lines to take the excess wind from northern wind farms to southern factories. A grid expansion project is underway to do exactly that. Nearly 5,000 miles of new transmission lines, at a cost of billions of euros, will be paid for by utility customers. So far, less than a fifth of the lines have been built.

The grid expansion is “catastrophically behind schedule,” Energy Minister Peter Altmaier told the Handelsblatt business newspaper in August. Among the setbacks: citizens living along the route of four high-voltage power lines have demanded the cables be buried underground, which has added to the time and expense. The lines won’t be finished before 2025—three years after Germany’s nuclear shutdown is due to be completed.

With this backlog, the government has put the brakes on wind power, reducing the number of new contracts for farms and curtailing the amount it pays for renewable energy. “In the past, we have focused too much on the mere expansion of renewable energy capacity,” Joachim Pfeiffer, a spokesman for the Christian Democratic Union, wrote to Newsweek. “We failed to synchronize this expansion of generation with grid expansion.”

Advocates of renewables are up in arms, accusing the government of suffocating their industry and making planning impossible. Thousands of people lost their jobs in the wind industry, according to Wolfram Axthelm, CEO of the German Wind Energy Association. “For 2019 and 2020, we see a highly problematic situation for the industry,” he wrote in an email.

 

Fueling the Gap

Nord Stream 2, by contrast, is proceeding according to schedule. A beige and black barge, Castoro 10, hauls dozens of lengths of giant pipe off Germany’s Baltic Sea coast, where a welding machine connects them for lowering onto the seabed. The $11 billion project is funded by Russian state gas monopoly Gazprom and five European investors, at no direct cost to the German taxpayer. It is slated to cross the territorial waters of five countries—Germany, Russia, Finland, Sweden and Denmark. All but Denmark have approved the route. “We have good reason to believe that after four governments said yes, that Denmark will also approve the pipeline,” says Nord Stream 2 spokesman Jens Mueller.

Construction of the pipeline off Finland began in September, and the gas is expected to start flowing in late 2019, giving Russia leverage to increase its share of the European gas market. It already provides a third of the gas used in the EU and will likely provide more after the Netherlands stops its gas production in 2030. President Donald Trump has called the pipeline “a very bad thing for NATO” and said that “Germany is totally controlled by Russia.” U.S. senators have threatened sanctions against companies involved in the project. Ukraine and Poland are concerned the new pipeline will make older pipelines in their territories irrelevant.

German leaders are also wary of dependence on Russia but are under considerable pressure to deliver energy to industry. Indeed, among the pipeline’s investors are German companies that want to run their factories, like BASF’s Wintershall subsidiary and Uniper, the German utility. “It’s not that Germany is naive,” says Kirsten Westphal, an energy expert at the German Institute for International and Security Affairs. It’s just pragmatic. “Economically, the judgment is that yes, this gas will be needed, we have an import gap to fill.”

The electricity transmission problem has also opened an opportunity for lignite coal, as coal generation in Germany remains significant, the most carbon-intensive fuel available and the source for nearly a quarter of Germany’s power. Mining companies are expanding their operations in coal-rich regions to strip out the fuel while it is still relevant. In the village of Pödelwitz, 155 miles south of Berlin, most houses feature a white sign with the logo of Mibrag, the German mining giant, which has paid nearly all the 130 residents to relocate. The company plans to level the village and scrape lignite that lies below the soil.

A resurgence in coal helped raise carbon emissions in 2015 and 2016 (2017 saw a slight decline), maintaining Germany’s place as Europe’s largest carbon emitter. Chancellor Angela Merkel has scrapped her pledge to slash carbon emissions to 40 percent of 1990 levels by the year 2020. Several members have threatened to resign from her policy commission on coal if the government allows utility company RWE to mine for lignite in Hambach Forest.

Only a few years ago, during the Paris climate talks, Germany led the EU in pushing for ambitious plans to curb emissions. Now, it seems to be having second thoughts. Recently, the European Union’s climate chief, Miguel Arias Cañete, suggested EU nations step up their commitment to reduce carbon emissions by 45 percent of 1990 levels instead of 40 percent by 2030. “I think we should first stick to the goals we have already set ourselves,” Merkel replied, even as a possible nuclear phaseout U-turn is debated, “I don’t think permanently setting ourselves new goals makes any sense.”

 

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Physicists Just Achieved Conduction of Electricity at Close to The Speed of Light

Attosecond Electron Transport uses ultrafast lasers and single-cycle light pulses to drive tunneling in bowtie gold nanoantennas, enabling sub-femtosecond switching in optoelectronic nanostructures and surpassing picosecond silicon limits for next-gen computing.

 

Key Points

A light-driven method that manipulates electrons with ultrafast pulses to switch currents within attoseconds.

✅ Uses single-cycle light pulses to drive electron tunneling

✅ Achieves 600 attosecond current switching in nano-gaps

✅ Enables optoelectronic, plasmonic devices beyond silicon

 

When it comes to data transfer and computing, the faster we can shift electrons and conduct electricity the better – and scientists have just been able to transport electrons at sub-femtosecond speeds (less than one quadrillionth of a second) in an experimental setup.

The trick is manipulating the electrons with light waves that are specially crafted and produced by an ultrafast laser. It might be a long while before this sort of setup makes it into your laptop, but similar precision is seen in noninvasive interventions where targeted electrical stimulation can boost short-term memory for limited periods, and the fact they pulled it off promises a significant step forward in terms of what we can expect from our devices.

Right now, the fastest electronic components can be switched on or off in picoseconds (trillionths of a second), a pace that intersects with debates over 5G electricity use as systems scale, around 1,000 times slower than a femtosecond.

With their new method, the physicists were able to switch electric currents at around 600 attoseconds (one femtosecond is 1,000 attoseconds).

"This may well be the distant future of electronics," says physicist Alfred Leitenstorfer from the University of Konstanz in Germany. "Our experiments with single-cycle light pulses have taken us well into the attosecond range of electron transport."

Leitenstorfer and his colleagues were able to build a precise setup at the Centre for Applied Photonics in Konstanz. Their machinery included both the ability to carefully manipulate ultrashort light pulses, and to construct the necessary nanostructures, including graphene architectures, where appropriate.

The laser used by the team was able to push out one hundred million single-cycle light pulses every single second in order to generate a measurable current. Using nanoscale gold antennae in a bowtie shape (see the image above), the electric field of the pulse was concentrated down into a gap measuring just six nanometres wide (six thousand-millionths of a metre).

As a result of their specialist setup and the electron tunnelling and accelerating it produced, the researchers could switch electric currents at well under a femtosecond – less than half an oscillation period of the electric field of the light pulses.

Getting beyond the restrictions of conventional silicon semiconductor technology has proved a challenge for scientists, but using the insanely fast oscillations of light to help electrons pick up speed could provide new avenues for pushing the limits on electronics, as our power infrastructure is increasingly digitized and integrated with photonics.

And that's something that could be very advantageous in the next generation of computers: scientists are currently experimenting with the way that light and electronics could work together in all sorts of different ways, from noninvasive brain stimulation to novel sensors.

Eventually, Leitenstorfer and his team think that the limitations of today's computing systems could be overcome using plasmonic nanoparticles and optoelectronic devices, using the characteristics of light pulses to manipulate electrons at super-small scales, with related work even exploring electricity from snowfall under specific conditions.

"This is very basic research we are talking about here and may take decades to implement," says Leitenstorfer.

The next step is to experiment with a variety of different setups using the same principle. This approach might even offer insights into quantum computing, the researchers say, although there's a lot more work to get through yet - we can't wait to see what they'll achieve next.

 

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How the 787 uses electricity to maximise efficiency

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.

 

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Wind Denmark - Danish electricity generation sets a new green record

Denmark 2019 electricity CO2 intensity shows record-low emissions as renewable energy surges, wind power dominates, offshore wind expands, and coal phase-out accelerates Denmark's energy transition and grid decarbonization, driven by higher CO2 prices and flexibility.

 

Key Points

It is 135 g CO2/kWh, a record low enabled by wind power growth, offshore wind, and a sharp coal decline.

✅ Average emissions fell to 135 g CO2/kWh, the lowest on record

✅ Wind and solar supplied 49.9% of national electricity use

✅ Coal consumption dropped 46% as CO2 allowance prices rose

 

Danish electricity producers set a new green record in 2019, when an average produced kilowatt-hour emitted 135 gr CO2 / kWh.

It is the lowest CO2 emission ever measured in Denmark and about one-seventh of what the electricity producers emitted in 1990.

Never has a kilowatt-hour produced emitted as little CO2 as it did in 2019. And that's according to Energinet's recently published annual Environmental Report on Danish electricity generation and cogeneration, two primary causes.

One reason is that more green power has been produced because the Horns Rev 3 offshore wind farm, which can produce electricity for 425,000 households, was commissioned in 2019. The other is that Danish coal consumption fell by 46 percent from 2018 to 2019, as coal phase-out plans gathered pace across the sector. the dramatic decline in coal consumption is partly due a significant increase in the price of CO2 quotas, and thus also the price of CO2 emissions.

'Historically, 135 gr CO2 / kWh is a really, really low figure, showing the impressive green travel that the Danish electricity system has been on. In 1990, a kilowatt-hour produced emitted over 1000 grams of CO2, ie about seven times as much as today, 'says Hanne Storm Edlefsen, area manager in Energinet Power Systems Responsibility.

Wind energy is the dominant form of electricity generation in Denmark, a pattern the UK wind beat coal in 2016 when shifting away from fossil fuels.

17.1 TWh. Danish wind turbines and solar cells generated so much electricity in 2019, corresponding to 49.9 per cent. of Danish electricity consumption, reflecting broader EU wind and solar growth trends as well. An increase of 15 per cent. The wind turbines alone produced 16 TWh, which is not only a new green record, but also puts a thick line that wind energy is by far the most dominant form of electricity generation in Denmark.

'Thanks to our large wind resources, turbines are by far the largest supplier of renewable energy in Denmark, and this will be for many years to come. The large price drop in new wind energy in recent years - for both onshore and offshore winds - will ensure that wind energy will drive a large part of the growth in renewable energy in the coming years, as new wind generation records are set in markets like the UK, 'says Soren Klinge, electricity market manager at Wind Denmark.

Conversely, total electricity generation from fossil and bio-based fuels decreased by 26 PJ (petajoule ed.), Corresponding to 34 per cent. from 2018 to 2019, mirroring renewables overtaking coal in Germany. Nevertheless, net electricity generation was just under 30 TWh both years.

'It is worth noting that while fossil fuels are being phased out, Denmark maintains its annual net production of electricity. The green, so to speak, replaces the black. It once again underpins that green conversion, high security of supply and an affordable electricity price can go hand in hand, 'says Hanne Storm Edlefsen.

Danish power system is ready for a green future

Including trade in electricity with neighboring countries, 1 kWh in a Danish outlet generates 145 gr CO2 / kWh.

'There has been a very significant development in the Danish electricity system in recent years, where the electricity system can now be operated solely on the renewable energy. It is a remarkable development, also from an international perspective where low-carbon progress stalled in the UK in 2019, that one would not have thought possible for just a few years ago, 'he says.

More than expected have phased out coal

The electricity from the Danish sockets will be greener , predicts Energinet's environmental report , which expects CO2 intensity in the coming years. This is explained by an expectation of increased electrification of energy consumption, together with a continued expansion with wind and solar.

'Wind energy is the cornerstone of the green transition. With the commissioning of the Kriegers Flak offshore wind farm and several major onshore wind turbine projects within the next few years, we can well expect that only the wind's share of electricity consumption will exceed 50 per cent hopefully as early as 2021,' concludes Soren Klinge.

 

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