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Grids Could Balance Themselves, Says Study

Germany’s huge investment in renewables has cut demand for fossil fuels, but it has also brought a new source of instability to the grid. Intermittent renewables, such as wind and solar power, increase the difficulty of monitoring and balancing the grid as the amount of power being produced fluctuates. Today, that balancing is done through centralized controls from grid operators, but researchers are looking at a how a grid might keep itself in trim without such control.

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Could Europe's New Grid Algorithm Black-out Belgium?

Two of the big European power grid stories from 2014 were the software-enabled enlargement of the European Union's common electricity market and a spate of nuclear reactor shutdowns that left Belgium bracing for blackouts. Those developments have now collided with revelations that the optimization algorithm that integrates Europe's power markets could potentially trigger blackouts.

The flaw resides, ironically, in a long-anticipated upgrade to Europe's market algorithm. This promises to boost cross-border electricity flows across Europe, expanding supplies available to ailing systems such as Belgium’s. Earlier this month market news site ICIS reported that the upgrade, in the works since the launch of market coupling in 2010, has been delayed once again by European transmission system operators (TSOs).

Europe’s market integration relies on software called the Pan-European Hybrid Electricity Market Integration Algorithm, or Euphemia, which crunches every buy and sell bid submitted to participating national and regional day-ahead power markets. (The number of which will grow to 19 when the Italian and Slovenian markets join in at the end of this month.) Euphemia matches up buy and sell bids that make optimal use of available transmission capacity and meet total power demand at the lowest overall cost.

Euphemia’s troubled upgrade would change the way that the transmission available between the markets is determined. Currently TSOs tell Euphemia how much trading will be possible over each border on the following day, based on their best guess of what grid flows will look like. Under “Euphemia 2.0” the algorithm itself calculates the cross-border capacities as it optimizes the following days’ power trades. 

In theory, such so-called flow-based coupling of the markets should boost security of supply across Europe. Since Euphemia can more precisely predict how power will flow across the network (it is, after all, aligning the next day's buy/sell orders) it allocates transmission capacity more agressively than the national TSOs.

Less-conservative capacity allocations means a greater potential for imports to tight markets such as Belgium’s. The enhanced liquidity should also reduce power costs. Shadow runs of daily power trades using flow-based optimization suggest the daily savings to European consumers could be as high as 900,000 euros (US $1 million).

However, flow-based optimization has a glitch: it occasionally leads to what economists call non-intuitive trading. For example, a state with the market’s most expensive power supplies might nevertheless be approved to export power, or vice versa. 

In early 2014 Europe’s TSOs approved a simple work-around that was to go live last November. Euphemia’s software engineers programmed in a patch that would check the trades approved by its optimization and drop any that were non-intuitive.

Then Belgium saw three reactors go unexpectedly out of service in rapid succession, knocking out one-third of the nation’s firm domestic power capacity. The context for the automated market system changed almost overnight.

Belgium’s reactor shutdowns left it extremely dependent on power imports, and nervous about the flow-based upgrade and its work-around. Amidst tightened supplies, such as Belgium foresaw during its winter demand peak, Belgian officials feared that Euphemia’s flow-based optimization could leave them short of power. 

In September 2014 TSOs decided to defer the flow-based upgrade to this March. Their announcement suggested the delay was about not further stressing out the Belgians, allowing that, “the implementation of a fundamentally new capacity allocation methodology generally contains a risk, even if thoroughly prepared and tested.”

The Belgians continued to be stressed however, and earlier this month, the TSOs deferred Euphemia’s upgrade once more. Belgium’s power regulator is now making it clear that they want further improvements to the software.

“Scenarios considered to be highly improbable when the project started 5 to 7 years ago have now become realistic. We felt that it was necessary to reevaluate the algorithm. They will have to develop a new patch,” says Annemarie De Vreese, spokesperson for Belgium's energy regulator, the Commission de Régulation de l'Électricité et du Gaz (CREG).

To sense how worried Belgium has been about electrical shortages this winter, consider the mobile app and website that Brussels-based TSO Elia created to keep consumers informed about blackout risk. They provide 7-day color-coded forecasts of blackout threat levels, providing advanced warning if pre-planned rolling blackouts might be required.

No blackouts have occured so far because mild weather has enabled Belgium to meet demand with imports from the Netherlands and France, and because one of its three troubled reactors came back online in December. There would have already had 25 days of blackouts if this winter had been as cold as the 2010-2011 winter, according to a spokesperson for Belgium’s energy ministry quoted by, the news site for Flemish public broadcaster VRT.

According to De Vreese, the tweaks required to make flow-based optimization safe for tight markets could be fairly straightforward. She expects a proposed fix to be available for review next month. The TSOs issued an official statement last week foreseeing sign-off by national regulators by late April. 

De Vreese says the fix is about more than just reassuring Belgium. She says that other regulators, including those in Germany and France, recognize that their states also face a future with less firm domestic power generation. Germany is phasing out nuclear reactors and also seeing conventional power plants shut down as rising solar generation depresses wholesale power prices. And France plans to increase reliance on renewable generation while reducing reliance on nuclear reactors

In other words Belgium’s misfortune this winter may be a glimpse of a generally less secure electrical future. “Belgium is a sort of forerunner,” says De Vreese. 

If Euphemia’s designers can get its non-intuitive trading glitch sorted out, flow-based optimization of the European power market may yet be part of the solution.


U.S. Electricity Demand Flat Since 2007

The U.S. economy has grown 8 percent since 2007, but the annualized electricity demand growth has been zero over that same period. That’s the first time in recent memory that U.S. energy use remained flat over multiyear span during which the economy expanded.

The third annual Sustainable Energy in America fact book from Bloomberg New Energy Finance found that electricity demand growth, which has slowed since 1990, has come to a grinding halt.

“There has been an outright decoupling between electricity growth and economic growth,” the report states. Furthermore, it notes, the U.S. economy has become less energy-intensive.

Although the trend has been going on for nearly a decade, the slowdown or rollback of energy efficiency policies, especially at the state government level, could mean the flat line representing electricity use will start to creep back up in the coming years.

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Does Hawaii Need a Unified Grid?

Since 2013, a big mainland energy firm has been raring to build Hawaii's first inter-island power cable, arguing that only a unified power grid can enable the renewable energy developments needed to break Hawaii's addiction to imported petroleum. Now that big outsider—Juno Beach, Florida-based NextEra Energy—is trying to absorb Hawaii's power providers in one big bite.

In December, NextEra announced plans for a friendly $4.3 billion acquisition of Hawaiian Electric Industries, which owns the vertical monopolies that run the archipelago's island grids (with the exception of Kauai's). Observers debating what the acquisition would mean for Hawaii's electrical future see at least three quite distinct outcomes: 

  • NextEra secures Hawaiian Electric and builds cables to unify its assets, unleashing renewable energy development
  • NextEra's bid for Hawaiian Electric is squashed by officials with longstanding mistrust of outside interests, and the island utilities proceed on their own
  • NextEra wins approval for the acquisition but drops its cable ambitions, focusing instead on bringing liquefied natural gas to Hawaii to repower Oahu's oil and coal-fired generators

Interconnecting the islands is an idea that dates all the way back to an 1881 meeting in New York City between Hawaii's then-King Kalakaua and Thomas Edison. Kalakaua's officials asked Edison if electricity could be generated from the Big Island's active volcano and delivered via subsea cable to Oahu to bring electric light to Honolulu, thus sparing Hawaii greater dependence on Australian coal. Edison said the scheme could work, according to a report by the New York Sun, but demurred that it, "would cost so much, that's all." 

134 years later, one hears essentially the same arguments for and against a unified Hawaiian grid. Proponents such as NextEra and the Hawaii State Energy Office say Oahu must hook up to its neighbors' grids because it lacks the renewable resources needed to meet even half of its power demand—over 7,500 gigawatt-hours (GWh) per year, or nearly three-quarters of the state's total.

Hawaii's other islands, by contrast, have renewable potential to spare, says a 2010 analysis commissioned by the U.S. Department of Energy's National Renewable Energy Lab. Lanai and Molokai could each generate over 1,000 GWh per year of wind power; Maui has over 2,000 GWh of viable geothermal, wind, and solar resources; and Hawai'i (better known as the Big Island) has over 6,000 GWh of geothermal potential. Sharing these resources with Oahu via subsea cables, the authors concluded, was the only way to meet Hawaii's goal to push renewables to 70 percent of the power supply by 2030.

In 2013, NextEra proposed to start with a 180-kilometer-long, high-voltage direct current (HVDC) link between Maui and Oahu dubbed NextGrid Hawaii. Last year, Pacific Business News reported that NextEra had secured property in downtown Honolulu for the converter station where NextGrid's pair of 200-megawatt cables would come ashore and link up with Oahu's AC grid. 

NextGrid would cost an "enormous" $600-800 million, according to Pacifc Business News, but NextEra said it would save the islands' utilities at least $4.8 billion over its first 40 years of operation. The State Energy Office conservatively pegs net savings to consumers at a more modest $423 million, plus $128 million in environmental benefits. 

One source of savings is avoided 'curtailment' of wind farms on Maui, which already produce more power at times than the local grid can handle. Hawaiian Electric's Maui subsidiary 'curtailed' 20.6 GWh of wind generation last year. (Kauai's utility expects to begin curtailing solar power generation this year.)

The promise of better renewable energy utilization earned NextEra support from some environmental groups. "We're stronger together," says Jeff Mikaluna, executive director for the Honolulu-based Blue Planet Foundation. In addition to better integrating renewables, says Mikaluna, tying the islands together should also reduce the need to keep fossil fueled power plants running in reserve.

NextGrid also appears to be spurring interest in cables to other islands, such as the Big Island. That island's biggest landholder, the historic Parker Ranch, says a cable to Oahu could benefit a pumped hydroelectricity storage project it is developing. "Parker Ranch could enable a large-scale storage solution as part of an integrated statewide grid," wrote Parker Ranch CEO Neil Kuyper in an August 2014 press release

Of course, as is usually the case for transmission proposals, the idea of inter-island cables also has its critics. Some question, as Thomas Edison did, whether cables will really pencil out economically. Henry Curtis, executive director for Honolulu-based environmental advocacy group Life of the Land and a blogger on energy issues, says technical challenges associated with laying power cable over steep subsea slopes could inflate project costs.

Curtis also questions the cables' environmental benefits, and highlights potential environmental harm. NextEra's Maui-Oahu cable, for example, would traverse a humpback whale sanctuary.

And cables might ultimately prove unnecessary if advances in grid and power generation technologies expand Oahu's indigenous renewable resources. Smarter inverters, for example, are helping Oahu's grid cope with increasing levels of distributed solar energy. Curtis says more energy may be available just offshore, citing the ocean thermal energy converter currently being tested by Hawaii-based Makai Ocean Engineering

Distributed generation advocates, meanwhile, are raising alarms about the track record of NextEra subsidiary Florida Power and Light (FPL), the utility that serves most of Florida. In December, Greentech Media noted that Florida ranks 29th in the country for overall renewable energy development, and blamed FPL for the sun-soaked state's shortage of solar power: "It’s not for lack of sunshine; it’s lack of policy. Florida has no renewable standard—FPL has crushed every effort to establish one."

Energy analyst William Pentland raised similar alarms in Forbes last month. "Hawaiians should think long and hard about NextEra’s track record in the Sunshine State before approving any merger," writes Pentland.

NextEra is, for its part, playing the grid unification card close to its chest as Hawaii's regulators weigh its offer for Hawaiian Electric. One thing appears certain: NextEra will face heightened expectations to deliver on Hawaii's renewable energy aspirations if the acquisition goes through. 

Blue Planet Foundation's Mikaluna says Hawaiian Electric was saying what state leaders wanted to hear at the state capitol earlier this week. During a hearing on a bill proposing a 100-percent-renewables standard for Hawaii's utilities for 2040, Hawaiian Electric's representative abandoned the utility's traditional tack. Rather than hedging on the prospects for zeroing-out fossil fuel consumption, the new message was 'How about 2050?' "That's a first," says Mikaluna. 


800,000 Microinverters Remotely Retrofitted on Oahu—in One Day

Utilities are asking more of the rooftop solar systems that increasingly are popping up throughout their distribition grids. As we profile in this month’s Spectrum, leading utilities are deputizing solar system’s inverters to function as junior grid regulators to help stabilize the grid. Hawaiian Electric Company and inverter manufacturer Enphase Energy just showed how swiftly such upgrades can happen.

In a single day Enphase and HECO remotely reprogrammed some 800,000 microinverters attached to individual photovoltaic panels on Oahu, accounting for roughly 60 percent of the island’s distributed solar capacity according to Ameet Konkar, Enphase Energy’s senior director for strategic initiatives. Those systems deliver up to 140 megawatts, nearly as much power as the state’s largest conventional power plant, says Konkar.

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Making Solar "Wallpaper" Cheaper, More Efficient

I’m sure that there are tons of reasons why solar panels aren’t absolutely everywhere. Expense, aesthetics, and so forth. But really, we should have them wherever light is, shouldn’t we? No reason not to harvest all of that energy, right? VTT Technical Research Centre of Finland has developed a beautiful, flexible, and entirely recyclable type of organic solar panel that can be mass-produced by printing it on film so that it can be as ubiquitous as wallpaper, and look like it, too.

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Japan Seeks to Rein In a Solar Juggernaut

Clashing energy interests on the Japanese island of Kyushu have prompted Japan's government to clamp down on solar power development nationwide. While the government calls it a necessary revision to assure grid stability amidst rapidly rising levels of intermittent solar energy, critics see a pro-nuclear agenda at work—one that could stunt Japan's renewable energy potential.

Solar development in Japan has exploded since the Fukushima nuclear disaster of 2011. Thanks to an attractive feed-in tariff (FIT) program that guarantees premium rates for renewable power generation pushed through in the disaster’s aftermath, developers have since installed over 10 gigawatts of solar capacity. The solar surge marks a return to glory for the country that once dominated the global PV industry.

But Japan’s solar revival has occured under a cloud. The pro-nuclear Liberal Democratic Party regained power in late 2012, intent on restarting idled nuclear reactors that once generated nearly one-third of Japan’s electricity. The nuclear cloud produced its first lightning bolts on Kyushu in September, and has now spread nationwide.

The conflict between the solar revival and hopes for a nuclear revival burst into the open on Kyushu just a few weeks after island utility Kyushu Electric Power had been given a green light to restart a pair of 890-megawatt reactors (the first restarts approved by Japan's nuclear regulators). On 28 September, Kyushu Electric announced that it had frozen the interconnection of large solar developments.

Kyushu Electric argued that rising solar power capacity threatened the stability of its grid. Since the FIT’s introduction, solar capacity on Kyushu had grown more than 40-fold to 3.4 gigawatts, and Japan’s Ministry of Economy, Trade, and Industry (METI) had qualified a further 8.4 gigawatts of solar projects for FIT pricing. If all of the latter were built, argued the utility, solar generation on Kyushu could at times exceed the island’s 8-GW minimum daytime power demand.

At least four more utilities followed Kyushu Electric’s lead and froze solar interconnections on their grids, arguing that the solar surge threatened their ability to balance supply and demand.

METI came to the utilities’ defense last month, affirming their argument that solar threatened grid stability and proposing new rules for solar and wind power installations aimed at combatting that supposed threat.

The proposals, to be formally adopted early this year, provide a slate of conditions under which utilities are empowered to refuse new interconnections. These include limits to how much renewable energy seven of Japan's 10 vertically-integrated utilities must accept under the FIT.

For Kyushu, it means the island's utility has METI's blessing to limit total solar installations to 8.17 GW. That means Kyushu Electric can refuse interconnections for 5 GW of pending solar projects already certified by METI and further gigawatts awaiting FIT certification.

The new rules also expand all utilities’ power to temporarily turn off PV systems without compensating solar developers.

Many analysts viewed the new rules as a game-changer for solar development in Japan. "It appears likely that a sizeable part of the 69.4 GW of projects that have gained approval under the country’s FIT will not be built," wrote PV Magazine in late December.

Gordon Johnson of Axiom Capital Research told stock market news outlet Benzinga that the utilities’ expanded curtailment powers would deal the solar market a “drubbing” this year. Previously utilities could curtail output from solar arrays on as many as 30 days per year. The new rules allow curtailment for up to 360 hours per year—a reformulation that would allow a utility to clip most of the output from a solar farm for over three months, according to Johnson. As a result, he said, solar project financiers would have difficulty determining the return on investment to be expected from solar projects.

Some developers say the market impacts will take a while to filter down. A source from Hamburg-based Conergy told solar industry business magazine PV Tech last week that the firm remains confident that previously-approved projects will keep the company busy for the next two years. However, the Conergy executive acknowledged that METI’s new provisions could complicate those projects.

Renewable energy advocates argue that METI has overreacted. METI’s revised rules go well beyond what is required to maintain grid stability according to the Tokyo-based Japan Renewable Energy Foundation, founded in 2011 by Japanese telecoms maverick Masayoshi Son (whose Softbank Corp. is itself a solar power investor). In an e-mail to IEEE Spectrum, JREF director Mika Ohbayashi called METI's calculation of renewable energy limits “very conservative (and not realistic).”

Ohbayashi says that METI’s calculations begin by setting aside transmission capacity and power demand for Japan's idled reactors. She says METI’s limits also fail to take account of each utility’s ability to export excess power generation to neighboring utilities.

Japan’s grid does have one notorious power-transfer limitation: the frequency divide that obstructs the free-flow of AC power between eastern and western Japan. However, Ohbayashi says, transmission lines amongst the utilities on either side of that divide offer considerable and vastly underused exchange capacity that can facilitate the integration of renewable energy.

Ohbayashi cites the example of Hokkaido, whose utility had 520 MW of solar power on its system as of last month. Under METI’s proposal, the utility can now limit additional solar installations to 650 MW. The total would equal just 40 percent of Hokkaido's minimum demand and, according to Ohbayashi, ignores the island's ability to export 600 megawatts of power via its cable interconnection with the main island of Honshu. In 2013, that cable carried 16,940 MWh of power from Hokkaido—equivalent to a little more than one day at full-power operation—leaving plenty of spare capacity to carry surplus renewable energy.

Eric Johnston, who frequently covers energy for the English-language daily The Japan Times, sees METI's revisions as evidence that solar, wind, and other renewables face a “bumpy road” in Japan, where they must confront more than just the technical and financial challenges renewable developers confront globally. In Japan, writes Johnston, renewable energy also confronts “political and bureaucratic hostility that makes overcoming the other issues all the more difficult.”


China Dominates the World of Wind, but the U.S. Wind Energy Market Rebounds

In 2014, the wind energy market in the United States grew sixfold, but it was still dwarfed by the world leader in wind: China.

China’s 2014 wind installations were up nearly 40 percent over 2013’s, according to new data from Bloomberg New Energy Finance (BNEF). China installed 20.7 gigawatts last year, nearly half of the world’s total and more than four times the 4.7 gigawatts installed in the United States.

The strong figures for wind reflect a solid year for clean energy investment worldwide. Global clean technology investment was $310 billion in 2014, according to BNEF—up 16 percent from the previous year, but still a little lower than its peak of $317.5 billion in 2011.

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AutoCharge is Microsoft Research's Take on Wireless Charging with Light

Remember a few years ago when the mere fact that we had ways of charging gadgets wirelessly was futuristic and awesome? Remember slightly after that when everyone realized that all of the wireless charging solutions involved compromises that made them not that that much better than plugging your stuff into a wall? Like, having to put your phone in one specific place to charge it, or (and this is especially dumb) having to plug some kind of dongle into your phone to take advantage of a plug-free wireless charging pad?

If you still have to think about charging a phone (or anything else), and you still have to plan around charging it, the fact that the actual charging itself is technically wireless becomes little more than a novelty. Really, what we want is mindless, effortless charging, and Microsoft Research has an idea of how that might happen.

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This Paper "Slinky" Could Power Internet of Things

Origami that harvests energy from the same effect behind most static electricity could eventually be used to power electronics in a cheap, lightweight, environmentally friendly way.

Static electricity usually results from a phenomenon called triboelectricity. When two different materials repeatedly come into contact and then separate, the surface of one material can steal electrons from the surface of the other. This is why rubbing your feet on a carpet or a running comb through your hair can build up static electricity.

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