Snowroof

In shogi, Snowroof or Snow Roof Fortress (雁木 "gangi", lit. 'goose-wooden') is a Static Rook opening that characteristically uses a Snowroof castle.
It is named after the covered sidewalks (雁木造) connected to buildings in Niigata Prefecture.
Originating in the Edo period, the opening had been a less common one after World War II although it was popular in the prewar era. However, around 2017, the opening has become popular with professional shogi players. The Snowroof structure often appears in computer shogi games.
Characteristics.
For Black, this castle positions the king on the 69 square while two golds are at the ears of king (78, 58) and the two silvers are on 67 and 57. The Snowroof castle is strong from headlong attacks from above especially headlong attacks around the central file.
Naitō (1981) notes that the Snowroof was once very popular and had a reputation for being very difficult for a Fortress opponent to defeat. However, by 1981, the Snowroof opening had become less popular because after the Snowroof's opponent trades off their rook pawn, the head of Snowroof player's bishop is vulnerable as it is only defended by an adjacent gold.
Initially, the bishop remains on its starting 88 square. In attack development, this bishop is often moved to the 26 square via three moves passing through B-77 and B-59.
Attacking on the fourth file is common by moving the rook to that file supporting an advancing right silver. However, it is also possible to attack on the third file (Sleeve Rook).
Snowroof game examples.
Hisao Hirotsu (Black) used a Snowroof castle against Osamu Katsūra's Fortress position in a 1977 Kisei tournament game on January 11. 
Here, Hirotsu has completed their Snowroof castle and has moved his king leftward for king safety to the 79 square aiming for the 88 square. His bishop has moved to the 59 square (via B-77) and is still defending the 86 square while it may also be developed for attacking. From this 59 square, the bishop may be mobilized on 25 or 37 (since the third pawn has been pushed to 36).
Katsūra (White) has partially completed their Fortress castle, which has been constructed with the Quick Fortress method (which saves one tempo). Since Katsūra's bishop has already been pulled back to 31 on the 31–97 diagonal, he has the possibility of aiming for an eighth file pawn trade plus a bishop trade via ...P-86, Px86 Bx86, Bx86 Rx86 (which actually occurs in the game after this position).
Yoshiharu Habu (White) used a Snowroof castle against Masayuki Toyoshima's Fortress position in a 2014 Asahi Open tournament on February 2.
Habu's Snowroof has been completed. His bishop has been developed completely out of the castle to its attacking position on 84 and his right knight has developed to 73 for attacking as well. Toyoshima constructed a Complete Fortress castle with his right silver on 57 (instead of playing a more common Silver-37 formation) that was subsequently developed into a Fortress Anaguma castle.
Silver Fortress development.
One way to improve upon the Snowroof castle's weakness is to develop it into a Silver Fortress. 
A Silver Fortress is also structurally more flexible than the typical Gold Fortress. 
However, building a Silver Fortress from a Snowroof castle takes several moves. Thus, taking this Snowroof to Silver Fortress approach will probably leave a player to having a strictly defensive position.
Game example.
Kinjirō Kimi (木見金治郎) vs Chōtarō Hanada (花田長太郎)
Double Snowroof position
Hanada (White) develops his Snowroof castle into a Silver Fortress castle along with a Sleeve Rook formation.
Right King development.
The basic Snowroof formation can transition to a Right King-like structure in which the king and right gold move upward to the fourth file.
Bishop Exchange Declined development.
In the 3.B-77 variation of the Bishop Exchange opening, White has a narrow window before making the bishop trade during which they can depart from the opening by closing their bishop diagonal with ...P-44 after it has been opened. After they do so, their position can be developed into a Snowroof strategy. Black's position will likely be some form of Fortress since Black's silver is on the 88 square; however, some professional players have also played other unnamed Static Rook positions as Black.
One reason for playing this move is that White wishes to avoid the large body of theory associated with Bishop Exchange (or Fortress, which also has a large amount of theory behind it) and so chooses a Snowroof form.
Another note about these positions concerns Black's left silver. 4.S-88 is the most common move in Bishop Exchange. However, moving the silver to the 88 square will restrict Black to a Fortress position since the silver cannot be moved to 78 for Left Mino or to 67 for Snowroof. (If Black wishes to keep other options open, then either 4.S-78 or 4.S-68 would have needed to be used instead. 4.S-68 is used for Snowroof while 4.S-78 is the most flexible being compatible with Fortress, Snowroof, and Left Mino.)
If Black wishes to prevent White's Snowroof development from the usual Bishop Exchange opening sequences (that is, 1.P-76 P-84 2.P-26 P-85), then Black will need to use an early 3.P-25 variation.
6.P-25. Once White has declined Bishop Exchange, Black is likely to press forward with a rook pawn aiming to exchange off their second file pawn.
6...B-33. Here White can prevent Black's rook pawn exchange by defending the 24 square with their bishop.
Although 6...G-33 would also prevent the pawn exchange, the gold on 33 is thought to be a bad configuration.
Here White has closed their bishop diagonal (...P-44) and prevented the second file pawn exchange with 6...B-33.
If White is aiming for Snowroof, 6...B-33 is very likely. But, White can also play Snowroof lines that do not stop the pawn exchange, in which case White will play 6...S-42 instead. Then, the pawn exchange 7.P-24 Px24 8.Rx24 is met with 8...S-43, in which the silver protects the pawns on the 34 and 44 squares. However, Yasuhiro Masuda suggests that these are difficult lines and recommends 6...B-33 in spite of the fact that computer shogi engines often play 6...S-42.
7.S-48. Black develops their right offensive silver.
7...S-42. White develops their left silver up to the fourth file for the castle.
8.K-69. Black starts to castle their king leftward. Since their castle will be a Fortress castle (as their silver is on 88), the king cannot move to the 68 square because this would block the bishop from moving to 68, which is necessary to make way for the silver to move 77 while maintaining defense of the 86 square (to prevent White's rook pawn exchange).
8...S-43. With this White completes the basic shape of the Snowroof castle.
After this Black will need to arrange their pieces to construct the Fortress castle and decide upon an attacking strategy. A common idea is to push the fifth file pawn and aim to exchange off the bishops with their bishop moved back to 68. Another is to push the fourth file pawn for a Reclining Silver formation. Since Fortress requires many moves to construct, Black needs to wary that White may attack first. White can develop their pieces naturally and has various attacking options available to them (e.g. using a traditional Snowroof formation with the right silver on 53 possibly paired with a Right Fourth File Rook attack or a Silver Horns structure with the silver on 63 that could shift to Reclining Silver).
Double Snowroof.
The Double Snowroof (相雁木 "ai-gangi") opening has both players utilizing Snowroof castles.
Old Double Snowroof opening.
This is an older opening used in the 20th century up until the end of World War II after which it lost popularity.
Double Snowroof can be developed from an older variant of the Double Wing Attack opening that uses advanced pawns on the central file supported by the right silver.
1. P-76 P-34, 2. P-26 P-84, 3. P-25 P-85, 4. G-78 G-32. An open bishop diagonal variation of the Double Wing is used as is common of the era. (See Double Wing Attack § Open bishop diagonal variation.)
5. P-24 Px24, 6. Rx24. Black trades off the second file rook pawns.
6...P*23, 7. R-28. White fortifies the second file by dropping the pawn back to its original position at the head of bishop. Black retreats their rook to its starting position.
7...P-86, 8. Px86 Rx86, 9. P*87 R-82. White does the same as Black resulting in a Double Retreating Rook variation of Double Wing.
10. S-48 S-62
11. P-56 P-54
12. K-69 K-41
13. S-57 S-53
14. P-16 P-14
15. P-96 P-94
16. P-36 P-74
17. G-58 G-52
18. P-46 P-64
19. P-66 P-44
20. S-68 S-42
21. S-67 S-43
Silver Horns Snowroof.

Declared net capacity

Declared net capacity (DNC) is a measure of the contribution that a power station makes to the overall capacity of a distribution grid. It is measured in megawatts (MW), or in "megawatts electrical" (MWe) for a thermal power station.
DNC is sometimes expanded as developed net capacity in British English; The two expansions have exactly the same meaning.
In a conventional power station, the DNC rating is simply the maximum rated output minus the power consumed onsite. It is sometimes termed the "switchyard" output, and takes no account of transmission losses in the grid, which may be considerable in the case of a remote hydro station for example. Most but not all quoted power station ratings are DNC ratings rather than the simple capacity of the alternators.
In the case of a wind power station, the situation is more complex. The alternator of a wind turbine is normally specified to match the strongest wind in which the turbine is designed to operate. This is because most of the cost of a wind turbine is in the rotor and the tower and bearings that support it, rather than in the alternator. It makes no economic sense to restrict the size of the alternator to anything less than the maximum that the rotor will deliver. However, this means that, unlike a conventional power station, a wind turbine rarely achieves its maximum rated output while operating.
While for conventional power stations, the station is only regarded as "available" if the full power output is achievable, for wind power stations no power at all may be available depending on the wind strength, and even if a turbine is operating it may be producing as little as a tenth of its maximum rated capacity. A typical average figure is between one-third and one-half of the maximum rated capacity. 
There are several suggested methods of allowing for this when quoting a DNC figure for a wind farm, but none has gained general acceptance, and the capacity quoted for a wind farm is normally a simple total of the maximum rated capacities of the turbines, sometimes termed the "peak capacity". Many wind schemes now also quote their expected or actual annual output in GWh, to allow more meaningful comparisons with other forms of generation than is possible just by considering this total rated output.