When it is good to tilt panels to the north.

This is photo of our power plant taken on early morning June 8, 2015:

At first glance there's nothing strange about this picture, but if you know the place, you'll soon notice one strange thing - panels are pointing to the north.
The photo was taken from the east, meaning cardinal directions are as follows:

Logically panels should be tilted to the opposite direction, like on this picture from March this year:

Well, our panels do usually face south, but we noticed that in summer, there are certain times of the day when panels capture most sun when tilted to the north. Those time frames are early morning and late afternoon. We noticed that power generation output can improve by 1-2 kilowatts when panels face the north in the right time of the day.

How to explain it?

The explanation is simple: Position of the sun at sunrise/sunset changes in summer and in winter.  Everyone knows that sun rises in the east and sets in the west. What most people don't notice is that usually it's not due east (exactly 90 degrees on compass) or due west (exactly 270 degrees on compass) -  It's just roughly the east and roughly the west.
It seems that the sun rises due east and sets due west only twice a year (on spring equinox and autumn equinox). On all other days, sun rises somewhat north or south of due east and sets somewhat north or south of due west.

So, when is it north-east and when south-east? When is it north-west and when south-west?

The answer here in Tsukuba, Japan (latitude: about 36 degrees on northern hemisphere), is as follows:

winter sunrise:  south-east
winter sunset:  south-west

summer sunrise: north-east
summer sunset: north-west

This is not a life saving knowledge but it's a fun fact to know! Moreover, now that we're raising chickens under the panels, I go to the power plant early mornings and late afternoons almost everyday. If I'm there anyway, why not change the tilt and improve performance for a few kilowatt hours a day.

Related article: Power generation - performance report (April 24, 2015).

Basic information / 基本情報

Basic information about our project　/ プロジェクトの基本情報

Name: Power plant Oo
名称：　おお発電所

Place: Tsukuba, Ibaraki prefecture, Japan
所在地：　茨城県つくば市

Installed capacity: 
  Installed capacity of inverters　 38.5 kW
  Installed capacity of solar panels　 40.71 kW

設備容量：
  パワコンの容量　　38.5 kW
　太陽光パネルの容量　　40.71kW


Solar panels: 354 panels x 115 W 
太陽光パネル：354枚 x　115 W


Land area: about 1000 m2
設置面積： 約1000平米


Height from ground: 3 m
パネルの地面からの高さ：　3m


Shading rate: about 33%
遮光率： 約33%


Operation start: 27 November 2014
運転開始：2014年11月27日


Design and construction by: Solar Culture, Ceratech Tsukuba
設計・施工： ソーラーカルチャー株式会社、有限会社セラテックつくば


Activities under the panels: Free range chickens / picnics & barbecues
パネル下の土地利用：　鶏の放し飼 ／　バーベキューやピクニック

Chickens flying

It's been a month since our chickens arrived. In the life of a chicken, one month is a long time. It takes humans several years to grow from cute babies into cheeky school-age children. Chickens can do it in a single month.


They are now less cute or fluffy , but they are  stronger and more independent than before. They have impressive wings and can fly!


This is how our chickens looked when they arrived a month ago (end of April):

And these are the same chickens one month later (end of May):

On the picture above, chickens are sitting on a perch that we just finished yesterday (May 31). Perch was an instant success, chickens love it.


Now we're working on a fence outside the coop so that chickens can play on the grass. As they grow bigger, the coop will soon be too small. Picture below shows the inside of the coop (this picture was taken just before finishing the perch yesterday).





That was a quick update.

Chickens arrived!

Two weeks ago 35 newborn chickens arrived! We've been doing our best to protect them from all sorts of chicken enemies. Many of the confirmed enemies are cats. We've noticed great increase in the number of cats around the farm. Cats' favorite place is right in front of the coop, watching what they hope to be their dinner, or breakfast, or lunch, depending on the hour. They are patient, but I'm proud to say that despite their patience, we are winning and there are still 35 chickens in our coop.

Chickens arrived on April 28, 2015, and here they are the following day, just getting used to the big world full of wonders (except for cats). 

They have fluffy bums, cute little wings and huge appetite :)

Power generation - performance report

Our solar sharing power plant has generated a lot of electricity since it started operation 5 months ago - precisely 22 952 kilowatt hours in the period from November 27, 2014 (operation start) to April 24, 2015 (today). That's not bad for an installed capacity of 40 kilowatts.

We use a monitoring service "Solar Monitor" that allows us to check real-time generation status online. Being able to check it anytime anywhere (that is, "anywhere with internet connection") is extremely convenient, and on sunny days it's also quite fun.

Picture below is Solar Monitor screenshot from today April 24, 2015, taken at 17:21. In the circle on the left you can see that the plant was still producing 2 kilowatts of power despite the late hour. That's one of the good things about days getting longer towards summer. From the screen you can see that today a total of 200.4 kWh was generated (for the record, it slightly increased to 201.9 kWh at the end of the day.)

For English explanation check an older screen shot below (click for enlargement):

By the way, the mechanism that allows us to change the panel tilt has been - as expected - a major contribution to performance.

I never noticed it before but the position of sun on the sky is really different in winter and in summer. I do remember learning at elementary school that sun is low in winter and high in summer (therefore shadows are longer in winter and shorter in summer), but I never quite observed the sky and sun to see how different "low" and "high" actually is. Until recently.

In terms of solar power generation, the position of sun has great implications. It means that while in winter you want to lean the panels into very steep tilt (as much as 60 degrees), in summer you want to put them in almost horizontal position (as little as 3 degrees). This greatly affects the amount of electricity produced.

Thanks to the panel adjustment mechanism ("Sora-karu system"), we're doing exactly this - optimizing the tilt every few days (or weeks) according to the seasonal height of the sun.

Graph below shows optimal tilt of solar panels for each month of the year. The graph is for the location of Hachiouji (Western Tokyo), which is some 100 km from here, but it's the same Kanto region so the data roughly apply to our place as well (observation-confirmed). According to this graph, optimal tilt is 60 degrees in January, 34.5 degrees in March, 2.6 in June and 40.8 in October.

You can find the original graph here:

http://www.solar-partners.jp/pv-eco-informations-32764.html

This was a quick performance report.

Our solar power plant construction in 4 minutes

Here's Part 2 of the video summarizing construction of our solar sharing power plant in Tsukuba.  Given that construction was finished in November last year and now it's already April, the video is badly overdue.


There was another video covering the same topic, which I posted in February, but it was so poorly edited that I eventually decided to remake it. This is the result.


Why was making Part 2 so much more difficult than Part 1? Here's a metaphor to explain it. If we compare construction of a power plant to building a house, Part 1 of this video shows how the very building of a house was made - brick walls, window holes, a roof. At first glance it's a complete house, but in fact it's not habitable yet. It has the shape of a house but there's nothing inside. Part 2 shows how the house is equipped with all the basic amenities that make it a real, habitable house: water supply, heating, electricity, furniture.


Part 1 shows the form, Part 2 adds the substance.


The thing is, form is much easier to convey in a video than the substance.


When a building is rising in front of our eyes, it's very comprehensible to our brains. It's interesting to watch.  When some cables are added here and some boxes there, but nothing new is really growing in front of our eyes, it's not very fun to watch.


Anyway I did try my best to convey the substance in Part 2.


Part 2, showing the construction in October and November 2014, is here:

Part 1, showing the construction in August - September 2014, is here:

Enjoy watching and let me know if you have any comments or questions!

Our New To Do List

Our most pressing tasks include:

1. Digging a well

2. Building a chicken coop

3. Planting a hedge

4. Making wooden benches and a signboard

Each task is discussed in detail below.

Our plant in February 2015. 

Photo was taken by our friend Shinozaki-san with a very big and very good camera.

1. Digging a well

Without water, you can't grow plants or keep animals.

We have two options:

A. to dig a shallow (several meters deep) well ourselves

B. to have a deep (50+ meters) well dug by a professional

Digging a well ourselves would be much cheaper and we would get a hands-on experience of digging a well and installing a pump. The demerit is that the water would be of bad quality, given the pesticides used every year on the rice fields around. It would be okay for watering the plants but not for drinking.

Having a deep well dug would be much more expensive and we would get zero practical experience, but we would have clean drinking water.

Access to drinking water might be the single decisive factor - we're now leaning towards having a deep well dug.

2. Building a chicken coop

This is now in progress. It'll take  a few more weeks given our not-so-excellent carpenter skills and the fact that we can work mostly on weekends only.

Nobu and me smiling to Shinozaki-san's camera. 
Thank you, Shinozaki-san, for taking great pictures!

3. Planting a hedge

This is in progress too. The first step is obviously to dig holes around the entire plot. I'm proud to say that hole digging has become my second nature. I've dug many holes of finest quality. If you need to dug a hole or two, ask me. I'm good at it.

The other day I planted ume - plum tree (blooming season is right now) and a sakura tree (to bloom in a few weeks). Sakura and ume are not hedge plants but will definitely add some beauty to the place.

This is plum (All photos below were taken by my iPhone. The difference from the photos above is obvious.):

This is plum with a cool I-don't-care-what-you-do-I'm-not-even-watching-you cat in the background:


This is the same plum in detail:

This is sakura tree:

Don't tell me you can't see it. It's right there. It's going to be a grand sakura tree in about half a century.

4. Building wooden benches and a signboard

Benches - we received a complaint from a visitor that there's no place to sit and rest. Very accurate observation indeed. We've added benches to our to do list.

A signboard - people walking around look bewildered, not knowing what's going on in here. Clearly, a signboard with minimum information about our solar sharing project is necessary. Ideally it will be made of wood and it will include our public Project Name (to be made up) and some curly ornaments in the corner.

I'll inform you about our progress in each area.

Our solar power plant: Two months since the start

Our solar power plant has been in operation for over 2 months now (since Nov. 27, 2014), so here's brief report:


So far, so good.

Everything has been working well. Every piece of equipment is doing  just what it's expected to do, which is great news. With technology based on a lot of complicated equipment, no news - no thrilling reports of breakdowns or accidents - is always the best news. Plus the weather has been mostly good. What more could we dream of. Photons are happily hitting black surface of our panels, cheerfully letting their electrons get transformed into electric current and fed to the grid. They end up consumed by someone's fridge or electric heating, and their mission is over. (What happens with those electrons after that, though?) New electrons seamlessly follow.  I know I shouldn't personify electrons, nor photons, but I can't help, it's so exciting to imagine what's happening on their way from the Sun through the panels and cables up to the the electric circuits of my table lamp. Electrons are so selfless. Well, they are literally selfless. But they could quite well come to life in a Pixar movie about a hero that saves the world, Mr. Superelectron. Coming right from the Sun.

Solar Monitor

The fun part for us is to watch how the kilowatt hours of electricity pile up. Well they don't pile up literally, they're being fed to the utility grid, but on our online "Solar Monitor" we can see how much electricity is being produced at the moment, how much has been generated on that day and on given month and year. And that is, for some reason, interesting to watch.

Here's a snapshot of a Solar Monitor display from about a week ago (31 January 2015). It was a perfect weather day.

Next picture is the same snapshot with English notes (You can enlarge the picture by clicking on it):

And that's it for now. Enjoy your winter!

Generation & selling electricity started!

Big news: On November 27, 2014, our solar sharing farm was connected to the public grid and started generating and selling electricity. Finally.

Now the most important thing in the world is weather :D 

The weather on the grid-connection day was perfect blue sky but that was followed by a string of cloudy and rainy days, so we are yet to experience the maximum generation. Waiting for the next blue sky.

On the picture below is TEPCO employee in the midst of the grid connection process. I have no idea what he was doing and he didn't look like he wanted to be asked. Hence, no caption to the picture.

The next picture is the power plant shortly after it was connected and started power generation at around noon. (Yes, it does look the same as before,  but well...)

And here's the same place on the next day, November 28. With this darkness the amount of electricity produced is almost zero. Dear Photons of the Sun, you're welcome back any time! (The love call from our 354 solar panels)

I'm sure once Nobuo and I get used to it, we'll stop talking about weather all the time. It's just now, so be patient with us.

発電・売電が始まりました！

嬉しいニュースです。2014年11月27日に系統連系が無事に終わり、うちの発電所もいよいよ発電・売電が始まりました。

系統連系の当日は天気が最高でしたが、その翌日からほとんど曇りや雨の日ばかりが続き、待ちに待っていたフル発電はまだ経験していません。これからは楽しみです。

系統連系の作業をしている東京電力の方：

系統連系日お昼ごろに、連系の作業が終わって発電が始まったばかりの発電所の様子（見た目は別に、まだ発電していない時の発電所とは変わりませんが）：

そしてその翌日28日の様子（これぐらいの暗さでは発電量がほぼゼロ）：

このようにいちいち天気を気にすることも、そのうち慣れて気にしなくなるでしょう。