Solar Sharing Now (2020) and Then (2014)

Overview of major changes in Japan's FIT system and solar sharing over the past six years.

It seems that many readers of this blog are interested in solar sharing rather in goats and chickens. I certainly get more inquiries about solar sharing. (Actually since we stopped selling eggs, I've got, unsurprisingly, exactly zero inquiries about chickens, while I got dozens about solar sharing.) 

Our farm, which started generating solar power in 2014 and pasture-raising chickens in 2015,  was one of the earlier solar sharing farms. The situation surrounding solar sharing have changed a lot since then. Now, in 2020, things couldn't be more different. The many developments in Japan and around the world in the past 6 years are quite exciting.

I summed up the major changes below. They are presented as a comparison between then (2014) and now (2020) .

Five major changes:

1. Solar sharing is finally in the global spotlight.

2. Number of solar sharing farms in Japan surged.

3. Feed-in-tariff (FIT) plummeted.

4. Many new rules and restrictions were added to the FIT system. 

5. Solar sharing is now part of Japan's official policy.

Below is each point in more detail.

Smart Life Power Plant in Shizuoka

(Japanese article is here.)

On July 6, 2014, I went to Smart Life Power Plant, a newly built solar sharing power plant in the town of Izunokuni, Shizuoka prefecture.

It takes about 3 hours to get there by train from my place in Tsukuba, Ibaraki prefecture. A small one-day trip.

I finally got off at a small station on Izuhakone railway line. The power plant should be 2.3 km from the station, so I decided go on foot. After some 30 minutes of walking, the power plant came into view:

... a bit closer:

 

Even though I arrived well before the scheduled start of the tour, a small crowd was already there. When you click on the photo to enlarge it, you can see people standing under the panels.

I received materials at the registration desk and went in,　and there I could see Mr. Iwahori from Hatsudenman - the company that constructed the plant - already absorbed in conversation with visitors. It's the group in the middle of the picture, standing on the border between rice field and taro potato field.

Afterwards, Mr. Iwahori gave a detailed explanation to all of us and patiently answered our questions.

Mr. Iwahori talking:

 

 

Overview:

Here is an overview of the Smart Life Power Plant.

 

Size (generation capacity):

   Block A  44 kW (“selling capacity”)※1

   Block B  44 kW (“selling capacity”)※2

   Block C  under construction

※１、２：The actual generation capacity is slightly higher, but the amount of electricity to sell to the grid (utility company) is 44 kW. This is what I mean by "selling capacity" (which is most probably not correct expression but I couldn't find anything better.)

Date of grid connection (selling electricity started):

   Block A, B  July 3, 2014

   Block C  some time in the future.

Land category: farmland (rice paddy and a [non-rice] field)

Crops cultivated:

   Block A, B : rice, taro potatoes (now being grown)

   Block C : field wasabi(=hatawasabi) (planned)

Construction company: Hatsuden-man Co.

Technical assistance:  Solar Culture Co.

Shading rate: 38%

Height from the ground: 3.5 m

Manual tilting system: Yes ( “solcul system”)

 

 

My comments

1. It's big!

First of all, Smart Life Power Plant is, as a solar sharing power plant, very big. Generation capacity of blocks A, B, C combined is well over 100 kW. It is the largest solar sharing power plant I've seen/heard of so far.

2. It's not dark despite higher shading rate

The shading rate is 38 %, which is somewhat higher than recommended level in solar sharing (up to 32 %), but it didn't feel particularly dark. Obviously this is due to the fact that sunlight comes not only from above, but also from the sides. Rice and taro potatoes under the panels were growing well.

As for myself, I wouldn't raise the shading rate that high, but my frank impression was that the field was surprisingly bright even at shading rate as high as 38%.

Next we just have to wait for the harvest and see whether the yield is lower, and if yes, how much. (Ministry of Agriculture guidelines stipulate that the yield cannot drop by more than 20%)

 

3. Solar sharing on farmland

The special feature of this power plant is that it is built over land that is registered as “farmland.” If you want to do solar sharing on farmland in Japan, you need permission from local agricultural committee.  This is a substantial challenge to overcome.

From what I heard, it was indeed the case with this power plant as well and it took a great deal of effort to get the permission. The hard thing was to prove that the crops will grow even with reduced sunshine, because scientific data are scarce. Eventually research data on light saturation point did help to persuade the committee.

 

In April 2013, Japan’s Ministry of Agriculture released Guidelines that allow solar sharing on farmland and set basic rules to follow, so one would think that getting local committee's permission is easy, but that seems not to be the case yet.

By the way the land for our power plant in Tsukuba is categorized as “miscellaneous,” so we are spared of any farming-related bureaucracy. Lucky us. (Well, we're not allowed to buy farmland anyway. )

This was the first time I saw solar panels generating electricity installed over a rice field. Solar sharing on a rice field is still rare in Japan.

It felt strange to see metal pipes (that support the construction) rise out of the water, because rice field is covered in water. Here’s how it looks like:

 

Another thing that popped up in my mind was that in case some maintenance or repair works on panels are needed in the months between planting (May) and harvesting (September), it must be really hard to do (e.g. you can't put a stepladder in without damaging rice plants around). But maybe that's not any issue at all - I don't know.

I hope the crops - both rice and taro potatoes - at the Smart Life Power Plant will keep doing well. From time to time I might ask Hatsudenman for an update!

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Absolutely unrelated postscript:

This has absolutely nothing to do with the power plant I visited, but I can’t help not mentioning it. When I walked from the station to the site, I again realized how bad walkability in Japan is. At one point the sidewalk simply disappeared and I had to walk on the road along the cars. It could have been such a nice walk otherwise. In Japan car drivers are first-class citizens,  pedestrians are second-class. It's not easy to get used to it. Japan would be so much nicer place to live were there more sidewalks around.

"Mega solar" construction regulated to protect scenery: Yufu

(Japanese article is here.)

The town of Yufu in Kyushu decided to protect its landscape against uncontrolled growth of large scale solar power generation facilities.

Yufu, in Oita prefecture, enacted ordinance that regulates construction of large scale solar power plants (called "mega solar" in Japanese).

The move aims to prevent destruction of Yufu's scenic landscape by large and unsightly stretches of solar panels.

Yufu's newly adopted regulation is so unusual that it was reported in online Sankei news, regional edition of Yomiuri Shimbun and other media.

The "Ordinance on harmonization of natural environment and renewable energy generation operations" requires companies that plan to construct solar power facility larger than 5,000 m2, to notify the town and provide explanation to local residents' council. Town authorities may ask to review the plan if detrimental effects on landscape are anticipated.

In addition, places of extraordinary natural or historical value and of outstanding scenic beauty may be designated as "inhibition zone,"where companies may be asked to refrain from any renewable energy development projects whatsoever.

This is the first ordinance regulating solar power generation in Kyushu, and it is an unusual measure nationally.

The town of Yufu, with its famous Yufuin-onsen, is among leading tourist destinations in Kyushu. Along with hot springs, beautiful scenery too is a valuable tourism resource that helps attract visitors.

(Yufu. Photo by Takasunrise 0921. Reproduced under GFDL+creative commons2.5)

Recenty, several plans for large scale solar power generation projects  have successively emerged in the town.

Local residents, fearing that such projects would have disastrous effect on their town's landscape, opposed them, but solar power plant construction on private land cannot be regulated under Japan's current Landscape Act. That is why Yufu started working on its own ordinance proposal in December 2013.

The proposal passed unanimously in the town council on January 28, 2014, and was enforced on the following day.

Boom in solar power construction in Japan was sparked by the launch of renewable energy feed-in tariff (FIT) system in July 2012.

We - Bo & Su - will also benefit from this system in our solar sharing power plant & farm that is now being designed.

FIT system has been a powerful boost to the spread of renewable energy, but (just as any other system) it is not perfect.

Installation costs of solar panels are high, but with high purchase price of panel-generated electricity, guaranteed for 20 years under the FIT scheme, it is now a very profitable business for those who can afford the initial investment. Unfortunately, companies that joined solar business do not care about lives and feelings of locals who suddenly must live next to big and sterile solar panel desert.

Solar power was - and still is - meant to help us reduce our dependence on fossil fuels and nuclear energy. It wasn't meant to be a villain, but insensitive "mega solar" business will only stir resentment among people.

Japan's government should act to put a stop to unrestricted growth of mega solar power plants.

But if government is too slow, then local authorities should follow Yufu's example and establish their own municipal regulations that will protect their landscape.

The best place for solar panels is either on the roof or about three meters above ground in solar sharing. I believe these are two most people-friendly ways of utilizing energy from sun.

Nishigoya Opening ceremony 2013/10/27

Nishigoya Solar Power Plant of Ken Matsuoka began operation on October 15, 2013. The opening ceremony was held soon after - on Sunday October 27.

It was the sunniest Sunday you could wish for an event at a solar power plant.

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Matsuoka started his address with self-introduction: "I'm Ken Matsuoka, chief of Nishigoya Solar Power Plant."

He laughed and the audience too. "Power plant chief" was an exact description of his role in the project, and yet the words somehow sounded too big. Not many people can introduce themselves as power plant chiefs. Not many people know someone who'd be a power plant chief. I was proud to be one of them.

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Among the guests there were family members and friends who volunteered their time to help build the plant, and also some VIPs - like the father of solar sharing Akira Nagashima and Japan's ex-prime minister Naoto Kan.

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Here at the ceremony I heard for the first time the story of how it all began a year and a half ago:

By a series of coincidences, Ken Matsuoka happened to visit the Naoto Kan's office as a technical support for an interview. During the interview, Mr. Kan showed them materials on his desk: "Look at these amazing renewable energy projects."

On the desk, Matsuoka saw a photo of solar sharing. "I just found what I want to do," he allegedly murmured.

Next day he contacted Akira Nagashima.

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About the plant:

Matsuoka's plant consists of 579 panels (100W/panel) installed on a metal frame at the height 3.5 meters over an area of about 1500 m2. The plant's capacity  - maximum output to sell to electric utility - is 49.9 kW.

A special feature of Matsuoka's plant is a winch allowing to change the tilt of all 579 panels (more than 8 tons) at once. The device, according to Matsuoka, didn't cost more than 1 % of the total investment, but it could increase the output by about 5 % - that is a significant number over 20 years.

We could see the effect of the winch at the ceremony.

First, Matsuoka and four selected guests turned on five inverters - this was a power plant version of ribbon-cutting ceremony:

At this point, the output rose from zero to over 30 kilowatts. As you can see on the picture, panels are in flat, horizontal position.

Next, panel tilt was adjusted to face the sun. A guest turning the winch:

On the next picture you can see that the panel angle has changed:

After the adjustment, the output reached 49 kilowatts - almost the maximum.

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Solar age

Akira Nagashima in his address talked about the future of solar power as cheap energy. "The price of solar panels is steadily falling. We're approaching the age of 100 yen per watt. " (100 JPY  = about 1 USD. Today typical retail price of solar panels in Japan is still about 500 yen/watt. )

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I believe Nagashima - who's been familiar with solar industry for over a decade - was right when he said: "Until now solar energy was considered to be safe but expensive. From now it will be safe and cheap."

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What next

For Matsuoka, opening the plant is not the goal but the beginning. Creating value from the soil under the panels is the core philosophy of solar sharing.

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Ken Matsuoka will certainly do his best to live up to this ideal.

The Inventor

On October 23, 2013, I met Akira Nagashima at his Solar Sharing Trial Site (ソーラーシェアリング実証試験場)　in Chiba prefecture.

Akira Nagashima, the inventor of solar sharing, is a celebrity in the community of solar sharing enthusiasts.

There are two plants on his trial site, both connected to public grid. Each has an output of about 4.5 kilowatts. There are many solar sharing projects in Japan, but this site is special because it's the first one. All others are imitations of this one.

Plant No. 1 (一号機) is installed above the garden. On the picture you can see peanuts, carrot, leek, taro and a row of unindentified leaves growing under the panels. Nagashima is standing on the side.

Plant No. 2 （2号機） is installed above a parking lot. Nagashima is standing below with a customized module that just arrived from manufacturer.

It still feels strange to call this kind of solar installation a power plant. For too long time we used to think of power plants as big unsightly buildings somewhere faraway.

Definition: Power plant is a complex of structures and equipment for generating electric energy from another source of energy.

Solar panels on the pictures above generate electricity from sun - they are legitimate power plants.

Monstrous appearance we expect from power plants is, luckily, optional. Solar sharing plants so far unticked this option - they're neither big nor ugly nor remote.

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Eureka moment

The idea of solar sharing first popped up in Nagashima's mind 10 years ago - in late 2003. Nagashima, now 70, was then studying law at Keio University in Tokyo (yes, at the age of 60). Nagashima got a biology textbook in his law course.

Why would one need a biology book in a law course?

Good question. I forgot to ask.

In that biology book, Nagashima came across the concept of light saturation point.

Light saturation point: Plants need sun to perform photosynthesis. We tend to believe that the more sunshine plants get the better, but this is not true for most plants. The reason is that most plants have a light saturation point - the amount of light intensity beyond which photosynthesis rate doesn't increase. All light beyond this saturation point is not only useless, but can even be stressful to the plant (for example causing overheating and water evaporation)

The concept of light saturation point led to Nagashima's eureka moment: If plants don't need all sunshine they're getting, why don't we use the excessive rays for power generation? Instead of laying solar moduls directly on the ground, we can put them a few meters higher and with spaces in between, so that plants below can still get their share of sun and keep growing.

The idea was out there and the time was ready for the next step: work out details and give it a real, tangible shape.

And a name.

Solar Sharing Trial Site was established in May 2010. Plant No. 1 started operation in August 2010 and plant No. 2 in April 2011. This was the only solar sharing project in Japan at that time.

Fukushima nuclear meltdowns occurred in March 2011. This event was an involuntary turning point in Japan' way of thinking about electricity. Suddenly everyone (okay, many people) were willing to turn off air-conditioning for a while and got interested in renewables. Japan's energy policy changed. The change involved introduction of renewable energy feed-in tariff system, making it mandatory for electric power companies to buy electricity from renewable sources for fixed (and quite high) prices.

Solar sharing, while not yet known among general public, went under the spotlight. Today there are tens of projects all over Japan, and visitors come for study tours to Nagashima's trial site every week.

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Low-tech

"You could hardly find anything more low-tech than this," Nagashima says. Except for solar panels, which are admittedly high-tech but available anywhere for increasingly reasonable prices, the supporting frame itself is simple and made of inexpensive materials found in any hardware store. A common assumption is that the metal construction stands on sturdy underground foundations so as to prevent blowing away in a typhoon or a storm. In fact,  foundations are minimal. Metal frame is light and flexible - a design that Nagashima describes as being "like a table - basically just standing on the ground." A strong typhoon can blow a house or a car away. There's no need to invest into expensive robust construction to withstand that kind of pressure. Quite the contrary, with flexible frame and by adjusting panel angle you can minimize the impact of the wind. So far there are no reports of panels being blown away.

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Rather than low-tech, I would call it intermediate technology - borrowing a term from Fritz Schumacher's Small is Beautiful. It is "technology which combines sophisticated ideas with cheap and readily available materials." (The Free Dictionary).

Intermediate technology is usually meant to be applied in developing countries, but I think it's just as relevant in "developed" nations like Japan. Reason: By not being too expensive, it's more democratic than the state-of-the-art super-capital-intensive technology that can only be built and operated by big companies. "Democratic" here means participatory. Tens of solar sharing projects now budding in Japan are all small scale projects launched by common people. With proper institutional backup, solar sharing promises participation of and additional income to hundreds of small farmers. (※１)

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We talked about many other interesting topics with Akira Nagashima and his colleagues on the trial site - from prices of renewables to necessary legal framework for solar sharing on farms - too much information to cover in a single article. I will save the rest for future articles.

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※１ For example offshore wind turbines like these near Fukushima http://www.nytimes.com/2013/10/25/business/international/to-expand-offshore-power-japan-builds-floating-windmills.html are being build by Japan's top companies including Hitachi and Mitsubishi Heavy Industries (with substantial government support). Local fishermen will not only have no profit from the wind farms, but will be left with disrupted fishing zones.

This approach simply copies the conventional mindset of nuclear and thermal power plants - that power generation should be concentrated in the hands of few companies because it's too complicated or dangerous to let us simple folks participate. But generating electricity is neither complicated nor dangerous, if you choose the right technology.

As Einstein said, "Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius - and a lot of courage - to move in the opposite direction."

Solar power (and biomass and geothermal energy, and even wind power) were created by a touch of genius. God save them from intelligent fools.

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How much electricity can solar sharing produce?

How much can solar sharing contribute to Japan’s energy self-sufficiency?

There are two basic indicators to describe the potential of an energy source:

1. Installed capacity

2. Estimated annual energy production

1. Installed capacity

Installed capacity (発電設備容量) is the maximum amount of

electricity that can be produced by a facility at a given time. It is measured
in watts （or kilowatts or megawatts...).

Example: If you install ten solar panels on your roof,

each panel with 100 watt nameplate capacity, then the installed capacity of
your roof-top solar plant will be 10 x 100 = 1000 watts, or 1kilowatt. Under perfect
conditions (full sunshine, the right angle), your panels can produce maximum of 1000 watts of
electricity.

If solar sharing was adopted on 15 % of

Japan’s farmland (4,549,000 ha in 2012) at a shading rate 25%, the total installed
capacity would be as much as 270 million kilowatts.

270 million kilowatts is a lot of electricity. It is
more than the peak demand in Japan in 2012 , which was about 156 million
kilowatts. Peak demand in today's Japan occurs on very hot summer days when
everyone turns on air-conditioning (Only In Hokkaido and Tohoku the peak demand occurs in winter due to heating).

As hot summer days are also sunny days when solar panels work at their maximum,  solar sharing could greatly contribute to energy supply in the summer peak demand.

Installed capacity, while an important indicator, can be a bit tricky though. No power plant generates electricity at maximum installed capacity all the time - either due to maintenance needs or lack of demand or - especially in case of renewables - because of the lack of “fuel”. The fuel for solar power is the sun. Solar panels on your roof produce nothing at night, and little
on cloudy days.

That's why we need the second indicator:

2. Estimated annual energy production

Annual energy production （年間可能発電電力量）shows
how much electricity over a given period of time the facility can actually
produce. The measurement unit is kilowatt hour.

Estimated annual energy production is calculated as:

installed capacity x capacity factor x 365 days x 24 hours

Capacity factor (設備利用率) is the ratio of the actual output over a period of time to the potential maximum output. If ten solar panels on your roof produced electricity only for six sunny hours on a day, their capacity factor for that day would be 25%  (6hours/24hours*100). (A bit simplified.)

Capacity factor differs for each type of energy. It is typically high and stable for nuclear and thermal plants – as much as 70 to 90 %, but
lower for renewables because they depend on the availability of sun or wind or water.

Actual capacity factor of solar panel installations in Japan in 2012 (average of 12 months from April 2012 to March 2013)
was 15%.

Taking into account this capacity factor, how  much energy could solar panels installed on 15% of Japan's farmland actually produce? The answer is: as much as 358 million megawatt hours of electricity yearly. This is about 40 % of Japan’s total electricity demand in 2012. Not so bad.

Who knows what Japan's energy infrastructure will look like in ten years. Solar sharing might be a vital part of it.

Project in Nishigoya, Tsukuba

Tsukuba is a city about 60 km northeast of Tokyo. One of the solar sharing pioneers Ken Matsuoka launched his project there in fall 2012.

He installed 579 solar panels on a metal frame over land area of about 1500m2.

The construction - from clearing the land and building metal frame to setting panels and cables, all based on Matsuoka's design and done DIY way - took him almost a year. Everything got ready in September 2013.

As of today October 14, 2013, the site is on a test
run. Actual selling of electricity to the grid is scheduled to start tomorrow – on October  15, 2013.

Matsuoka
will sell maximum of 49.9 kW to Tokyo Electric Power Company for the fixed
price of 42 JPY/kWh, guaranteed for 20 years.

Matsuoka also introduced manual tilting system to regulate the amount of light that can reach either the panels or the ground. He can now turn panels with a total weight of more than 8 tons using a single winch. Shading rate is 25.5 % (at panel tilt 0°). The purpose of tilting is not necessarily to maximize power generation output but quite the contrary, it can be used to provide more sunshine to crops when necessary, e.g. at critical growth stages like budding.

Matsuoka adjusting panel tilt:

Matsuoka is not a professional farmer but he does have experience growing his own food. He is now producing soybeans, tomatoes, eggplants and other crops for personal consumption under the panels. The site is registered as miscellaneous land - meaning Matsuoka has to pay higher taxes compared to agricultural land, but he has more freedom to choose how to use the land, what to grow and at what quantities. When we spoke last time, Matsuoka was envisioning a rice field on one part of the land, and a community garden on another. Both are great ideas because there are few on-site trials of growing rice under solar panels, and a community garden with many people coming and growing their vegetables just sounds good. Let's see what will eventually become reality.

The best thing about solar sharing is that building and running a power plant is not anymore something that only big power companies can do. Both technologically and financially, the hurdle is now low enough so that almost anyone can build their own small solar power plant and grow food below it. This will undoubtedly change our way of thinking about electricity.

Link to Ken Matsuoka's blog (Japanese):

http://gba03100.cocolog-nifty.com/tsukuba_ss/

History

Solar sharing was proposed in 2004 by Akira Nagashima, who turned his attention to the fact that most plants do not need all sunshine they receive in an open field. Plant photosynthesis depends on light – increased amount of light leads to higher photosynthesis rate – but only to a certain point. The amount of light beyond this saturation point not only doesn’t contribute to photosynthesis, but can even be harmful.

Based on this fact, Nagashima devised a system where solar panels use the excessive sunlight for energy generation while crops are cultivated below them. Nagashima applied for a patent in 2004 and made the technology freely available in 2005 (Patent publication No.
2005-277038).

Many trial projects have been launched since then, especially in the past two years. After the March 2011 East Japan earthquake and tsunami , followed by meltdowns at Fukushima Daiichi Nuclear Power Plant, Japan revised its energy policy and introduced feed-in tariff system to promote diffusion of renewable energy. Electric power companies now must buy
energy from renewable sources for fixed prices.

On March 31, 2013, Ministry of Agriculture, Forestry and Fisheries issued a guideline, acknowledging solar sharing system and setting rules for farmers who want to introduce it on land registered as agricultural. This was the first time that Japanese government recognized the already existing technology.

Why so revolutionary?

Why is solar sharing so revolutionary?

An oft-cited drawback of solar power generation is the requirement of a vast surface area. If solar panels are to produce the amount of electricity comparable with nuclear or thermal power
plants, the rooftops alone will not suffice. All over the world, low quality land as well as farmland has been used for large scale solar power development.

However, paving agricultural land with solar panels has drawn criticism for curtailing food production potential and destroying agro-ecological landscapes and biodiversity.

The prevalent mindset has been that on one piece of land we can have either agriculture or solar panels, but not both. Solar sharing, in which solar panels are installed above the field with crops,
overturns this mindset.

What is solar sharing?

The system is called “solar sharing” (ソーラーシェアリング) in Japan. Who knows what expression will eventually take root in English. We’re talking about a new way of producing clean energy without compromising food production.

How does it work?

Solar panels are installed on a frame about 3 meters above the ground, with wide spacing between panel rows. About three quarters of sunlight reach the ground and the remaining quarter reaches the panels. In this way, the same area is used simultaneously for both agriculture and power generation.

Picture: Solar sharing project of Ken Matsuoka in Tsukuba, Ibaraki prefecture, Japan.

This revolutionary idea is based on the fact that most plants don't need all sunshine they receive in an open field. Plants do need light for photosynthesis, but only to a certain point. Everything beyond this saturation point does not increase photosynthesis rate and can even be harmful (e.g. causing more evaporation and lack of moisture). Solar sharing takes advantage of this fact - panels use the excessive sunlight for power generation while crops are cultivated below them.

Solar sharing was invented by a Japanese Akira Nagashima in 2003 and today there are numerous trial projects all over Japan.

This blog aims to introduce these projects and everything related –from institutional background to on-site technological challenges.

Link to the inventor Akira Nagashima's project in Chiba prefecture　(website is in Japanese):

http://www.d3.dion.ne.jp/~higashi9/sola1.htm