A place in the sun

About a year ago, many people in our part of Chiba Prefecture were still struggling with loss of electricity after two typhoons plowed through the peninsula in rapid succession. Our house was lucky and only lost power intermittently for short periods. Not far from where we live, however, there were some households who didn’t have power for more than a month, and the local authorities, not to mention the regional power providers, seemed at a loss as to what to do about it. Moreover, they didn’t seem sure of how to prevent such problems from recurring in the future, seeing how, with climate change and all, it was likely that these kinds of extreme weather events would happen again and perhaps more frequently.

Extended blackouts are, of course, a serious matter. In addition to loss of lighting function, it means your refrigerator won’t work and thus all your food contained inside will spoil; it means no air conditioning, which could be a big problem at the height of summer; it means no television, which provides emergency information in times when disasters like this strike; and it means no cell phones because no recharging capability. These are all problems that can occur to anyone in the path of a typhoon, but in the cases of the people mentioned above it could be even more serious. We live in an area where a lot of infrastructure is not available. Most of us get our water from wells, and so we need pumps that are run by electricity, so that means no water for bathing and toilets. We also aren’t hooked up to natural gas lines, so unless you get propane deliveries, it probably means you run your household on an all-electric system, so that means no cooking or hot baths/showers. 

At least one local municipality has taken preliminary action to be more prepared, and in doing so may spark a trend that should be promoted nationwide. In the city of Sosa, on the Pacific coast, a group of environmental activists has set up a “solar sharing” operation that started out with farmers who allowed the group to install solar panels on tall stanchions above their fields. The panels absorb sunlight, but are far enough from the ground to allow peripheral sunlight to reach most of the ground underneath them, so the fields still produce crops. The farmers still sell their wares, and the sharing group sells excess electricity from the solar setup to the local power company and puts the revenue back into the local government, which uses the money to promote solar energy on a household-by-household basis. According to an article in Harbor Business Online, Sosa seems to be the only local government carrying out such a program. What’s particularly interesting is that, besides the money made from selling the electricity, the program has no relationship with any major power companies, which makes sense. Electricity providers are very concerned about people generating their own power for their own use, since it means using less electricity from the grid, which they control. However, after last year’s typhoons, many residents of Chiba have realized they can’t count on the grid and its overlords to guarantee service in the event of an emergency. 

For example, 35 families in Sosa recently attended a workshop at which each was given several used solar panels for free and then taught how to hook the panels up to a portable power source (5 kilograms; AC/DC and USM connectivity; between ¥40,000 and ¥50,000 at almost any home electronics retailer) that can be used during blackouts to do things like power TVs, charge cell phones, and even run (relatively small) refrigerators. The power sources have storage capability, so one full day of charging through solar panels can provide enough emergency electricity for several days. For those families with enough money, the workshop recommended buying two power sources, so that while one is being used the other is recharging.

This is obviously a makeshift solution to the blackout problem. A permanent solution would be built-in solar capacity that can not only be used to store energy in case of emergency, but provide electricity on a real-time, ongoing basis; and the fact is, many people already have this capacity because, if they had their homes built or renovated in the past decade, they had the option of integrating solar collection devices into their electrical systems. The problem is that these systems as built were designed with the idea of selling electricity back to the power companies. That, in fact, was their sales point. But the group also insists that the system can be easily switched over to usage mode, which means the house uses all the electricity generated. And many people have responded to this capability by asking how they can tap into it.

The idea of selling solar energy to the power companies was enacted in order to promote solar energy when it was practically non-existent. When we were looking to buy a house in 2013, we visited one small subdivision in Chiba that was being developed by a housing company that specialized in solar capability, but the pitch was that you sold the power to Tepco and used the money to pay off your mortgage. At the time, Tepco was paying way above market rates for solar-produced electricity, so this plan was very attractive. The odd part was that the household itself would not use any of the electricity it produced, and that also made a certain amount of sense since the price of electricity was very cheap in relation to the amount of money being paid for the solar energy. This way, Tepco could have its cake and eat it, too: It could “promote” solar energy in line with government strategies but it also kept homes hooked up to the grid. At the time, the housing company we talked to said that Tepco would pay about ¥42 per kilowatt/hour, but as more people have availed themselves of home solar systems, the power companies have reduced the price they pay for the resulting electricity. Now, Tepco pays ¥21 per kW/hour for solar system sizes of less than 10kW, and only ¥12-¥13 for systems of between 10kW and 50kW. (Anything over 50kW qualifies as a commercial entity, which means Tepco buys the electricity at market rates) At these prices, there isn’t much difference between the money one makes selling electricity and the money one spends buying power from the grid. Tepco’s strategy is obvious: without such an incentive, people will be less likely to install solar systems, and thus their power monopoly will continue to be the only game in town.

But that strategy still sees solar systems as inherently expensive to install and maintain, and that isn’t the case any more. Prices have come way down since we visited that solar subdivision, and according to various technical media, it will come down even farther as worldwide mass production kicks in. In terms of the price of electricity, parity has already been breached. Unbeknownst to most consumers, the price of electricity has increased since the 2011 quake-tsunami by about 30 percent because the nation’s nuclear plants were shut down. The reason people haven’t really noticed that rise is because household devices have become exponentially more energy efficient, and people took the post-quake directives to heart by consciously using less power. This is a very good development, and in the scheme of things more meaningful than switching to renewable energy. As a planet and a species we have to reduce our footprint by consuming less, and that starts with electricity. The next step is full responsibility for our electrical usage, meaning we use only what we make. 

Consequently, the price of selling electricity to Tepco by households will drop below the market price and, someday, the buyback system will be terminated altogether, but contrary to Tepco’s belief, it will likely mean that more people will install solar systems for their own use, meaning they will connect their electrical systems straight into their panels, and with the efficiency and capacity of home storage devices increasing as their prices fall, there is no reason to think that homes in the near future can’t become completely self-sufficient off-grid. In such a situation, “emergency power” will come to represent something totally different than what it means today. We will get supplemental and makeshift power from the grid, which could become increasingly smaller and community-based. What’s particularly ironic about these developments is that they are market-based. Yes, the authorities essentially kick-started the greater use of solar systems, but it was people out to make money that found out how to make it pay, much to Tepco’s chagrin. 


  1. Daren · October 17, 2020

    We’re getting ready to do something similar here in Mie and up in Tohoku next year.


  2. Cory · October 19, 2020

    Nicely written, and informative as usual. Was surprised you didn’t mention the programs that will pay for your solar equipment in exchange for a ten year contract of selling them your excess electricity, like Hot Denki: https://hotdenki.jp/. Lixil is also doing something similar with Tepco. We are in the process of building a house now and stuck on whether to do solar because of the cost, so these were interesting options. Hot Denki said the weather is not consistent enough in our area, and Lixil said the weather is ok, but they want to force us to use their other goods in our home – windows, etc. I don’t like the idea of being tied to a bit company like that so am hoping we can come up with the money ourselves, but if it encourages more people to create sustainable energy, that should be a good thing, although I much prefer the community based approach you describe in your article!


  3. Lee · November 1, 2020


    Enjoyed reading your article, but there are a few things that you should know about rooftop solar systems and the such.

    First of all the price of such systems in Japan is very expensive compared to other places in the world. This is similar to the old case of being able to buy Fuji film cheaper in, for example, the USA than in Japan way back in the days when there were no digital cameras or mobile phones. The high cost of solar systems in Japan has reduced demand for them and made the return on investment (ROI) much lower than in other countries.

    Second, putting a system on your roof may or may not be a good idea depending on your pattern of electricity consumption and the amount of that consummption along with how much you get paid for excess generation and how much you pay for purchased electricity.

    You have to sit down and figure out how much electricity you use and when you use it along with when and how much electricity you buy from the utility company.

    This of course will vary according to the time of year and weather. The main problem with solar is that it is variable and the amount generated is not within your control. (Big baseload nuclear, coal, or NG generation is a known and generally constant quantity.)

    In summer the amount of electricity a system will generate can be as much as 5 times the amount produced during a winter day. This means that even with a system you’ll still be buying a lot more electricity from the utility in winter than in summer.

    You also have to determine how the utility measures the excess generated electricity. Is it measured in 5 minute, 10 minute, 30 minute or some other time block? I’m not familair with that aspect in Japan.

    Third, the whole idea of putting a solar system on your roof from an ECONOMIC point of view is to be able to sell excess generated electricity to the utility company to recoup the cost of your system and then after time reduce the amount of your electricity bill.

    Now for an example using my system where I live.

    Years ago we put up a small system as it was quite expensive and we wanted to see how it would work. Unfortunately the rules changed regarding increasing the size of system and the amount we would get paid for the excess electricity we generated would be slashed if we increased the size.

    Our excess electricity generated and used is measured in 30 minute blocks of time. Let’s keep things simple. We’ll use round numbers and units. We also have a variable cost electricity system where peak periods cost more than off peak. Peak is weekdays from 7:00am to 11:00pm. The rest of the time is off peak. Peak prices are twice the cost of off peak. Japan has similar time based electricity pricing in some of its plans.

    We’ll use the following prices as an example: generated excess electricity is paid at 60 cents per unit; peak electricity cost 40 cents a unit; off peak is 20 cents per unit.

    We’ll use three different scenarios to show how things work.

    1. In the first example during peak hours in the 30 minute period you use 2 units of electricty and generate 1 unit. Your net usage is one unit of electricity which you buy from the utility. So you pay the utility 20 cents.

    2. In the next example during peak hours in the 30 minute period you use 1 unit and generate 2 units. So the utility will pay you for 1 excess unit or 60 cents

    3. In the last example during peak hours in the 30 minute period you are taking a nap and don’t use any electricity at all, but it is the middle of the afternoon and bright and sunny day with a light breeze and cool temps. Your system is operating at peak efficiency and pumps out 4 units. The utility pays you for $2.40 for the excess electricity you generate.

    So in the example you want to maximise the amount of generated electricty that you sell to the utility as your generated electricity pay is much higher than what it costs you. You also want to use as much electricity off peak as possible when you are not generating any electricity.

    If you have to use electricity during the day, you want to use as much as possible when generation is low and use as much as possible during a 30 minute interval…………………

    if prices differ and the consumption pattern differs then the above scenario changes. If you have a system on your roof and the price of electricity you buy from the utility during the day is high compared to what you get paid, then you’ll want to use as much of your generated electricity as possible during the day and not one unit more.

    A completely different scenario from the one above.

    Lastly, while I’m all for solar rooftop systems, the idea of going ‘off grid’ using systems is basically impossible for most people and will be for a long, long time.


    As stated above the ‘problem’ with solar is the variablity which results in the amount of generation being beyond your control.

    To go ‘off grid’ and totally rely on your own generated power is a complex problem as you must engineer for the worst possible scenario.

    A system will have to be able to generate and store enough electricity to last over periods of extremely low output. Where I live we can get days and days of cloudy weather that reduces output to very low levels. To overcome this you’d need to increase the size of the system to compensate. (This past month we had 17 of the 31 days in October with solar insolation at the long term mean or less. Twice we had periods of 6 days in a row where that happened.)

    How many panels would you need to do that? In summer 15 panels may be more than enough. To get the same output in winter you might need 75 panels or even more.

    Adding a battery or batteries would help, but again, you’d have to be able to charge the battery AND also generate for you required usage. More panels again………………….

    I doubt that there are many houses or apartment buildings in Japan have the space for enough panels for them to go ‘off the grid’.

    And then there is the problem of orientation……………………..You just can not slap panels on a roof facing in any ole direction. You have to place them so that they maximise their output. North or south is best depending on where you live (southern or northhern hemisphere). Don’t have the best facing roof? More panels………………….

    So before you plop down big bucks for system, there are a lot of calculations that need to be done……………….


  4. ashley · December 1, 2020

    I had no idea! Thanks for sharing your knowledge, I’m doing some research for a client of mine, I don’t know much about solar PV trends, but I’ll have to read more about this.


  5. Lee · March 13, 2021

    For those of you that want to read more about solar systems and get an idea of what is involved, here is a web site from Australia with a bunch of good stuff to read:


    Yes, it is from Australian and talks about the Australian market and prices, but it still has a lot of good information.

    You can also see how cheap solar systems and panels are here and how prices have changed.


    There also is a bunch of calculators in English that you can manipulate to see how payback works,

    From July here in Victoria the amount people are being paid for excess generated electricity is falling by some 34% as a result of the drop in wholesale electricity prices. This drop in price will make the payback period even longer for people that put panels on their houses.

    Unfortunately, there has been very little drop in the price of RETAIL electricity for residential customers.

    But compared to the rest of world, we still have on the best (if not the best) solar programs in the world.

    If you want to see a totally screwed up residential solar system all you have to do is look at is Oahu and their program there.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s