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Published on June 4th, 2015 | by Matthew Klippenstein


Sekisui Sells Solar & Storage With Star Wars Spokesdroids

June 4th, 2015 by  

Japanese construction company Sekisui Heim deployed the droids in a recent television ad promoting its “Smart Power Station”–branded net zero houses.

Though it probably paid a pretty penny to draft C-3PO and R2-D2 as spokesdroids, it will have been a manageable expense: not only is parent company Sekisui Chemical a sprawling 20,000-employee conglomerate, but Sekisui Heim itself has a Guinness Book of World Records entry for having built the most solar PV–equipped houses in the world, with 160,000.

The chart below – excerpted from its 2014 CSR report – only covers construction through 2013, but shows that Sekisui has been in this for the long haul, having built its first solar-equipped homes when Japan began ramping up photovoltaic production in the late 1990s. (Those interested in the Japanese government’s policy support over time, can refer to this webpage from the IEA.)


The company’s near-net-zero efforts date back to 2003, with its introduction of feed-in-tariff-assisted “net-zero utility cost” homes. Its current “Smart Power Station” residences are designed to be net electricity generators.

To be fair, this is easier to achieve in Japan than most other developed countries, given the high solar insolation (an average of 4.5 kWh per square metre per day) and residents’ relative electric thrift: Japanese households use an average of 15 kWh of electricity per day, in line with European countries, and about half the North American average. (Big, big tip of the hat to Shrink That Footprint for compiling the data.)

But solar panels are only half of the Smart Power Station equation; the homes aim to give their owners partial electric autonomy by combining solar with lithium-ion battery storage, as shown in the screen grab from the 0:19 mark of the ad. Given that the battery powers a hairdryer at around 0:22, we can infer that either the battery can discharge faster than a Tesla Powerwall, or the marketing agency doesn’t appreciate just how much power those things draw!

Sekisui Solar

Screen capture of 0:19 mark of Sekisui Star Wars / Smart Power Station ad.

A Home Energy Management System (or “HEMS”) and the company’s proprietary “Kaiteki Airy” Energy Recovery Ventilation unit round out the product, with the latter using the heat and humidity (or lack thereof) of indoor air to pre-condition fresh air brought into the house.

The human side of residential solar…

In light of Zachary’s commitment to highlight the human side to cleantech, I’ll note in passing that I first saw the Sekisui ad on TV while visiting in-laws in Japan, whose rooftop solar array produces about one and a half times their annual electric consumption, which includes electric heating and hot water.

It was simultaneously mortifying and encouraging that my pragmatic relatives beat me to net-zero house status.

It was mortifying because I’m an aspirational environmentalist who forgoes red meat, chose cleantech over crude with his Canadian chemical engineering degree, and even convinced his infinitely-patient wife that the family should buy a plug-in hybrid electric vehicle, despite not being able to charge at home or work! (Thanks to local infrastructure, about 40% of our miles have been electric thus far.)

I first learned about net-zero homes in 2007, and determined that we’d one day live in one, but alas, the price of housing in Vancouver kept rising faster than our savings. (An added challenge is that much of the Pacific Northwest is a rainforest, so a lot of solar panels are needed to generate one North American household’s worth of electricity.)

But it was simultaneously encouraging because my relatives didn’t go net-zero for any idealistic reasons; theirs was largely a wallet-driven decision. The feed-in tariff they receive is good for 10 years – long enough to pay the system off – at which point they’ll enjoy net savings. If at that point utilities don’t fully value their solar electrons, battery storage will have become cheap enough to make purchasing one worthwhile.

…and the economic side

And while market purists may frown at cleantech subsidies in the abstract, it’s worth reinforcing that we live in a real-and-messy world, where fossil fuels impose $10 million of social costs on societies every minute while flooring the gas on the warming that will worsen those costs by the year.

Besides which, the very notion that societies shouldn’t invest in what they perceive benefits their future lest they guess wrong is dumbfoundingly short-sighted. Taken to its illogical conclusion, this reasoning suggests that the adults who constitute our societies shouldn’t invest in their children – the future – lest the money be wasted.

One imagines that a consensus of, oh, let’s say 97% of market purists would agree that investing in one’s children is justified!

Solar Japan

My in-laws’ house in Japan, featuring 5 kW solar array on roof, and clothes being air-dried in foreground (electric dryers consume about 3 kWh per cycle).

Kyocera solar

Kyocera solar PV interface, showing that to that point in May, PV panels had generated 525 kWh (with a peak power generation of 5.4 kW) while the household consumed 257 kWh.

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About the Author

Matthew Klippenstein is a renewable energy consultant in Vancouver, Canada. He has chronicled the Canadian electric car market for GreenCarReports.com since 2013, and has provided commentary (in English and French) for print, television, radio, web and podcast media. An early guest on "The Energy Transition Show", his work has also been discussed on "The Energy Gang". An occasional contributor to CleanTechnica, he co-hosts our own CleanTech Talk with Nicolas Zart.

  • Wayne Williamson

    cool article. We need more companies like this that build houses that are energy efficient with integrated solar and battery in the USA.

  • Right. I think the point was: electricity prices are much higher than the US while solar resources are better than Germany.

    • GodoStoyke

      Well put.

    • @ZShahan3:disqus Yep, that’s what I’d been going for. 🙂 It’s not Australia — but at least it’s no Germany! (in terms of received sun)

  • heinbloed

    But Spain isn’t Japan, Godo Stoyke.

    You aren’t working for Fox News, are you 🙂

    The South of Japan has a tropical climate, pineapples and bananas are farmed there.Might be lanterns the farmers use there ……


    • GodoStoyke

      “But Spain isn’t Japan, Godo Stoyke.
      You aren’t working for Fox News, are you :)”

      Definitely not! 🙂 Fox News claimed that solar is successful in Germany because “they have way more sunshine than the US”, which is complete nonsense as you can see above. Here is a solar map of Japan: https://upload.wikimedia.org/wikipedia/commons/0/0c/SolarGIS-Solar-map-Japan-en.png Be careful with the colours though: the US scale goes up to 2,500 kWh/a while the Japanese goes only to 1,600 kWh/a (i.e. different colouring scheme). I am concerned that readers of this article think “Oh, solar works in Japan because of the great sun” when it is actually only a moderate resource, not nearly as good as the US.

    • @heinbloed, I’m told by my in-laws that some farmers (presumably in the south) are actually installing some panels in their fields, to provide partial shading during the day (maybe for crops which don’t do well when they’re too hot?) — while getting paid for the electricity generated.
      I’m sure it’s cheaper to plant trees to create shade, but since solar panels can go up in a matter of days, maybe in the future farmers looking to keep moisture in the soil and/or avoid heat stress, might alternate crops with the occasional solar array for the shading benefits?

      • heinbloed

        A lot of crops,esp.the leafy ones like spinach and lettuce can be damaged by the sun as well as by strong rain and hail.
        Tress would take to much water in arid areas and can be knocked down by storm and also get killed by weedkillers.

        So PV can make sense on agriculture land indeed.

        The largest PV plant in Europe is currently build not far from Bordeaux, they build the panels extra high at about 1.5 m to allow for farming (sheep, maybe fowl as well) keeping the vegetation short.
        They are planting 6000-7000 panels a day using robots and screw pile foundation.


        a better picture here:


        Use the translation engine for the text, its worth it:)

        It can get very hot there in summer, fire is a huge risk. Western Europe’s largest pine forest there can’t be insured anymore, to many fires and storms in the last two decades.
        And formerly heavily subsidized water charges for farmers are going up as well.

        The shading will help to keep more moisture in the ground as well I’d say.

  • heinbloed

    Thanks, Mr. Klippenstein.
    Sekisui Heim is a fantastic building company, I’ve heard about them about 15 years ago but never seen a building from them in situ.
    I think clients can have every room individually pr-assembled in the factory to optimize design and outlay.


    Here another human touch from the cleantech building sector:



    The first passive house bordello opens in Heidelberg tomorrow, heat and power is timber sourced via the district heating system.
    And a very,very clean-tech feature they advertise: clients must use condoms 🙂

  • Ronald Brakels

    A Tesla Powerwall puts out 2 kilowatts continuous and 3.3 peak. That’s enough to power a mighty Australian hair dryer and more than enough for a puny 1,200 watt Japanese ones, which are so weak they can’t even be used to launch huntsman spiders across the room.

    • @ronaldbrakels:disqus – well now, I stand corrected… thanks for pointing that out!

  • MarTams

    Have they paid royalties to the Star Wars franchise for using the likeness? At one time, Vanna White of Wherl Of Fortune have successfully sued Samsung for their robot mimicking her actions in a setup similar to wheel of fortune. They’d better have permission from Star Wars franchise!

    • Hi @MarTams, I’m sure they have, since they used the actual droids. 🙂 If they didn’t have authorization, Disney’s lawyers would’ve probably taken everything down by now…!

  • Michael G

    Japanese electric rates are $0.26/kWh vs US about $0.12 so PV + storage makes economic sense right this minute, while the US will vary a lot. Some states like Hawaii are ready now, parts of CA and NY very soon, other states further out.

    Electric rates here:

    • heinbloed

      It depends where you live in Japan, from former reports about Sekisui Heim I heard that the household day-time tariff can be $ 0.50/kWh.

      The IEA price list (shrinkthatfootprint) is from 2011,in the mean time there have been hefty increases.But PV and storage costs went down considerable, as far as I know they are now at the same lavel as US costs (for small home systems) and about twice the cost compared to Germany.

      Sekisui Heim offered storage in the past without PV-system to make use of cheaper night rates.

      • Hi @heinbloed, sorry for the delayed reply – the rest of the family got back from Japan. 🙂 If memory serves, in the region they’re in, they get a 10-year 32 yen/kWh tariff, while their normal rates are about 22 yen/kWh. (Not sure about time-of-day pricing.) In their case they probably wouldn’t need storage until utilities try to give them less than their currently-regulated electricity rate. 🙂

  • Dag Johansen

    Sounds super silly.

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