ozone day massacre 12 Jumbo modules for installation savings 12
Japan ramps Up Home Energy Management
by DAN BiHN
Following the Fukushima nuclear disaster last March, Japan’s electric consumption had to be kept within the
limits of the surviving generators. That meant reducing the
summer peak demand by 15 percent.
household appliances, allowing you to reduce energy costs
without compromising convenience and comfort.
That’s what nearly half of Japan did last summer, with
impressive results. The government asked for 15 percent.
The people gave them 18 percent reduction in peak demand.
There were no blackouts. It was an amazing thing to experience (and you can read that story online, solartoday.org/
I visited the Daiwa House, where the entire home can
be controlled from an iPad. The lights are LEDs with nonreplaceable bulbs designed to outlive the house. The lights
in the bedroom are integrated with the alarm-clock app
— they wake you up by gently progressing from a warm
sunrise glow to cheerful daylight.
Northern Japan and Tokyo made it through the summer
by enduring and doing without. In three years, there might
be a better way, starting at home.
Since the rolling blackouts immediately following the
March 11 disasters, people have been particularly interested
in this home’s prototype lithium-ion battery pack, designed
to run the home for several hours.
For the past decade the Japanese government has been
aggressively funding efforts to understand exactly what happens when a neighborhood goes completely solar. Starting in 2002, the New Energy Development Organization
(NEDO) invested nearly $100 million to test 553 homes
it equipped with complete photovoltaic (PV) systems. The
compact housing development, 50 miles outside of Tokyo,
is called Pal Town.
As appealing as that vision is, the biggest barrier to the
adoption of HEMS and smart appliances is compatibility.
Think about the half-dozen remote control devices that
clutter your TV room table. You can thank the secretive,
closed culture of the TV manufacturers, most of them Japanese (even though Japan has all but stopped making TVs
Photos: dan bihn.com
NEDO also wants to understand the technical problems
on a global level so that the Japanese solar industry can
produce products and solutions that work well outside of
Japan. To that end, NEDO is developing similar test communities around the world (including one just launched in
New Mexico that I’ll report on in a subsequent article).
That just won’t work for HEMS. On July 12, the HEMS
Alliance was announced in Tokyo. It consists of 10 Japanese home appliance manufacturers, the telecommunication giant KDDI, and Tokyo’s utility company, TEPCO.
Their goal: create an interoperability standard for smart
consumer appliances within three years.
The knowledge gleaned from these projects is invaluable. It may lead to huge government infrastructure investments into complex smart grid technology. Or it might
simply lead to a beautiful house that everyone
wants to own.
HEMS makes a house not only smart, but valuable. By
bringing everything together — PV, EV, new appliances,
small thermal energy storage systems (hot and cold) and
perhaps a residential battery — HEMS can reshape the
home’s electricity consumption and generation profile to
minimize its impact on the local distribution grid and maximize its value to the regional grid.
The heart and brain of a
smart home is the Home
Energy Management System (HEMS)
The Yokohama Home Collection is a
small, artificial neighborhood of 18 unoccupied model “eco homes” (including “smart
homes”) from various homebuilders around
the country. It temporarily occupies a quarter of a city block within walking distance of
downtown Yokohama — not really the sort of
place you’d expect to find a home of any kind.
Yokohama Smart City Project sponsored this
project to showcase the beauty of living green.
A smart house with PV produces energy that is carbon-free and domestic. A smart house, with all its cool appliances, creates local and global markets for Japan.
So will a smart energy revolution really happen in Japan?
Japan has the intellectual and technological leadership to
do it. And it has an amazingly sophisticated bunch of consumers excited about solving Japan’s energy problems and
participating in the future.
And the homes really are beautiful.
For the full story on Fukushima and home energy
use, go to solartoday.org/
The heart and brain of a smart home is the Home Energy
Management System (HEMS). The HEMS can do a lot of
things. It manages the comfort and security of the occu-
pants, regulating temperature, lighting, locks on doors and
windows. It also manages the home’s energy infrastructure,
integrating energy from the rooftop PV array, recharging
the electric vehicle (EV) and the optional home-scale stor-
age batteries. Ultimately, a HEMS will manage most of the
Still, the voices of the past are heard daily on the news:
“Nuclear energy is needed to keep the Japanese economy
globally competitive. Our idled nuclear plants need to be
restarted as soon as humanly possible.”
It will be tragically sad if the energy released by the great
earthquake of March 11 will have only nudged the axis of
the Earth, and not changed the direction of our world.
Japan stands on the brink of redefining the world’s energy systems. It can create a future where mothers needn’t
worry about their children playing in radioactive playgrounds. I’m hopeful.
Copyright © 2012 by the American Solar Energy Society Inc. All rights reserved.
dan bihn (dan@dan
bihn.com) is a technical
marketing and communication engineer and a
frequent contributor to