IEEE Spectrum October, 2016 - 53

Closed-Loop Solar Energy Conversion System
H2 (gas)

Hydrogen storage

Electrical
converter
HBr
(liquid)

Thermal panels

Br2 + HBr
(liquid)

Electric
power utility

Fuel-cell
converter

Household
electricity

Water

Heat and energy: This diagram, based on a
sketch in a Texas Instruments report, shows
how a TI solar energy system might be used to
generate heat, hot water, and electricity for a
home. To generate electricity, hydrogen bromide
(HBr) would be broken down by solar cells into
hydrogen (H2) and bromine (Br2). The hydrogen
could be stored separately and then recombined
on demand with bromine to create electricity.

boTTom, from lefT: mike blackwell/Texas insTrumenTs; beTTmann/geTTy images;
Texas insTrumenTs; ken goff/The life images collecTion/geTTy images

Heat exchanger

eral funding agencies under his own
name without revealing that he was
also acting on tI's behalf.
tI was cautious in part because Project Illinois was an unproven technology with significant risks. It was unclear
how efficient the system would be.
What's more, hydrogen bromide is
extremely toxic and corrosive-a rather
unlikely chemical for homeowners to
keep on their roofs in large volumes.
And one of the key components of the
system was a fuel cell, a notoriously
finicky technology.
A more fundamental problem, however, lay in the project's business model.
tI expected it would first need to sell
the system at high cost to very wealthy
homeowners in order to generate
enough revenue, knowledge, and economies of scale to bring the price down
for the middle-class market. But there
was little evidence that high-end homeowners would embrace costly and arguably ugly solar panels on their property.

1975
Kilby presents the idea for a residential
solar system to TI. The company takes
on the project, first calling it by the
code name Project Illinois and then
later the Texas Instruments Solar
Energy System (TISES).

illustration by

McKibillo

Heat pump
Water tank

If only there was some entity with
very deep pockets that could subsidize development of the technology
or provide a captive market to help
drive down the cost of deployment-or
both. of course, such an entity existed:
the government. Indeed, the u.s. military had already played that role in the
development and commercialization of
tI's integrated circuits.
Conveniently, the u.s. government
was investing heavily in renewable
energy. In 1973, President richard
nixon had announced Project Independence, an "Apollo program" for
energy that aimed to make the united
states energy self-sufficient by 1980. tI
executives believed they could find fed-

eral partners who would help the company bring solar energy to the masses.
tI executives and Kilby began looking up old friends in government to see
who might contribute to Project Illinois.
the answer turned out to be the newly
formed Department of energy (Doe).
In January 1978, after several years of
small-scale research, George heilmeier,
a tI vice president who had recently
led the Defense Advanced research
Projects Agency (DArPA), sat down
with John Deutch, the Doe's director
of energy research, to talk about Project Illinois. In a memo, heilmeier later
reported that Deutch said the Doe's
expertise in solar energy was limited,
and that he would therefore be will-

1979
Texas Instruments enters into a
four-year, US $18 million agreement
with the U.S. Department of Energy,
which allows Kilby and colleagues
to begin work on a prototype solar
energy system.

SPectrUm.ieee.orG

1980
Oil prices
begin to
drop.

1983
Texas Instruments
discontinues the
TISES program.

North AmericAN

oct 2016

http://SPectrUm.ieee.orG

Table of Contents for the Digital Edition of IEEE Spectrum October, 2016