IEEE Spectrum February, 2007 - 8

ROCK OF AGES: Oil shale is
rock containing burnable oil.

New Tech, Old Fuel
Estonia wrests a future from a filthy past

ToP:	DoUglAS	c.	PIzAc/AP	PhoTo;	BoTTom:	mIchAEl	DUmIAk

The	Baltic	state	of	Estonia	has	
cultivated	a	sophisticated	and	
wired	image	ever	since	the	
Soviet	Union	broke	up	over	a	
decade	ago-laptops	are	everywhere,	wi-Fi	availability	is	commonplace,	and	the	country	is,	
after	all,	the	home	of	Skype.
But	this	broadband	brain	
is	fed	by	a	victorian	belly.	The	
national	fuel	is	a	pale	brown	
stone	called	oil	shale.	Estonia	
burns	it	for	electricity	in	two	
massive,	Soviet-era	power	
plants	located	in	the	border	
town	of	Narva,	cheek	by	jowl	
with	Russia.	one	of	the	twin	
Narva	plants	still	sports	a	
15-meter-tall	Soviet	hammer	
and	sickle	on	its	brick	face.
According	to	Dmitri	lipatov,	
the	plant's	deputy	manager,	
shale	supplies	between	
70	percent	and	90	percent	of	
the	country's	electricity.	This	
is	the	only	place	in	the	world	
where	"fire	rock,"	as	it's	known	
locally,	is	responsible	for	supplying	such	a	large	portion	of	a	
nation's	power.
Because	of	oil	dependence	
and	climate	change,	a	global	
push	for	energy	alternatives	is	
on	like	never	before.	oil	shale	
of	the	kind	found	in	Estonia,	
formed	by	ancient	algae	compressed	over	time,	is	one	possible	alternative	fuel:	upon	
extraction,	it	can	be	pulverized	
www.spectrum.ieee.org			

and	burned	like	coal	to	drive	
electric	generators.	Some	day,	
indeed,	the	new	oil	shale	technology	coming	online	here	could	
help	other	countries	reduce	
their	energy	dependency	at	an	
acceptable	environmental	cost.	
But	the	fuel's	recent	history	in	
Estonia,	to	be	frank,	is	about	as	
dirty	as	it	gets.
As	you	drive	east	from	
Tallinn	along	the	gulf	of	Finland,	
just	before	the	Narva	plants'	
250-meter	chimneys	thrust	up	
over	the	horizon,	dusty	slag	
mesas	start	to	loom	off	the	side	

NO FISHING: This enticing lake is
actually a chemical stew, formed
from water used to pump waste ash.

of	the	road,	nearly	100	meters	
high.	Every	year	the	burned	
shale	produces	some	5	million	
metric	tons	of	ash,	which	is	
collected	and	piled	up	behind	
a	pale	30-meter-high	levee	
about	1.5	kilometers	from	the	
plants.	water	is	used	to	pump	
the	ash	into	the	inexorably	
growing	field,	so	a	copper-

alkaline	wastewater	and	rain	
pond	floats	atop	it:	it's	a	surreal,	
brilliant	blue-green	chemical	
caribbean,	full	of	potassium,	
sulfate,	hydroxide,	and	zinc	
[see	photo,	"No	Fishing"].
That's	not	all.	Burning	the	
shale	also	creates	tons	of	
small	airborne	particles	laced	
with	heavy	metals.	Also	going	
into	the	air	is	nitrous	oxide,	a	
potent	greenhouse	gas,	and	
sulfur	dioxide,	which	causes	
acid	rain.	last	year	the	Narva	
plants	spewed	close	to	10	million	metric	tons	of	carbon	dioxide	and	gave	off	enough	of	the	
other	pollutants	to	match	the	
emissions	from	Finland's	entire	
energy	sector.	And	that's	an	
improvement-during	the	Soviet	
era,	the	plants'	emissions	were	
three	times	as	high.	
one	answer	to	this	environmental	nightmare	would	be	to	
simply	shut	down	the	plants	and	
import	power	from	Russia	or	
germany.	But	state-owned	Eesti	
Energia,	in	Tallinn,	having	metamorphosed	from	its	sleepy	old	
Soviet-era	self	into	an	up-andcoming	regional	player,	thinks	
it	can	put	a	clean	new	shine	on	
this	rusty	technology.
In	the	Eesti	plant,	there	are	
now	eight	200-megawatt	power	
units.	Built	in	St.	Petersburg's	
leningrad	metal	works	and	
stenciled	with	cyrillic	characters,	each	unit	looks	like	an	

sidiary	of	Foster	wheeler,	based	
in	clinton,	N.J.,	25	years	ago.	
Now	it	is	possible	to	deploy	it	
in	the	huge	sizes	needed	at	the	
Eesti	station,	delivering	much	
more	efficient	power	generation	
and	yielding	fuel	cost	savings	of	
20	percent.	
Shale	crushed	into	6-	to	
10-millimeter	particles	is	fed	
into	the	bottom	of	the	furnace,	
and	as	the	mixture	burns,	it	is	
blown	upward	by	air	nozzles	at	
a	steady	rate	until	it	exits	the	
furnace	into	a	"cyclone,"	which	
catches	the	larger	unburned	
particles	and	sends	them	back	
down	into	the	furnace-a	circulating	loop.	Because	of	this	
recycling	through	the	boiler,	
combustion	can	be	kept	at	lower,	
much	more	even	temperatures,	
reducing	the	amount	of	ash	and	
emissions.	Unit	No.	8	also	has	
more	efficient	electrostatic	precipitator	filters.
Foster	wheeler	overhauled	
the	unit	and	one	other	at	a	cost	of	
US	$325	million.	It	still	makes	the	
same	roar	as	its	neighbors,	but	
lipatov	points	to	nearby	gauges	
which	show	sulfur	dioxide	emissions	at	zero	and	nitrous	oxide	
emissions	at	110	milligrams	per	
cubic	meter	of	ambient	air,	well	
under	the	European	Union	limit	of	
200	milligrams	per	cubic	meter.
This	is	not	by	any	means	
environmental	perfection.	Eesti	
Energia	has	to	pay	$20	million	
in	variances	and	pollution	fines	
every	year.	There's	still	the	matter	of	fixing	the	ash	pool,	which	
is	planned	for	the	next	three	
years,	using	new	disposal	technology.	And	as	a	new	member	of	
the	EU,	Estonia	soon	will	have	
to	come	into	compliance	with	
tougher	environmental	rules,	
which	will	not	be	easy.
The	Eesti	story	does	show,	
however,	what	some	basic	
investment	and	long-term	thinkovergrown	car	battery.	lipatov	
ing	can	do.	"There	is	a	lack	
goes	to	unit	No.	8	and	points	
of	energy	in	this	region	and	a	
to	a	towering	tangle	of	shiny	
growth	in	power	demand,"	Eesti	
pipes.	Stretching	far	upward	is	
director	Ilmar	Petersen	says.	
the	first	of	what	will	be	16	new	
"This	is	an	independent	energy	
circulating	fluidized-bed	boilers,	 source:	we	must	be	happy	we	
two	to	a	unit,	which	drastically	
have	this	source	here,	and	we're	
reduce	emissions	from	burning	
much	more	interested	to	use	it	
oil	shale.	The	technology	was	
than	look	somewhere	else."	
first	developed	by	Finland's	sub	
	 -MICHAEL DUMIAk
February	2007	|	IEEE	Spectrum	|	NA							13
http://www.spectrum.ieee.org
Table of Contents for the Digital Edition of IEEE Spectrum February, 2007
