<s>
Load	B-Algorithm
balancing	I-Algorithm
,	O
load	O
matching	O
,	O
or	O
daily	O
peak	O
demand	O
reserve	O
refers	O
to	O
the	O
use	O
of	O
various	O
techniques	O
by	O
electrical	O
power	O
stations	O
to	O
store	O
excess	O
electrical	O
power	O
during	O
low	O
demand	O
periods	O
for	O
release	O
as	O
demand	O
rises	O
.	O
</s>
<s>
Telephone	O
exchanges	O
often	O
have	O
arrays	O
of	O
batteries	O
in	O
their	O
basements	O
to	O
power	O
equipment	O
and	O
in	O
the	O
past	O
metro	O
systems	O
such	O
as	O
the	O
London	O
Underground	O
had	O
their	O
own	O
power	O
stations	O
,	O
not	O
only	O
giving	O
some	O
redundancy	O
but	O
also	O
using	O
the	O
grid	O
for	O
load	B-Algorithm
balancing	I-Algorithm
.	O
</s>
<s>
Today	O
these	O
supplies	O
often	O
have	O
been	O
replaced	O
by	O
direct	O
supply	O
from	O
the	O
grid	O
and	O
so	O
are	O
no	O
longer	O
available	O
for	O
the	O
purpose	O
of	O
load	B-Algorithm
balancing	I-Algorithm
.	O
</s>
<s>
Solutions	O
to	O
the	O
load	B-Algorithm
balancing	I-Algorithm
problem	O
focus	O
on	O
"	O
smart	B-Architecture
grid	I-Architecture
"	O
technology	O
,	O
in	O
which	O
many	O
consumer	O
and	O
industrial	O
appliances	O
would	O
communicate	O
with	O
the	O
utility	O
using	O
digital	O
means	O
,	O
and	O
could	O
be	O
switched	O
on	O
and	O
off	O
by	O
the	O
utility	O
to	O
run	O
at	O
off-peak	O
hours	O
.	O
</s>
