1. 1
Anaerobic
Digestion:
An
Overview
of
Current
Practices,
Planning
Procedure
and
Policy
in
the
UK.

2. 2
Overview
During
the
course
of
this
paper,
I
present
a
case
for
the
adoption
and
development
of
Anaerobic
Digestion
(AD)
as
an
answer
to
combating
the
UK’s
ever
increasing
energy
and
waste
disposal
needs.
During
the
writing
of
the
‘Anaerobic
Digestion
Strategy
and
Action
Plan’,
a
report
published
in
2011
which
highlights
the
need
for
the
development,
and
expansion
of,
anaerobic
digestion
facilities
in
the
UK
to
help
meet
targets
in
waste
management,
the
coalition
Government
pledged
to
be
the
‘Greenest
Government
ever’.
Although
this
term
of
government
is
now
over,
the
UK
is
still
required
to
reduce
its
waste
production
and
energy
consumption
in
line
with
targets
set
out
by
the
Kyoto
Protocol.
Although
it
is
currently
a
priority
in
the
UK
to
reduce
waste
rather
than
focus
on
its
disposal
(especially
that
of
food
and
drink),
one
may
argue
that
realist
approaches
to,
and
options
for
this
type
of
waste
must
be
created
in
the
near
future.
WRAP,
whose
mission
is
to
accelerate
the
move
to
a
sustainable
resource-­‐efficient
economy,
found
that
in
2007,
22%
of
food
and
drink
purchases
that
were
brought
into
the
home
were
being
thrown
away
(a
staggering
8.3
million
tonnes).
Not
only
are
the
repercussions
of
this
waste
large
on
the
environment,
but
also
an
unnecessary
financial
drain
on
consumers
and
local
governments
who
have
to
pay
for
waste
collection
and
treatment.
Since
producing
these
findings
and
campaigns
to
reduce
food
waste,
WRAP
has
calculated
a
21%
reduction
in
the
amount
of
food
and
drink
being
thrown
away
from
2007-­‐2012.
However,
WRAP
also
reports
that
4.2
million
tonnes
of
avoidable*
food
and
drink
is
being
wasted
each
year
–
worth
an
eye
watering
£12.5
billion.
The
savings
in
greenhouse
gas
emission
associated
with
the
reductions
in
avoidable
food
and
drink
waste
(between
the
2007-­‐2012
time
period)
amounted
to
4.4
million
tonnes
of
CO2
equivalents;
the
same
as
taking
1.8
million
cars
off
UK
roads.
This
data
evidences
how
the
need
for
effective
and
efficient
food
and
drink
waste
management
is
very
much
required.
The
focus
of
this
paper
is
to
outline
the
current
planning
policies
concerning
anaerobic
digestion,
complete
a
broad
analysis
of
where
AD
is
currently
being
practiced
in
the
UK,
and
to
evaluate
the
success
of
these
practices.
*Avoidable
food
waste
is
defined
by
WRAP
as
food
and
drink
that
would
have
been
edible
at
some
point
prior
to
being
thrown
away,
for
example
slices
of
bread,
apples,
yoghurt,
etc.
Unavoidable
food
and
drink
waste
constitutes
as
items
such
as
tea
waste,
banana
skins,
poultry
bones.

3. 3
Contents
Page:
Title
Page
-­‐
Page
1
Overview
-­‐
Page
2
Contents
Page
-­‐
Page
3
Table
of
Figures
-­‐
Page
4
Introduction
-­‐
Page
5
Current
AD
Planning
Policies
-­‐
Page
8
Application
of
AD
in
the
UK
-­‐
Page
11
Financial
Aspect
-­‐
Page
13
Evaluation
of
UK
AD
Practices
-­‐
Page
15
Conclusion
-­‐
Page
16
Figures
-­‐
Page
17
References
-­‐
Page
21

4. 4
Table
of
Figures:
Title
Page
Image
–Accessed
from:
http://www.theguardian.com/environment/2014/jul/27/is-­‐
it-­‐harmful-­‐to-­‐burn-­‐my-­‐rubbish
Figure
1
–Image
of
an
AD
plant.
Photo
courtesy
of
Greenfinch
Ltd.
Figure
2
–Diagram
of
the
AD
process.
Accessed
from:
http://www.ionacapital.co.uk/page/95/Anaerobic-­‐Digestion-­‐Adoption.htm
Figure
3
–
Diagram
of
the
AD
process.
Accessed
from:
http://www.sciencedirect.com/science/article/pii/S0961953411000146
Figure4
-­‐
Table
of
incentives
of
the
Feed-­‐In-­‐Tariff
scheme
and
Renewables
Obligation.
–
Accessed
from:
The
Anaerobic
Digestion
and
Bioresources
Association.
Figure
5
–
Table
showing
future
changes
to
biomethane
tariffs.
–Access
from:
The
Anaerobic
Digestion
and
Bioresources
Association.
Figure
6
–Table
showing
the
cost
and
profits
of
a
planned
AD
plant.
Accessed
from:
http://www.nuffieldinternational.org/rep_pdf/1226661015Yeatman,_Owen.pdf
Figure
7
-­‐
Map
showing
AD
plant
locations
in
the
UK.
Accessed
from:
http://www.biogas-­‐
info.co.uk/resources/biogas-­‐map/

5. 5
Introduction:
During
this
section,
I
shall
be
exploring
and
outlining
the
chemical
and
physical
processes
undergone
in
AD.
In
particular,
I
shall
be
focusing
upon
the
outputs
of
these
processes.
Also
included
will
be
a
simplified
summary
of
the
advantages
and
disadvantages
of
AD.
“Anaerobic
digestion
is
a
process
which
breaks
down
organic
matter
in
simpler
chemicals
components
without
oxygen”
Monnet
(2:2003).
Although
this
process
can
be
very
useful
to
treat
arising
organic
waste
such
as
food
and
drink,
before
being
digested
the
feedstock
has
to
undergo
pre-­‐treatment.
In
the
case
of
food
and
drink,
this
pre-­‐treatment
usually
consists
of
adding
water
to
remove
undesirable
materials
such
as
plastics
and
glass
to
allow
for
better
digestate
quality
and
efficiency,
however
different
practices
are
adopted.
The
process
itself
takes
place
in
a
digester,
such
as
the
one
in
figure
1;
a
digester
may
be
classified
in
relation
to
its
temperature,
the
water
content
of
the
feedstock
(i.e.
food
and
drink),
and
the
number
of
stages
(single
or
multi-­‐stage).
Mesophilic
digesters
process
feedstock
at
35
degrees
Celsius,
while
thermophilic
digesters
run
at
55
degrees
or
above.
Multi-­‐stage
digester
processes
aim
at
optimizing
digestion
and
improving
the
control
of
the
process
by
separating
states
of
digestion.
However,
this
type
of
digester
requires
more
attention
and
surveillance
than
that
of
a
single-­‐stage
digester.
The
by-­‐products
of
anaerobic
digestion,
biogas
and
digestiate,
can
be
used,
not
only
as
energy
and
fertiliser,
but
also
in
order
to
create
a
source
of
incomes
to
support
the
digester.
According
to
Monnet
(2003),
Biogas
can
be
upgraded,
most
of
the
time,
by
removing
the
carbon
dioxide
and
the
water
vapour.
It
can
then
be
used
in
a
CHP*
unit
to
produce
electricity
and
heat.
The
digestate
can
be
used
as
either
a
fertiliser,
or
further
processed
into
compost
to
increase
its
quality.
See
figure
2.
Put
simply,
AD
is
a
naturally
occurring
process
of
decomposition
and
decay,
by
which
organic
matter
is
broken
down
to
its
simpler
chemical
components
under
anaerobic
conditions.
Anaerobic
microorganisms
digest
the
organic
materials,
in
the
absence
of
oxygen,
to
produce
methane
and
carbon
dioxide
as
end-­‐products
under
ideal
conditions.
The
biogas
produced
in
an
AD-­‐plant
usually
contains
small
amounts
of
hydrogen
sulphide
and
ammonia,
as
well
as
traces
of
various
other
gases.
The
science
underlying
AD
can
be
complex
and
the
process
is
best
understood
is
split
into
three
main
stages:
hydrolysis,
acidogenesis
and
methanogenesis.
During
hydrolysis,
the
fermented
bacteria
convert
the
insoluble
complex
organic
matter,
such
as
cellulose,
into
soluble
molecules
such
as
fatty
acids,
amino
acids
and
sugars.
This
process
includes
the
hydrolysing
polymeric
matter
to
monomers
(i.e.
cellulose
to
sugars
or
alcohols),
which
is
of
significant
importance
in
wastes
with
high
organic
content,
such
as
food
and
drink.
In
the
acidogenesis
stage,
acetogenic
bacteria,
also
known
as
acid
formers,
convert
the
products
into
simple
organic
acids,
carbon
dioxide
and
hydrogen.
The
principle
acids
produces
are
acetic
acid,
butyric
acid,
propionic
acid
and
ethanol.
*A
CHP
unit
is
a
gas
driven
combined
heat
and
power
unit
which
generates
heat
and
power
simultaneously.

6. 6
Finally,
methane
is
produced
during
methanogenesis
by
bacteria
known
as
methane
formers.
Either
by
means
of
generating
carbon
dioxide
or
by
the
reduction
of
carbon
dioxide
with
hydrogen,
as
shown
in
Figure
3.
It
is
important
however
to
note
that
some
organic
materials
remain
effectively
undigested,
such
as
lignin
(a
complex
organic
polymer).
Historically,
AD
has
been
used
in
the
UK
since
the
industrial
revolution
of
the
nineteenth
century.
By
1895,
biogas
was
recovered
from
a
sewage
treatment
facility
and
used
to
fuel
street
lamps
in
Exeter.
Increasing
energy
prices
and
more
stringent
environmental
regulations
are
pushing
European
countries
such
as
the
UK
to
explore
the
AD
market.
There
are
now
currently
more
than
600
farm-­‐scale
digesters
operating
in
Europe.
Associated
with
anaerobic
digestion
are
both
advantages
and
disadvantages,
an
over
view
of
which
is
outlined
below:-­‐
Advantages
of
AD:
-­‐ AD
contributes
to
reducing
greenhouse
gases.
A
well-­‐managed
AD
system
will
aim
to
maximise
methane
production,
but
not
release
any
gases
to
the
atmosphere,
thereby
reducing
overall
emissions.
AD
also
provides
a
source
of
energy
with
no
net
increase
in
atmospheric
carbon
which
contributes
to
climate
change.
-­‐ The
feedstock
for
AD
is
a
renewable
source,
and
therefore
does
not
deplete
finite
fossil
fuels.
Energy
generated
through
this
process
can
help
in
reducing
the
demand
for
fossil
fuels.
The
use
of
the
digestate
also
participates
to
this
reduction
by
decreasing
synthetic
fuels
use
in
fertiliser
manufacturing,
which
is
an
energy
intensive
process.
-­‐ AD
creates
an
integrated
management
system
which
reduces
the
likelihood
of
soil
and
water
pollution
to
happen,
compared
to
disposal
of
untreated
animal
manure/slurries.
The
treatment
can
also
lead
to
a
reduction
of
up
to
80%
of
the
odour
and
it
destroys
virtually
all
weed
seeds,
thus
reducing
the
need
for
herbicide
and
other
weed
control
measures.
-­‐ Finally,
an
advantage
of
using
AD
is
that
one
can
convert
residues
into
potentially
saleable
products:
biogas,
soil
condition,
and
liquid
fertilizer.
It
can
also
contribute
to
the
economic
viability
of
farms
by
keeping
costs
and
benefits
within
the
farm
if
the
products
are
used
on-­‐site.
Disadvantages
of
AD:
-­‐ AD
projects,
as
with
many
developments,
will
create
some
risks
and
have
some
potential
negative
environmental
impacts.
These
need
to
be
removes
wherever
possible
or
a
least
minimised.
-­‐ AD
has
significant
capital
and
operational
costs.
It
is
unlikely
that
AD
will
be
viable
as
an
energy
source
alone
and
therefore
must
be
seen
as
an
integrated
system.
It
is
likely
to
be
cost
effective
for
those
who
can
use
the
other
products
of
AD:
better
waste
management,
fertiliser.
-­‐ All
waste
management
systems
create
traffic
movement.
Therefore
alternative
methods
of
transport
should
be
investigated
as
transport
greatly
influences
costs
and
emissions.
The
location
of
the
plant
should
be
chosen
carefully
so
that
distances
travelled
are
minimised
between
the
production
of
the
feedstock,
the
storage
tanks
and
the
digester.
Nuisance
for
the
local
surroundings
must
also
be
taken
into
account.

7. 7
-­‐ Health
and
safety.
There
may
be
some
risks
to
human
health
with
the
pathogenic
content
of
the
feedstock,
but
it
can
be
avoided
with
an
appropriate
plant
design
and
feedstock
handling
procedures.
There
may
also
be
some
risks
of
fire
and
explosion,
although
no
greater
than
for
natural
gas
installation.
-­‐ There
may
also
be
visual
impact
on
the
environment,
although
the
digester
can
be
partially
sunk
into
the
ground
to
reduce
visual
impact
and
make
it
easier
to
load
and
unload
material.
The
document
PAS
110:2014,
produced
by
WRAP,
specifies
whole
digestate,
separated
liquor
and
separated
fibre
derived
from
the
anaerobic
digestion
of
source-­‐segregated
biodegradable
materials.
I
mention
this
because
it
outlines
the
legislation
regarding
the
use
of
digestate,
a
by-­‐
product
of
AD,
as
a
fertiliser.
By
returning
organic
matter
to
soils
through
digestate,
one
may
reduce
the
environmental
impact
if
manures
and
biowaste
streams
by
lowering
methane
emissions
and
controlling
odours.
Such
applications
have
the
potential
to
reduce
nitrogen
losses
to
groundwater,
surface
water
and
the
atmosphere.
See
this
document
for
further
clarification.
Another
by-­‐product
of
AD
is
heat.
When
generating
electricity
through
AD,
heat
is
also
produced.
This
tends
to
be
of
a
low
grade
heat,
around
90
degrees
Celsius,
which
is
ideal
for
the
heating
of
houses
and/or
other
buildings.
A
well
placed
AD
plant
can
sell
its
heat
to
many
different
consumers
or
indeed
an
additional
enterprise,
such
as
biomass
drying
or
horticulture
could
be
placed
adjacent
to
a
plant.

8. 8
Current
Planning
Policies
Concerning
Anaerobic
Digestion:
The
National
Planning
Policy
Framework
(NPPF),
published
March
2012,
slimmed
national
planning
guidance
into
a
document
of
fewer
than
60
pages,
with
its
centrepiece
being
a
‘presumption
in
favour
of
sustainable
development’.
As
a
result,
the
NPPF
does
not
contain
a
specific
waste
policies,
since
national
waste
planning
policy
will
be
outlined
as
part
of
the
National
Waste
Management
Plan
for
England,
expected
to
be
published
soon
by
the
Department
for
Communities
and
Local
Government
(DCLG).
Sustainability
is
defined
by
the
Anaerobic
Digestion
and
Bioresources
Association
(ADAB)
as
“having
an
economic,
social
and
environmental
dimension”
(2015).
In
practice
this
means
that:-­‐
For
plan-­‐making:
-­‐ Local
planning
authorities
should
positively
seek
opportunities
to
meet
the
development
needs
of
their
area;
-­‐ Local
plans
should
meet
objectively
assessed
needs,
with
sufficient
flexibility
to
adapt
to
rapid
change,
unless:
any
adverse
impacts
of
doing
so
would
significantly
and
demonstrably
outweigh
the
benefits,
when
assessed
against
the
policies
in
this
Framework
taken
as
a
whole;
or
specific
policies
in
this
Framework
indicate
development
should
be
restricted.
For
decision-­‐taking
it
means:
-­‐ Approving
development
proposals
that
accord
with
the
development
plan
without
delay;
and
-­‐ Where
the
development
plan
is
absent,
silent
or
relevant
policies
are
out-­‐of-­‐date,
granting
permission
unless:
any
adverse
impacts
of
doing
so
would
significantly
and
demonstrably
outweigh
the
benefits,
when
assessed
against
the
policies
in
this
Framework
taken
as
a
whole;
or
specific
policies
in
this
Framework
indicate
development
should
be
restricted.
AD
projects
in
general
appear
to
comply
perfectly
within
the
definition
of
‘sustainable
development’
offered
in
the
NPPF.
It
is
however
too
early
to
yet
analyse
if
the
new
regulation
is
having
this
effect,
but
given
the
role
that
AD
can
play
in
supporting
sustainable
agriculture,
transport
and
economic
growth,
AD’s
role
in
contributing
to
sustainable
development
is
clear.
Permitted
development
rights
allow
development
to
take
place
without
the
need
for
planning
permission.
The
Government
introduced
two
new
regulations
under
the
Town
and
Country
Planning
Act
in
April
2012,
offering
permitted
development
rights
for
flues
on
non-­‐domestic
premises
and
from
structure
to
house
AD
systems
installed
on
agricultural
and
forestry
units.
Localism:
-­‐ The
Localism
Act
passed
in
November
2011
also
ingrained
‘sustainable
development’
into
the
planning
system.
Localism
aims
to
give
local
communities
greater
involvement
in
decisions
in
their
area.
Assuming
AD
operators
engage
with
local
communities
at
an
early
state
and
effectively
communicate
the
benefits
of
their
project;
this
may
ease
the
passage
of
projects
through
the
planning
process.

9. 9
Currently,
planning
permission
is
required
for
all
anaerobic
digesters.
Most
planning
applications
for
anaerobic
digesters
are
processed
within
the
Local
Area
Offices.
Planning
applications
for
anaerobic
digesters
should
be
submitted
on
a
P1
form
along
with
the
appropriate
maps,
drawings
and
fees.
Specifically,
the
following
information
should
be
submitted:
-­‐ A
site
plan
and
elevation
drawings
to
determine
visual
impact.
-­‐ Photomontages
of
the
digester,
plant,
building(s)
and
chimney
stack
with
a
clear
indication
of
building
material
and
finishes.
-­‐ Information
on
grid
connection
works,
including
transformer
and
transmission
lines.
-­‐ Details
of
potential
noise
or
emissions
to
air
and
an
assessment
of
their
impact.
•
Details
of
vehicular
access
and
vehicular
movement.
-­‐ Landscaping
provisions.
-­‐ Site
management
measures
during
construction
phase.
-­‐ Model
of
emissions
dispersion.
-­‐ Community
consultation
plans.
From
11
April
2011,
the
fee
for
an
application
for
an
anaerobic
digester
in
tanks
on
an
open
site
is
£1,775
for
each
0.5
hectare
of
the
site
area
subject
to
a
maximum
of
£38,400.
The
fee
for
anaerobic
digestion
in
tanks
within
a
building(s)
falls
within
Category
4
of
the
Fee
Regulations
which
is:
(a)
Where
no
floor
space
is
to
be
created
by
the
development,
£170;
(b)
Where
the
area
of
gross
floor
space
to
be
created
by
the
development
does
not
exceed
40sq.m.,
£170;
(c)
Where
the
area
of
the
gross
floor
space
to
be
created
by
the
development
exceeds
40sq.m.,
but
does
not
exceed
75sq.m.,
£335;
(d)
Where
the
area
of
the
gross
floor
space
to
be
created
by
the
development
exceeds
75sq.m.,
but
does
not
exceed
3750sq.m.,
£335
for
each
75sq.m.,
of
that
area;
(e)
Where
the
area
of
gross
floor
space
to
be
created
by
the
development
exceeds
3750sq.m.,
£16,750;
and
an
additional
£100
for
each
75sq.m.
in
excess
of
3750sq.m.,
subject
to
a
maximum
in
total
of
£250,000.
In
considering
an
application
for
an
anaerobic
digester,
the
Department
is
required
to
have
regard
to
the
development
plan,
so
far
as
it
is
material
to
the
application,
and
to
any
other
material
considerations.
Material
considerations
include
any
responses
from
the
public
and
consultees
as
well
as
amongst
other
things
relevant
policy.
In
terms
of
anaerobic
digesters
the
relevant
policy
includes:
-­‐ Planning
Policy
Statement
18
–
Renewable
Energy
including
the
‘Best
Practice
Guide
to
PPS18’
which
specifically
deals
with
anaerobic
digesters
in
Section
3;
-­‐ Planning
Policy
Statement
11
–
Planning
and
Waste
Management:
WM
1
and
WM
2;
and

10. 10
-­‐ Planning
Policy
Statement
21
–
Sustainable
Development
in
the
Countryside:
CTY
13
and
CTY
14.
Each
planning
application
for
an
anaerobic
digester
is
assessed
on
its
own
merits
against
the
prevailing
planning
policy
and
taking
into
account
all
material
considerations.
It
is
the
responsibility
of
the
applicant/agent
to
submit
the
necessary
information
to
demonstrate
that
the
proposal
complies
with
the
prevailing
policy
and
to
enable
the
Department
to
determine
the
application.
There
may
be
site
specific
issues
that
the
applicant/agent
may
wish
to
address
when
submitting
any
planning
application
for
an
anaerobic
digester,
such
as
odour
issues
if
there
are
sensitive
receptors
in
the
locality.
Additional
site
specific
issues
may
include:
-­‐ Noise
-­‐ Air
pollution
-­‐ Visual
impact
of
the
anaerobic
digester
and
associated
infrastructure
-­‐ Impact
of
any
increase
in
vehicles
to
site
and
along
local
road
network.
Developments
that
use
waste
to
provide
energy
may
require
an
Environmental
Impact
Assessment.
Such
projects
could
fall
within
projects
listed
in
Schedule
2(3)
and/or
2(11)
of
the
Planning
(Environment
Impact
Assessment)
Regulations
(Northern
Ireland)
2012.
In
support
of
the
ongoing
development
of
the
renewable
energy
sector
in
Northern
Ireland
the
Minister
has
proposed
a
public
consultation
exercise
to
consider
the
introduction
of
permitted
development
rights
for
renewable
energy
development
including
anaerobic
digesters.
The
public
consultation
exercise
is
likely
to
take
place
later
this
year.

11. 11
A
broad
analysis
of
the
application
of
AD
in
the
UK:
The
growth
of
the
AD
sector
is
highlighted
by
the
available
Ofgen
data,
which
shows
a
total
of
161
AD
facilities
(excluding
the
regulated
water
industry)
on
the
various
registers
as
of
November
2014,
with
an
increase
in
installed
MW
capacity
from
106.2
MW
to
142.7
MW
-­‐
an
increase
of
34
per
cent
from
the
2013
report.
As
of
January
2015,
an
estimated
30
MWe
of
additional
capacity
has
been
identifies
as
under
construction.
Using
previous
DECC
assumptions
of
a
median
cost
of
£4.4m
per
1
MW
of
installed
capacity;
the
increase
in
operational
AD
capacity
(and
in
AD
plants
in
construction)
is
the
equivalent
to
an
investment
of
circa
£160m
since
summer
2013.
However,
the
AD
sector
remains
highly
fragmented
and
currently
no
operator
has
more
than
five
operational
facilities.
There
is
therefore
scope
for
consolidation
in
the
market.
But
one
of
the
challenged
the
sector
faces
is
that
many
facilities
have
been
designed
to
suit
project
specific
requirements:
-­‐ Feedstock
is
ideally
stored
from
local
markets
–
and
whilst
there
may
be
a
benefit
to
providing
a
regional
or
national
coverage,
this
offering
is
likely
to
appeal
to
only
a
very
small
number
of
potential
customers.
Most
of
those
of
any
scale
have
already
put
regional
solutions
in
place.
-­‐ Digestate
management
requires
a
local
solution
due
to
transport
costs.
-­‐ Technology
–
the
wide
range
of
technical
solutions
is
considered
to
be
a
particular
barrier.
This
is
where
the
AD
industry
differs
from
other
technologies
such
as
landfill
gas
where
engines
can
be
readily
interchanged
between
sites.
One
of
the
key
factors
influencing
the
development
of
the
AD
market
is
the
availability
of
source
segregated
food
waste.
To
ensure
the
sustainable
development
of
AD
capacity,
there
is
a
need
to
balance
the
rate
at
which
food
waste
is
collected
separately
from
the
residential
waste
stream.
Thereby
supporting
new
plants
and
the
ongoing
pressure
to
reduce
food
waste
arising
at
source.
However,
competitive
pressure
means
that
very
little
food
waste
is
landfilled.
Much
of
the
food
waste
arising
in
the
sector
is
currently
spread
on
land,
converted
to
animal
feed,
or
sent
to
sewer.
The
key
to
the
ongoing
success
of
the
AD
sector
is
that
it
is
able
to
successfully
market
the
superior
environmental
performance
of
AD
projects
against
alternatives
to
encourage
waste
producers
to
direct
their
food
waste
to
AD.
Using
various
sources
and
focusing
only
on
source
segregated
food
waste
AD
facilities,
as
at
the
end
of
2014,
the
headline
capacity
of
operational
source
segregated
food
waste
AD
facilities
in
the
UK
was
estimated
to
be
2.6
Mtpa,
with
an
increase
in
capacity
of
around
1.2
Mpta
over
the
past
2
years.
The
figure
is
an
estimate
as
a
number
of
facilities
di
not
solely
process
food
waste,
and
capacities
of
individual
facilities
vary
with
feedstock
and
residence
time.
It
is
also
estimated
that
there
is
a
further
0.5
Mtpa
of
AD
capacity
currently
wither
in
construction
or
for
which
funding
is
in
understood
to
be
in
place.
(Information
correct
of
April
2015).

12. 12
In
October
2014,
the
NNFCC
indicated
that
food
waste
AD
projects
‘under
development’
had
a
total
capacity
of
5.7
Mtpa.
Taken
together
with
continuing
digression
in
tariffs,
the
limited
availability
of
feedstock
will
affect
the
commercial
feasibility
of
projects
and
can
be
expected
to
restrict
the
number
of
projects
proceeding
to
construction
From
analysis
of
the
data
and
discussions
with
industry,
GIB
has
identified
the
following
macro
factors
to
compete
in
the
market
and
deliver
an
upper
quartile
operational
and
financial
performance:
-­‐ Operational
reliability
–
the
consistent
ability
to
source
feedstock
competitively,
achieve
high
plant
availability,
maintain
a
culture
of
continuous
maintenance
and
improvement,
retain
adequate
storage
capacity,
and
have
appropriate
contingency
arrangements.
-­‐ Competitive
cost
base
–
both
in
terms
of
capital
cost
and
operating
costs,
the
key
drivers
include
plant
efficiency,
appropriate
digestate
disposal
arrangements,
strong
relationships
with
technology
and
EPC
providers,
and
competitive
energy
sales
arrangements.
-­‐ Understanding
feedstocks
–
to
competitively
secure
an
optimal
biology
including
biogas
yields,
retention
times,
reject
rates,
sustainability
etc.

13. 13
Financial
Aspect:
There
are
three
main
financial
aspects
associated
with
the
building
and
running
of
an
AD
plant.
These
include:
-­‐
-­‐ Capital
Costs
-­‐ Operating
Costs
-­‐ Sources
of
Income
However,
it
is
difficult
to
provide
accurate
or
even
approximate
capital
costs
without
the
specifications
of
an
AD
plant
due
to
dependant
factors
such
as
plant
size,
engineering
location
and
waste
composition.
Operating
costs
will
include
staffing
costs,
insurance,
transportation
of
feedstock
and
materials,
annual
licences,
pollution
abatement
and
control,
and
other
maintenance.
Sources
of
income
are
likely
to
include
revenue
from
the
sale
of
electricity,
heat
sale,
digestate
(liquor
and
fibre)
and
gate
fees.
Gate
fees
refer
to
charges
made
for
processing
waste.
It
is
likely
that
gate
fees
would
have
to
be
competitive
with
alternate
waste
management
solutions
available
locally
to
the
AD
plant.
However,
it
is
essential
that
operators
of
AD
plants
ensure
that
they
have
sufficient
feedstock
material
to
operate
their
plant
at
optimum
capacity
in
order
to
maximise
the
potential
sources
of
revenue.
Long-­‐term
contacts
are
common
practice
as
a
result.
The
Government
incentive
schemes
are
designed
to
support
the
development
of
renewable
energy
generation
in
the
UK,
allowing
producers
to
compete
with
fossil
fuel
generated
technologies
which
may
be
cheaper
in
the
short
term.
Renewable
energy
is
essential
is
Britain
is
to
meet
its
binding
climate
change
targets
–
to
deliver
15%
of
all
energy
from
renewable
sources
by
2020
and
to
reduce
greenhouse
gas
emissions
by
80%
by
2050
(relative
to
1990
levels).
A
report
published
by
Oxford
Economics
in
2011
has
shown
that
the
negative
impact
that
spikes
in
global
oil,
gas
and
coal
prices
have
on
the
UK
could
be
reduced
by
over
50%
in
2050
by
increasing
the
deployment
of
renewable
energy.
Biogas
is
innately
flexible-­‐
it
can
be
used
to
generate
heat
or
power,
or
be
upgraded
to
biomethane
where
it
can
be
stores
in
the
national
grid
or
used
as
transport
fuel.
AD
can
be
supported
by
a
number
of
incentive
schemes
depending
on
how
the
biogas
is
used
–
the
RO*
or
FIT
for
electricity
generation,
RHI
for
supplying
heat
or
injecting
biomethane
to
the
gas
grid,
or
the
RTFO
for
transport
fuel.
See
Fig
4
for
table
of
financial
incentives
of
the
RO
and
FIT..
*RO
refers
to
the
Renewables
Obligation.
FITs
is
the
Feed-­‐In
Tariff
scheme.
RHI
means
Renewable
Heat
Incentive,
while
RTFO
refers
to
the
Renewable
Transport
Fuels
Obligation.

14. 14
Heat
from
biogas
combustion
(RHI):
The
Renewable
Heat
Incentive
(RHI)
supports
heat
produced
from
biogas
combustion
(up
to
200
kWth
limit)
at
7.5/kWh
for
20
years.
Biomethane
grid
injection
(RHI):
Injecting
biomethane
into
the
grid
is
also
supported
for
20
years,
at
all
levels,
under
the
RHI.
This
incentive
was
introduced
in
January
2012,
and
supports
biomethane
injection
at
7.5p/kWh.
Biomethane
as
a
transport
fuel:
The
use
of
biomethane
as
a
transport
fuel
is
supported
under
the
Renewable
Transport
Fuels
Obligation
as
the
level
of
two
Renewable
Transport
Fuels
Certifications
(RTFCs)
per
kilo
of
biomethane
if
the
feedstock
is
from
waste
sources
and
one
RTFC
otherwise.
The
price
of
a
RTFC
is
approximately
20p/kg.
The
EU
is
considering
increasing
the
number
of
RTFCs/kilo
of
biomethane
to
four
if
the
feedstock
is
from
waste
sources.
See
figure
5
for
future
changes
to
incentives.
Gate
fees:
Gate
fees
can
form
a
large
element
of
an
income
stream
for
an
AD
plant.
With
the
increase
in
landfill
tax
now
on
an
escalator
basis,
further
controls
on
routes
of
disposal
being
closed
off
for
organic
waste
streams.
The
potential
to
earn
gate
fees
from
waste
streams
is
an
important
potential
area
of
income
to
a
plant
developer.
The
category
of
waste
the
feedstock
is
categorised
as
dictates
the
likely
size
of
the
gate
fee
and
also
the
regulatory
burden
that
needs
to
be
complied
with,
which
can
also
have
substantial
cost
implications.
As
each
AD
plant
is
a
very
specific
site,
economics
is
therefore
hard
to
generalise
and
approximate.
However,
Figure
6
refers
to
a
planned
plant
in
the
UK.
It
is
for
a
340
kWh
unit
with
manure
from
400
dairy
cows
and
97
ha
of
energy
crops.
The
figures
are
from
example
purposes
only;
however
they
do
give
an
indication
as
to
the
potential
returns
available
from
an
investment
in
an
AD
plant.
See
figure
7
for
a
map
showing
AD
plant
locations
in
the
UK.

15. 15
Evaluation
regarding
the
success
of
AD
practices:
Taking
into
account
current
and
past
literature
on
AD,
below
in
a
condensed
note
on
the
key
features
that
have
contributed
to
the
success
of
AD
plant
implementation:-­‐
-­‐ Minimise
rain
ingress
to
the
slurry.
Heating
a
substrate
which
has
no
biogas
potential
is
a
waste
of
energy
and
a
waste
of
digester
space
and
can
significantly
affect
the
economics
of
digestion
in
terms
of
gas
output
per
meter
squared
of
substrate
loaded;
-­‐ Maintain
the
biogas
potential
of
the
feedstock.
Studies
have
shown
that
this
potential
can
be
lost
in
two
ways:
by
oxidation
and
by
methane
emission.
Where
the
surface
area
of
the
tank
is
large,
such
as
those
under
slats,
there
are
significant
aerobic
carbon
dioxide
emissions,
as
well
as
CH4
emissions
from
lower
down
the
substrate
which
is
anaerobic,
with
both
processes
causing
loss
of
methane
potential.
-­‐ Incorporate
redundancy.
All
of
the
systems
which
used
gas
locally
in
boilers,
Rayburns
or
Aga
also
had
at
least
one
other
form
of
heating:
wood
burners
with
back
boilers,
immersion
heaters,
solar
thermal,
oil
boilers.
Maintaining
digester
temperature
is
most
crucial
to
the
AD
process,
therefore
a
secondary
method
of
heating
is
essential.
-­‐ Monitoring
and
keeping
appropriate
records.
Monitoring
can
aid
complexity,
cost
and
potential
for
breakdown
and
should
not
be
done
needlessly.
There
is
no
‘one-­‐size-­‐
fits-­‐all’
when
it
comes
to
record-­‐keeping.
-­‐ Training,
Certification
and
Maintenance.
-­‐ Technology.
The
number
of
digester
technologies
can
be
bewildering;
however
it
is
essential
that
engineering
technology
must
be
appropriate
to
the
situation.

16. 16
Conclusion:
In
his
foreword
to
the
Renewable
Heat
Incentive,
DECC
Minister
of
State
Greg
Barker
notes
that
‘we
must
take
action
now
to
protect
our
environment’
and
‘we
have
signed
up
to
carbon
reduction
targets
and
have
committed
to
reducing
our
emissions
by
at
least
80
per
cent
by
2050’.
Although
it
is
unrealistic
to
comment
that
AD
could
prove
to
be
the
solution,
it
does
provide
a
feasible
option
to
help
meet
these
targets.
To
conclude,
AD
should
be
considered
by
the
UK
Government
and
relevant
organisations
(such
as
retailers)
wishing
to
reduce
the
carbon
foot
print
of
their
supply
chain
or
as
an
investment
opportunity.
However,
this
is
admittedly
highly
dependent
upon
the
availability
of
credit;
banks
and
institutions
would
be
required
to
‘partner’
with
plant
suppliers
in
order
to
offer
assistance
with
funding.
This
relationship
would
also
be
essential
to
promote
greater
undertint
of
the
technology
and
its
potential
impact
on
the
economy,
such
as
that
experience
by
food
wastage
reported
by
WRAP.
My
findings
have
also
lead
me
to
the
conclusion
that
it
is
necessary
to
inform
and
educate
farmers,
bankers
and
regulators
about
the
potential
for
small
scale
AD
plants.
This
may
be
facilitated
by
working
with
organisations
such
as
WRAP
and
NNFCC.
Successful
competition
enabled
by
Government
grants,
and
better
information
availability
on
the
benefits
of
AD
will
surely
increase
its
adoption
in
the
UK.
From
a
purely
planning
perspective,
the
ideal
proposed
site
for
an
AD
plant
is
that
it
should
be
1km
away
from
any
houses,
close
to
a
duel
carriage
way,
situated
on
arable
land
and
screened
by
trees.
In
reality
however,
land
with
this
criteria
is
rarely
found
and
the
nest
strategy
is
often
to
work
with
what
you
have
and
submit
a
solid
planning
application
following
advice.
As
the
UK
population
continues
to
rise,
economic
growth
can
only
be
sustainable
if
we
better
manage
our
resources,
cut
carbon
emissions
and
invest
in
our
ageing
infrastructure.
By
offering
closed-­‐loop
recycling
(AD)
for
the
essential
nutrients
in
our
food
waste,
baseload
renewable
energy,
and
ultra-­‐low
carbon
transport
fuel
that
dramatically
improves
air
quality
–
AD
can
play
a
pivotal
role
in
supporting
greener,
smarter
cities.
As
it
evolves,
our
industry
also
has
the
potential
to
deliver
new
high-­‐value
products
such
as
biochemicals
and
bioplastics.

17. 17
Figures:
Figure
1:
Figure
2:

18. 18
Figure
3
:
Figure
4:
Incentive
FIT
RO
Eligibility
Electricity
generating
plants
under
Electricity
generating
plants
5MW
(FIT
not
available
if
plant
has
of
all
sizes.
received
any
other
state
aid).
Tariff
Rate
≤250kW =
12.46p/kWh
2
ROCs/MWh
≈
9p/kWh
>250-­‐500
kW
=
11.52p/kWh
>500-­‐5000
kW
=
9.949p/kWh
Tariff
Length
20
years
20
years

19. 19
Figure
5:
Incentive
Change
announced/expected
FIT
Review
of
the
scheme
in
2015,
where
operation
of
the
digression
mechanism
may
be
considered.
RHI
Current
200kWh
limit
for
biogas
combustion
to
be
extended,
with
new
support
levels
in
place.
RHI
Biomethane
injection
tariff
under
review,
to
tackle
"risk
of
overcompensation"
for
larger
projects.
RHI
For
plants
above
1MW
treating
non-­‐waste
feed-­‐
stocks,
GHG
emissions
sustainability
criteria
mandatory
for
reporting
purposes
from
Autumn
2014.
Land
use
criteria
due
to
be
implemented
from
April
2015.
RHI
Tariff
guarantee
for
larger
projects
(over
1MW)
proposed
to
be
introduced
from
Spring
2015.
RO
Final
strike
prices
confirmed
ahead
of
RO
being
replaced
by
FIT
with
Contracts
for
Difference
for
new
generation
in
2017.
Figure
6
–
Income
2,829,480
@
9p
£254,653
Costs:
Feedstock
£38,520
Other
-­‐
Labour
etc.
£73,140
Total
Costs
£111,662
Operating
Margin
£142,991
Capital
Cost
£741,562
Operating
Margin
£142,990
Finance
Costs
£75,390
Margin
£67,600
Project
Return
19.28%
Figure
7:

20. 20

21. 21
References:
Anaerobic
Digestion
and
Bioresources
Association
(2015)
Planning.
Accessed
from:
http://adbioresources.org/about-­‐ad/government-­‐policy/planning/
Connor,
P
(2003)
UK
renewable
energy
policy:
a
review.
Accessed
from:
http://www.sciencedirect.com/science/article/pii/S1364032102000540
Department
for
Communities
and
Local
Government
(2012)
The
National
Planning
Policy
Framework.
Accessed
from:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/607
7/2116950.pdf
Department
of
Energy
and
Climate
Change
(2011)
Anaerobic
Digestion
Strategy
and
Action
Plan:
A
commitment
to
increase
energy
from
waste
from
Anaerobic
Digestion.
Accessed
from:https://www.gov.uk/government/uploads/system/uploads/attachment_data/file
/69400/anaerobic-­‐digestion-­‐strat-­‐action-­‐plan.pdf
Green
Investment
Bank
(2015)
The
UK
anaerobic
digestion
market.
Accessed
from:
http://www.greeninvestmentbank.com/media/44758/gib-­‐anaerobic-­‐digestion-­‐report-­‐
march-­‐2015-­‐final.pdf
Monnet,
F
(2003)
An
Introduction
to
Anaerobic
Digestion
of
Organic
Wastes:
Final
Report.
Accessed
from:
http://www.biogasmax.co.uk/media/introanaerobicdigestion__073323000_1011_2404
2007.pdf
Oxford
Economics
(2011)
Fossil
fuel
price
shocks
and
a
low
carbon
economy.
Accessed
from:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/688
31/5276-­‐fossil-­‐fuel-­‐price-­‐shocks-­‐and-­‐a-­‐low-­‐carbon-­‐economy-­‐.pdf
Royal
Agricultural
Society
of
England
(2011)
A
Review
of
Anaerobic
Digestion
Plants
on
UK
Farms.
Accessed
from:
http://www.fre-­‐energy.co.uk/pdf/RASE-­‐On-­‐Farm-­‐AD-­‐
Review.pdf
WRAP
(2013)
Household
Food
and
Drink
Waste
in
the
United
Kingdom
2012.
Accessed
from:
http://www.wrap.org.uk/sites/files/wrap/hhfdw-­‐2012-­‐main.pdf.pdf
WRAP
(2014)
Specification
for
whole
digestate,
separated
liquor
and
separated
fibre
derived
from
the
anaerobic
digestion
of
source-­‐segregated
biodegradable
materials.
Accessed
from:
http://www.wrap.org.uk/system/files/private/PAS110_2014_final.pdf
Yeatman,
C.
(2006)
The
Profitable
use
of
Anaerobic
Digestion
(AD)
on
UK
Farms.
Accessed
from:
http://www.nuffieldinternational.org/rep_pdf/1226661015Yeatman,_Owen.pdf