District heating: smart grid and heat storage - DBDH

Lars Gullev
Managing director, VEKS
Smart Grid
Can we find a Smarter Grid?
Smart Grid and heat storage
Visit from Holland, 9th December 2010

Agenda
• What is a Smart Grid?
Couldn’t it be Smarter?
Why built a heat storage?
Centralised heat storage.
Decentralised heat storage.
Summary

What is a Smart Grid?
Let’s start with the Power Sector

Power system
From production to end-user
Thousands of power plants generate
electricity using wind energy, nuclear
energy, coal, oil, natural gas, hydro and
a variety of other resources.
Power plants produce electricity at a
certain electrical voltage. This voltage is
then “stepped-up” (increased) to very
high voltages, such as 500 kV, to
increase the efficiency of power
transmission over long distances.

Power system
From production to end-user
Once this electrical power gets near
your town or city, the electrical voltage
is “stepped-down” (decreased) in a
transformer to a lower voltage for
distribution around your town or city.
As this electrical power gets closer to
your home, it is stepped-down by
another transformer to the voltage you
use in your home.
This power enters your home through
your electrical meter. The voltage in
your home is typically 220/240 - 380 V.

The challange
The electricity grid is getting old and
worn out.
Population growth in some areas has
caused the entire transmission system
to be over used and fragile.
Probably more electronic devices are
added to your home, such as
computers, high-definition TV’s,
microwave ovens, wireless telephones,
and even electronic controls on
refrigerators and dishwashers.

The challange
New appliances are more sensitive to
variations in electric voltage than old
appliances, motors, and incandescent
light bulbs.
Unfortunately, the entire electrical grid
is becoming more fragile at the same
time the appliances in your home are
getting more sensitive to electrical
variations.
In short, the reliability of electrical
power will decline unless we do
something about it now.

The challange
Adding new transmission lines will help the
utilities get more power from the power
plants to your home.
However, many communities don’t want new
power lines in their areas.
What is needed is a new approach that
significantly increases the efficiency of the
entire electrical delivery system.
This approach will not only increase
reliability, but will also reduce energy in the
delivery process and thereby reduce
greenhouse house emissions.
This new approach is called Smart Grid.

What is a Smart Grid?
Will allow utilities to move electricity around the system as
efficiency and economically as possible.
Will allow the homeowner and business to use electricity
as economically as possible.

What is a Smart Grid?
You will have the choice and flexibility to manage
your electrical use while minimizing your costs.
Examples
You may want to keep your house set at 22 O C in
the summer time when prices are low, but you
may be willing to increase your thermostat to
25 O C if prices are high (cooling).
You may want to dry your clothes for 5 € cents
per kWh at 9:00 pm in stead of 10 € cents per
kWh at 2:00 pm in the afternoon.

What is a Smart Grid?
Summary
To day
In principle a simple upgrade of
20th century power grids which
generally "broadcast" power
from a few central power
generators to a large number of
users.
Tomorrow
Be capable of routing power in
more optimal ways to respond
to a very wide range of
conditions.

What’s the problem with the concept?
Couldn’t it be Smarter?

What’s the problem with the concept?
Couldn’t it be Smarter?

Right…
Inadequate focus on energy efficiency
Low-grade energy resources are not utilized!

What we need is…..
Smarter production
Smarter customers
Smarter tariffs
Can District Energy offer that?

Yes - What we need is…..
Community or District Energy

Smarter Production
Low-grade energy ressources, RE and storage

Auning DH Company
Heat accumulators
Capacity of the small one to
the right: 400 m 3 .
Capacity of the larger one to
the left: 1,000m 3 .

Brørup DH Company
Heat accumulator with an
effective volume of 1,200 m 3 .
Height 14.5 m.

Energy Viborg
Plant:
CHP CC
Power capacity of 57 MW.
Heat capacity of 57 MJ/s.
Heat accumulator:
Effective volume of 19,000 m 3 .
900 MWh heat

Smart production / customer
Heat storage
Photo: Energi E2
Volume: 22,000 m3 each
Heigh: 50 m
Temperature: Max 118oC Load and reload: 330 MJ/s

AVV CHP plant in Copenhagen
Heat storage with effective volume of 2 * 22,000 m3 Photo: DONG Energy
Centralised
heat storages

Why built a heat storage?
Increase the flexibility of
production facilities.
Possible to produce electricity
when prices at power market
are high, but heat demand is
low.
Possible to produce heat
during night time when heat
demand is low.
Heat demand in the morning
peak can be covered partial
from reloading the heat
storage tank.

Why built a heat storage?
Increase the flexibility of production facilities.
Possible to integrate DH and wind power by using electricity for
water heating when electricity prices are low.
Photo: Vattenfall

Why built a heat storage?
Improve the DH company’s
opportunities for making
business at the market for
power regulation.
Availability payment for having
engines standing in reserve to
start-up, when the electricity
system needs up-regulation.

Helsinge DH Company
Heat accumulator with an
effective volume of 2,500 m3

Smart customer
Solar collectors

Smart customer
System integration

Smart Tariffs
Brøndby DH Company
2*500 m 3 heat storage – Former fueloil tanks

Smart tariff
Incentive (load-factor) to smooth the heat demand
Load-factor f = 0,90 + 0,23 * Tv
Tv is the annual uniformity-factor calculated as followed:
Qt - heat demand/hour.
Qm - Average heat demand for one day.
Fq - Proportion between heat demand/hour (Qt) and average
heat demand/day (Qm).
For all Fq > 1.0 the uniformity-factor for the day (Td) is
calculated:
Td = ((Fq1 - 1,0) 2 + (Fq2 - 1,0) 2 .... + (Fq24 - 1,0) 2 ) 0,5
Tv – calculated as the average of the values of Td weighted
based on the heat demand/day.

GJ
1000
900
800
700
600
500
400
300
200
100
0
GJ
Calculation of load-factor for one day
Average heat demand/day (Qm) = 747,29 GJ
1000
900
800
700
600
500
400
300
200
100
0
Heat demand
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
One day
Heat demand
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
One day
Uniformity-factor for the day
Td = 0.437791
Load-factor for the day
f = 0.90+0.23*0.437791
= 1.000692
Uniformity-factor for the day
Td = 0.0
Load-factor for the day
f = 0.90

Load-factor
Development in load-factor
1,01
1,00
0,99
0,98
0,97
0,96
0,95
0,94
0,93
0,92
0,91
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Years
Brøndby DH Company Average VEKS consumer

Smart Tariff
Smooth the heat demand
Smaller pipe dimensions in the
DH transmission network.
Reduce the pumping costs.
Reduce the need for peak-load
production.
Possibility for reduced flow
temperature.

Greater Copenhagen DH System
18 18 municipalities
municipalities
4 4 integrated integrated systems
500,000 500,000 end end – – users users
34,500 34,500 34,500 TJ TJ (9,600 (9,600 GWh, GWh,
32,700 32,700 GBtu) GBtu)
Heat storage

Load dispatching
-2008
The duty to secure the optimisation of
the total heat and power production in
Greater Copenhagen (CPH) belonged
to the power company DONG Energy.
As a consequence of the liberalisation
of the electricity market the company
Vattenfall bought one of the CHP
plants in CPH.
Two power companies in competition
with each other on the DH market in
CPH.
Another body had to take over the
responsibility for securing the total
optimisation of the heat and power
production.
DONG
Vattenfall

Varmelast.dk - Background
Four different main principles of load
dispatching and pricing were analyzed:
The preconditions for an efficient, liberalised
DH market is not present in the Greater
Copenhagen area's DH system. Producers will
have market power, which gives theoretical
possibility of increasing DH payments with up to
30 million €/year.
The economic impact of splitting the heat
market in two areas supplied by each
producer could be increased DH costs in size
from 4 to 10 million €/year. This is because the
DH transmission network is not utilised optimal
with this principle.

Varmelast.dk - Background
Four different main principles of load
dispatching and prizing were analyzed:
One single heat price / volume agreement
would also likely lead to increasing DH prices. Such
an agreement would not address the fundamental
problems with collaboration between commercial
producers on load dispatch.
One coherent market with DH companies as
load dispatchers based on an overall
optimization of heat and power production and
agreed sharing of the benefits coming from CHP
production seemed to imply most advantages and
fewest disadvantages for the DH consumers.

Varmelast.dk (Heat-load.dk)
An important DH operator in Greater Copenhagen
2008-
Concrete cooperation – named
Varmelast.dk - between the DH
companies in Greater CPH - VEKS,
CTR and KE - started.
The task for the cooperation was to
secure the economical optimisation
of the heat and power production in
Greater CPH.
Varmelast.dk went into operation 7
January 2008 by taking care of the
optimisation of the water based DH
system.
Since 27 April 2009 Varmelast.dk has
also been responsible for
optimisation of the steam based DH
in the area.
DONG
Vattenfall

Varmelast.dk - Responsibility
Planning the next operating day in
collaboration with the owners of the
CHP plants.
Adjust the heat-plans at 8 am, at 3:30
pm and at 10 pm.
Daily operational monitoring.
Developing tools for joint optimisation.
Securing the necessary data base.
Cooperation with VEKS and CTR
control room and back office functions
for each of the three companies –
VEKS, CTR and KE.
DONG
Vattenfall

Varmelast.dk - Challange
First and foremost maintain
confidentiality between the parties,
who also acts in the electricity
market.
Ensure an optimal production of both
electricity and heat, taking into
account priority heat from waste
incineration plants and the
geothermal plant.
Ensure that three integrated DH
systems play together and that all
customers constantly around the
clock are supplied with DH.
DONG
Vattenfall

Varmelast.dk – Daily heat-plan
The heat-plan is based on heat
demand and the total production
costs.
The tender procedure for the next day
starts before 8 am when forecasts for
next day's water and steam
production are sent to the producers.
Later Varmelast.dk receives tenders
from both producers.
DONG
Vattenfall

Varmelast.dk – Daily heat-plan
Varmelast.dk calculates the cheapest way
to get heat demand covered and order the
desired quantity of hot water and steam
from each of the producers.
Producers calculate the cheapest way to
meet Varmelast.dk 's order for DH water
and steam hour by hour, taking into
account:
Production of electricity,
Fuel prices,
CO 2 quotas
Energy taxes
DONG
Vattenfall

Varmelast.dk – Daily heat-plan
Varmelast.dk receives preliminary
heat-plans from the producers.
The plans are corrected with
regard to hydraulic limitations in
the DH network and optimum
utilization of the heat
accumulators at the two CHP
plants AMV and AVV based on the
basis of marginal costs.
DONG
Vattenfall

Varmelast.dk – Daily heat-plan
The final heat-plans are sent to each
producer with an indication of heat
production for each block hour by
hour for the next day.
Heating-plan must be in place within
am 10.30, to ensure that the
producers know how much heat
they have to produce – and thus
how much electricity they can offer
for sale on the power pool - Nord
Pool.
DONG
Vattenfall

Why is DH a “Smarter Grid”?
Utilise low-grade energy resources
and hereby reduce the consumption
of primary resources.
Increase the integration between RE
(biomass, solar, wind, geothermal
energy) and DH.
Flexibility.

Thank you
Further information:
www.veks.dk
lg@veks.dk