Sustainable Heat for Buildings
Martien Visser, Energy Transition and Networks
Thursday, September 21
th, Springtij, Terschelling
My energy bill in
2016: €160/month
Distribution costs electricity > commodity costs Since March 2017, I have solar
LT heat & power
Gas vs electricity
LT-heat vs power
4x more volume
10x more capacity
Note: In the city of Groningen there hardly energy intensive industry and almost 100% of the buildings are heated by natural gas. Thus: natural gas demand = LT heat demand
Synchronicity; power
versus LT-heat
Typically, households have a connection of 3x25A electricity 16 kW Planning electricity grids requires 1,2 kW (8%) per household
Typically, households have a connection of 2-3 m3/hr for gas 25 kW Planning gas networks requires 15 kW (60%)
Significant usage of electricity for heating purposes will
require adjustment of this planning criterion for electricity
networks
Demand for low temperature heat is primarily due to ambient
temperature and occurs synchronous
December-15 Page
Heat demand
versus effective
temperature
City of Groningen (data 2012)
Many other factors play a role, => uncertainty (normal distribution). How to deal with it? A different choice for other energy carriers?
Lengthy cold winters
Demand for LT-heat Severity of a winter
Measured in (summed) heating-degree-days
HD = max (0, 17-T
eff)
(Teff = Tamb – 2/3 U (in m/s)Planning for a 1:20 cold winter
is currently associated with gas
(energy) in storage.
Could we anticipate on winter
climate change and
extrapolate?
LT Heating: The
energy system
• Gas is produced in base-load with little overcapacity • Demand variations are covered by gas storages
• Gas storages have typically a volume of 15-20% of the annual gas demand • Also to cope with exceptional weather, technical failures (and geopolitics) • Power production follows demand and varies
significantly (non base-load)
• Typically, significant overcapacity is required: 50-70% above base-load.
• The fuel (gas or coal) may be stored
• This fundamental difference is due to economics; gas storage is typically 1000x cheaper (per unit of energy) than electricity storage.
Saving energy at the
buildings
• Saving energy is usually beneficial;
Saving significant amounts of energy for existing buildings may be
challenging
• Since 1990, gas demand per NL
household has been reduced by 35%, but total consumption of gas has
remained the same
• The costs energy saving (per ton CO2 reduction) increase if more is required • The optimal level of insulation requires economic optimization and varies: with
heat networks, green gas, all-electric. • Will this be socially acceptable?
Energy costs and
consumer behaviour
Many sustainable
alternatives
• Various technologies to replace natural gas • Heat Networks
• waste energy, biomass, geothermal energy • All electric with heat pumps and strict isolation • Green gas with/without (hybrid) heat pumps • Hydrogen (under development, green/blue) • Wood stoves or pellet burners
• Combinations of these techniques
• Each technique has advantages - and disadvantages – • and could result in near-zero CO2
• Differences occur in: production, networks, storage, insulation, costs, risks … … and vary for customers, producers, suppliers, networks, companies, etc..
How to make a region
or city CO2-free?
• Project Development is required
• Which alternative is most attractive? Where? • What is the optimal sequence?
• How to minimize the costs while delivering what is needed • Organize (detailed) engineering, permitting and tendering • Realize fairness and societal acceptance?
• The business case & how to distribute the costs and risks • Steering the stakeholder process
• Build the new infrastructure • Operate & Trouble shooting
Leiden
Bottleneck identification Feasibility studies Concept selection Engineering
