The electrification of transportation and heating is not only the next big step in decarbonisation, it will also ease the way, both physically and commercially, for much greater uptake of renewables in electricity systems.
When Danish wind turbines are turning at full force at three in the morning, electricity surplus to immediate need heats water stored in district heating networks, reducing demand on the grid for warming up buildings at another time. Heat is easier and cheaper to store than power. Forging a close-knit relationship between the two comes with further added value. First, the scope for balancing demand and supply is greatly increased as the market for renewable energy grows. Second, the risk of green power going to waste is reduced on windy or sunny days.
Going forward, the electrification of heating, along with that of cooling and transport, is an essential element for creating the demand and supply flexibility needed to run entire power systems on renewable energy. Electrification has the added advantage of helping other industrial sectors reach their emission reduction targets by greening their energy use.
“Electrification is the lifeblood of the energy transition,” says Kristian Ruby, head of industry association Eurelectric. “The electricity sector has been decarbonising faster than others and will continue to drive the energy transition. It has the potential to deliver clean energy to transport and heating and cooling as well.”
LOAD WITH A DIFFERENCE
Power demand will increase with electrification, but what is more interesting is that the type of load associated with heating and transport is different, says Jochen Kreusel of ABB Power’s power grids division. “To a certain extent, both heating and charging an electrical vehicle are dispatchable loads. You can pre-heat or pre-cool buildings because all buildings are storage,” he says.
Kreusel also sees demand management, the shifting of demand for electricity to another time, being integrated into infrastructure from the beginning of electric mobility due to grid constraints. “Electric mobility without the opportunity to influence the time of charging won’t work or will result in expensive grids,” he says.
The shift to a greater share of electricity in meeting energy demand will also bring efficiency gains. Exchanging an oil burner with a heat pump can save, on average, almost 50% of annual primary energy consumption, Eurelectric notes in a 2015 report. In road and rail transport the numbers can be equally impressive.
HEATING USES HALF OF ALL ENERGY
The delivery of clean energy to heating and cooling is further advanced than for transport, although much remains to be done. District heating networks receive energy from a variety of sources, including combined heat and power (CHP). Electricity from renewable sources, typically wind energy surpluses, can be used to power a large heat pump or an electric boiler which heats up water that is then stored for use in the network. The lower the temperature in the network, helped by better insulated pipes and buildings, the greater energy efficiency achieved. Heating and cooling accounts for roughly half of Europe’s energy consumption, with about 75% of this still satisfied by fossil fuels.
Paul Voss of industry association Euroheat & Power says European cities are looking towards the district heating networks common to Denmark and other Scandinavian countries as a model. These networks, in which heated water is transported via underground pipes from a central source to suburbs, city centres and even remoter groups of buildings, take advantage of aggregate demand and are seen as an important tool for introducing greater shares of renewable energy in urban settings. “They are a bridge between the heating and power systems and provide the best way to decarbonise the heating sector,” says Voss.
CITIES LEAD ON DISTRICT HEATING
Only about 10% of heating in Europe is provided by district heating networks with the remainder coming from individual oil or gas boilers. That proportion looks set to rise rapidly in coming years. Among cities moving are Amsterdam, which is rolling out district heating as it seeks to completely decarbonise its heating network, now reliant on natural gas, by 2050. For its part, the UK is to invest £320 million over the next five years in district heating.
In Copenhagen’s Carlsberg City a district cooling system cools some 300,000 square meters of office space. A chiller, a type of heat pump, uses outside air to help cool four million litres of water contained in underground storage tanks. “We generate cooling when [electricity] prices are low, thereby also helping to integrate renewable energy,” says Anders Dyrelund at consultant engineering company Ramboll Energy, which helped implement the project. In a second stage, a heat pump will allow the cooling system to push surplus heat into Copenhagen’s district heating system. “Almost everyone immediately grabs for batteries when you talk about storage,” notes Dyrelund, “But it can be more effective when you set up new buildings to adjust your consumption.”
A recent study by German energy consultancy Tilia looked into the potential for district heating and cooling (DHC). “DHC grids can be supplied by a very broad range of renewable and recycled energies, providing an off-take base for those local energies and stimulating their development,” it says. “Coupling the electricity and heating systems through DHC can help to efficiently manage intermittency from wind and solar PV at an affordable cost. This can be done through the optimised use of thermoelectric equipment like heat pumps, electric boilers and CHP, together with thermal storage, which is already contributing to a higher integration of intermittent generation in some countries like Denmark.”
ELECTRIC TRANSPORT OUR BEST CHANCE
While progress has been made on lowering overall levels of greenhouse gas emissions in Europe, emissions from transport continue to rise.
“The bottom line is that we need to decarbonise transport and about 75% of transport emissions come from vehicles,” says Jelena Simjanovic at Transport & Environment, an NGO based in Brussels promoting sustainable transport. “There aren’t that many options. We use fossil fuels, we thought biofuels were okay but they’re not because they emit the same or even more. Electricity is our best chance because the power sector will continue to get cleaner over time.”
Uptake of battery electrical vehicles (BEVs) has been slower than many expected and in 2015 the global stock had reached no more than 1.3 million. Even though growth has been faster recently, low oil prices, concerns about the limited driving range offered by current batteries and the general lack of a fast-charging infrastructure have impeded a faster rollout.
That could change in the medium term, for both private cars and light duty vehicles (LDVs). “Around 2025, fundamental technology and industry trends are expected to enable BEVs to be cost competitive against conventional vehicles without subsides, underlining the likelihood that LDVs will eventually be electric rather than any other alternative,” American consultancy Navigant Research said in a recent report. The International Energy Agency (IEA) expects 35-40% of all new cars on the road worldwide to be electric by 2040.
Inroads have been made in places with supportive policies. A clear example is Norway, which now has some 136,000 EVs (just over 100,000 BEVs) and has provided tax breaks and other bonuses such as access to bus lanes alongside an extensive charging network.
“There aren’t that many options. We use fossil fuels, we thought biofuels were okay but they’re not because they emit the same or even more. Electricity is our best chance because the power sector will continue to get cleaner over time.”
MAYBE SOME GRID STORAGE
Looking further ahead, some see electric vehicles as a possible source of stored electricity, which can be fed back into the grid from full batteries connected to charging stations. Specialised batteries would need to be developed along with essential hardware and software to facilitate extraction of electricity on demand. For the process to be affordable, it is reliant on economies of scale. “A single car is too small to do this,” notes Simjanovic, “But if I’m an aggregator and have contracts with 10,000 cars, for example, I could pull this power together and have electricity to sell.”
Meanwhile, electrification of rail transport is more advanced, paving the way for further advances in system flexibility. Trains are routinely instructed to coast into stations to save energy and during braking can even feed power into the grid. The Dutch rail system has been electrifying its trains since the 1950s and as of January they are now 100% powered by wind. Dutch energy supplier Eneco has contracted to cover the 1.4 TWh needed each year by the entire rail system using renewable energy generated from extensions to wind farms in the Netherlands, Sweden, Belgium and Finland. “Fossil fuels are not the way to go forward. That’s over and done,” says Eneco’s Michel Kerhof. •
TEXT Heather OʼBrian / PHOTO Tine Sletting