Creating carbon-free communities: Renewables and beyond

How urban communities can realize their potential as drivers of decarbonization and embrace their role in the energy transition.

With cities home to an increasing share of humanity and responsible for three quarters of primary energy consumption, urban communities must be at the heart of global decarbonization action. Gauri Singh, Deputy Director General of the International Renewable Energy Agency (IRENA), talks about the levers that urban areas have to cut emissions. Grid edge technologies play a major role. 


By Ward Pincus

It is clear that cities, which are home to so many people and so much human activity, will play a crucial role in driving the energy transition and moving humanity toward a decarbonized future. What’s more, there are good reasons for cities to embrace a low-carbon future. Fifteen years have passed since the historic milestone when more than 50 percent of the world’s population were estimated to be living in cities. By 2050, that share will be nearly 70 percent. At the same time, cities account for about 75 percent of global primary energy use and more than 70 percent of global energy-related GHG emissions, according to the International Renewable Energy Agency (IRENA).


Urban populations, especially the huge number that live along coastlines, will disproportionately feel the impact of climate change, due to rising sea levels and the impact of extreme weather. Action taken to support decarbonization can build city resiliency and foster economic growth and job creation. Cities also know that, given their outsized contribution to GHG emissions, their actions can have an outsized impact.

What is the grid edge?

The grid edge is the interface of distributed energy supply and demand with the electricity grid. The solutions and technologies at that interface include all demand assets, distributed generation assets, and services that enable those technologies to work. Examples include distributed photovoltaic generation, buildings and smart building controls, smart meters, electric vehicles, battery storage, and many others.

Shrinking the urban footprint

There is much that cities can do to drive decarbonization. For a start, buildings and construction are responsible for 36 percent of global energy use and 39 percent of energy-related CO2 emissions annually. Heating and cooling are major contributors to building emissions, so the electrification of these systems is key.


Switching from fossil-fuel furnaces to electric heat pumps “can increase energy efficiency in most cases by at least three times,” says Gauri Singh, IRENA’s Deputy Director General, adding that district heating and cooling systems can significantly improve the efficiency of these services. Buildings also can house photovoltaic panels and solar thermal hot-water heaters, as well as onsite electric batteries. 

Cities are key actors in the energy transition, and the importance of their role will only strengthen.
Gauri Singh, Deputy Director General of the International Renewable Energy Agency (IRENA)

Connecting these assets within a building or across a campus or neighborhood through a smart building energy management system (BEMS) can dramatically lower energy demand. Using sensor data from buildings and weather forecasts, a BEMS can predict energy requirements and production to determine how much of the energy produced onsite should be stored for later use, or fed into the grid. Such a system is being piloted in a five-building area of the Aspern Seestadt district in Vienna that links BEMSs, shared electric battery storage, hot-water storage, solar PV, and heat pumps to minimize energy consumption of the whole system.

Renewable energy in the city

In cities, PV is the most likely renewable energy technology to be deployed, says Singh. Panels can be mounted on built structures including homes, apartment and office buildings, government buildings, factories, hospitals and parking garages. Net metering can encourage private entities to install these systems by crediting homeowners or other private operators for the electricity they send to the grid.


Widespread adaptation of roof-mounted solar PV or electric vehicles requires enabling technologies – most importantly a smart grid that can manage the variability of renewable energy supply, increasingly decentralized power generation, and the added demand requirements of increased electrification. To help a smart grid cope, city districs can design for maximum demand flexibility, Singh says. This can include smart appliances and BEMS that respond to rising electricity tariffs or other grid signals by switching to onsite battery power or reducing consumption.


In Copenhagen, the EnergyLab Nordhavn research project has developed a smart grid that integrates electricity, heat, and transport in the Nordhavn neighborhood. The project is exploring demand flexibility to address the high share of wind energy on the grid, through use of batteries, electric vehicles for energy storage, intelligent heating in apartments, and heat pumps and thermal storage to enable load shifting off the district heating system and a reduction in temperatures required in the system.

Mobility goes electric

“Electrification is essential in the transport sector,” says Singh, given that more than 95 percent of the total energy used in the transport sector is fossil-fuel based. This means deploying and encouraging electric cars, trucks and buses, and rail. Smart charging networks can encourage the switch by simplifying the process of vehicle charging

Electrification is essential in the transport sector.
Gauri Singh, Deputy Director General of the International Renewable Energy Agency (IRENA)

London’s Borough of Westminster Borough, for example, already offers 1,000 charging points for electric vehicles. On Sutherland Avenue alone, 24 connections have been discreetly installed as black plugs cut into existing lampposts. Remote mobile metering allows the system to seamlessly handle all billing.In total, London has 5,900 charging points, including more than 3,000 Ubitricity chargers, making the British capital the leader in Europe in terms of density, far ahead of Amsterdam, Paris, and Berlin, and underscoring its commitment to the electrification of transport. 

Sector coupling

Coupling the power sector with transportation and other sectors enhances flexibility and drives efficiencies. The Düren District in Germany is building a PV and electrolyzer plant to produce clean hydrogen. Designed to interact with the local grid, the plant will produce sufficient hydrogen for the district’s hydrogen buses and hydrogen trains. The plant is expandable if transport demand grows.


Sector coupling also can link waste management and transportation, as Singh notes, with biomethane from landfills and wastewater sludge from municipal wastewater treatment plants presenting cost-effective sources of low-cost fuels, “while diverting methane from being released into the atmosphere.”

Good policy is crucial

While technological advances are part of the solution, policymakers and regulators must encourage long-term investment in low- or zero-carbon systems, Singh notes. “Without long-term policy signals, investors, developers, and consumers may lose confidence and a willingness to engage in the necessary activities.” She adds that this policymaking must consider all stakeholders “to ensure sustainable governance, a transition that is tailored for local communities, and a just and inclusive transition that leaves no one behind.”


Without long-term policy signals, investors, developers, and consumers may lose confidence and a willingness to engage in the necessary activities.
Gauri Singh, Deputy Director General of the International Renewable Energy Agency (IRENA)

Cities can begin with local sustainability goals, says Singh, adding that urban governments can set municipal building codes that require high-efficiency new construction and the retrofit of existing buildings. Local governments can issue ordinances or offer incentives to encourage rooftop solar for heating and cooling, ban combustion vehicles, and develop a charging infrastructure to support adoption of electric vehicles. Electrification of public transport is one way cities can advance a low-carbon future. Cities such as Leipzig are deploying charging infrastructure to power bus routes.


Given the many opportunities for decarbonization in cities, alongside the continued growth of urban populations, Singh reiterates: “Cities are key actors in the energy transition, and the importance of their role will only strengthen.”


June 15, 2021


Author: Ward Pincus is a freelance business and technology journalist. He lives and works in Dubai, UAE.

Picture credits: Siemens, Getty Images

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