800 million people living in coastal cities will face energy disruptions due to flooding

Energy supply is intrinsic to global economic and social progress and it is a critical component of urban security and resilience. Cities, in particular, account for more than 75 percent of global primary energy use and have the most to lose from climate-linked energy disruptions. Such disruptions in cities can affect the provision of electricity, transportation, water, healthcare and other critical services and cause cascading failures across the entire economy of a city or a country.

But how secure are energy supplies in major cities across the globe? The Future We Don’t Want research shows that over 800 million people living in cities will be impacted by 270 plants facing increased risk of flooding from coastal inundation due to sea level rise by mid-century. These power plants produce over 180,000 megawatts of energy per year, enough to power almost 90 percent of homes in the United States. As energy demand from urban areas rise, energy security and reliability will be a priority for decision makers, but energy system choices will also need to consider climate vulnerabilities and emission reductions in line with the Paris Agreement to prevent the worst impacts of climate change.

Coastal cities’ energy infrastructure are particularly vulnerable
to climate change

More frequent climate events such as hurricanes, storm surges, and coastal flooding are expected to result in recurring energy disruptions in the network, decreased reliability of production and transmission, higher costs for cities and consumers, and in the long run, stranded energy assets that dot the shores of our increasingly exposed coasts.

Thermoelectric plants in many parts of the world have been located along the coasts, at low elevations, to gain access to sea water for cooling purposes. World-wide, more than 6,700 power generation plants fall in the Low Elevation Coastal Zone (LECZ). In Europe, coastal energy systems are predominantly in the 0-5 metre elevation level range, making them particularly vulnerable to sea level rise.

Figure 1 – Sea level rise and power supply vulnerability

Cities whose nearby power plants are vulnerable to coastal flooding as a result of 0.5 meters of sea level rise in the 2050s.

One country that is largely dependent on coastal energy infrastructure is the United Kingdom. Its capital, London, lies in the Low Elevation Coastal Zone and the city faces the risk of tidal flooding from the North Sea, fluvial flooding from the Thames and its tributaries, as well as surface water flooding due to heavy rainfall. All of these climate impacts put assets worth $277 billion as well as 1.25 million people living along the Thames River, in London and surrounding areas, at risk. Cassie Sutherland, the Policy and Programme Manager (Environment) in Greater London Authority notes that while London is protected from storm surges by the Thames barrier and a series of other flood barriers, surface water flooding is where London is most vulnerable. “It’s difficult to protect from, it happens very quickly, and is localized.” Moreover, most of the energy for London is generated outside the city, where it can be exposed to climate extremes.

“We rely on the licensing arrangements for energy utilities to carry out the necessary risk assessments… but they are [increasingly] showing concern about the frequency of extreme events.” – Peter North, Senior Manager – Programme Delivery, Sustainable Energy, Greater London Authority

London receives its energy (both electricity and heating) from a combination of sources through centralised electricity and gas grids, however all of the country’s nuclear plants and many of its coal, oil and gas fired power stations are located along the coast. These plants are vulnerable to tidal floods which can, in turn, impact London’s power supply. Moreover, London and its surrounding areas house a number of critical electricity substations that are vulnerable to local flooding.

A 2016 article, drawing on model-based scenarios developed by the UK Climate Change Committee, predicted what would happen if the great tide of 1953 – a once-in-a-100-year flood event – hit the UK again. The article paints a chilling picture of a five-meter tide damaging oil and gas facilities in Scotland and impacting the petrochemical complex at Grangemouth, which handles 40 percent of the United Kingdom‘s oil supplies. Such a tidal event would likely breach the Thames barrier, inundate major buildings and monuments in London, flood at least 50 tube stations, and submerge over half a million homes. At the same time, major electricity grids would go offline, impacting basic government services including transport, water supply, and critical healthcare.

“There is a change in the culture of the country, that energy can be a matter of local management… We really don’t have the capacity to deal with increasing consumption and if we add climate risks we will have a really serious problems.” – Flávia Carloni, Flávia Carloni, Assessor of the Planning office, City Hall of Rio de Janeiro

Rio de Janeiro is another iconic megacity that is vulnerable to coastal flooding and resultant energy disruptions. 70 percent of Brazil’s energy comes from hydropower plants, and Rio de Janeiro – a heavily populated seaside city – generates very little of its own power. Most of the city’s energy comes from hydropower stations, through a central grid and a complex network of transmission lines, which means that the city’s transmission and distribution network is susceptible to coastal disturbances and storm surges, and the hydropower supply is sensitive to water disruptions. In November 2009, a third of Brazil, including all residents of Rio de Janeiro and São Paulo suffered a power blackout when heavy rains and strong winds caused three transformers on a high-voltage transmission line to short circuit. According to news reports, Rio de Janeiro plunged into darkness and the city’s underground railway network was paralysed. The blackout left hundreds of people trapped in elevators all over the city and brought the airport to a standstill.

Coastal surges and heavy precipitation events could result in similar, more intense, disruptions in the future with cascading impacts in other critical sectors. Flávia Carloni, Assessor of the Planning office at the City Hall of Rio de Janeiro adds that, “during the winter we have a lot of storm surges in the city, and the predications are that (in the future) we will have them with less frequency but higher intensity.” According to Rio de Janeiro’s 2017 Resilience Strategy, a half-a-meter rise in sea levels, could likely inundate 30 square kilometres of the city, impacting the Rio’s energy infrastructure, water and drainage network as well as its tourism services. Additionally, Brazil’s only nuclear plant is located along the coast, close to Rio de Janeiro, and tidal flooding could result in loss of power at nuclear facilities, and in extreme cases, damage the facility “to the point of releasing radioactive material.

Like Rio de Janeiro, Seattle, is a port city that is exposed to both sea level rise and disruptions in hydropower, which provides 90 percent of its electricity. More variable and reduced mountain snowpack, earlier and faster spring snowpack melt, and reduced summer river flow in recent years have reduced Seattle’s electricity generation during spring and summer months. Jessica Finn Coven, Director of the Office of Sustainability and Environment at the City of Seattle, adds that these climatic changes have reversed the energy demand in the city; there is “less demand in the winter for heating, and more demand in the summer for cooling. This could exacerbate the issue that the (energy) utility already has (with changing supply).”

Seattle City Light, the public utility that provides electricity to the city, has a climate change vulnerability assessment and adaptation plan which projects an increased risk from sea level rise and coastal flooding that could result in equipment damage and “financial consequences” for the utility. These local findings mirror the climate change vulnerability within the energy sector in the country as a whole. According to the International Energy Agency, weather-related disturbances to the US power sector have resulted in more customer hour interruptions than “component failures, physical attacks and cyber incidents combined.” The total cost of these disruptions was estimated between $25 to $70 billion annually.

Cities & energy infographic
© C40

Keeping the lights on

Energy security remains a crucial prerogative for cities across the world and it is a sector closely linked to climate mitigation and adaptation considerations. Decentralised renewable energy has been linked to co-benefits such as improved air quality, reduced dependence on external resources and local job creation. Recognising that climate change is a threat to energy systems, Seattle, London and Rio de Janeiro, among many other cities, are planning ahead.

“As part of the London climate change partnership, we are convening experts on adaptation. They will be taking sector-based plans and looking particularly at interdependencies between them.” – Cassie Sutherland, Policy and programme manager (Environment), Greater London Authority

The floating solar farm by Thames Water (UK’s largest water and wastewater company) is one such development. It is an effort by the company to generate a third of its own energy by 2020. Deriving energy from renewables not only mitigates greenhouse gas emissions, but also reduces dependence on centralised power systems prone to disruptions, as a result of extreme weather events such as tidal surges. The city has also developed its Sustainable Drainage Action Plan to improve city-wide drainage infrastructure to withstand heavy flooding. Moreover, two recent plans by the city, the draft London Environment Strategy and the draft London Plan focus, among other policies, on tackling extreme weather events and interdependencies across multiple sectors. Finally, UK Environment Agency’s Thames Estuary 2100 Plan (TE2100) was developed in 2012 to manage tidal flood risk. While the current Thames barrier is designed to withstand up to a 0.9 metre rise in sea level by 2100, according TE2100, plans are in place to factor as much as a 4 metre rise in the future.

Seattle is a leading player in urban climate adaptation in the United States and has undertaken a slew of actions to reduce energy demand and improve energy-efficiency to prevent energy susceptibility. In 2005, Seattle City Light was the first large electric utility in the U.S. to become carbon neutral. The company is presently implementing a range of adaptation strategies to prepare for climate impacts and reduce its carbon footprint. These strategies include developing a utility-wide adaptation plan, assessing fire and landslide risk, upgrading equipment to withstand landslides and fire, as well as planning for hydro-climatic variability and high winds. Newly introduced building efficiency programmes in Seattle, aim to reduce 81,000 metric tons of building-sector greenhouse gas emissions through strategies, regulations, technical and financial assistance, and building performance data. Besides making the energy system cleaner and more robust, energy savings on utility bills are pegged at $44 million annually by 2050 as a result of this programme.

“We’re currently in the process of applying for a grant that will allow us to change how some transmission towers respond to an extreme event. Right now, if a transmission tower goes down, it has the potential to take down a few adjacent towers.” – Jessica Finn Coven, Director, Office of Sustainability and Environment, City of Seattle

Rio de Janeiro is also working towards a low-carbon energy matrix. The city is looking to source more of its energy from decentralised renewable sources to reduce greenhouse gas emissions, lessen its dependency on water intensive energy sources, and reduce its vulnerability to sea level rise. One of the key objectives of the city’s resilience plan is to develop and implement a solar energy strategy. In terms of heating, solar thermal systems have been mandatory for new and renovated buildings in Rio de Janeiro since 2008 and solar energy is expected to cover 40 percent of the city’s hot water demand in the coming years.

What the three cities have in common is a growing recognition that energy disruptions driven by extreme weather events are risky and costly. To prevent destabilising disruptions to the electricity supply – that can have cascading impacts on public transport, water, and healthcare systems – cities need to assess their local risks and plan for climate resilient energy systems. After all, their economic survival depends on it.

This content is from 2018. View the full “The Future We Don’t Want” report.