Resilient cities

Zoe Green | 23 Oct 2015 | Comments

Resilient cities: Why should cities care about energy?

We take for granted that energy will be available in the form we need it, when we need it. However, our UK cities our increasingly at risk from blackouts on a comparable scale to those experienced in New York in 2012. Research published in October 2013 by the Prime Minister’s Council for Science and Technology openly acknowledged that significant blackouts could occur in the UK as soon as 2020.

Our capacity to produce enough energy to power our cities will soon become critical. Tougher environmental targets and EU policy directives (e.g. the Large Combustion and Plant Directive) along with the closure of ageing power stations has placed greater pressure on our cities to meet energy demands and has led to an increasing reliance on gas imports. The impact of a power outage could mean our cities face disruption to travel services and loss of economic output. For this reason it’s important our UK cities become more resilient and less reliant on energy imports from Europe.

Diversification is key

Cities will have to adapt and evolve to better manage their resources, infrastructure and human capital if they are to remain successful. For this reason we need to be ‘future proofing cities’ by utilising and developing their capabilities enabling them to respond to the risks and challenges of the next century and beyond.

Cities can secure the benefits of localised energy generation to act as a catalyst for addressing issues of fuel poverty and as a tool for economic growth. In order to do this, cities need to diversify their energy mix and whilst they won’t be able to rely on this immediately, it will provide a far more robust system in the long term. The benefit of diversification is that, at times when a particular energy source becomes scarce or abundant, the network can respond accordingly. Take wind energy as an example; on windy days surplus power could be stored as hot water within heat networks and then distributed by pumps.

So what does this mean in practice at the local level? Delivering such networks will depend on the infrastructure being built into our systems as part of new developments. A more resilient energy infrastructure, for example, may benefit from site-wide energy centres that have the ability to interconnect and evolve in tandem with the city itself. Communities investing in long-term infrastructure, such as energy centres and associated distribution lines, will become less exposed to variable global pricing structures due to better energy demand management and a more diverse energy mix.

Mapping the opportunities

Many cities are now beginning to look at decentralised energy opportunities for a number of reasons, including meeting carbon reduction targets, providing cheaper energy to alleviate fuel poverty and to increase resilience to potential shortfalls in traditional energy supplies.

One of the preferred routes for delivering decentralised energy is to use combined heat and power (CHP). It’s a proven reliable technology and a very efficient use of the primary fuel. The key to successful deployment of CHP is the effective use of the waste heat, whether that is via a process load or a heat network.

One example is Portsmouth City Council, their future electricity supply is likely to be constrained due to inadequate primary infrastructure. The council are now considering the use of a viable heat network in the City Centre, in the nearby Naval Base and around the new City Deal Developments. Using geospatial techniques utilising freely available data, it was possible to build up a picture of heat demands from existing building stock across the entire City area as well as the proposed developments. A scoring test was applied to each of the 95,000 buildings and the results were mapped. Some simple metric tests such as heat area density were applied, which confirmed that there was definitely potential for a network in the City Centre and Naval Base.

The scheme was progressed by developing several network options and undertaking a techno-economic analysis of a preferred scheme. This option was then identified through a scenario testing exercise that determined which sites should be considered for the creation of a future network.

The conclusion Portsmouth reached was that heat networks were indeed viable and that coupled with available gas supply a decentralised CHP network could deliver on a number of objectives including, alleviating future constraints on the power network and helping to reach their carbon reduction targets.

Tailoring Solutions

Future proofing can deliver tangible social and economic benefits in the short and longer term. The amount of new development planned and needed over the future decades across our core cities (e.g. London, Birmingham, Manchester and Bristol) creates a significant opportunity to ‘future proof’ our cities energy infrastructure and improve the energy efficiency of the built environment. Strategic energy planning can lead to better energy demand management and a more diverse energy mix, which will ultimately result in more resilient energy infrastructure.