A tale of two [not even close to net zero] cities

Having recently spent time in Sri Lanka, I have been giving some thought to the contrasts – and common challenges – faced by its capital city, Colombo where I was raised and my current home city of Perth in Western Australia.

Both have faced major energy price increases that are causing challenges, particularly for lower income households and small businesses. In Colombo, there has been an increase in energy prices of between 40% and 65% in the past 12 months.

This is significant in a nation ranked by the World Bank as falling into the lower middle-income band of household incomes based on gross national income per capita. While energy costs are hurting in Australia, it is ranked as a high-income nation, which would indicate the impact is comparatively less for the majority of people.

Both Perth and Colombo rely on fossil fuels as a significant share of the energy supply. In Colombo, this varies seasonally, as hydroelectricity supplies up to 30% or more of the national grid in the rainy season. The balance is met by coal and diesel-powered generation, and in the dry season the fossil fuel technology is the majority of capacity. About 10% comes from slowly increasing renewable energy options which includes solar, wind and biomass.

Perth has a less seasonal pattern and is reliant on coal and gas year-round for the majority of the electricity supply, with a small albeit growing fraction of wind and solar.

The emissions picture

In 2019, the greenhouse gas emissions for Sri Lanka were roughly one third of the emissions of the state of Western Australia (WA), yet the population of WA is 1/10 of the size of Sri Lanka's.

One major difference is emissions in Sri Lanka – and therefore Colombo – are mostly due to fossil fuel combustion, while Western Australia’s emissions footprint has been growing due to fossil fuel extraction and fugitive emissions from gas projects. WA’s emissions in 2019 had increased by 20.8% on 2005 levels, both from fossil fuel activities and from growth in transport due to both increasing population and growth in internal combustion engine vehicle fleet numbers. It is also worth noting that WA coal power plants operate with 80’s technologies which are contributing to more emissions due to the general use of brown coal in the generation instead of high-grade coal sources.

In Sri Lanka, emissions increased between 2017 and 2019 which can partly be explained by drought, which reduced the availability of water for hydroelectricity in addition to its impacts on agriculture and human wellbeing.

This should give us pause for thought in all the regions where climate change projections signal increased occurrence and intensity of droughts – and Australia is one of the nations most exposed to this risk.

Tasmania, for example, with its reliance on hydroelectricity and Eastern Australia with its reliance on the Snowy Mountains hydroelectric scheme as a proposed ‘big battery’ are both exposed to potential drought disruption to power supplies. In 2007, Australia’s east coast had its first taste of this when the Millennium Drought saw water levels so low that the Snowy Mountains Hydro operators had to close down key generating turbines and consider cloud-seeding to attempt to increase the necessary inflows to keep the system working.

Addressing emissions from generation

One of the oft-cited objections to increasing the share of renewables in the Australian grid is challenges around fuel-switching, as levels of solar and wind power fluctuate with time of day and weather conditions. But Colombo has built-in fuel switching already, scaling up and down the input from hydro or fossil fuel generators as conditions require.

Perth also has rules that make it difficult for new buildings or existing buildings in the city to remain off-grid, and it is also currently challenging in regulatory terms for buildings to be equipped to operate in ‘island mode’, that is, disconnected from the grid and using on-site power and renewable storage only.

There are, however, some promising signs in new estate developments where the homes are supplied with solar PV, batteries and an inverter, with the inverter controlled by the energy provider so it can be managed when required as part of a smart demand management strategy, for example during peak energy demand events such as a heatwave. It’s not the same as energy self-sufficiency, but it does potentially improve energy resilience at the household and broader community level.

In Colombo off-grid solar and battery installations are both permitted and becoming more popular, and I believe the rise in energy prices will increase uptake quite aside from concerns around emissions and climate change.

However, the pressing need of this moment in history calls for innovative and drastic changes, which engineers can play a substantial part in through introducing new technologies and challenging the status quo. For example, Sri Lanka’s offshore technical wind potential is estimated at 92 GW, but to harness that energy they may have to connected to a more extensive electricity grid such as India’s. WA on the other hand is blessed with an abundance of solar energy and undeveloped land areas which can be used to generate renewable power and we can come up with innovative ways to store the energy.

So much waste

Another benefit of local generation is there is less loss in the system, compared to business-as-usual in many Australian states of having centralised large generation with the power transported over vast distances to end users. The Australian Energy Market Operator estimates that approximately 10% of all electricity generated by power stations is lost during the process of transporting it to customers.

That is a substantial amount of energy – and associated emissions. So localised energy generation and storage also helps reduce waste of energy and means we can more closely align demand and supply.

Then there is the ‘waste’ energy in the form of heat that is a by-product of industrial processes, air conditioning, data racks, agricultural feedlots, engines… and so forth. Wherever heat is given off but is not being put to a productive use, we need to get more engaged in circular thinking about energy and treat it as a valuable resource beyond the point at which the meter prices what goes into a building or facility.

Smarter approaches

There are multiple levels of technology that can facilitate better managing energy supply, demand and reducing energy-related emissions.

In Sri Lanka, researchers have found uptake of smart building features still lags behind many other nations. However, the benefits are clearly understood, particularly for commercial buildings, which are the most energy-intensive buildings in Colombo. According to data published by the Institute of Engineers Sri Lanka, commercial buildings and industrial facilities together consume nearly 60% of the nation’s energy supply. The majority of this is for air conditioning, heating and lighting – a very similar profile to the energy consumption pattern of buildings in Perth.

What is needed in Sri Lanka to boost uptake of smart building features is industry capacity-building in relation to skills, supply chain and integration of smart building features. Similarly to Australia, the attention appears to be on new buildings at this point, however there are good reasons for this to change as there are calls for the nation to adopt a more stringent approach to building energy efficiency standards, as the current voluntary system for commercial buildings is not having the impact that could be desired. Flashback to Perth in the days before the Australian Federal Government passed the Commercial Buildings Disclosure legislation and suddenly NABERS ratings went from ‘nice to have’ to ‘must have’!

Smart technology also plays a role in improving – and optimising – energy supply and demand at both the local and the city or regional scale. We have the technology right now to have a bird’s eye view of energy consumption patterns – what is needed is the investment in deploying and using it! And this is something that is true for both cities.