Building a Renewable Energy City
Victorian cities rely heavily on fossil fuels for electricity. We use them to power our homes and communal spaces. But as we realised that the emissions from fossil fuels are the dominant cause of global warming, as a community, we look to more renewable solutions.
The burning of fossil fuels releases large amounts of carbon dioxide and this greenhouse gas traps heat in our atmosphere. According to the International Energy Agency, coal is the dirtiest fossil fuel and has contributed over 0.3°C of the 1°C increase in global average temperatures above pre-industrial levels, making it the single largest source of global temperature rise. The IPCC warns that warming above 1.5°C risks further sea level rise, extreme weather events, loss of biodiversity, food scarcity, and worsening health and poverty worldwide.
There is worldwide pressure to reduce carbon emissions and move towards a greener future. The Victorian government has set a target of 25% renewable energy production by 2020, increasing to 40% by 2025. Iceland, Costa Rica and Uruguay have already achieved over 90%.
Over two days, secondary school students can rise to the challenge of powering a city with renewable energy in a program developed by Gippsland Tech School.
Students are challenged to draft a proposal for how they might convert a city to run on solely on renewable energy. The goal is to have the entire city: homes, streetlights, public transport, etc. powered by hydrogen, solar, wind and geothermal energy.
Students have to keep in mind that the city will always require power: night or day, rain or shine. Like most places, the Latrobe Valley sees changes in amount of sunlight, amount of water in the river, and the wind changes directions. The students are introduced to renewable energy sources, discussing their advantages and disadvantages to ensure that there is enough backup power for when the sun is not shining or wind is not blowing.
Working with models, students conduct experiments around each energy type. They test the energy output of solar panels, adjust wind turbine blades to harness optimal amounts of wind, and make group decisions based on their data on how to power the city. The students investigate ways of storing the excess renewable energy so that there is energy available when the wind is not blowing and the sun is not shining. One method they explore is the production of hydrogen and the use of a hydrogen fuel cell. Hydrogen gas has the largest energy content of any fuel and its stability allows longer-term storage, making it ideal for energy storage and distribution. Students learn that hydrogen fuel cells are good way to store excess energy for when needed, but this energy must first come from somewhere else. They are given a budget to work with and decide on how they might use a single power source or multiple, as long as they generate enough energy while staying within budget.
On the second day of the program, students plan, design, build and test a city powered completely by renewable energy. They use 3D-design and laser cut cardboard to build a model city fitted with lights that are connected to their power source(s) of choice. Finally, students present their simulated city powered by renewable energy to an industry member from the energy sector for feedback.
This is project is particularly topical as the chimneys of the defunct, brown coal-fired Hazelwood power station were demolished on the 25th of May 2020. The chimneys operated for more than half a century before being shut down in March 2017. For some time this power station was producing up to 25% of Victoria’s electricity.
Now the Latrobe Valley is home to a world-first hydrogen project: the Hydrogen Energy Supply Chain at AGL Loy Yang is currently being constructed. Hydrogen gas can be produced from Loy Yang mine coal by reacting it with oxygen under high pressures and temperatures to form synthesis gas (syngas), primarily consisting of hydrogen and carbon monoxide (which is later converted to additional hydrogen and carbon dioxide). Moving forward, this may be a cleaner way to use our brown coal – as long as the carbon dioxide produced is captured and reused or sequestered (stored).
Working in close partnership with local energy providers, Gippsland Tech School has offered students the chance to put themselves in the shoes of machinery operators, electricians, architects, product testers and designers. Additionally, the Tech School is now looking at expanding the program with new partners in the energy sector.
By rapidly prototyping and building model cities that run solely on renewable energy, students are encouraged to think about the cities of the future. They also work collaboratively to develop solutions that we, as a community, need now.