What would it take to run a city with 100% clean energy? Speak Lovers of Engineering, my name is Igor Felipe and today we are going to talk a little about the massive use of renewable energy in cities. Is it possible to have a city running entirely on clean energy?
Most claims of running on “clean” electricity come with caveats, and many technologies needed for 24/7 renewable energy are not yet ready. In 2014 in Burlington, Vermont in the US, they announced that they had reached an energy milestone. The city of 42,000, which sits on the shores of Lake Champlain, has produced enough energy from renewable sources to cover all of its electricity needs.
This made it one of the first “renewable cities” in America. But are 100% renewable cities really… 100% renewable? The reality is a little complicated, and shows the challenges of true and “deep” energy decarbonization.
First, switching to clean electricity does not mean that a city eliminates its carbon footprint as residents may still be driving gasoline-guzzling cars or, in cases of cold countries, heating their homes with natural gas. Even most claims to run on “clean” electricity come with caveats. What cities really mean is that they buy enough electricity from wind, solar or other clean sources to balance the energy they use throughout the year.
For places full of renewable energy, this is no big deal. But in other areas, a city may not be using all its renewable electricity in real time. Even when the sun isn't shining and the wind isn't blowing, electrons still have to flow through the lines to keep the lights on.
And right now, much of this more consistent energy comes from non-renewable sources, mainly natural gas and coal. There is really no city that functions as an island of self-sufficient electricity, as it will be connected to a larger grid. There are no “fossil fuel electrons” and “renewable electrons”, because in the end there is only one energy, whether renewable or not.
Once it is mixed in the transmission lines, it is not possible to say 100% that the energy that arrives in the city is 100% renewable. This means that even a 100% renewable city can, from time to time, get its electricity from fossil fuels, as the lines continue and need to be interconnected. Because of this, targets to run exclusively on renewable energy are more like accounting mechanisms than actually pure renewable energy from a city's energy sources.
At the moment this is not a big problem as most cities have a long way to go to get to this stage. In Brazil, the most used energy sources are renewable, with great emphasis on hydroelectric plants, which are the main base of our energy matrix. According to 2019 data from the National Interactive Energy Balance, 64.
9% of the energy consumed in Brazil comes only from hydroelectric plants. And on balance, Brazil uses almost 83% of renewable sources for energy production, while the world average is only 25%. In addition to more sustainability, this also generates lower operating costs for plants that choose renewable energy.
In addition to hydroelectric power with its 64. 9%, Brazil's energy matrix is also divided into natural gas representing 9. 3%, wind energy representing 8.
6%, biomass with 8. 4%, coal and derivatives with 3, 3%, nuclear energy with 2. 5%, petroleum derivatives with 2.
0% and finally we have solar energy with only 1. 0%. But the big challenge here is to make cities manage this energy from renewable sources.
Renewable energies like wind and solar are only available at certain times of the day, but a truly “clean” grid would have carbon-free sources of electricity ready to go at all times. For example, if we could have solar farms that sustain the demand throughout the day in a city, and when nightfall they stop producing energy, we could use wind or hydroelectric energy. Local governments have not yet tried to reach that level and it is hard to blame them.
Many of the technologies needed for electricity to clean 24 hours a day are not yet ready. This could include giant batteries, nuclear power and even geothermal energy, as well as the use of hydrogen fuel and perhaps even natural gas combined with carbon capture. But these energy sources are not ready for widespread use or are so expensive that they are cost prohibitive.
We need to spend the next decade very proactively pushing these technologies forward and seeing which ones will succeed and how quickly they mature and how quickly we can scale them up in the future. Successfully decarbonizing economies requires a lot of resources. The International Renewable Energy Agency estimates that Asia and the Pacific needs to invest between $825 billion to $1.
2 trillion a year in renewable energy development and energy efficiency. Funding these amounts is something that developing countries cannot do alone, particularly at a time when government resources have been severely strained by other concerns such as COVID-19, rising fuel and food prices and rising costs of living. loans.
The point is that the path towards the conscious and renewable use of energy needs a lot of investment and needs to be aligned with other priorities. And as I said, we have almost 83% of our energy matrix coming from renewable energies, and the effort here is how we are going to transform the other 17% into renewable and clean energy. And you, what is your opinion on the challenge of using renewable energy in our cities?
Have you ever thought about producing your own energy at home and not relying on energy from utilities? Leave it here in the comments. I'll leave two videos here that you might like too, so click on one of them to check it out.
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