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With the heat wave affecting Brazil, air conditioning has become an indispensable ally for many. However, the increase in the use of this appliance directly reflects on the electricity bill. An alternative that has gained prominence is the offgrid system, which allows the use of air conditioning without additional costs on electricity.
But the question arises: how many batteries are needed to maintain this comfort? To properly size the number of batteries, it is necessary to consider the consumption of the air conditioning.
Taking a 9,000 BTU appliance as an example, which operates for 8 hours daily, we have a monthly consumption of 136.8 kWh. But that’s not all. It is necessary to consider the inherent losses in the system, such as the efficiency of the inverter and the battery itself.
In an offgrid system, one cannot ignore efficiency losses. For example, a lead-acid battery has an efficiency between 80 to 90%, and an inverter can have similar efficiency. This means that to meet the consumption of the air conditioning, it is necessary to generate more energy than the appliance actually consumes.
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Brazilian scientists are simultaneously advancing two research projects on clean hydrogen and driving solutions that could transform the energy matrix, enhance industrial competitiveness, and accelerate large-scale emission reduction targets.
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Advancement in renewable energy: A R$ 150 million project launched by Petrobras and Finep aims to create state-of-the-art electrolyzers for green hydrogen, strengthening national research and preparing Brazil to compete in a billion-dollar energy market.
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Illiterate or semi-literate grandmothers were trained to repair solar systems, open rural workshops, and light up homes that still depended on kerosene.
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The world has bet on green hydrogen as the fuel of the future, but now faces the side effect: producing 1 kilogram requires about 9 liters of ultrapure water, and the largest projects on the planet are precisely in the driest regions of the Earth, where water is already scarce for people.
Autonomy And Voltage: Crucial Factors In Choosing Batteries
When choosing batteries, two factors are crucial: the desired autonomy and the system voltage. For one day of autonomy and a 24-volt system, it is necessary to calculate the total energy that needs to be stored, considering the depth of discharge of the batteries.
After all calculations, considering a system with lead-acid batteries of 111 Ah, the conclusion is that 16 batteries would be needed to keep the air conditioning running for a whole day without recharging, in a 24-volt system.
Cost-Benefit: Is It Worth Investing In Offgrid?
The investment in an offgrid system is not low. Each battery can cost around R$ 770, totaling a considerable amount for the necessary set.
However, it is important to weigh the long-term costs with the savings on the electricity bill and the energy independence that an offgrid system provides.
In times of intense heat and rising energy bills, offgrid systems emerge as a viable and sustainable alternative. Despite the initial investment, the long-term savings and the comfort of air conditioning functioning without additional costs are attractive that cannot be ignored.
